CN114729681A - Gear reduction components - Google Patents

Abstract

The gear reduction assembly includes input and output shafts extending along an axis, a ring gear disposed about the axis, a sun gear coupled to one of the shafts, a carrier extending about the shaft, and a plurality of planet gears rotatably coupled to the carrier. The carrier is movable along an axis between a direct drive position, a neutral position, and a deceleration position. The planet gears mesh with the sun gear and the carrier is coupled with one of the shafts in each position. In the direct drive position, the bracket is fixed to both shafts. In the neutral position, at least one of the shafts is disconnected from the carrier. In the reduction position, the planet gears are rotatably meshed with a sun gear and a ring gear fixed to one shaft, and the carrier is fixed to the other shaft.

Description

Gear reduction components

1. Technical field

A gear reduction assembly used to transfer torque between the prime mover and the wheels.

2. Background technology

Gear reduction assemblies are used in vehicles with wheels to selectively multiply torque delivered to the wheels. Gear reduction assemblies are ideal for applications requiring towing or towing heavy loads, such as material handling and mining applications, agricultural applications, commercial trucks, construction, defense, forestry, ground support equipment, waste, transportation and other specialty vehicles. Gear reduction assemblies typically allow for the selection of different gear ratios between the wheels and the prime mover driving the wheels. Thus, the gear reduction assembly can transmit more torque to the wheels when desired (eg, when transporting heavy loads and/or traversing off-road terrain), and when desired (eg, when unloaded and/or traversing highway terrain at high speed) , the torque can be reduced.

Typically, a gear reduction assembly includes one or more gear combinations capable of applying different gear ratios between the prime mover and the wheels. The gear combinations are selectively engaged and disengaged by friction clutches. While effective at selectively multiplying the torque delivered to the wheels, friction clutches tend to wear out over time and add weight to the gear reduction assembly. Accordingly, there remains a need to provide an improved gear reduction assembly for a vehicle.

SUMMARY OF THE INVENTION

The present invention provides a gear reduction assembly for transmitting torque between a prime mover and a wheel. The assembly includes an input shaft extending along the axis and configured to be rotated by the prime mover and an output shaft extending along the axis spaced from the input shaft and configured to rotate a wheel. The assembly also includes a ring gear (ring gear) disposed about the axis, a sun gear coupled to one of the input shaft and the output shaft, and a carrier (planet carrier) extending along the axis and about the input and output shafts. The assembly also includes a plurality of planet gears radially spaced about the axis and rotatably coupled to the carrier. The carriage is movable along the axis between a direct drive position, a neutral position, and a deceleration position. In each of the direct drive position, the neutral position, and the deceleration position, a plurality of planet gears are meshed with the sun gear, and the carrier is coupled with one of the input shaft and the output shaft.

In the direct drive position, the bracket is secured to both the input and output shafts such that the input and output shafts rotate in unison about the axis at equal rotational speeds. In the neutral position, at least one of the input shaft and the output shaft is disconnected from the carrier such that the input shaft and the output shaft rotate about the axis independently of each other. In the deceleration position, the plurality of planetary gears are rotatably meshed with the sun gear and the ring gear fixed to one of the input shaft and the output shaft, and the carrier is fixed to the other of the input shaft and the output shaft, so that the input shaft and the output shaft are rotatably engaged. The output shaft rotates around the axis at different rotational speeds.

Accordingly, the gear reduction assembly provides the advantage of reducing the number of components required to selectively vary the torque delivered to the wheels. In each of the direct drive, neutral and reduction positions, the continuous meshing of the planet gears with the sun gear and the coupling of the carrier with one of the input and output shafts maintain proper alignment of the input shaft, output shaft and carrier along the axis Aligned to facilitate movement of the carriage between the direct drive, neutral and retarded positions. Therefore, the gear reduction assembly does not require a friction clutch to selectively engage the sun, planet and ring gears. In addition, the reduction in the number of components reduces the weight of the gear reduction assembly, which facilitates a smaller package size of the gear reduction assembly, thereby reducing the volume area occupied by the gear reduction assembly.

Description of drawings

The advantages of the present invention will be readily appreciated and better understood by reference to the following detailed description when considering the accompanying drawings.

1A is a perspective view of a vehicle having an axle system.

Figure IB is a perspective view of the axle system showing the prime mover, gearbox and gear reduction assembly.

2 is a perspective cross-sectional view of the gear reduction assembly showing the carrier in a direct drive position.

3 is a perspective cross-sectional view of the gear reduction assembly showing the carrier in a neutral position.

4 is a perspective cross-sectional view of the gear reduction assembly showing the bracket in the reduction position.

Figure 5 is a schematic diagram of the gear reduction assembly showing the carrier in the direct drive position.

Figure 6 is a schematic diagram of the gear reduction assembly showing the carrier in the neutral position.

Figure 7 is a schematic diagram of the gear reduction assembly showing the bracket in the reduction position.

Detailed ways

Referring to the drawings, wherein like reference numerals indicate like or corresponding parts throughout the several views. A gear reduction assembly 20 for transmitting torque between the prime mover 22 and the wheels 24 of the vehicle 21 is generally shown in FIGS. 1A and 1B . The gear reduction assembly 20 may be configured for use with an axle system 26 . The axle system 26 may include a subframe 28 for mounting to the frame of the vehicle 21 .

