WO2014165259A1

WO2014165259A1 - Transmission with cvt and ivt variator drive

Info

Publication number: WO2014165259A1
Application number: PCT/US2014/025001
Authority: WO
Inventors: Mark R. J. VERSTEYHE; James F. Ziech
Original assignee: Dana Ltd
Current assignee: Dana Ltd
Priority date: 2013-03-13
Filing date: 2014-03-12
Publication date: 2014-10-09
Anticipated expiration: 2015-09-13

Abstract

Variable transmissions and methods of running such transmissions in different operating modes. Variable transmissions may include a first carrier assembly comprising an annular arrangement of a plurality of tiltable first variator balls each having first ball axle shafts. Variable transmissions may include a second ring assembly rotatably disposed in the housing about the main shaft and drivingly engaged with an output shaft, the second ring assembly comprising a variator ball engagement surface that is in driving engagement with each of the second variator balls. One or more clutch elements are used to change the operating mode in the variable transmissions.

Description

TRANSMISSION WITH CVT AND IVT VARIATOR DRIVE

CROSS-REFERENCES TO RELATED APPLICATIONS

[0001] The present application claims the benefit of U.S. Provisional Patent Application No.

61/780,754, filed March 13, 2013 which application is incorporated herein by reference.

BACKGROUND OF THE INVENTION

[0002] A vehicle having a driveline including a continuously variable transmission allows an operator of the vehicle or a control system of the vehicle to vary a drive ratio in a stepless manner, permitting a power source of the vehicle to operate at its most efficient rotational speed. However, the driveline including the continuously variable transmission requires a torque converter or a clutch to permit the vehicle to stop and to increase start-ability of the vehicle.

SUMMARY OF THE INVENTION

[0003] Provided herein is a variable transmission comprising a main shaft and two carrier assemblies. The variable transmission can change between a continuously variable operating mode and an infinitely variable operating mode using a clutch that is coupled to a double ring assembly in driving engagement with both of the carrier assemblies. The double ring assembly places the two carrier assemblies in series with each other. Each of the carrier assemblies comprises an annular arrangement of a plurality of tiltable first variator balls each having first ball axle shafts. A transaxle could comprise this configuration of carrier assemblies in driving engagement with a double ring assembly and configured to change between a continuously variable operating mode and an infinitely variable operating mode, at least, using a clutch that is coupled to the double ring assembly. Various clutch types could be used, such as a wet plate clutch, a dry plate clutch, a cone clutch, or any other clutch type that may be variably engaged. Alternatively, or additionally, an overrunning clutch may be used. Another embodiment of a series arrangement of two carrier assemblies having a double ring assembly in driving engagement with both of the carrier assemblies uses two clutches which can change the transmission between a continuously variable operating mode and an infinitely variable operating mode, at least.

[0004] Thus, provided herein is a variable transmission comprising a main shaft; a first carrier assembly rotatably disposed in a housing and drivingly engaged with the main shaft, the first carrier assembly comprising an annular arrangement of a plurality of tiltable first variator balls each having first ball axle shafts, and comprising a first engagement portion extending from a surface of the first carrier assembly between the first variator balls and second variator balls of the second carrier assembly; a first ring assembly fixed with respect to the housing and comprising a first variator ball engagement surface that is in driving engagement with each of the first variator balls; a double ring assembly rotatably disposed in the housing and selectively drivingly engaged with the first carrier assembly using a clutch, the double ring assembly comprising a second variator ball engagement surface in driving arrangement with each of the first variator balls, and a third variator ball engagement in driving arrangement with each of a plurality of second variator balls of the second carrier assembly, and a second engagement portion extending inwardly from a surface of the double ring assembly; a second carrier assembly disposed in the housing and fixed relative to the housing, the second carrier assembly comprising an annular arrangement of a plurality of tiltable second variator balls each having second ball axle shafts; and a second ring assembly rotatably disposed in the housing about the main shaft and drivingly engaged with an output shaft, the second ring assembly comprising a fourth variator ball engagement surface that is in driving engagement with each of the second variator balls. In certain embodiments, the clutch comprises the first engagement portion and the second extending portion, whereby said transmission has an infinitely variable operating mode and a continuously variable operating mode.

[0005] In certain embodiments, the operating mode depends on an engagement status of the clutch, a position of the plurality of first ball axle shafts of the first carrier assembly, and a position of the plurality of second ball axle shafts of the second carrier assembly.

[0006] In some embodiments, the infinitely variable operating mode is a result of disengaging the clutch. In some embodiments, disengaging the clutch drives the first carrier assembly and the first variator balls therein using the main shaft.

[0007] In some embodiments, a forward infinitely variable operating mode, a powered neutral operating mode, or a reverse infinitely variable operating mode result from adjusting the position of the first ball axle shafts when the clutch is disengaged.

[0008] In some embodiments, disengaging the clutch places the plurality of second ball axle shafts in their neutral position. In some embodiments, disengaging the clutch places the plurality of second ball axle shafts in an overdrive position. In some embodiments, disengaging the clutch places the plurality of second ball axle shafts in a low gear position.

[0009] In some embodiments, the continuously variable operating mode is a result of engaging the clutch and thereby fixing the double ring assembly with respect to the first carrier assembly. In some embodiments, the continuously variable operating mode is a result of engaging the clutch and thereby rotating the first variator balls about the plurality of first ball axle shafts without transmitting power. In some embodiments, the continuously variable operating mode is a result of engaging the clutch and thereby driving the second ring assembly by the double ring assembly through the second variator balls.

[0010] In some embodiments, the clutch is an overrunning clutch. In some embodiments, the overrunning clutch is configured to engage the double ring assembly with the first carrier assembly when a rotational speed of the double ring assembly is equal to a rotational speed of the first carrier assembly. In some embodiments, the overrunning clutch is configured to disengage the double ring assembly from the first carrier assembly when a rotational speed of the double ring assembly is less than a rotational speed of the first carrier assembly.

[0011] Provided herein is a variable transmission comprising: a main shaft comprising a first end portion drivingly coupled to an engine, a middle portion, and a second end portion; a first carrier assembly rotatably disposed in a housing and selectively drivingly engaged with the main shaft or a portion thereof using a first clutch, the first carrier assembly comprising an annular arrangement of a plurality of tiltable first variator balls each having first ball axle shafts; a first ring assembly fixed with respect to the housing and comprising a first variator ball engagement surface that is in driving engagement with each of the first variator balls; a double ring assembly rotatably disposed in the housing and selectively drivingly engaged with the main shaft or a the second end portion thereof using a second clutch, the double ring assembly comprising a second variator ball engagement surface in driving arrangement with each of the first variator balls, a third variator ball engagement in driving arrangement with each of a plurality of second variator balls of the second carrier assembly, and a first engagement portion extending inwardly from a surface of the double ring assembly between the first variator balls of the first carrier assembly and a plurality of second variator balls, wherein the first engagement portion forms a portion of the second clutch; a second carrier assembly rotatably disposed in the housing, the second carrier assembly comprising an annular arrangement of a plurality of tiltable second variator balls each having second ball axle shafts; and a second ring assembly rotatably disposed in the housing about an axis coincident with the main shaft and drivingly engaged with an output shaft, the second ring assembly comprising a fourth variator ball engagement surface that is in driving engagement with each of the second variator balls; wherein said variable transmission has an infinitely variable operating mode and a continuously variable operating mode.

[0012] In some embodiments, the operating mode depends on an engagement status of the first clutch, a position of the plurality of first ball axle shafts of the first carrier assembly, an engagement status of the second clutch, and a position of the plurality of second ball axle shafts of the second carrier assembly. In some embodiments, the infinitely variable operating mode is a result of engaging the first clutch and disengaging the second clutch.

[0013] In some embodiments, a forward infinitely variable operating mode, a powered neutral operating mode, or a reverse infinitely variable operating mode result from adjusting the position of the first ball axle shafts when the first clutch is engaged and the second clutch is disengaged. In some embodiments, the infinitely variable operating mode the plurality of second ball axle shafts are in their neutral position. In some embodiments, the infinitely variable operating mode the plurality of second ball axle shafts are in an overdrive position. In some embodiments, the infinitely variable operating mode the plurality of second ball axle shafts are in a low gear position.

[0014] In some embodiments, the continuously variable operating mode is a result of disengaging the first clutch and engaging the second clutch. In some embodiments, engaging the second clutch drivingly engages the double ring assembly with the main shaft. In some embodiments, the second ring assembly is driven by the double ring assembly through the second variator balls of the second carrier assembly.

[0015] In some embodiments, the main shaft and the output shaft are at least partially disposed in the housing.

