JP2012219957A - Torque limiter and power transmission device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a torque limiter, along with a power transmission device, capable of reducing a manufacturing cost by eliminating the need for providing a thrust bearing between an inner tubular member and an outer tubular member, and capable of reducing an installation space by reducing a gap, in an axial direction, between the inner tubular member and the outer tubular member.SOLUTION: A spline groove 53b formed in a tubular section 53B of a clutch hub 53 extends from an open end 53a of the tubular section 53B to the middle of an outer periphery of the tubular section 53B and a wall surface, which is formed in a terminal in the extending direction of the spline groove 53b, in the axial direction of the outer periphery of the tubular section 53B constitutes an abutment surface 53c to which a friction plate 55B positioned in a terminal in the axial direction is abutted.

Description

  The present invention relates to a torque limiter and a power transmission device, and more particularly to a torque limiter interposed between a first component of a planetary gear mechanism and a rotating shaft of a rotating electrical machine, and a power transmission device having the torque limiter.

  Conventionally, as a power transmission device for a vehicle, there are a power transmission device for an electric vehicle and a hybrid power transmission device in which an internal combustion engine and a motor generator are used together.

  As a hybrid power transmission device, an internal combustion engine as a prime mover, a motor generator driven by the internal combustion engine, and a gear train that is drivingly connected to wheels via a differential device are connected via a planetary gear mechanism. Therefore, it is possible to mutually transmit power between the internal combustion engine, the motor generator, and the wheel, driving the motor generator by the internal combustion engine, assisting the driving force using the motor generator as a motor, starting the internal combustion engine, and differential from the wheel. It is known that the generator can be regenerated by an inertial driving force that returns to the planetary gear mechanism via the device according to the traveling state (for example, see Patent Document 1).

  This power transmission device uses a planetary gear mechanism and is configured to perform torque transmission by meshing between the gears of the planetary gear mechanism, thereby ensuring high torque transmission efficiency and reliability.

  However, when excessive input torque is transmitted from the internal combustion engine to the power transmission device, or when excessive reverse input torque is transmitted from the wheels to the power transmission device, the excessive input torque or reverse input torque is released to the outside. Since this is not possible, an excessive load may be applied to the planetary gear mechanism.

Therefore, in order to release the input torque and the reverse input torque to the outside, there is one in which a torque limiter is interposed between the motor and the planetary gear mechanism (for example, see Patent Document 2).
This power transmission device can release an excessive input torque transmitted from the internal combustion engine to the planetary gear mechanism and an excessive reverse input torque transmitted from the drive wheel to the planetary gear mechanism by a torque limiter. Can be protected.

  Here, for example, consider a case where a torque limiter interposed between the motor generator and the planetary gear mechanism is configured as shown in FIG.

  In FIG. 5, a clutch hub 2 having a cylindrical portion 3 is attached to a sun gear 1 that is a bevel gear of a planetary gear mechanism, and a spline groove 3 a is formed on the outer peripheral portion of the cylindrical portion 3. . The inner peripheral surfaces of the plurality of inner plates 4 are spline-fitted in the spline grooves 3a, and the inner plates 4 are rotatable together with the clutch hub 2 and are movable in the axial direction.

  A clutch drum 7 is attached to the rotor shaft 6 of the motor generator, and a spline groove 7 a is formed on the inner peripheral surface of the clutch drum 7. The outer peripheral surfaces of the plurality of outer plates 8 are spline-fitted in the spline grooves 7a, and the outer plates 8 are rotatable integrally with the clutch drum 7 so as to be alternately positioned between the inner plates 4, and It is movable in the axial direction.

  Also, a disc spring 9 is interposed between the clutch drum 7 and the outer plate 8 located at the left end, and the disc spring 9 biases the outer plate 8 toward the clutch hub 2 so as to urge the outer plate. 8 and the inner plate 4 are in frictional contact.

  For this reason, when the clutch hub 2 and the clutch drum 7 are integrally rotated via the inner plate 4 and the outer plate 8, the sun gear 1 and the rotor shaft 6 of the motor generator are integrally rotated.