A prime mover 22 may be mounted to the subframe 28 and configured to generate torque. As shown in the figures, the prime mover 22 is configured as an electric motor (electric motor) capable of generating motion that rotates the wheels 24 . However, the prime mover 22 may be an internal combustion engine, a hydrogen fuel cell, or any other suitable mechanism capable of producing motion that rotates the wheels 24 .

The axle system 26 may also include a gearbox 30, as shown in Figure IB. Gearbox 30 is mounted to subframe 28 and is coupled with each of prime mover 22 and gear reduction assembly 20 . The gearbox 30 is configured to transmit and vary torque from the prime mover 22 to the gear reduction assembly 20 . More specifically, the gearbox 30 may have multiple gears, which may be individually selected. Each gear can have a different gear ratio (gear ratio). Accordingly, the gearbox 30 may vary the torque transmitted to the gear reduction assembly 20 . Such configurations are commonly referred to as transmissions in vehicle applications.

The prime mover 22 and gearbox 30 may be coupled to a single wheel 24 (or, more specifically, as shown in FIG. 1 , a set of dual wheels 24 ). Thus, if the vehicle 21 has multiple driven wheels 24 or sets of driven dual wheels 24, each wheel 24 or set may have separate and distinct prime movers, gearboxes and gear reduction assemblies. For example, as shown in FIG. 1A , the axle system 26 includes a pair of prime movers 22 , a pair of gearboxes 30 and a pair of gear reduction assemblies 20 , each individually driving a set of dual wheels 24 . However, the prime mover 22 , gearbox 30 and gear reduction assembly 20 may be configured to drive more than one wheel 24 or more than one set of dual wheels 24 .

Axle system 26 is a rear drive axle, but it is to be understood that the advantageous features of the present disclosure to be described may alternatively be applied to front drive axles (ie, steerable), or preferably to both front and rear drive axles both.

The axle system 26 is adapted to be fixedly mounted on the vehicle 21 to which the wheels 24 are coupled so that the axle system 26 supports the weight of the vehicle 21 and cargo. Additionally, the gear reduction assembly 20 is capable of multiplying the torque transmitted from the prime mover 22 to the wheels 24 for reasons that will be described. Accordingly, the gear reduction assembly 20 of the present disclosure may be particularly suitable for heavy-duty material handling and mining applications. However, other suitable applications may include agricultural applications (eg, seeders, sprayers, and other farm-related vehicles), commercial trucks, construction, defense, forestry, ground support equipment, waste, transportation, and other specialty vehicles.

A gear reduction assembly 20 is mounted to the subframe and coupled with the prime mover 22 . The assembly 20 is configured to transfer torque between the prime mover 22 and the wheels 24 . As shown in FIGS. 2-7 , the gear reduction assembly 20 includes an input shaft 32 extending along an axis A and configured to be rotated by the prime mover 22 and an output shaft 34 extending along the axis A in communication with the input shaft 32 Spaced and configured to rotate the wheels 24 .

The gear reduction assembly 20 also includes a ring gear (ring gear) 36 arranged about the axis A, a sun gear 38 coupled to one of the input shaft 32 and the output shaft 34 , and a sun gear 38 extending along the axis A and about the input shaft 32 and the output shaft 34 . Carrier (planet carrier) 40 . The gear reduction assembly 20 also includes a plurality of planet gears 42 radially spaced about the axis A and rotatably coupled to the carrier 40 .

The carriage 40 is movable along axis A between a direct drive position (see FIGS. 2 and 5 ), a neutral position (see FIGS. 3 and 6 ), and a deceleration (see FIGS. 4 and 7 ) positions. More specifically, the carrier 40 and the plurality of planetary gears 42 move in unison (moving together) along the axis A between the direct drive position, the neutral position, and the deceleration position. In each of the direct drive position, neutral position and reduction position, a plurality of planetary gears 42 mesh with the sun gear 38 and the carrier 40 is coupled with the input shaft 32 and the output shaft 34, which causes the input shaft 32, the output shaft to 34 and carriage 40 maintain proper alignment along axis A to facilitate movement of carriage 40 between direct drive, neutral, and deceleration positions, as will be described in more detail below.

In the direct drive position (see FIGS. 2 and 5 ), bracket 40 is secured to both input shaft 32 and output shaft 34 such that input shaft 32 and output shaft 34 rotate in unison about axis A at equal rotational speeds. Furthermore, in the neutral position (see FIGS. 3 and 6 ), at least one of input shaft 32 and output shaft 34 is disconnected from bracket 40 such that input shaft 32 and output shaft 34 rotate about axis A independently of each other. Furthermore, in the deceleration position (see FIGS. 4 and 7 ), the plurality of planetary gears 42 are rotatably meshed with the sun gear 38 fixed to one of the input shaft 32 and the output shaft 34 and with the ring gear 36 , and the carrier 40 is fixed to the other of the input shaft 32 and the output shaft 34, so that the input shaft 32 and the output shaft 34 rotate about the axis A at different rotational speeds.