[0016] In some embodiments, an axial force generator configured to generate sufficient axial force to properly operate the vehicle transmission. In some embodiments, the axial force generator comprises one or more clamping mechanism. In some embodiments, the axial force generator comprises a ball ramp. In some embodiments, the axial force generator comprises a load applied during assembly of the variable transmission.

[0017] In some embodiments, the main shaft is drivingly engaged with a torsional dampener disposed between an engine and the variable transmission.

[0018] In some embodiments, a middle portion of the main shaft is drivingly engaged with the first carrier assembly.

[0019] In some embodiments, the clutch comprises a wet plate clutch, a dry plate clutch, a cone clutch, or any other clutch type that may be variably engaged. In some embodiments, the first clutch comprises a wet plate clutch, a dry plate clutch, a cone clutch, or any other clutch type that may be variably engaged. In some embodiments, the second clutch comprises a wet plate clutch, a dry plate clutch, a cone clutch, or any other clutch type that may be variably engaged.

[0020] In some embodiments, each of the first ball axle shafts and/or the second ball axle shafts are adjusted using a cam style tilting mechanism. In some embodiments, each of the first ball axle shafts and/or the second ball axle shafts are adjusted using a split carrier axle skewing mechanism.

[0021] In some embodiments, the first variator balls and the first engagement portion are driven when the main shaft is rotated.

[0022] In some embodiments, the first ring assembly is integrally formed with the housing. In some embodiments, the first ring assembly is coupled to the housing.

[0023] In some embodiments, the first variator ball engagement surface is formed in a distal end of the first ring assembly. In some embodiments, the first variator ball engagement surface is formed in an input ring of the first ring assembly. In some embodiments, the first variator ball engagement surface is a conical surface or a concave toroidal surface in contact with or slightly spaced apart from each of the first variator balls. In some embodiments, the second variator ball engagement surface is a conical surface or a concave toroidal surface in contact with or slightly spaced apart from each of the first variator balls. In some embodiments, the third variator ball engagement surface is a conical surface or a concave toroidal surface in contact with or slightly spaced apart from each of the second variator balls. In some embodiments, the fourth variator ball engagement surface is a conical surface or a concave toroidal surface in contact with or slightly spaced apart from each of the second variator balls.

[0024] In some embodiments, the first variator ball engagement surface is in driving engagement with each of the first variator balls of the first carrier assembly through one of a boundary layer type friction and an elastohydrodynamic film. In some embodiments, the second variator ball engagement surface is in driving engagement with each of the first variator balls of the first carrier assembly through one of a boundary layer type friction and an elastohydrodynamic film. In some embodiments, the third variator ball engagement surface is in driving engagement with each of the second variator balls of the second carrier assembly through one of a boundary layer type friction and an

elastohydrodynamic film. In some embodiments, the fourth variator ball engagement surface is in driving engagement with each of the second variator balls of the second carrier assembly through one of a boundary layer type friction and an elastohydrodynamic film.

[0025] Provided herein is a vehicle driveline comprising the variable transmission of any one of the types described herein, or is obvious to one of ordinary skill in the art upon reading the disclosure herein. The variable transmission, in such embodiments, is disposed between an engine and a vehicle output. In some embodiments, the vehicle output comprises a differential and a drive axle. In some embodiments, the vehicle output comprises a plurality of bearings and a plurality of wheels. In some embodiments, a torsional dampener disposed between the engine and the variable transmission. In some embodiments, the torsional dampener comprises at least one torsional spring.

[0026] Provided herein is a method of changing from a continuously variable transmission mode to an infinitely variable transmission mode in a variable transmission comprising disengaging a clutch positioned between a first carrier assembly and a second carrier assembly, wherein the variable transmission is one of any one of the types described herein, or that is obvious to one of ordinary skill in the art upon reading the disclosure herein.

[0027] Provided herein is a method of changing from an infinitely variable transmission mode to a continuously variable transmission mode in a variable transmission comprising disengaging a clutch positioned between a first carrier assembly and a second carrier assembly, wherein the variable transmission is one of any one of the types described herein, or that is obvious to one of ordinary skill in the art upon reading the disclosure herein. INCORPORATION BY REFERENCE

[0028] All publications, patents, and patent applications mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication, patent, or patent application was specifically and individually indicated to be incorporated by reference.

BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The novel features of the invention are set forth with particularity in the appended claims. A better understanding of the features and advantages of the present invention will be obtained by reference to the following detailed description that sets forth illustrative embodiments, in which the principles of the invention are utilized, and the accompanying drawings of which:

[0030] Figure 1 depicts an embodiment variable transmission comprising a single clutch that allows the transmission to run in at least two variable operating modes.

[0031] Figure 2 depicts an embodiment variable transmission comprising overrunning clutch that allows the transmission to run in at least two variable operating modes.

[0032] Figure 3 depicts an embodiment variable transmission comprising a first clutch and a second clutch that allow the transmission to run in at least two variable operating modes.

[0033] Figure 4 is a cutaway view of a currently known and used continuously variable transmission

(CVT).

[0034] Figure 5 is a magnified cutaway view of a ball and ring of the CVT of Figure 4.

DETAILED DESCRIPTION OF THE INVENTION

[0035] The torque converter or the clutch included in the driveline may be heavy, inefficient, difficult to control, or expensive. Further, the driveline including the continuously variable transmission having a reverse operating mode requires the addition of a separate mechanism.

[0036] Provided herein is a transmission having a continuously variable variator drive operating mode and an infinitely variable variator drive operating mode, capable of having a wide ratio range, and capable of placing the vehicle into a reverse operating mode and a neutral operating mode.

Additional continuously variable transmission details are described in US Application No.

13/743,951 filed Jan 17, 2013, and/or PCT/US2013/026037 filed Feb. 14, 2013, incorporated herein by reference in their entirety.

[0037] In a vehicle, a variable transmission may be used to replace a conventional transmission and a clutch in a vehicle driveline. As a non-limiting example, the variable transmission may replace a conventional transmission and a clutch in a front wheel drive vehicle, such as an automobile.

[0038] Basic concepts of a ball type Continuously Variable Transmissions are described in

US20040616399 and AU2011224083A1, incorporated herein by reference in their entirety. Such a CVT, adapted herein as described throughout this specification, comprises a number of balls, depending on the application, two discs with a conical surface contact with the balls, as input and output, and an idler as shown on FIG. 4. The type of CVT provided herein comprises a variator comprising a plurality of variator balls, depending on the application, two discs or annular rings 995, 996 each having an engagement portion that engages the variator balls 997, at least. The engagement portions are optionally in a conical or toroidal convex or concave surface contact with the variator balls, as input (995) and output (996). The variator optionally includes an idler 999 contacting the balls as well as shown on FIG. 4. The variator balls are mounted on axles 998, themselves held in a cage or carrier allowing changing the ratio by tilting the variator balls^" axes. The balls are mounted on axes, themselves held in a cage or carrier allowing changing the ratio by tilting the ball's axes. Other types of ball CVTs also exist, like the one produced by Milner but are slightly different.

[0039] The working principle of such a CVT of FIG. 4 is shown on FIG. 5. The CVP itself works with a traction fluid. The lubricant between the ball and the conical rings acts as a solid at high pressure, transferring the power from the input ring, through the balls, to the output ring. By tilting the ball's axis, the ratio can be changed between input and output. When the axis is horizontal the ratio is one, when the axis is tilted the distance between the axis and the contact point change, modifying the overall ratio. All the ball's axes are tilted at the same time with a mechanism included in the cage. In a car, the CVT is used to replace traditional transmission and is located between the engine and the differential, at least.

[0040] Provided herein is a variable transmission comprising a main shaft and two carrier assemblies. The variable transmission can change between a continuously variable operating mode and an infinitely variable operating mode using a clutch that is coupled to a double ring assembly in driving engagement with both of the carrier assemblies. The double ring assembly places the two carrier assemblies in series with each other. Each of the carrier assemblies comprises an annular arrangement of a plurality of tiltable first variator balls each having first ball axle shafts. A transaxle could comprise this configuration of carrier assemblies in driving engagement with a double ring assembly and configured to change between a continuously variable operating mode and an infinitely variable operating mode, at least, using a clutch that is coupled to the double ring assembly. Various clutch types could be used, such as a wet plate clutch, a dry plate clutch, a cone clutch, or any other clutch type that may be variably engaged. Alternatively, or additionally, an overrunning clutch may be used. Another embodiment of a series arrangement of two carrier assemblies having a double ring assembly in driving engagement with both of the carrier assemblies uses two clutches which can change the transmission between a continuously variable operating mode and an infinitely variable operating mode, at least.