  Further, for example, when an excessive torque is input from the sun gear 1 to the motor generator, the rotational difference is caused between the clutch hub 2 and the clutch drum 7 by sliding the inner plate 4 and the outer plate 8.

  Therefore, a rotational difference can be generated between the sun gear 1 and the rotor shaft 6, and an excessive torque generated between the sun gear 1 and the motor generator can be released to the outside.

Further, when a leftward thrust load is generated in the sun gear 1 in FIG. 5 with a rotational difference between the clutch hub 2 and the clutch drum 7, the clutch hub 2 moves to the left.
Specifically, since the sun gear 1 meshes with a carrier pinion gear made of a bevel gear, the direction in which the sun gear 1 moves in the thrust direction depending on the direction of the rotational torque of the motor generator is either the right side or the left side. It becomes.

  For example, when the motor generator rotates in one direction, a leftward thrust load is generated in the sun gear 1 due to the engagement between the sun gear 1 and the pinion gear, and when the motor generator rotates in the other direction, the sun gear 1 and the pinion gear engage with each other. As a result, a rightward thrust load is generated on the sun gear 1.

Since a spline groove 3a is formed on the outer peripheral portion of the tubular portion 3 over the entire axial direction of the tubular portion 3, when a leftward thrust load is generated in the sun gear 1, as shown in FIG. The clutch hub 2 moves to the left with respect to the inner plate 4 over the formation region 3a.
As a result, the clutch hub 2 and the clutch drum 7 rotate integrally with the open end of the cylindrical portion 3 of the clutch hub 2 in contact with the clutch drum 7.

  In this state, for example, if excessive torque is input to the sun gear 1 and slip occurs between the inner plate 4 and the outer plate 8, a difference in rotation occurs between the clutch hub 2 and the clutch drum 7. 3 and the contact surface of the clutch drum 7 are worn out or damaged.

  For this reason, when a leftward thrust load is generated in the sun gear 1 and the clutch hub 2 moves to the left side, the clutch hub 2 is brought into contact with the clutch drum 7 via the thrust bearing 10 to cause the clutch hub 2 and the clutch drum 7 to contact each other. It is conceivable to prevent the opening end of the cylindrical portion 3 and the contact surface of the clutch drum 7 from being worn or damaged by generating a difference in rotation.

JP 2003-191760 A JP 2008-64281 A

  However, in such a conventional torque limiter, since the thrust bearing 10 is interposed between the clutch hub 2 and the clutch drum 7, the number of parts of the torque limiter is as much as the thrust bearing 10 is provided. This increases the manufacturing cost of the torque limiter.

  Further, since it is necessary to secure a space for providing the thrust bearing 10 between the clutch hub 2 and the clutch drum 7 in the axial direction, the torque limiter becomes longer in the axial direction, and the installation space for the torque limiter increases. Will end up.

  The present invention has been made to solve the above-described problems, and it is unnecessary to provide a thrust bearing between the inner cylindrical member and the outer cylindrical member, and the manufacturing cost can be reduced. In addition, an object is to provide a torque limiter and a power transmission device that can reduce the installation space by reducing the axial gap between the inner cylindrical member and the outer cylindrical member.

  In order to achieve the above object, a torque limiter according to the present invention includes: (1) a planetary gear mechanism having a plurality of components attached so as to be differentially rotatable; and a plurality of components of the planetary gear mechanism. A rotating shaft of a rotating electrical machine having a rotating shaft connected to the first component is interposed between the first component and the rotating electrical machine within a preset torque range. A torque limiter for transmission, which is attached to either the first component or the rotary shaft, and has an outer periphery having an open end that opens at an axial end and a first spline groove. A cylindrical member, a plurality of outer plates that are spline-fitted in the first spline groove so as to be slidable in the axial direction, and attached to either one of the first component or the rotary shaft, At the edge An inner cylindrical member having an open end facing the outer cylindrical member and an outer peripheral portion formed with a second spline groove facing the inner peripheral portion of the outer cylindrical member; A plurality of inner plates which are spline-fitted to the spline grooves in the axial direction and arranged alternately with the outer plates, and the outer cylindrical member and the outer plate or the inner cylindrical member and the inner A biasing member provided between the first and second plates, and biasing the outer plate and the inner plate in an axial direction so that the adjacent outer plate and the inner plate are frictionally engaged with each other; The spline groove or the second spline groove is formed on the inner peripheral part of the outer cylindrical member or the outer peripheral part of the inner cylindrical member from the open end of the outer cylindrical member or the open end of the inner cylindrical member. An axial wall surface of the inner peripheral portion of the outer cylindrical member or the inner cylindrical member that extends to the middle in the linear direction and is formed at the end of the first spline groove or the second spline groove in the extending direction. A wall surface in the axial direction of the outer peripheral portion of the outer peripheral portion constitutes a contact surface with which the inner plate or the outer plate positioned at the end portion in the axial direction contacts.