The neutral position of the carriage 40 may be arranged between the direct drive position and the deceleration position of the carriage 40 . Additionally, the direct drive position and the decelerated position may define opposite ends of the travel of the carriage 40 . Referring to the drawings, the direct drive position of the carriage 40 is the leftmost position of the carriage 40 (see FIGS. 2 and 5 ), the deceleration position is the rightmost position of the carriage 40 (see FIGS. 4 and 7 ), and the neutral position places the carriage 40 in Between the direct drive position and the decelerated position (see Figures 3 and 6). However, the relative position (ie, left/right) of the brackets 40 is with respect to the orientation of the drawings and may vary depending on the view of the gear reduction assembly 20 . Furthermore, although the neutral position of the carriage 40 is shown as being disposed between the direct drive position and the deceleration position of the carriage 40, in other embodiments not explicitly shown herein, the direct drive position, the neutral position and the deceleration position The positions may be arranged in a different order. Furthermore, the direct drive position and the deceleration position may not define opposing ends of travel of the carriage 40 . Additionally, the carrier 40 may include one or more additional positions between or outside the direct drive position, neutral position, and deceleration position.

As shown in FIGS. 2-4 , the gear reduction assembly 20 may also include a housing 44 defining an interior 46 along the axis A, and the input shaft 32 , the output shaft 34 , the sun gear 38 , the plurality of planet gears 42 and the carrier 40 are disposed at the inside the housing 44 . Accordingly, the housing 44 may provide protection for the components of the gear reduction assembly 20 disposed therein by reducing the ingress of contaminants such as dust and water that may degrade the components.

Input shaft 32 and output shaft 34 may be fixed longitudinally along axis A, and bracket 40 is configured to move along input shaft 32 and output shaft 34 while moving between direct drive, neutral, and deceleration positions. As shown in FIGS. 2-4 , the gear reduction assembly 20 may include an input bearing 48 coupled with the housing 44 and supporting the input shaft 32 . Although not shown in the figures, the gear reduction assembly may also include an output bearing coupled with the housing 44 and supporting the output shaft 34 . Input bearing 48 and output bearing respectively locate input shaft 32 and output shaft 34 within housing 44 and facilitate rotation of input shaft 32 and output shaft 34 about axis A. Furthermore, the bearings reduce movement of the shafts 32, 34 transverse to the axis A. Input bearing 48 and output bearing may also be defined as thrust bearings, which reduce movement of input shaft 32 and output shaft 34 along axis A under axial loads. An example of an axial load exerted on the gear reduction assembly 20 is the centripetal force exerted on the wheels 24 along the axis A during a turn of the vehicle 21 .

The housing 44 may be a structural member configured to carry lateral loads between the frame and the wheels 24 . In this configuration, the housing 44 is commonly referred to in the art as a bridge tube. In addition, the structural rigidity of housing 44, along with the bearings, may reduce the potential to inhibit this on the rotating components of gear reduction assembly 20 (ie, input and output shafts 32 and 34, carrier 40, sun gear 38, planet gears 42, etc.). a rotating lateral load. In addition, reducing lateral loads on rotating components reduces deflection of components that may cause axial misalignment, which results in inefficiency and excessive wear on assembly 20 .

As shown in FIGS. 2-4 , the ring gear 36 may be secured to the housing 44 within the interior 46 . Furthermore, as shown in the figures, the ring gear 36 may be integrally formed with the housing 44 such that the ring gear 36 and the housing 44 comprise a single common material. However, ring gear 36 and housing 44 may be separate components that are secured to each other in any suitable manner (eg, fasteners, welding, etc.). Additionally, the ring gear 36 and the housing 44 may be spaced apart from each other, and an intermediate member may be disposed therebetween to secure the ring gear 36 to the housing 44 .

As shown in FIGS. 2-4 , each of input shaft 32 , output shaft 34 , and bracket 40 may include splines 52 , 54 , 56 extending longitudinally along axis A, and splines 56 of bracket 40 are configured to follow The carriage 40 is moved longitudinally along the axis A between the direct drive position, the neutral position and the deceleration position to engage and slide the splines 52 , 54 of the input shaft 32 and the output shaft 34 . Thus, the splines 56 of the bracket 40 and the splines 52 of the input shaft 32 have corresponding opposing configurations that rotationally lock the bracket 40 with the input shaft 32, while the extension of the splines 52, 56 along the axis A allows the bracket 40 to rotate along the axis A A slides and maintains the rotational lock between the bracket 40 and the input shaft 32 . Similarly, splines 56 of bracket 40 and splines 54 of output shaft 34 have corresponding opposing configurations that rotationally lock bracket 40 with output shaft 34, while the extension of splines 54, 56 along axis A allows bracket 40 to rotate along axis A. Axis A slides and maintains a rotational lock between bracket 40 and output shaft 34 .

As shown in FIGS. 2-4 , the bracket 40 may extend along the axis A between the first end 58 and the second end 60 . Bracket 40 may define a bore 62 extending completely through bracket 40 along axis A, with input shaft 32 entering bore 62 at first end 58 and output shaft 34 entering bore 62 at second end 60 . Splines 56 of bracket 40 may extend inwardly toward axis A in bore 62 . The splines 52 , 54 of the input shaft 32 and output shaft 34 may extend outwardly away from the axis A to engage the splines 56 of the bracket 40 . However, the opposite may be true (ie, input shaft 32 and output shaft 34 may define bores and have splines 52, 54 extending inwardly toward axis A, while bracket 40 may have outwardly extending away from axis A from the outer surface of bracket 40 of splines 56). Additionally, input shaft 32 and output shaft 34 may have opposite configurations (eg, input shaft 32 may have inwardly extending splines 52 to engage a portion of outwardly extending splines 46 of bracket 40, and output shaft 34 may have The outwardly extending splines 54 to engage a portion of the inwardly extending splines 56 of the bracket 40).