[0041] Thus, provided herein is a variable transmission comprising a main shaft; a first carrier assembly rotatably disposed in a housing and drivingly engaged with the main shaft, the first carrier assembly comprising an annular arrangement of a plurality of tiltable first variator balls each having first ball axle shafts, and comprising a first engagement portion extending from a surface of the first carrier assembly between the first variator balls and second variator balls of the second carrier assembly; a first ring assembly fixed with respect to the housing and comprising a first variator ball engagement surface that is in driving engagement with each of the first variator balls; a double ring assembly rotatably disposed in the housing and selectively drivingly engaged with the first carrier assembly using a clutch, the double ring assembly comprising a second variator ball engagement surface in driving arrangement with each of the first variator balls, and a third variator ball engagement in driving arrangement with each of a plurality of second variator balls of the second carrier assembly, and a second engagement portion extending inwardly from a surface of the double ring assembly; a second carrier assembly disposed in the housing and fixed relative to the housing, the second carrier assembly comprising an annular arrangement of a plurality of tiltable second variator balls each having second ball axle shafts; and a second ring assembly rotatably disposed in the housing about the main shaft and drivingly engaged with an output shaft, the second ring assembly comprising a fourth variator ball engagement surface that is in driving engagement with each of the second variator balls. In certain embodiments, the clutch comprises the first engagement portion and the second extending portion, whereby said transmission has an infinitely variable operating mode and a continuously variable operating mode.

[0042] In certain embodiments, the operating mode depends on an engagement status of the clutch, a position of the plurality of first ball axle shafts of the first carrier assembly, and a position of the plurality of second ball axle shafts of the second carrier assembly.

[0043] In some embodiments, the infinitely variable operating mode is a result of disengaging the clutch. In some embodiments, disengaging the clutch drives the first carrier assembly and the first variator balls therein using the main shaft.

[0044] In some embodiments, a forward infinitely variable operating mode, a powered neutral operating mode, or a reverse infinitely variable operating mode result from adjusting the position of the first ball axle shafts when the clutch is disengaged.

[0045] In some embodiments, disengaging the clutch places the plurality of second ball axle shafts in their neutral position. In some embodiments, disengaging the clutch places the plurality of second ball axle shafts in an overdrive position. In some embodiments, disengaging the clutch places the plurality of second ball axle shafts in a low gear position.

[0046] In some embodiments, the continuously variable operating mode is a result of engaging the clutch and thereby fixing the double ring assembly with respect to the first carrier assembly. In some embodiments, the continuously variable operating mode is a result of engaging the clutch and thereby rotating the first variator balls about the plurality of first ball axle shafts without transmitting power. In some embodiments, the continuously variable operating mode is a result of engaging the clutch and thereby driving the second ring assembly by the double ring assembly through the second variator balls.

[0047] In some embodiments, the clutch is an overrunning clutch. In some embodiments, the overrunning clutch is configured to engage the double ring assembly with the first carrier assembly when a rotational speed of the double ring assembly is equal to a rotational speed of the first carrier assembly. In some embodiments, the overrunning clutch is configured to disengage the double ring assembly from the first carrier assembly when a rotational speed of the double ring assembly is less than a rotational speed of the first carrier assembly.

[0048] Provided herein is a variable transmission comprising: a main shaft comprising a first end portion drivingly coupled to an engine, a middle portion, and a second end portion; a first carrier assembly rotatably disposed in a housing and selectively drivingly engaged with the main shaft or a portion thereof using a first clutch, the first carrier assembly comprising an annular arrangement of a plurality of tiltable first variator balls each having first ball axle shafts; a first ring assembly fixed with respect to the housing and comprising a first variator ball engagement surface that is in driving engagement with each of the first variator balls; a double ring assembly rotatably disposed in the housing and selectively drivingly engaged with the main shaft or a the second end portion thereof using a second clutch, the double ring assembly comprising a second variator ball engagement surface in driving arrangement with each of the first variator balls, a third variator ball engagement in driving arrangement with each of a plurality of second variator balls of the second carrier assembly, and a first engagement portion extending inwardly from a surface of the double ring assembly between the first variator balls of the first carrier assembly and a plurality of second variator balls, wherein the first engagement portion forms a portion of the second clutch; a second carrier assembly rotatably disposed in the housing, the second carrier assembly comprising an annular arrangement of a plurality of tiltable second variator balls each having second ball axle shafts; and a second ring assembly rotatably disposed in the housing about an axis coincident with the main shaft and drivingly engaged with an output shaft, the second ring assembly comprising a fourth variator ball engagement surface that is in driving engagement with each of the second variator balls; wherein said variable transmission has an infinitely variable operating mode and a continuously variable operating mode.

[0049] In some embodiments, the operating mode depends on an engagement status of the first clutch, a position of the plurality of first ball axle shafts of the first carrier assembly, an engagement status of the second clutch, and a position of the plurality of second ball axle shafts of the second carrier assembly. In some embodiments, the infinitely variable operating mode is a result of engaging the first clutch and disengaging the second clutch. [0050] In some embodiments, a forward infinitely variable operating mode, a powered neutral operating mode, or a reverse infinitely variable operating mode result from adjusting the position of the first ball axle shafts when the first clutch is engaged and the second clutch is disengaged. In some embodiments, the infinitely variable operating mode the plurality of second ball axle shafts are in their neutral position. In some embodiments, the infinitely variable operating mode the plurality of second ball axle shafts are in an overdrive position. In some embodiments, the infinitely variable operating mode the plurality of second ball axle shafts are in a low gear position.

[0051] In some embodiments, the continuously variable operating mode is a result of disengaging the first clutch and engaging the second clutch. In some embodiments, engaging the second clutch drivingly engages the double ring assembly with the main shaft. In some embodiments, the second ring assembly is driven by the double ring assembly through the second variator balls of the second carrier assembly.

[0052] In some embodiments, the main shaft and the output shaft are at least partially disposed in the housing.

[0053] In some embodiments, an axial force generator configured to generate sufficient axial force to properly operate the vehicle transmission. In some embodiments, the axial force generator comprises one or more clamping mechanism. In some embodiments, the axial force generator comprises a ball ramp. In some embodiments, the axial force generator comprises a load applied during assembly of the variable transmission.

[0054] In some embodiments, the main shaft is drivingly engaged with a torsional dampener disposed between an engine and the variable transmission.

[0055] In some embodiments, a middle portion of the main shaft is drivingly engaged with the first carrier assembly.

[0056] In some embodiments, the clutch comprises a wet plate clutch, a dry plate clutch, a cone clutch, or any other clutch type that may be variably engaged. In some embodiments, the first clutch comprises a wet plate clutch, a dry plate clutch, a cone clutch, or any other clutch type that may be variably engaged. In some embodiments, the second clutch comprises a wet plate clutch, a dry plate clutch, a cone clutch, or any other clutch type that may be variably engaged.

[0057] In some embodiments, each of the first ball axle shafts and/or the second ball axle shafts are adjusted using a cam style tilting mechanism. In some embodiments, each of the first ball axle shafts and/or the second ball axle shafts are adjusted using a split carrier axle skewing mechanism.

[0058] In some embodiments, the first variator balls and the first engagement portion are driven when the main shaft is rotated.

[0059] In some embodiments, the first ring assembly is integrally formed with the housing. In some embodiments, the first ring assembly is coupled to the housing. [0060] In some embodiments, the first variator ball engagement surface is formed in a distal end of the first ring assembly. In some embodiments, the first variator ball engagement surface is formed in an input ring of the first ring assembly. In some embodiments, the first variator ball engagement surface is a conical surface or a concave toroidal surface in contact with or slightly spaced apart from each of the first variator balls. In some embodiments, the second variator ball engagement surface is a conical surface or a concave toroidal surface in contact with or slightly spaced apart from each of the first variator balls. In some embodiments, the third variator ball engagement surface is a conical surface or a concave toroidal surface in contact with or slightly spaced apart from each of the second variator balls. In some embodiments, the fourth variator ball engagement surface is a conical surface or a concave toroidal surface in contact with or slightly spaced apart from each of the second variator balls.

[0061] In some embodiments, the first variator ball engagement surface is in driving engagement with each of the first variator balls of the first carrier assembly through one of a boundary layer type friction and an elastohydrodynamic film. In some embodiments, the second variator ball engagement surface is in driving engagement with each of the first variator balls of the first carrier assembly through one of a boundary layer type friction and an elastohydrodynamic film. In some embodiments, the third variator ball engagement surface is in driving engagement with each of the second variator balls of the second carrier assembly through one of a boundary layer type friction and an

[0062] Provided herein is a vehicle driveline comprising the variable transmission of any one of the types described herein, or is obvious to one of ordinary skill in the art upon reading the disclosure herein. The variable transmission, in such embodiments, is disposed between an engine and a vehicle output. In some embodiments, the vehicle output comprises a differential and a drive axle. In some embodiments, the vehicle output comprises a plurality of bearings and a plurality of wheels. In some embodiments, a torsional dampener disposed between the engine and the variable transmission. In some embodiments, the torsional dampener comprises at least one torsional spring.