  In this torque limiter, for example, the second spline groove of the inner cylindrical member extends from the open end of the inner cylindrical member to the middle of the outer peripheral portion of the inner cylindrical member in the axial direction, and the second spline groove A contact surface with which the inner plate located at the end in the axial direction contacts the axial wall surface of the outer peripheral portion of the inner cylindrical member formed at the end in the extending direction is configured.

  Therefore, for example, when a thrust load is generated on the first component for some reason in a state where excessive torque is input to the planetary gear mechanism and slipping occurs on the inner plate and the outer plate, the inner cylindrical member Since the axial wall surface of the outer peripheral portion can be brought into contact with the inner plate located at the end in the axial direction, the inner cylindrical member is restricted from moving toward the outer cylindrical member.

Therefore, it is possible to prevent the inner cylindrical member and the outer cylindrical member from coming into contact with each other in the axial direction, thereby causing a rotation difference between the inner cylindrical member and the outer cylindrical member.
As a result, the thrust bearing can be eliminated to reduce the manufacturing cost of the torque limiter, and the axial clearance between the inner cylindrical member and the outer cylindrical member can be reduced to reduce the installation space for the torque limiter. Can be reduced.

  In the torque limiter according to (1), (2) the axial width of the first spline groove or the second spline groove is the axial wall surface of the outer cylindrical member or the inner cylindrical shape. The inner plate, the outer plate, and the axis of the urging member installed between the axial wall surface of the member and the outer cylindrical member with which the urging member abuts or the abutting surface of the inner cylindrical member It is comprised from the thing smaller than the plate | board thickness of a direction.

  In this torque limiter, for example, the axial width of the second spline groove is set between the axial wall surface of the inner cylindrical member and the contact surface of the outer cylindrical member with which the biasing member contacts. Since it is smaller than the plate thickness in the axial direction of the plate, the outer plate and the biasing member, a thrust load is generated on the first component for some reason, and the axial wall surface of the outer peripheral portion of the inner cylindrical member is the end in the axial direction. When the inner cylindrical member and the outer cylindrical member are in contact with each other, the inner cylindrical member and the outer cylindrical member are more reliably prevented from coming into contact with each other. A rotational difference can be produced in

In the torque limiter described in (1) or (2) above, (3) the second component of the planetary gear mechanism that meshes with the first component and the first component is constituted by an inclined gear. Has been.
In this torque limiter, since the first component and the second component meshing with the first component are composed of bevel gears, for example, when the motor generator rotates in one direction, One axial load in the axial direction is generated in the first rotating element due to the engagement of the component and the second rotating element.

  When one axial load is generated in the first rotating element, for example, the axial wall surface of the outer peripheral portion of the inner cylindrical member can be brought into contact with the inner plate located at the end in the axial direction. Therefore, it is possible to restrict the movement of the inner cylindrical member toward the outer cylindrical member.

  A power transmission device having the torque limiter described in (1) to (3) above, (4) an input shaft to which power is transmitted from an internal combustion engine, and the input shaft connected to the input shaft via the planetary gear mechanism. A second rotating shaft having a first rotating shaft comprising the rotating shaft, a first rotating electric machine constituting the rotating electric machine, and a second rotating shaft provided in parallel with the first rotating shaft. A rotating electric machine, wherein the planetary gear mechanism includes a sun gear constituting the first component attached to the first rotating shaft, and a pinion gear meshing with the sun gear, and is connected to the input shaft. A carrier constituting the two constituent elements, and a ring gear constituting the third constituent element coupled to the axle and the second rotating electric machine via the power transmission unit and meshing with the pinion gear, The inner cylindrical member or the One of the side cylindrical members is provided on the sun gear, and the other of the inner cylindrical member and the outer cylindrical member is provided on the first rotating shaft so that the torque limiter is provided on the sun gear. And the first rotary shaft, the ring gear is provided integrally with the counter drive gear, and the counter drive gear is connected to the second rotary shaft and the axle via the power transmission unit. Consists of things that are linked.