As shown in FIGS. 2-4 , the sun gear 38 may be fixed to the input shaft 32 . Thus, the planet gears 42 surround and mesh with the sun gear 38 on the input shaft 32 and the ring gear 36 is positioned about the sun gear 38 on the input shaft 32 . However, the opposite may be the case. More specifically, the carrier 40 can be inverted such that the planet gears 42 surround and mesh with the sun gear 38 fixed to the output shaft 34 and the ring gear 36 is positioned about the sun gear 38 on the output shaft 34 .

The sun gear 38 may define splines 52 , 54 of one of the input shaft 32 and the output shaft 34 . More specifically, in the embodiment shown in the figures, the sun gear 38 defines the splines 52 of the input shaft 32 . Thus, the splines 52 of the input shaft 32 and the sun gear 38 can be referred to interchangeably below, the sun gear 38 can be meshed with the splines 56 of the carrier 40 , and the splines 52 of the input shaft 32 can be meshed with the planet gears 42 .

As shown in FIGS. 2-4 , the sun gear 38 and the input shaft 32 may be an integral part comprising a single material. In other words, the sun gear 38 may be formed on the input shaft 32 . However, the sun gear 38 and the input shaft 32 may be separate components that are secured to each other in any suitable manner (eg, fasteners, welding, etc.).

The bracket 40 may include a wall 64 extending transverse to the axis A and bisecting the splines 56 to define an input portion 66 of the splines 56 and an output portion 68 of the splines 56, the input portion 66 of the splines 56 being configured to The splines 52 of the input shaft 32 are engaged, and the output portion 68 of the splines 56 is configured to mesh with the splines 54 of the output shaft 34 . The wall 64 can engage at least one of the input shaft 32 and the output shaft 34 to define an end stop to prevent further movement of the carriage 40 beyond one of the direct drive position, neutral position and deceleration position. More specifically, the splines 56 of each of the input portion 66 and the output portion 68 may extend inwardly toward the axis A, with one of the input portion 66 and the output portion 68 extending further toward the axis A than the other, the wall 64 at Transition between input portion 66 and output portion 68 . In the embodiment shown in the figures, the splines 56 of the input portion 66 extend further towards the axis A than the output portion 68 .

As shown in FIGS. 2-4 , the input shaft 32 and the output shaft 34 are sized to receive the input portion 66 and the output portion 68 of the splines 56 of the bracket 40 . More specifically, the input shaft 32 and the output shaft 34 are dimensioned such that the splines 52 of the input shaft 32 are arranged between and engage the input portions 66 of the respective splines 56 of the bracket 40 and the splines 54 of the output shaft 34 are arranged Between and engaging the output portion 68 of each spline 56 of the bracket 40 .

In the embodiment shown in the figures, the splines 56 of the input portion 66 extend further towards the axis A than the splines 56 of the output portion 68 . Therefore, the splines 54 of the output shaft 34 extend further away from the axis A than the splines 52 of the input shaft 32 .

Wall 64 may be substantially orthogonal to axis A. As shown in FIG. 4 , the wall 64 may engage the output shaft 34 . Thus, wall 64 defines an end stop that prevents bracket 40 from moving further beyond the decelerated position (ie, as shown in FIG. 4 , wall 64 inhibits further rightward movement beyond the decelerated position ). Thus, the decelerated position of the carriage 40 may define the endpoint (end) of movement of the carriage 40, and the wall 64 prevents movement of the carriage 40 beyond the decelerated position. The end stops that prevent the carrier 40 from moving further beyond the reduced position ensure proper alignment and meshing of the planet gears 42 with both the sun gear 38 and the ring gear 36 . Although wall 64 defines an end stop for engagement with output shaft 34 to prevent movement of bracket 40 beyond the decelerated position, wall 64 may define an end for engagement with input shaft 32 or any other suitable component A stopper to prevent movement of the bracket 40 into or out of any position, including positions expressly described and not expressly described herein.

The splines 56 of the carrier 40 may be longitudinally spaced and disconnected along the axis A with the splines 52 , 54 of one of the input shaft 32 and the output shaft 34 when the carrier 40 is in the neutral and decelerated positions. More specifically, the splines 56 of the carrier 40 may be longitudinally spaced and disconnected along the axis A from the splines 52 of the input shaft 32 when the carrier 40 is in the neutral and decelerating positions, as shown in FIGS. 3 and 4 . Since the splines 56 of the bracket 40 are spaced and disconnected from the splines 52 of the input shaft 32, the input and output shafts 32, 34 do not rotate in unison together, thereby facilitating independent rotation of the input shaft 32 and the output shaft 34 (neutral position) and rotating at different rotational speeds (deceleration position).

In the embodiment shown in FIG. 2 , in the direct drive position, the splines 56 of the carrier 40 are engaged with the splines 52 of the input shaft 32 . Movement of carriage 40 from the direct drive position to the neutral and decelerated positions (ie, from left to right as shown in FIGS. 2-4 ) causes carriage 40 to move away from input shaft 32 (which remains stationary along axis A) and causes carriage 40 Disconnected from input shaft 32 . Additionally, the output portion 68 of the splines 56 of the carrier 40 is configured to remain engaged with the splines 54 of the output shaft 34 in each of the direct drive position, the neutral position, and the deceleration position, as will be described in greater detail below.