[0063] Provided herein is a method of changing from a continuously variable transmission mode to an infinitely variable transmission mode in a variable transmission comprising disengaging a clutch positioned between a first carrier assembly and a second carrier assembly, wherein the variable transmission is one of any one of the types described herein, or that is obvious to one of ordinary skill in the art upon reading the disclosure herein.

[0064] Provided herein is a method of changing from an infinitely variable transmission mode to a continuously variable transmission mode in a variable transmission comprising disengaging a clutch positioned between a first carrier assembly and a second carrier assembly, wherein the variable transmission is one of any one of the types described herein, or that is obvious to one of ordinary skill in the art upon reading the disclosure herein.

[0065] The variable transmission 2 is located between an engine 4 and a vehicle output 6 as shown in FIG. 1. The vehicle output 6 comprises a differential 8 and a drive axle 10, and can include bearings 12a, 12b, 12c, 12d and wheels 14a, 14b as depicted in FIG. 1 ; however, it is understood that other vehicle outputs may be used. A torsional dampener 16 is also included; the torsional dampener 16 can be disposed between the engine 4 and the variable transmission 2 to reduce vibration and torque peaks, and can include at least one torsional spring 18a.

[0066] A first configuration of a vehicle driveline including a variable transmission 2 according to an embodiment of the invention is shown in FIG. 1. The variable transmission 2 includes a main shaft 20 including a first carrier assembly, a first ring assembly, a double ring assembly, a second carrier assembly, a second ring assembly, and an output shaft 22. The main shaft 20 and the output shaft 22 are at least partially disposed in a housing (not shown). The first carrier assembly, the double ring assembly, and the second ring assembly are rotatably disposed in the housing. Ball ramps 24a-c indicated in FIG. 1 by a circle between a pair of vertical lines, are disposed between components of the variable transmission as shown to generate an amount of axial force necessary for proper operation of the variable transmission; however, it is understood that the amount of axial force necessary for proper operation may be generated by a clamping mechanism (not shown) or as a load applied during assembling of the variable transmission.

[0067] The main shaft 20 has a first end drivingly engaged with the torsional dampener 16, a middle portion drivingly engaged with the first carrier assembly, and a second end drivingly engaged with a pump (for example, oil pump 26). The first carrier assembly drivingly engaged with the middle portion may be selectively drivingly engaged with the double ring assembly using a clutch 28. The clutch 28 may be a wet plate clutch, a dry plate clutch, a cone clutch, or any other clutch type that may be variably engaged.

[0068] The first carrier assembly is rotatably disposed in the housing and includes a plurality of first ball axle shafts 30a, 30b tiltably disposed therein in an annular arrangement. Each of the first ball axle shafts 30a, 30b may be adjusted using one of a cam style tilting mechanism and a split carrier axle skewing mechanism. Each of the first ball axle shafts 30a, 30b includes a first variator ball 32a, 32b rotatably disposed thereon. The first carrier assembly includes an engagement portion 34 extending outwardly from a surface of the first carrier assembly, between the variator balls of the first carrier assembly and a plurality of first variator balls 32c, 32d of the second carrier assembly. The first variator balls 32a, 32b and the first engagement portion 34 of the first carrier assembly are driven when the main shaft 20 is rotated. [0069] The first ring assembly is an annular member fixed with respect to the housing. It is understood that the first ring assembly may be integrally formed with the housing or coupled thereto in any conventional manner. The first ring assembly includes a first variator ball engagement surface 36a. The first variator ball engagement surface 36a is formed in a distal end or input ring 42 of the first ring assembly. The first variator ball engagement surface 36a may be a conical surface or a concave toroidal surface in contact with or slightly spaced apart from each of the first variator balls 32a, 32b. The first variator ball engagement surface 36a is in driving engagement with each of the variator balls of the first carrier assembly through one of a boundary layer type friction and an elastohydrodynamic film.

[0070] The double ring assembly is an annular member rotatably disposed in the housing. The double ring assembly is drivingly engaged with each of the first variator balls 32a, 32b of the first carrier assembly and each of the first variator balls 32c, 32d of the second carrier assembly. A second variator ball engagement surface 36b is formed in a first end or output ring 44 of the double ring assembly. The output ring 44 is so called because it can transmit the output of the first carrier assembly to the second carrier assembly (depending on the state of the clutch 28). The second variator ball engagement surface 36b may be a conical surface or a concave toroidal surface in contact with or slightly spaced apart from each of the first variator balls 32a, 32b, of the first carrier assembly. The second variator ball engagement surface 36b is in driving engagement with each of the first variator balls 32a, 32b through one of a boundary layer type friction and an elastohydrodynamic film. A third variator ball engagement surface 36c is formed in a second end of the double ring assembly. The third variator ball engagement surface 36c is part of an input ring 45 that transmits drive from first variator balls 32a, 32b, of the first carrier assembly to the second variator balls 32c, 32d of the second carrier assembly. The third variator ball engagement surface 36c may be a conical surface or a concave toroidal surface in contact with or slightly spaced apart from each of the second variator balls 32c, 32d, of the second carrier assembly. The second variator ball engagement surface 36c is in driving engagement with each of the second variator balls 32c, 32d through one of a boundary layer type friction and an elastohydrodynamic film. The double ring assembly includes a second engagement portion 38 extending inwardly from a surface of the double ring assembly, between the variator balls of the first carrier assembly and a plurality of second variator balls of the second carrier assembly. The second engagement portion 38 of the double ring assembly and the first engagement portion 34 of the first carrier assembly form a portion of the clutch.

[0071] The second carrier assembly is disposed in the housing and includes a plurality of second ball axle shafts 30c, 30d tiltably disposed therein in an annular arrangement. Each of the second ball axle shafts 30c, 30d may be adjusted using one of a cam style tilting mechanism and a split carrier axle skewing mechanism. Each of the second ball axle shafts 30c, 30d includes a second variator ball 32c, 32d rotatably disposed thereon. The second carrier assembly includes a third engagement portion 60 extending outwardly from a cage surface (not shown) of the second carrier assembly. The cage surface is part of cage that retains the ball axle shafts and may include the cam style tilting mechanism or a split carrier axle skewing mechanism. The third engagement portion and the second carrier assembly are fixed with respect to the housing.

[0072] The second ring assembly is an annular member rotatably disposed in the housing about the main shaft 20. The second ring assembly is drivingly engaged with the output shaft 22. An output gear 40 formed in an outer surface of the second ring assembly 47 is in driving engagement with the output shaft 22. The second ring assembly includes a fourth variator ball engagement surface 36d. The fourth variator ball engagement surface 36d is formed in a distal end of the second ring assembly. The fourth variator ball engagement surface 36d may be a conical surface or a concave toroidal surface in contact with or slightly spaced apart from each of the second variator balls 32c, 32d. The fourth variator ball engagement surface 36d is in driving engagement with each of the second variator balls 32c, 32d of the second carrier assembly through one of a boundary layer type friction and an elastohydrodynamic film.

[0073] The countershaft 66 has the first end drivingly engaged with second ring assembly through a first gear (that is, output gear 40) formed in the output shaft 22 and a second end drivingly engaged with the vehicle output 6 through a second gear 62 formed in the countershaft. It is understood that the first gear and the second gear may have differing diameters to adjust a drive ratio between the second ring assembly and the vehicle output.

[0074] The embodiment of a variable transmission as shown in FIG. 1 may be operated in at least two different operating modes, depending on an engagement status of the clutch 28, a position of the plurality of first ball axle shafts 30a, 30b of the first carrier assembly, and a position of the plurality of second ball axle shafts 30c, 30d of the second carrier assembly. The variable transmission may be operated in an infinitely variable operating mode or a continuously variable operating mode.

[0075] The variable transmission may be operated in an infinitely variable operating mode when the clutch is placed in a disengaged position. The first carrier assembly and the first variator balls 32a, 32b rotatably disposed therein are driven via the main shaft 20.

[0076] Depending on the position of the plurality of first ball axle shafts 30a, 30b of the first carrier assembly, the variable transmission 2 may be placed in a forward infinitely variable operating mode, a powered neutral operating mode, or a reverse infinitely variable operating mode. Typically, when the variable transmission is placed in the infinitely variable operating mode, the plurality of second ball axle shafts 30c, 30d of the second carrier assembly are placed in the neutral position; however, it is understood that the plurality of second ball axle shafts 30c, 30d of the second carrier assembly may be adjusted to change an overall drive ratio of the variable transmission 2. [0077] The variable transmission may be operated in a continuously variable operating mode when the clutch 28 is placed in an engaged position. Engaged position occurs, in the embodiment of FIG. 1 , when first engagement portion 34 of the first carrier assembly is engaged with second engagement portion 38 of the double ring assembly. When the clutch 28 is placed in an engaged position, the double ring assembly is fixed with respect to the first carrier assembly and the first variator balls 32a, 32b of the first carrier assembly rotate about the plurality of first ball axle shafts 30a, 30b but do not transmit power. The second ring assembly is driven by the double ring assembly through the first variator balls 32c, 32d of the second carrier assembly.