In this power transmission device, the thrust bearing can be eliminated to reduce the manufacturing cost of the torque limiter, and the axial gap between the inner cylindrical member and the outer cylindrical member can be reduced to reduce the torque limiter. Installation space can be reduced.
As a result, the manufacturing cost of the power transmission device can be reduced and the power transmission device can be downsized.

  Further, an excessive input torque transmitted from the internal combustion engine to the planetary gear mechanism and an excessive reverse input torque transmitted from the drive wheel to the planetary gear mechanism can be released by the torque limiter. For this reason, it is possible to protect the planetary gear mechanism by preventing the planetary gear mechanism from being damaged.

  According to the present invention, it is not necessary to provide a thrust bearing between the inner cylindrical member and the outer cylindrical member, the manufacturing cost can be reduced, and between the inner cylindrical member and the outer cylindrical member. Thus, it is possible to provide a torque limiter and a power transmission device that can reduce the space in the axial direction and reduce the installation space.

1 is a diagram showing a first embodiment of a torque limiter and a power transmission device according to the present invention, and is a main system configuration diagram of a power system centering on a transaxle of a hybrid vehicle. It is a figure which shows 1st Embodiment of the torque limiter and power transmission device which concern on this invention, and is sectional drawing of a torque limiter. It is a figure which shows 1st Embodiment of the torque limiter and power transmission device which concern on this invention, and is sectional drawing of the torque limiter of another structure. It is a figure which shows 2nd Embodiment of the torque limiter and power transmission device which concern on this invention, and is sectional drawing of a torque limiter. It is sectional drawing of the torque limiter provided with the thrust bearing. It is a figure which shows the state of a torque limiter when a thrust load is input.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of a control device for a power transmission device according to the present invention will be described with reference to the drawings.
(First embodiment)
1-3 is a figure which shows 1st Embodiment of the power transmission device which concerns on this invention.
First, the configuration will be described.
In FIG. 1, a transaxle 20 as a power transmission device includes a rotating electrical machine that converts kinetic energy of an engine 21 that is an internal combustion engine into electrical energy, a motor generator MG1 as a first rotating electrical machine, and an auxiliary power source of the engine 21. Motor generator MG2 serving as a second rotating electrical machine that functions as a power generator, and a power distribution device 22 that distributes the output of the engine 21 to each of two systems of the motor generator MG1 and the drive wheels 45.

  As shown in FIG. 1, the power distribution device 22 includes a planetary gear mechanism, and an external gear sun gear 23S that rotates around the center of a plurality of gear elements, and around the sun gear 23S while circumscribing the sun gear 23S. An externally toothed pinion gear 23P that revolves while rotating, an internal gear ring gear 23R formed in a hollow annular shape so as to mesh with the pinion gear 23P, and the pinion gear 23P are rotatably supported and rotated through the revolution of the pinion gear 23P. And a carrier 23C.

  Note that the sun gear 23S, the pinion gear 23P, and the ring gear 23R are constituted by bevel gears such as a helical gear. The sun gear 23S is a first component, the carrier 23C having the pinion gear 23P is a second component, and the ring gear 23R. Constitutes a third component.

  A one-way clutch 24 that prevents reverse rotation of the engine 21 is connected to the carrier 23 </ b> C, and the one-way clutch 24 is attached to a case 25 of the transaxle 20.

  Rotational torque generated by rotationally driving the engine 21 is transmitted to an input shaft 28 as an input shaft via a crankshaft 26 of the engine 21 and a coil spring type damper device 27.