As shown in FIGS. 2-4 , the bracket 40 may have a flange 70 at the first end 58 extending outwardly away from the axis A. As shown in FIGS. Each of the planet gears 42 may be rotatably coupled to the flange 70 . The planet gears 42 may be configured as spur gears having radially extending teeth. However, the planet gears 42 may have any suitable configuration for meshing with each of the sun gear 38 and the ring gear 36 .

In the decelerating position, the planet gears 42 may be disposed between the ring gear 36 and the sun gear 38 and spaced radially about the sun gear 38 , as shown in FIG. 4 . Thus, in the deceleration position, the plurality of planet gears 42 may be rotatably meshed with the ring gear 36 and the input shaft 32 through the sun gear 38 . Rotation of input shaft 32 and sun gear 38 about axis A at the first rotational speed causes planet gears 42 meshing with both sun gear 38 and ring gear 36 to each independently rotate and move along sun gear 38 and ring gear 36 . Therefore, the planetary gears 42 move about the axis A at a second rotational speed different from the first rotational speed. Because the planet gears 42 are rotatably coupled to the carrier 40, movement of the planet gears 42 about the axis A causes the carrier 40 to also rotate about the axis at the second rotational speed. Since the output portion 68 of the splines 56 of the carrier 40 engages the splines 54 of the output shaft 34 in the decelerated position, the output shaft 34 also rotates at the second rotational speed. Thus, rotation of the input shaft 32 at the first rotational speed in the decelerated position results in rotation of the output shaft 34 at the second rotational speed in the decelerated position. In the reduced position, the plurality of planet gears 42 may be rotatably meshed with the ring gear 36 and the sun gear 38 to have a gear ratio of at least 3:1. Thus, the gear reduction assembly 20 in the reduced position may provide a mechanical advantage to the wheels 24 attached to the output shaft 34 for increasing the torque delivered to the wheels 24 . Although the planetary gears 42 shown in FIGS. 2-4 have a 3:1 gear ratio, the planetary gears 42 may have any suitable gear ratio to provide a mechanical advantage to the wheels 24 .

As shown in FIGS. 2-4 , the planet gears 42 may be arranged in a plane P orthogonal to the axis A, with the planet gears 42 spaced apart from the splines 56 of the carrier 40 to define a gap 72 having a distance X along the axis A . The ring gear 36 may have a length L along the axis A that is less than or equal to the distance X of the gap 72 between the planet gears 42 and the splines 56 of the carrier 40 , wherein when the carrier 40 is in the neutral position, the ring gear 36 Arranged within the gap 72 . As shown, in the neutral position, the planet gears 42 are arranged to the left of the ring gear 36 . Furthermore, the input portion 66 of the splines 56 of the bracket 40 is dimensioned along axis A such that movement of the bracket 40 to the neutral position causes the bracket 40 to disconnect from the input shaft 32 . Thus, in the neutral position, the input shaft 32 in the carrier 40 rotates non-uniformly. Furthermore, because the planet gears 42 do not mesh with the ring gear 36 in the neutral position, the planet gears 42 simply rotate independently on the sun gear 38 without causing rotation of the carrier 40 about axis A. In other words, in the neutral position, the planet gears 42 are freewheeling on the sun gear 38 . Therefore, in the neutral position, the input shaft 32 and the output shaft 34 may rotate at different rotational speeds. In the embodiment shown in the figures, the arrangement of the neutral position between the direct drive position and the deceleration position prevents simultaneous direct engagement between the input shaft 32 and the output shaft 34 and the passage of the sun between the input shaft 32 and the output shaft 34 Gears 38 , planet gears 42 , and ring gear 36 perform gear reduction, which can damage the gear reduction assembly 20 .

As shown in FIGS. 2-4 , each planet gear 42 may have an outer surface 74 facing away from the carrier 40 and spaced a first distance D1 from the wall 64 along axis A. The sun gear 38 may extend along the axis A a second distance D2 at least equal to the first distance D1 so that the sun gear 38 is coupled with the carrier 40 and at least one of the plurality of planet gears 42 . Accordingly, movement of carrier 40 along axis A can occur between the direct drive position, neutral position, and reduction position without requiring input shaft 32 to be disengaged from both carrier 40 and planetary gears 42 . Disengagement of input shaft 32 from both carrier 40 and planet gears 42 may result in a rotational misalignment between sun gear 38 and planet gears 42/carrier 40, which may result in engagement therebetween as movement of carrier 40 attempts to re-engage input shaft 32. Similarly, the output portion 68 of the splines 56 of the carrier 40 may extend along the axis A a third distance D3 at least equal to the first distance D1 to maintain the carrier 40 and the carrier 40 in each of the direct drive, neutral and deceleration positions. Meshing between the output shafts 34 .

In the direct drive position, the input shaft 32 may be secured to the carrier 40 by the sun gear 38 . As shown in FIGS. 2 and 5 , the planetary gears 42 and the carrier 40 are arranged at their furthest left positions. The input portion 66 of the splines 56 of the carrier 40 meshes with the sun gear 38/splines 52 of the input shaft 32 , thereby securing the input shaft 32 to the carrier 40 . The planet gears 42 mesh with the sun gear 38, but cannot rotate along the sun gear 38 because the input shaft 32 and the carrier 40 cannot rotate independently of each other. As described above, the output portion 68 of the splines 56 of the bracket 40 engages the splines 54 of the output shaft 34 , thereby securing the output shaft 34 to the bracket 40 . Thus, in the direct drive position, the input shaft 32, carrier 40 and output shaft 34 rotate in unison.