[0078] Depending on the position of the plurality of second ball axle shafts 30c, 30d of the second carrier assembly, the overall drive ratio of the variable transmission 2 may be adjusted.

[0079] A second configuration of a vehicle driveline including a variable transmission according to an embodiment of the invention is shown in FIG. 2. The elements of FIG. 2 that are in common with FIG. 1 are not labeled on FIG. 2, but are similarly named and numbered as described and depicted in FIG. 1. Nevertheless, the features of the specific embodiment of FIG. 2, as compared to the more general embodiment of FIG. 1 as well as the resulting functionality and advantages are labeled in FIG. 2 and are described herein with reference to FIG. 2. The primary difference between FIG. 1 and FIG. 2 is that FIG. 2 describes a specific embodiment of FIG. 1 that uses an overrunning clutch 46. In other embodiments contemplated herein, the device is adapted to include a one-way clutch alternatively to the overrunning clutch.

[0080] Thus, the embodiment depicted in FIG. 2 includes the variable transmission, includes a main shaft including a first carrier assembly, a first ring assembly, a double ring assembly, a second carrier assembly, a second ring assembly, and an output shaft. The main shaft and the output shaft are at least partially disposed in a housing (not shown). The first carrier assembly, the double ring assembly, and the second ring assembly are rotatably disposed in the housing. Ball ramps, indicated in FIG. 2 by a circle between a pair of vertical lines, are disposed between components of the variable transmission as shown to generate an amount of axial force necessary for proper operation of the variable transmission; however, it is understood that the amount of axial force necessary for proper operation may be generated by a clamping mechanism (not shown) or as a load applied during assembling of the variable transmission.

[0081] The main shaft has a first end drivingly engaged with the torsional dampener, a middle portion drivingly engaged with the first carrier assembly, and a second end drivingly engaged with a pump. The first carrier assembly drivingly engaged with the middle portion may be selectively drivingly engaged with the double ring assembly using an overrunning clutch 46. The overrunning clutch 46 permits the double ring assembly to drivingly engage with the first carrier assembly when a rotational speed of the double ring assembly is equal to a rotational speed of the first carrier assembly. Further, when a rotational speed of the double ring assembly is less than a rotational speed of the first carrier assembly, the double ring assembly is drivingly disengaged from the first carrier assembly.

[0082] The first carrier assembly is rotatably disposed in the housing and includes a plurality of first ball axle shafts tiltably disposed therein in an annular arrangement. Each of the first ball axle shafts may be adjusted using one of a cam style tilting mechanism and a split carrier axle skewing mechanism. Each of the first ball axle shafts includes a first variator ball rotatably disposed thereon. The first carrier assembly includes a first engagement portion extending outwardly from a surface of the first carrier assembly, between the first variator balls of the first carrier assembly and a plurality of second variator balls of the second carrier assembly. The engagement portion forms a portion of the overrunning clutch 46. The first variator balls and the first engagement portion of the first carrier assembly are driven when the main shaft is rotated.

[0083] The first ring assembly is an annular member fixed with respect to the housing. It is understood that the first ring assembly may be integrally formed with the housing or coupled thereto in any conventional manner. The first ring assembly includes a first variator ball engagement surface. The first variator ball engagement surface is formed in a distal end of the first ring assembly. The first variator ball engagement surface may be a conical surface or a concave toroidal surface in contact with or slightly spaced apart from each of the first variator balls. The first variator ball engagement surface is in driving engagement with each of the first variator balls of the first carrier assembly through one of a boundary layer type friction and an elastohydrodynamic film.

[0084] The double ring assembly is an annular member rotatably disposed in the housing. The double ring assembly is drivingly engaged with each of the first variator balls of the first carrier assembly and each of the second variator balls of the second carrier assembly. A second variator ball engagement surface is formed in a first end of the double ring assembly. The second variator ball engagement surface may be a conical surface or a concave toroidal surface in contact with or slightly spaced apart from each of the first variator balls of the first carrier assembly. The second variator ball engagement surface is in driving engagement with each of the first variator balls through one of a boundary layer type friction and an elastohydrodynamic film. A third variator ball engagement surface is formed in a second end of the double ring assembly. The third variator ball engagement surface may be a conical surface or a concave toroidal surface in contact with or slightly spaced apart from each of the second variator balls of the second carrier assembly. The third variator ball engagement surface is in driving engagement with each of the second variator balls through one of a boundary layer type friction and an elastohydrodynamic film. The double ring assembly includes a second engagement portion extending inwardly from a surface of the double ring assembly, between the first variator balls of the first carrier assembly and a plurality of second variator balls of the second carrier assembly. The engagement portion of the double ring assembly forms a portion of the overrunning clutch 46.

[0085] The second carrier assembly is disposed in the housing and includes a plurality of second ball axle shafts tiltably disposed therein in an annular arrangement. Each of the second ball axle shafts may be adjusted using one of a cam style tilting mechanism and a split carrier axle skewing mechanism. Each of the second ball axle shafts includes a second variator ball rotatably disposed thereon. The first carrier assembly includes an engagement portion extending outwardly from a cage surface (not shown) of the first carrier assembly. The cage surface is part of cage that retains the ball axle shafts and may include the cam style tilting mechanism or a split carrier axle skewing mechanism. The engagement portion and the first carrier assembly are fixed with respect to the housing.

[0086] The second ring assembly is an annular member rotatably disposed in the housing about the main shaft. The second ring assembly is drivingly engaged with the output shaft. An output gear formed in an outer surface of the second ring assembly is in driving engagement with the output shaft. The second ring assembly includes a fourth variator ball engagement surface. The fourth variator ball engagement surface is formed in a distal end of the first ring assembly. The fourth variator ball engagement surface may be a conical surface or a concave toroidal surface in contact with or slightly spaced apart from each of the second variator balls. The second variator ball engagement surface is in driving engagement with each of the second variator balls of the second carrier assembly through one of a boundary layer type friction and an elastohydrodynamic film.

[0087] The output shaft has the first end drivingly engaged with second ring assembly through a first gear formed in the output shaft and a second end drivingly engaged with the vehicle output through a second gear formed in the output shaft. It is understood that the first gear and the second gear may have differing diameters to adjust a drive ratio between the second ring assembly and the vehicle output.

[0088] The variable transmission as shown in Fig. 2 may be operated in at least two different operating modes, depending on an engagement status of the clutch, a position of the plurality of ball axle shafts of the first carrier assembly, and a position of the plurality of ball axle shafts of the second carrier assembly. The variable transmission may be operated in an infinitely variable operating mode or a continuously variable operating mode.

[0089] The variable transmission may be operated in an infinitely variable operating mode when the overrunning clutch is disengaged. The first carrier assembly and the variator balls rotatably disposed therein are driven via the main shaft. Depending on the position of the plurality of ball axle shafts of the first carrier assembly and the overrunning clutch, the variable transmission may be placed in a forward infinitely variable operating mode, a powered neutral operating mode, or a reverse infinitely variable operating mode. Typically, when the variable transmission is placed in the infinitely variable operating mode, the plurality of ball axle shafts of the second carrier assembly are placed in the neutral position; however, it is understood that the plurality of ball axle shafts of the second carrier assembly may be adjusted to change an overall drive ratio of the variable transmission.

[0090] The overrunning clutch facilitates a transition from the infinitely variable operating mode to the continuously variable operating mode. When the position of the plurality of ball axle shafts of the first carrier assembly cause the double ring assembly to rotate at a speed substantially equal to a speed of the first carrier assembly, the overrunning clutch engages the double ring assembly with the first carrier assembly.

[0091] The variable transmission may be operated in a continuously variable operating mode when the overrunning clutch is engaged. When the overrunning clutch is engaged, the double ring assembly is fixed with respect to the first carrier assembly and the variator balls of the first carrier assembly rotate about the plurality of ball axle shafts but do not transmit power. The second ring assembly is driven by the double ring assembly through the variator balls of the second carrier assembly.

Depending on the position of the plurality of ball axle shafts of the second carrier assembly, the overall drive ratio of the variable transmission may be adjusted.