  Motor generator MG1 includes a rotary shaft provided on the axis of input shaft 28 and a rotor shaft 31 as a first rotary shaft, a rotor 32R comprising a permanent magnet attached to rotor shaft 31, and a three-phase winding. Is constituted by an AC synchronous generator provided with a stator 32S wound around, and is adapted to supply electric power for battery charging and motor driving (not shown).

  The motor generator MG2 includes a rotor shaft 33 as a second rotating shaft that is rotatably installed in parallel with the input shaft 28, a rotor 34R made of a permanent magnet attached to the rotor shaft 33, and a three-phase winding. And a stator 34S wound with an AC synchronous generator. By supplying a three-phase AC current to the three-phase winding, a rotating magnetic field is generated in the motor generator MG2, and a predetermined rotation is achieved. Output torque.

  The motor generator MG2 assists smooth start and acceleration as an auxiliary power source for the engine 21, and the motor generator MG2 converts the kinetic energy of the vehicle into electric energy and charges the battery when the regenerative braking is activated. It is supposed to be.

  In the power distribution device 22, the carrier 23 </ b> C is coupled to the input shaft 28 of the engine 21, and the sun gear 23 </ b> S is connected to the rotor shaft 31 via the torque limiter 51.

  The ring gear 23R is provided integrally with a counter drive gear 35. The counter drive gear 35 is connected to a motor generator MG2 and a drive shaft 37 as an axle via a gear train 36 constituting a power transmission unit. Yes.

  The power distribution device 22 transmits a part of the output of the engine 21 to the drive wheels 45 through the input shaft 28, the carrier 23C, the pinion gear 23P, the ring gear 23R, and the counter drive gear 35, and the remaining part of the output shaft. 28, is transmitted to the rotor 32R of the motor generator MG1 via the carrier 23C, the pinion gear 23P and the sun gear 23S and used for power generation.

Transaxle 20 of the present embodiment has a two-axis configuration in which motor generators MG1 and MG2 are parallel, and the gear train has a four-axis configuration including two axes of motor generators MG1 and MG2.
On the main shaft, a motor generator MG1, a power distribution device 22, and a counter drive gear 35 are arranged around the input shaft 28.

Also, on the second shaft, a counter driven gear 38 to which the rotational torque of the counter drive gear 35 is transmitted, a counter driven gear 40 that is provided integrally with the counter driven gear 38 and attached to one end of the counter drive shaft 39, A differential drive pinion 41 provided at the other end of the counter drive shaft 39 is disposed around the counter drive shaft 39.
The counter driven gear 38, the counter driven gear 40 and the differential drive pinion 41 constitute a gear train 36.

  On the third axis, a rotor shaft 33 of motor generator MG2 and a counter driven gear 42 provided at the end of rotor shaft 33 and transmitting the rotation of rotor 34R to counter driven gear 40 are arranged.

On the fourth shaft, there are a differential ring gear 43 to which power is transmitted from the differential drive pinion 41, a differential device 44 for distributing rotational torque so as to absorb the rotational difference between the inner and outer wheels of the drive wheel 45, and the differential device 44 A drive shaft 37 that transmits the differential output to the drive wheels 45 is disposed.
The power distribution device 22, the gear train 36, the differential device 44, and the motor generators MG1 and MG2 are housed in the case 25 of the transaxle 20.

On the other hand, torque limiter 51 transmits torque between sun gear 23S and motor generator MG1 within a preset torque range.
In FIG. 2, the torque limiter 51 includes a clutch drum 52 as an outer cylindrical member attached to the rotor shaft 31 so as to be spline fitted to the rotor shaft 31.

  The clutch drum 52 includes a plate portion 52A extending radially outward from the rotor shaft 31, an opening end 52a projecting in the axial direction from the plate portion 52A toward the sun gear 23S, and opening at the axial end. And a cylindrical portion 52B having an inner peripheral portion formed with a spline groove 52b as a spline groove.

The spline groove 52b is formed from the opening end 52a of the clutch drum 52 to the plate portion 52A along the axial direction. In addition, the axis line of the rotor shaft 31 and the axis line of the sun gear 23S are the same axis line, and hereinafter, the axial direction refers to the axial direction of the rotor shaft 31 and the sun gear 23S.
The torque limiter 51 includes a clutch hub 53 as an inner cylindrical member attached to the sun gear 23S by welding or the like.