As shown in FIGS. 2-4 , the input shaft 32 may include a second wall 76 extending transverse to the axis A and engageable with the planetary gears 42 to define a position that prevents further movement of the carrier 40 to the direct drive position, neutral The end stop outside one of the position and the deceleration position. The second wall 76 may be at the end of the splines 52 of the input shaft 32 , the second wall 76 transitioning to the smooth outer surface of the input shaft 32 .

The second wall 76 may be substantially orthogonal to the axis A. As shown in FIG. 2 , in the direct drive position, the second wall 76 may engage the planet gears 42 (ie, the planet gears 42 engaged with the splines 52 of the input shaft 32 may move along axis A until the planet gears 42 abut against the against the second wall 76 at the end of the splines 52). Accordingly, the second wall 76 defines an end stop that prevents further movement of the bracket 40 beyond the direct drive position (ie, as shown in FIG. 2 , the second wall 76 inhibits further leftward movement out of the direct drive position). Thus, the direct drive position of the carriage 40 may define the endpoint (end) of the carriage 40 movement, and the second wall 76 prevents movement of the carriage 40 beyond the direct drive position. An end stop that prevents further movement of the carrier 40 beyond the direct drive position ensures that the splines 52 of the input shaft 32 are properly engaged with the input portion 66 of the splines 56 of the carrier 40 to transmit torque to the wheels 24 . Although the second wall 76 defines an end stop for engagement with the planet gears 42 to prevent movement of the carrier 40 out of the direct drive position, the second wall 76 may define an end stop for engagement with the carrier 40 or any other suitable Component engagement end stops to prevent movement of the bracket 40 to or beyond any position, including those expressly described and not expressly described herein.

For illustrative purposes only, the operation of moving the carrier 40 from the direct drive position to the deceleration position to increase the torque transmitted to the wheels 24 will be described below in accordance with the embodiment shown in the figures.

When the carrier 40 is in the direct drive position (see FIGS. 2 and 5 ), the input portion 66 of the splines 56 of the carrier 40 is engaged with the splines 52 of the input shaft 32 and the output portion 68 of the splines 56 of the carrier 40 is engaged with the output shaft 34 The splines 54 engage. The planet gears 42 mesh with the sun gear 38/splines 52 of the input shaft 32 but are spaced from the ring gear 36 and thus remain stationary about the input shaft 32 . Rotation of input shaft 32 (driven by prime mover 22 ) causes carriage 40 and output shaft 34 to rotate in unison with input shaft 32 . Rotation of the output shaft 34 causes rotation of the wheels 24 .

To move the carriage 40 to the decelerated position, the carriage 40 is moved along the axis A away from the input shaft 32 . The bracket 40 is first moved to the neutral position (see Figures 3 and 6). In the neutral position, the output shaft 34 remains coupled with the bracket 40 and rotates in unison with the bracket 40 . However, the input portion 66 of the splines 56 of the bracket 40 is moved away from the splines 52 of the input shaft 32 and is spaced therefrom. Therefore, the bracket 40 is disconnected from the input shaft 32 . The bracket 40 and the output shaft 34 are rotatable independently of the input shaft 32 . The planet gears 42 remain meshed with the sun gear 38/splines 52 of the input shaft 32 and remain spaced from the ring gear 36 . Therefore, any rotation of the carrier 40 of the input shaft 32 causes the planetary gears 42 to freewheel around the input shaft 32 . In the neutral position, torque cannot be transferred between the input shaft 32 and the output shaft 34 .

The carriage 40 continues to move along the axis A away from the input shaft 32 from the neutral position to the deceleration position. In the decelerated position (see FIGS. 4 and 7 ), the output shaft 34 remains coupled with the carrier 40 and rotates in unison with the carrier 40 . The input portion 66 of the splines 56 of the bracket 40 remains spaced apart from the splines 52 of the input shaft 32 . The planet gears 42 remain meshed with the sun gear 38/splines 52 of the input shaft 32 and are now meshed with the ring gear 36 . Rotation of input shaft 32 and sun gear 38 about axis A at the first rotational speed causes planet gears 42 meshing with both sun gear 38 and ring gear 36 to each independently rotate and move along sun gear 38 and ring gear 36 . Therefore, the planetary gears 42 move about the axis A at a second rotational speed different from the first rotational speed. Movement of planet gear 42 about axis A causes carrier 40 and output shaft 34 to also rotate about axis A at the second rotational speed. Thus, rotation of the input shaft 32 at the first rotational speed in the decelerated position results in rotation of the output shaft 34 at the second rotational speed in the decelerated position.

The present invention also provides a method of operating the gear reduction assembly 20 for transmitting torque between the prime mover 22 and the wheels 24 . As described above and shown in FIGS. 2-4 , assembly 20 includes input shaft 32 extending along axis A. As shown in FIG. The input shaft 32 is configured to be rotated by the prime mover 22 . The output shaft 34 extends along the axis A spaced apart from the input shaft 32 and is configured to rotate the wheel 24 . The ring gear 36 is arranged around the axis A. The sun gear 38 is coupled to one of the input shaft 32 and the output shaft 34 . Bracket 40 extends along axis A and around input shaft 32 and output shaft 34 . A plurality of planet gears 42 are radially spaced about axis A and rotatably coupled to carrier 40 . The carriage 40 is movable along axis A between a direct drive position, a neutral position and a decelerated position. In each of the direct drive position, neutral position and reduction position, a plurality of planet gears 42 mesh with the sun gear 38 and the carrier 40 is coupled with one of the input shaft 32 and the output shaft 34 .