[0092] A third configuration of a vehicle driveline including a variable transmission according to an embodiment of the invention is shown in FIG. 3. The elements of FIG. 3 that are in common with FIG. 2 or FIG.1 are not labeled on FIG. 3, but are similarly named, numbered, and depicted in the image and understood according to the description of FIG. 1 or as alternatively described in reference to FIG. 2, herein. Nevertheless, the features which differ from FIG. 1 or FIG. 2 in FIG. 3, and the resulting functionality and advantages are labeled in the FIG. 3 and are described below. The primary difference between FIG. 1 and FIG. 3, or between FIG. 2 and FIG. 3, is the use and placement of a first clutch 48 and a second clutch 50 in FIG. 3.

[0093] This, according to FIG.3, the variable transmission includes a main shaft, a first carrier assembly, a first ring assembly, a double ring assembly, a second carrier assembly, a second ring assembly, and an output shaft. The main shaft and the output shaft are at least partially disposed in a housing (not shown). The first carrier assembly, the double ring assembly, and the second ring assembly are rotatably disposed in the housing. Ball ramps, indicated in FIG. 3 by a small rectangle adjacent a vertical line, are disposed between components of the variable transmission as shown to generate an amount of axial force necessary for proper operation of the variable transmission;

however, it is understood that the amount of axial force necessary for proper operation may be generated by a clamping mechanism (not shown) or as a load applied during assembling of the variable transmission. [0094] The main shaft has a first end drivingly engaged with the torsional dampener, a middle portion selectively drivingly engaged with the first carrier assembly, and a second end portion selectively drivingly engaged with the double ring assembly. The middle portion of the main shaft may be selectively drivingly engaged with the first carrier assembly using a first clutch 48. The first clutch 48 may be a wet plate clutch, a dry plate clutch, a cone clutch, or any other clutch type that may be variably engaged. The second end portion of the main shaft may be selectively drivingly engaged with the double ring assembly using a second clutch 50. The second clutch 50 may be a wet plate clutch, a dry plate clutch, a cone clutch, or any other clutch type that may be variably engaged.

[0095] The first carrier assembly is rotatably disposed in the housing and includes a plurality of first ball axle shafts tiltably disposed therein in an annular arrangement. Each of the first ball axle shafts may be adjusted using one of a cam style tilting mechanism and a split carrier axle skewing mechanism. Each of the first ball axle shafts includes a first variator ball rotatably disposed thereon. The first variator balls are driven through the first carrier assembly when the main shaft is rotated.

[0096] The first ring assembly is an annular member fixed with respect to the housing. It is understood that the first ring assembly may be integrally formed with the housing or coupled thereto in any conventional manner. The first ring assembly includes a first variator ball engagement surface. The first variator ball engagement surface is formed in a distal end of the first ring assembly. The first variator ball engagement surface may be a conical surface or a concave toroidal surface in contact with or slightly spaced apart from each of the variator balls. The first variator ball engagement surface is in driving engagement with each of the first variator balls of the first carrier assembly through one of a boundary layer type friction and an elastohydrodynamic film.

[0097] The double ring assembly is an annular member rotatably disposed in the housing. The double ring assembly is drivingly engaged with each of the first variator balls of the first carrier assembly and each of the second variator balls of the second carrier assembly. A second variator ball engagement surface is formed in a first end of the double ring assembly. The second variator ball engagement surface may be a conical surface or a concave toroidal surface in contact with or slightly spaced apart from each of the first variator balls of the first carrier assembly. The second variator ball engagement surface is in driving engagement with each of the first variator balls through one of a boundary layer type friction and an elastohydrodynamic film. A third variator ball engagement surface is formed in a second end of the double ring assembly. The third variator ball engagement surface may be a conical surface or a concave toroidal surface in contact with or slightly spaced apart from each of the second variator balls of the second carrier assembly. The third variator ball engagement surface is in driving engagement with each of the second variator balls through one of a boundary layer type friction and an elastohydrodynamic film. The double ring assembly includes a first engagement portion extending inwardly from a surface of the double ring assembly, between the first variator balls of the first carrier assembly and a plurality of second variator balls of the second carrier assembly. The first engagement portion of the double ring assembly forms a portion of the second clutch 50. The double ring assembly is selectively drivingly engaged with the second end portion of the main shaft through the second clutch 50.

[0098] The second carrier assembly is rotatably disposed in the housing and includes a plurality of second ball axle shafts tiltably disposed therein in an annular arrangement. Each of the second ball axle shafts may be adjusted using one of a cam style tilting mechanism and a split carrier axle skewing mechanism. Each of the second ball axle shafts includes a variator ball rotatably disposed thereon. The second carrier assembly includes an engagement portion extending outwardly from a cage surface (not shown) of the second carrier assembly. The cage surface is part of cage that retains the ball axle shafts and may include the cam style tilting mechanism or a split carrier axle skewing mechanism. The engagement portion and the second carrier assembly are fixed with respect to the housing

[0099] The second ring assembly is an annular member rotatably disposed in the housing about an axis coincident with the axis of the main shaft. The second ring assembly is drivingly engaged with the output shaft. As shown in FIG. 3, the output shaft forms a portion of the second ring assembly. Alternately, the second ring assembly may include an output gear formed in an outer surface of the second ring assembly in driving engagement with the output shaft. The second ring assembly includes a fourth variator ball engagement surface. The fourth variator ball engagement surface is formed in a distal end of the first ring assembly. The fourth variator ball engagement surface may be a conical surface or a concave toroidal surface in contact with or slightly spaced apart from each of the variator balls. The fourth variator ball engagement surface is in driving engagement with each of the second variator balls of the second carrier assembly through one of a boundary layer type friction and an elastohydrodynamic film.

[00100] The output shaft has the first end drivingly engaged with second ring assembly and a second end drivingly engaged with the vehicle output through a gear formed in the output shaft. It is understood that a diameter of the gear formed in the output shaft may be configured to adjust a drive ratio between the second ring assembly and the vehicle output.

[00101] The variable transmission as shown in FIG. 3 may be operated in at least two different operating modes, depending on an engagement status of the first clutch 48, a position of the plurality of first ball axle shafts of the first carrier assembly, an engagement status of the second clutch 50, and a position of the plurality of second ball axle shafts of the second carrier assembly. The variable transmission may be operated in an infinitely variable operating mode or a continuously variable operating mode. [00102] The variable transmission may be operated in an infinitely variable operating mode when the first clutch 48 is placed in an engaged position and the second clutch 50 is placed in a disengaged position. The first carrier assembly and the variator balls rotatably disposed therein are driven via the main shaft. Depending on the position of the plurality of ball axle shafts of the first carrier assembly, the variable transmission may be placed in a forward infinitely variable operating mode, a powered neutral operating mode, or a reverse infinitely variable operating mode. Typically, when the variable transmission is placed in the infinitely variable operating mode, the plurality of ball axle shafts of the second carrier assembly are placed in the neutral position; however, it is understood that the plurality of ball axle shafts of the second carrier assembly may be adjusted to change an overall drive ratio of the variable transmission.

[00103] The variable transmission may be operated in a continuously variable operating mode when the first clutch 48 is placed in a disengaged position and the second clutch 50 is placed in an engaged position. When the second clutch 50 is placed in an engaged position, the double ring assembly is drivingly engaged with the main shaft 20. The second ring assembly is driven by the double ring assembly through the second variator balls of the second carrier assembly. Depending on the position of the plurality of second ball axle shafts of the second carrier assembly, the overall drive ratio of the variable transmission may be adjusted.

[00104] Embodiments of the variable transmission described herein or that would be obvious to one of skill in the art upon reading the disclosure herein are contemplated for use in a variety of vehicle drivelines. For non-limiting example, the variable transmissions disclosed herein may be used in bicycles, mopeds, scooters, motorcycles, automobiles, electric automobiles, trucks, sport utility vehicles (SUV^'s), lawn mowers, tractors, harvesters, agricultural machinery, all terrain vehicles (ATV's), jet skis, personal watercraft vehicles, airplanes, trains, helicopters, buses, forklifts, golf carts, motorships, steam powered ships, submarines, space craft, or other vehicles that employ a transmission. In some embodiments, the variable transmission described herein can be used with a transaxle.

[00105] While the figures and description herein are directed to two of the ball-type variators

(CVTs) in series in order to function in CV or IV modes, another embodiment may use one ball-type variator (CVT) in series with another version of a variator (CVT), such as a Variable-diameter pulley (VDP) or Reeves drive, a toroidal or roller-based CVT (Extroid CVT), a Magnetic CVT or mCVT, Ratcheting CVT, Hydrostatic CVTs, Naudic Incremental CVT (iCVT), Cone CVTs, Radial roller CVT, Planetary CVT, or any other version CVT.