  The clutch hub 53 has a hub plate portion 53 </ b> A extending radially outward from the sun gear 23 </ b> S, projects axially from the hub plate portion 53 </ b> A toward the clutch drum 52, and opens at an axial end facing the clutch drum 52. And a cylindrical portion 53B having a spline groove (second spline groove) 53b that is located in the cylindrical portion 53B of the clutch drum 52 and is opposed to the spline groove 52b on the outer peripheral surface. The clutch drum 52 is disposed on the same axis.

  The clutch drum 52 includes a radial inner peripheral portion 52c that is close to the clutch hub 53 with the bent portion interposed therebetween, and a radial outer peripheral portion 52d that is positioned in a direction away from the clutch hub 53 with respect to the radial inner peripheral portion 52c. And.

  The spline grooves 52b of the clutch drum 52 are spline-fitted with spline portions 54a, 54b, 54c provided on the outer peripheral portions of the clutch plates 54A, 54B, 54C as outer plates, and the clutch plates 54A, 54B, 54C. Is movable in the axial direction and rotates integrally with the clutch drum 52.

  Spline grooves 55a and 55b provided on the inner peripheral portions of friction plates 55A and 55B as inner plates are spline-fitted in the spline grooves 53b of the cylindrical portion 53B. The friction plates 55A and 55B are It is movable in the axial direction and rotates integrally with the clutch hub 53.

  Note that the spline grooves 52b and 53b are formed of concave and convex portions continuous in the circumferential direction of the clutch drum 52 and the clutch hub 53, respectively, and the spline portions 54a, 54b and 54c of the clutch plates 54A, 54B and 54C and the friction plates 55A and 55B. , 55a and 55b are constituted by concave and convex portions continuous in the circumferential direction of the clutch plates 54A, 54B and 54C and the friction plates 55A and 55B.

  The friction plates 55A, 55B are alternately arranged with the clutch plates 54A, 54B, 54C, and a pair of friction plates 55A, 55B facing the clutch plates 54A, 54B, 54C have a predetermined friction coefficient. Friction materials 56a and 56b are affixed.

  Further, a disc spring 57 as an urging member is interposed between the clutch drum 52 and the clutch plate 54A located at the left end in the axial direction. The disc spring 57 is adjacent to the clutch plates 54A, 54B, 54C. The friction plates 55A and 55B are urged in the axial direction to be frictionally engaged.

  Further, a snap ring 58 is provided on the inner peripheral portion of the clutch drum 52, and this snap ring 58 is fitted to the convex portion of the spline groove 52b.

  The snap ring 58 abuts against the clutch plate 54C at the right end to prevent the clutch plates 54A, 54B, 54C from coming out of the clutch drum 52, and the disc spring 57 is applied so as to apply a biasing force to the disc spring 57. I try to bend it.

Further, the spline groove 53b extends from the opening end 53a of the cylindrical portion 53B of the clutch hub 53 to the middle of the inner peripheral portion of the cylindrical portion 53B in the axial direction, and is a cylinder at the end of the extending direction of the spline groove 53b An axial wall surface of the outer peripheral portion of the shaped portion 53B constitutes the contact surface 53c.
That is, the spline groove 53b is not formed on the hub plate portion 53A side, and thus is not formed over the entire axial direction of the cylindrical portion 53B.
Further, the inner peripheral portion of the friction plate 55B located at the right end in the axial direction is in contact with the contact surface 53c of the spline groove 53b.

Also, the axial width W of the spline groove 53b is such that the friction plate 55B and the clutch plate installed between the contact surface 53c and the contact surface of the radially outer peripheral portion 52d of the clutch drum 52 with which the disc spring 57 contacts. 54B, the friction plate 55A, the clutch plate 54A and the disc spring 57 are formed to be smaller than the axial thickness.
The plate spring 57 may have a plate thickness in which the disc spring 57 is contracted to the maximum in the axial direction or in a state in which the disc spring 57 is expanded to the maximum.

Next, the operation will be described.
The rotational torque generated by rotationally driving the engine 21 is transmitted to the input shaft 28 via the crankshaft 26 of the engine 21 and the damper device 27 with a torque limiter, and the rotational torque is driven by the power distribution device 22 with the motor generator MG1. Distributed to the wheel 45.