The method includes the steps of arranging the bracket 40 in a direct drive position, wherein the bracket 40 is fixed to both the input shaft 32 and the output shaft 34 such that the input shaft 32 and the output shaft 34 are in unison about the axis A at equal rotational speeds Rotate as shown in Figures 2 and 5. The method further includes the step of causing bracket 40 to rotate along axis A with at least one of input shaft 32 and output shaft 34 disconnected from bracket 40 such that input shaft 32 and output shaft 34 rotate about axis A independently of each other Move to the neutral position as shown in Figures 3 and 6. The method also includes the steps of rotatably meshing a plurality of planetary gears 42 with a sun gear 38 and a ring gear 36 fixed to one of the input shaft 32 and the output shaft 34 and the carrier 40 is fixed to the input shaft 32 and the output shaft 34 The other moves the carriage 40 along axis A to a decelerated position with input shaft 32 and output shaft 34 rotating about axis A at different rotational speeds, as shown in FIGS. 4 and 7 .

As described above, the neutral position of the carriage 40 may be arranged between the direct drive position and the deceleration position of the carriage 40 . Accordingly, the method may further include the steps of moving the carriage 40 in a single direction along the axis A from the direct drive position (see FIGS. 2 and 5 ) to the neutral position (see FIGS. 3 and 6 ) and from the neutral position to the deceleration position ( See Figures 4 and 7).

The present invention has been schematically described, it is to be understood that the terminology used is intended to be words of description and not limitation. Many modifications and variations of the present invention are possible in light of the above teachings, as will be apparent to those skilled in the art. Thus, it is to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described, in which reference numerals are used for convenience only and not limitation.

Claims (21)