[00106] It is to be understood that the invention may assume various alternative orientations and step sequences, except where expressly specified to the contrary. It is also to be understood that the specific devices and processes illustrated in the attached drawings, and described in the specification herein are simply exemplary embodiments of the inventive concepts defined herein. Hence, specific dimensions, directions or other physical characteristics relating to the embodiments disclosed are not to be considered as limiting, unless expressly stated otherwise.

[00107] In accordance with the provisions of the patent statutes, the present invention has been described in what is considered to represent its preferred embodiments. However, it should be noted that the invention can be practiced otherwise than as specifically illustrated and described without departing from its spirit or scope.

[00108] While preferred embodiments of the present invention have been shown and described herein, it will be obvious to those skilled in the art that such embodiments are provided by way of example only. Numerous variations, changes, and substitutions will now occur to those skilled in the art without departing from the invention. It should be understood that various alternatives to the embodiments of the invention described herein may be employed in practicing the invention. It is intended that the following claims define the scope of the invention and that methods and structures within the scope of these claims and their equivalents be covered thereby.

Claims

CLAIMS WHAT IS CLAIMED IS:

1. A variable transmission comprising:

a main shaft;

a first carrier assembly rotatably disposed in a housing and drivingly engaged with the main shaft, the first carrier assembly comprising an annular arrangement of a plurality of tiltable first variator balls each having first ball axle shafts, and comprising a first engagement portion extending from a surface of the first carrier assembly between the first variator balls and a plurality of tiltable second variator balls of a second carrier assembly;

a first ring assembly fixed with respect to the housing and comprising a first variator ball engagement surface that is in driving engagement with each of the first variator balls;

a double ring assembly rotatably disposed in the housing and selectively drivingly engaged with the first carrier assembly using a clutch, the double ring assembly comprising a second variator ball engagement surface in driving arrangement with each of the first variator balls, and a third variator ball engagement surface in driving arrangement with each of the plurality of second variator balls of the second carrier assembly, and a second engagement portion extending inwardly from a surface of the double ring assembly;

the second carrier assembly disposed in the housing and fixed relative to the housing, the second carrier assembly comprising an annular arrangement of the plurality of tiltable second variator balls each having second ball axle shafts; and

a second ring assembly rotatably disposed in the housing about the main shaft and drivingly engaged with an output shaft, the second ring assembly comprising a fourth variator ball engagement surface that is in driving engagement with each of the second variator balls wherein the clutch comprises the first engagement portion and the second engagement portion, whereby said transmission has an infinitely variable operating mode and a continuously variable operating mode.

2. The variable transmission of claim 1, wherein the operating mode depends on an engagement status of the clutch, a position of the plurality of first ball axle shafts of the first carrier assembly, and a position of the plurality of second ball axle shafts of the second carrier assembly.

3. The variable transmission of claims 1 or 2, wherein the infinitely variable operating mode is a result of disengaging the clutch.

4. The variable transmission of any one of claims 1 - 3, wherein disengaging the clutch drives the first carrier assembly and the first variator balls therein using the main shaft.

5. The variable transmission of any one of claims 1 - 4, wherein a forward infinitely variable operating mode, a powered neutral operating mode, or a reverse infinitely variable operating mode result from adjusting the position of the first ball axle shafts when the clutch is disengaged.

6. The variable transmission of any one of claims 1 - 5, wherein disengaging the clutch places the plurality of second ball axle shafts in their neutral position.

7. The variable transmission of any one of claims 1 - 6, wherein disengaging the clutch places the plurality of second ball axle shafts in an overdrive position.

8. The variable transmission of any one of claims 1 - 7, wherein disengaging the clutch places the plurality of second ball axle shafts in a low gear position.

9. The variable transmission of any one of claims 1 - 8, wherein the continuously variable operating mode is a result of engaging the clutch and thereby fixing the double ring assembly with respect to the first carrier assembly.

10. The variable transmission of any one of claims 1 - 9, wherein the continuously variable operating mode is a result of engaging the clutch and thereby rotating the first variator balls about the plurality of first ball axle shafts without transmitting power.

11. The variable transmission of any one of claims 1 - 10, wherein the continuously variable operating mode is a result of engaging the clutch and thereby driving the second ring assembly by the double ring assembly through the second variator balls.

12. The variable transmission of any one of claims 1 - 11, wherein the clutch is an overrunning clutch.

13. The variable transmission of claim 12, wherein the overrunning clutch is configured to engage the double ring assembly with the first carrier assembly when a rotational speed of the double ring assembly is equal to a rotational speed of the first carrier assembly.

14. The variable transmission of claim 12 or 13, wherein the overrunning clutch is configured to disengage the double ring assembly from the first carrier assembly when a rotational speed of the double ring assembly is less than a rotational speed of the first carrier assembly.

15. A variable transmission comprising:

a main shaft comprising a first end portion drivingly coupled to an engine, a middle portion, and a second end portion;

a first carrier assembly rotatably disposed in a housing and selectively drivingly engaged with the main shaft or a portion thereof using a first clutch, the first carrier assembly comprising an annular arrangement of a plurality of tiltable first variator balls each having first ball axle shafts;

a first ring assembly fixed with respect to the housing and comprising a first variator ball engagement surface that is in driving engagement with each of the first variator balls; a double ring assembly rotatably disposed in the housing and selectively drivingly engaged with the main shaft or a the second end portion thereof using a second clutch, the double ring assembly comprising a second variator ball engagement surface in driving arrangement with each of the first variator balls, a third variator ball engagement in driving arrangement with each of a plurality of second variator balls of the second carrier assembly, and a first engagement portion extending inwardly from a surface of the double ring assembly between the first variator balls of the first carrier assembly and a plurality of second variator balls, wherein the first engagement portion forms a portion of the second clutch;

a second carrier assembly rotatably disposed in the housing, the second carrier assembly comprising an annular arrangement of a plurality of tiltable second variator balls each having second ball axle shafts; and

a second ring assembly rotatably disposed in the housing about an axis coincident with the main shaft and drivingly engaged with an output shaft, the second ring assembly comprising a fourth variator ball engagement surface that is in driving engagement with each of the second variator balls;

wherein said variable transmission has an infinitely variable operating mode and a continuously variable operating mode.

16. The variable transmission of claim 15, wherein the operating mode depends on an engagement status of the first clutch, a position of the plurality of first ball axle shafts of the first carrier assembly, an engagement status of the second clutch, and a position of the plurality of second ball axle shafts of the second carrier assembly.

17. The variable transmission of claim 15 or 16, wherein the infinitely variable operating mode is a result of engaging the first clutch and disengaging the second clutch.

18. The variable transmission of any one of claims 15 - 17, wherein a forward infinitely variable operating mode, a powered neutral operating mode, or a reverse infinitely variable operating mode result from adjusting the position of the first ball axle shafts when the first clutch is engaged and the second clutch is disengaged.

19. The variable transmission of any one of claims 15 - 18, wherein in the infinitely variable operating mode the plurality of second ball axle shafts are in their neutral position.

20. The variable transmission of any one of claims 15 - 19, wherein in the infinitely variable operating mode the plurality of second ball axle shafts are in an overdrive position.

21. The variable transmission of any one of claims 15 - 20, wherein in the infinitely variable operating mode the plurality of second ball axle shafts are in a low gear position.

22. The variable transmission of any one of claims 15 - 21, wherein the continuously variable operating mode is a result of disengaging the first clutch and engaging the second clutch.

23. The variable transmission of claim 22, wherein engaging the second clutch drivingly engages the double ring assembly with the main shaft.

24. The variable transmission of claim 23, wherein second ring assembly is driven by the double ring assembly through the second variator balls of the second carrier assembly.

25. The variable transmission of any one of claims 1 - 24, wherein the main shaft and the output shaft are at least partially disposed in the housing.

26. The vehicle transmission of any one of claims 1 - 25, comprising an axial force generator configured to generate sufficient axial force to properly operate the vehicle transmission.

27. The vehicle transmission of claim 26, wherein the axial force generator comprises one or more clamping mechanism.

28. The vehicle transmission of claim 26 or 27, wherein the axial force generator comprises a ball ramp.

29. The vehicle transmission of any one of claims 26 - 28, wherein the axial force generator comprises a load applied during assembly of the variable transmission.

30. The variable transmission of any one of claims 1 - 29, wherein the main shaft is drivingly engaged with a torsional dampener disposed between an engine and the variable transmission.

31. The variable transmission of any one of claims 1 - 30, wherein a middle portion of the main shaft is drivingly engaged with the first carrier assembly.

32. The variable transmission of any one of claims 1 - 14, wherein the clutch comprises a wet plate clutch, a dry plate clutch, a cone clutch, or any other clutch type that may be variably engaged.

33. The variable transmission of any one of claims 15 - 31, wherein the first clutch comprises a wet plate clutch, a dry plate clutch, a cone clutch, or any other clutch type that may be variably engaged.

34. The variable transmission of any one of claims 15 - 31 and 33, wherein the second clutch comprises a wet plate clutch, a dry plate clutch, a cone clutch, or any other clutch type that may be variably engaged.

35. The variable transmission of any one of claims 1 - 34, wherein each of the first ball axle shafts and/or the second ball axle shafts are adjusted using a cam style tilting mechanism.

36. The variable transmission of any one of claims 1 - 35, wherein each of the first ball axle shafts and/or the second ball axle shafts are adjusted using a split carrier axle skewing mechanism.

37. The variable transmission of any one of claims 1 - 36, wherein the first variator balls and the first engagement portion are driven when the main shaft is rotated.

38. The variable transmission of any one of claims 1 - 37, wherein the first ring assembly is integrally formed with the housing.

39. The variable transmission of any one of claims 1 - 38, wherein the first ring assembly is coupled to the housing.

40. The variable transmission of any one of claims 1 - 39, wherein the first variator ball engagement surface is formed in a distal end of the first ring assembly.

41. The variable transmission of any one of claims 1 - 40, wherein the first variator ball engagement surface is formed in an input ring of the first ring assembly.

42. The variable transmission of any one of claims 1 - 41, wherein the first variator ball engagement surface is a conical surface or a concave toroidal surface in contact with or slightly spaced apart from each of the first variator balls.

43. The variable transmission of any one of claims 1 - 42, wherein the second variator ball engagement surface is a conical surface or a concave toroidal surface in contact with or slightly spaced apart from each of the first variator balls.

44. The variable transmission of any one of claims 1 - 43, wherein the third variator ball engagement surface is a conical surface or a concave toroidal surface in contact with or slightly spaced apart from each of the second variator balls.

45. The variable transmission of any one of claims 1 - 44, wherein the fourth variator ball engagement surface is a conical surface or a concave toroidal surface in contact with or slightly spaced apart from each of the second variator balls.

46. The variable transmission of any one of claims 1 - 45, wherein the first variator ball engagement surface is in driving engagement with each of the first variator balls of the first carrier assembly through one of a boundary layer type friction and an elastohydrodynamic film.

47. The variable transmission of any one of claims 1 - 46, wherein the second variator ball engagement surface is in driving engagement with each of the first variator balls of the first carrier assembly through one of a boundary layer type friction and an elastohydrodynamic film.

48. The variable transmission of any one of claims 1 - 47, wherein the third variator ball engagement surface is in driving engagement with each of the second variator balls of the second carrier assembly through one of a boundary layer type friction and an elastohydrodynamic film.

49. The variable transmission of any one of claims 1 - 48, wherein the fourth variator ball engagement surface is in driving engagement with each of the second variator balls of the second carrier assembly through one of a boundary layer type friction and an elastohydrodynamic film.

50. A vehicle driveline comprising the variable transmission of any one of claims 1 -49 disposed between an engine and a vehicle output.

51. The vehicle driveline of claim 50, wherein the vehicle output comprises a differential and a drive axle.

52. The vehicle driveline of claim 50 or 51, wherein the vehicle output comprises a plurality of bearings and a plurality of wheels.

53. The vehicle driveline of any one of claims 50 - 52, comprising a torsional dampener disposed between the engine and the variable transmission.

54. The vehicle driveline of any one of claims 50 - 53, wherein the torsional dampener comprises at least one torsional spring.

55. A method of changing from a continuously variable transmission mode to an infinitely variable transmission mode in a variable transmission comprising disengaging a clutch positioned between a first carrier assembly and a second carrier assembly, wherein the variable transmission is one of any of claims 1-49.

56. A method of changing from an infinitely variable transmission mode to a continuously variable transmission mode in a variable transmission comprising disengaging a clutch positioned between a first carrier assembly and a second carrier assembly, wherein the variable transmission is one of any of claims 1-49.

57. A variable transmission comprising:

a main shaft;

a first carrier assembly rotatably disposed in a housing and drivingly engaged with the main shaft, the first carrier assembly comprising an annular arrangement of a plurality of tiltable first variator balls each having first ball axle shafts;

a double ring assembly rotatably disposed in the housing, the double ring assembly comprising a second variator ball engagement surface in driving arrangement with each of the first variator balls, and a third variator ball engagement surface in driving arrangement with each of a plurality of second variator balls of the second carrier assembly;

a second carrier assembly disposed in the housing and fixed relative to the housing, the second carrier assembly comprising an annular arrangement of a plurality of tiltable second variator balls each having second ball axle shafts; and

a second ring assembly rotatably disposed in the housing about the main shaft and drivingly engaged with an output shaft, the second ring assembly comprising a fourth variator ball engagement surface that is in driving engagement with each of the second variator balls whereby said transmission has an infinitely variable operating mode and a continuously variable operating mode.

58. The variable transmission of claim 57, wherein

the first carrier assembly further comprising a first engagement portion extending from a surface of the first carrier assembly between the first variator balls and second variator balls of the second carrier assembly;

the double ring assembly is selectively drivingly engaged with the first carrier assembly using a clutch, the double ring assembly further comprising a second engagement portion extending inwardly from a surface of the double ring assembly

wherein the clutch comprises the first engagement portion and the second engagement portion.

59. The variable transmission of claim 57 or 58, wherein the main shaft and the output shaft are at least partially disposed in the housing.

60. The vehicle transmission of any one of claims 57 - 59, comprising an axial force generator configured to generate sufficient axial force to properly operate the vehicle transmission.

61. The vehicle transmission of claim 60, wherein the axial force generator comprises one or more clamping mechanism.

62. The vehicle transmission of claim 60 or 61, wherein the axial force generator comprises a ball ramp.

63. The vehicle transmission of any one of claims 60 - 62, wherein the axial force generator comprises a load applied during assembly of the variable transmission.

64. The variable transmission of any one of claims 57 - 63, wherein the main shaft is drivingly engaged with a torsional dampener disposed between an engine and the variable transmission.

65. The variable transmission of any one of claims 57 - 64, wherein a middle portion of the main shaft is drivingly engaged with the first carrier assembly.

66. The variable transmission of any one of claims 58 - 65, wherein the clutch comprises a wet plate clutch, a dry plate clutch, a cone clutch, or any other clutch type that may be variably engaged.

67. The variable transmission of any one of claims 57 - 66, wherein each of the first ball axle shafts and/or the second ball axle shafts are adjusted using a cam style tilting mechanism.

68. The variable transmission of any one of claims 57 - 67, wherein each of the first ball axle shafts and/or the second ball axle shafts are adjusted using a split carrier axle skewing mechanism.

69. The variable transmission of any one of claims 58 - 68, wherein the first variator balls and the first engagement portion are driven when the main shaft is rotated.

70. The variable transmission of any one of claims 57 - 69, wherein the first ring assembly is integrally formed with the housing.

71. The variable transmission of any one of claims 57 - 70, wherein the first ring assembly is coupled to the housing.

72. The variable transmission of any one of claims 57 - 71, wherein the first variator ball engagement surface is formed in a distal end of the first ring assembly.

73. The variable transmission of any one of claims 57 - 72, wherein the first variator ball engagement surface is formed in an input ring of the first ring assembly.

74. The variable transmission of any one of claims 57 - 73, wherein the first variator ball engagement surface is a conical surface or a concave toroidal surface in contact with or slightly spaced apart from each of the first variator balls.

75. The variable transmission of any one of claims 57 - 74, wherein the second variator ball engagement surface is a conical surface or a concave toroidal surface in contact with or slightly spaced apart from each of the first variator balls.

76. The variable transmission of any one of claims 57 - 75, wherein the third variator ball engagement surface is a conical surface or a concave toroidal surface in contact with or slightly spaced apart from each of the second variator balls.

77. The variable transmission of any one of claims 57 - 76, wherein the fourth variator ball engagement surface is a conical surface or a concave toroidal surface in contact with or slightly spaced apart from each of the second variator balls.

78. The variable transmission of any one of claims 57 - 77, wherein the first variator ball engagement surface is in driving engagement with each of the first variator balls of the first carrier assembly through one of a boundary layer type friction and an elastohydrodynamic film.

79. The variable transmission of any one of claims 57 - 78, wherein the second variator ball engagement surface is in driving engagement with each of the first variator balls of the first carrier assembly through one of a boundary layer type friction and an elastohydrodynamic film.

80. The variable transmission of any one of claims 57 - 79, wherein the third variator ball engagement surface is in driving engagement with each of the second variator balls of the second carrier assembly through one of a boundary layer type friction and an elastohydrodynamic film.

81. The variable transmission of any one of claims 57 - 80, wherein the fourth variator ball engagement surface is in driving engagement with each of the second variator balls of the second carrier assembly through one of a boundary layer type friction and an elastohydrodynamic film.