1. A gear reduction assembly for transmitting torque between a prime mover and a wheel; the assembly includes: an input shaft extending along an axis and configured to be rotated by the prime mover; an output shaft extending along the axis spaced from the input shaft and configured to rotate the wheel; a ring gear arranged about the axis; a sun gear coupled to one of the input shaft and the output shaft; a bracket extending along the axis and around the input shaft and the output shaft; and a plurality of planet gears radially spaced about the axis and rotatably coupled to the carrier, wherein the carrier is operative along the axis in a direct drive position, a neutral position, and a reduction position and in each of the direct drive position, the neutral position and the deceleration position, the plurality of planet gears are meshed with the sun gear, the carrier is engaged with the input shaft and A coupling in the output shaft; wherein, in the direct drive position, the bracket is secured to both the input shaft and the output shaft such that the input shaft and the output shaft rotate in unison about the axis at equal rotational speeds ; wherein, in the neutral position, at least one of the input shaft and the output shaft is disconnected from the carrier such that the input shaft and the output shaft rotate independently of each other about the axis; and wherein, in the deceleration position, the plurality of planetary gears are rotatably meshed with the sun gear and the ring gear fixed to the one of the input shaft and the output shaft, and the A bracket is fixed to the other of the input shaft and the output shaft so that the input shaft and the output shaft rotate about the axis at different rotational speeds. 2 . The gear reduction assembly of claim 1 , wherein each of the input shaft, the output shaft, and the bracket includes splines extending longitudinally along the axis, and along the axis. 3 . The splines of the bracket are configured to engage the splines of the input shaft and the output shaft when the bracket moves longitudinally along the axis between the direct drive position, the neutral position and the deceleration position and slide along it. 3 . The gear reduction assembly of claim 2 , wherein when the bracket is in the neutral position and the deceleration position, the splines of the bracket are in contact with the input shaft and the output shaft. 4 . The splines of one of the splines are longitudinally spaced and disconnected along the axis. 4. The gear reduction assembly of claim 3, wherein when the bracket is in the neutral position and the deceleration position, the splines of the bracket and the splines of the input shaft are along the The axes are longitudinally spaced and disconnected. 5. The gear reduction assembly of claim 2, wherein the planetary gears are arranged in a plane orthogonal to the axis, and the planetary gears are spaced apart from the splines of the carrier to define A gap with a distance along the axis. 6. The gear reduction assembly of claim 5, wherein the length of the ring gear along the axis is less than or equal to the distance of the gap between the planet gear and the splines of the carrier, Wherein, the ring gear is disposed within the gap when the carrier is in the neutral position. 7. The gear reduction assembly of claim 2, wherein the bracket includes a wall extending transverse to the axis and bisecting the splines to define an input portion of the splines and The output portion of the spline, the input portion of the spline is configured to engage with the spline of the input shaft, the output portion of the spline is configured to engage with the spline of the output shaft, and the wall engageable with at least one of the input shaft and the output shaft to define an end stop to prevent further movement of the carriage to any of the direct drive position, the neutral position and the deceleration position beyond one. 8. The gear reduction assembly of claim 7, wherein each of the planet gears has an outer surface facing away from the carrier and spaced a first distance from the wall along the axis, the The sun gear extends along the axis a second distance at least equal to the first distance to facilitate coupling of the sun gear with the carrier and at least one of the plurality of planet gears. 9. The gear reduction assembly of claim 7, wherein the splines of each of the input portion and the output portion extend inwardly toward the axis, the input portion and the output portion One of the sections extends further towards the axis than the other, and the wall transitions between the input section and the output section. 10. The gear reduction assembly of claim 7, wherein the reduction position of the bracket defines an endpoint of movement of the bracket and the wall prevents movement of the bracket beyond the reduction position . 11. The gear reduction assembly of claim 2, wherein the sun gear defines splines for one of the input shaft and the output shaft. 12. The gear reduction assembly of claim 1, wherein the sun gear and the input shaft are a unitary component comprising a single material. 13. The gear reduction assembly of claim 1, wherein the neutral position of the carrier is disposed between the direct drive position and the reduction position of the carrier. 14. The gear reduction assembly of claim 1, wherein the input shaft and the output shaft are fixed longitudinally along the axis, and the bracket is configured in the direct drive position, the neutral position It moves along the input shaft and the output shaft while moving between the decelerated positions. 15. The gear reduction assembly of claim 1, further comprising a housing defining an interior along the axis, the input shaft, the output shaft, the sun gear, the plurality of planet gears and the bracket is disposed within the housing, and the ring gear is fixed to the housing within the interior. 16. The gear reduction assembly of claim 1 wherein, in the direct drive position, the sun gear is fixed to the input shaft and the input shaft is fixed to the input shaft through the sun gear a carrier, and in the reduced position, the plurality of planet gears are rotatably meshed with the ring gear and the input shaft through the sun gear. 17. The gear reduction assembly of claim 1, wherein the plurality of planet gears rotatably meshing with the ring gear and the sun gear in the reduction position have a ratio of at least 3:1 gear ratio. 18. An axle system for transmitting torque to wheels of a vehicle, the axle system comprising: a subframe for mounting to the frame of the vehicle; a prime mover mounted on the subframe and configured to generate torque; and a gear reduction assembly mounted to the subframe and coupled to the prime mover, the assembly configured to transmit torque between the prime mover and the wheels; the assembly comprising: an input shaft extending along an axis and configured to be rotated by the prime mover; an output shaft extending along the axis spaced from the input shaft and configured to rotate the wheel; a ring gear arranged about the axis; a sun gear coupled to one of the input shaft and the output shaft; a bracket extending along the axis and around the input shaft and the output shaft; and a plurality of planet gears radially spaced about the axis and rotatably coupled to the carrier, wherein the carrier is operative along the axis in a direct drive position, a neutral position, and a reduction position and in each of the direct drive position, the neutral position and the deceleration position, the plurality of planet gears are meshed with the sun gear, the carrier is engaged with the input shaft and A coupling in the output shaft; wherein, in the direct drive position, the bracket is secured to both the input shaft and the output shaft such that the input shaft and the output shaft rotate in unison about the axis at equal rotational speeds ; wherein, in the neutral position, at least one of the input shaft and the output shaft is disconnected from the carrier such that the input shaft and the output shaft rotate independently of each other about the axis; and wherein, in the deceleration position, the plurality of planetary gears are rotatably meshed with the sun gear and the ring gear fixed to the one of the input shaft and the output shaft, and the A bracket is fixed to the other of the input shaft and the output shaft so that the input shaft and the output shaft rotate about the axis at different rotational speeds. 19. The axle system of claim 18, further comprising a gearbox mounted to the subframe and coupled to each of the prime mover and the gear reduction assembly, the gearbox is configured to transmit and vary torque from the prime mover to the gear reduction assembly. 20. A method of operating a gear reduction assembly for transmitting torque between a prime mover and wheels, the assembly comprising: an input shaft extending along an axis and configured to be rotated by the prime mover; an output shaft, The output shaft extends along the axis spaced from the input shaft and is configured to rotate the wheel; a ring gear disposed about the axis; a sun gear coupled to the one of an input shaft and the output shaft; a carrier extending along the axis and around the input shaft and the output shaft; and a plurality of planet gears around the axis diameter is spaced apart and rotatably coupled to the carriage, and the carriage is movable along the axis between a direct drive position, a neutral position, and a deceleration position, and in the direct drive position, the neutral position, and all In each of the deceleration positions, the plurality of planet gears are meshed with the sun gear, the carrier is coupled to one of the input shaft and the output shaft, and the method includes the steps of: Arranging the bracket in the direct drive position, the bracket being fixed to both the input shaft and the output shaft such that the input shaft and the output shaft rotate about the axis at equal speeds rotate in unison; moving the bracket along the axis to the neutral position with at least one of the input shaft and the output shaft disconnected from the bracket so that the input shaft and the output shaft surround the axis rotate independently of each other; and moving the carrier along the axis to the reduction position, the plurality of planet gears rotatably meshing with the sun gear and the ring gear fixed to one of the input shaft and the output shaft , and the bracket is fixed to the other of the input shaft and the output shaft, so that the input shaft and the output shaft rotate around the axis at different rotational speeds. 21. The method of claim 20, wherein the neutral position of the carriage is disposed between the direct drive position and the deceleration position of the carriage, and further comprising the step of : move the carriage in a single direction along the axis from the direct drive position to the neutral position and from the neutral position to the deceleration position.

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