  Here, in the power distribution device 22 using the planetary gear mechanism, when an excessive input torque is transmitted from the engine 21 to the power distribution device 22, the sun gear 23S, the ring gear 23R, and the carrier 23C try to rotate. Nevertheless, the motor generator MG1 and the gear train 36 are suppressed by the inertia or rotational resistance.

  Further, when excessive reverse input torque is transmitted from the drive wheel 45 to the power distribution device 22 via the drive shaft 37, the motor generator is generated despite the sun gear 23S, the ring gear 23R and the carrier 23C attempting to rotate. It is suppressed by the inertia or rotational resistance of MG1 and engine 21.

  In the present embodiment, a torque limiter 51 for transmitting torque between sun gear 23S and motor generator MG1 within a preset torque range is interposed between sun gear 23S and rotor shaft 31 of motor generator MG1. ing.

  That is, the clutch plates 54A, 54B, 54C that rotate integrally with the clutch drum 52 and the friction plates 55A, 55B that rotate integrally with the clutch hub 53 are frictionally engaged, so that the clutch drum 52 and the clutch hub 53 are not rotated. As a result, the torque is transmitted between the sun gear 23S and the motor generator MG1.

  When the torque limiter 51 receives an excessive input torque or reverse input torque that is larger than a preset range, that is, greater than the limiter torque value set by the torque limiter 51, the clutch plates 54A, 54B are transmitted. 54C and the friction plates 55A and 55B are slipped, and a rotational difference is generated between the clutch drum 52 and the clutch hub 53, so that an excessive input torque or reverse input torque is released by the torque limiter 51. For this reason, it can prevent that the planetary gear mechanism which comprises the power distribution device 22 is damaged, and can protect a planetary gear mechanism.

  On the other hand, operation by the engine 21, motor travel by the motor generator MG2, and power generation by the motor generators MG1 and MG2 are performed according to the vehicle operating state such as start, acceleration, steady travel, and energy regeneration during deceleration.

  For this reason, the rotation directions of the sun gear 23S, the carrier 23C, and the ring gear 23R of the planetary gear mechanism of the motor generator MG1 and the power distribution device 22 are changed depending on the driving state of the vehicle.

  In power distribution device 22 including the planetary gear mechanism according to the present embodiment, sun gear 23S, ring gear 23R, and pinion gear 23P are configured with bevel gears, so that sun gear 23S is thrust in the thrust direction depending on the direction of rotational torque of motor generator MG1. The moving direction is either the right side or the left side.

  For example, when the motor generator MG1 rotates in one direction, a leftward thrust load in FIG. 2 is generated in the sun gear 23S due to the engagement of the sun gear 23S and the pinion gear 23P, and the motor generator MG1 rotates in the other direction. A rightward thrust load is generated on the sun gear 23S by the meshing of the sun gear 23S and the pinion gear 23P.

  A torque greater than the limiter torque value is applied to the torque limiter 51, causing a rotational difference between the clutch drum 52 and the clutch hub 53, and the clutch drum 52 and the clutch hub 53 rotating together. When the thrust load is generated, the clutch hub 53 moves in the axial direction toward the clutch drum 52 together with the sun gear 23S.

  In the present embodiment, the spline groove 53b formed in the cylindrical portion 53B of the clutch hub 53 extends from the opening end 53a of the cylindrical portion 53B to the middle of the outer peripheral portion of the cylindrical portion 53B, and the spline groove 53b extends. The axial wall surface of the outer peripheral portion of the cylindrical portion 53B formed at the end in the present direction constitutes a contact surface 53c with which the friction plate 55B positioned at the end portion in the axial direction contacts.

  Therefore, when the input torque or the reverse input torque as described above is transmitted to the planetary gear mechanism constituting the power distribution device 22, the clutch plates 54A, 54B, 54C and the friction plates 55A, 55B are slipped. 2, when a leftward thrust load in FIG. 2 is generated in the sun gear 23S, the contact surface 53c contacts the friction plate 55B, thereby restricting the clutch hub 53 from moving to the clutch drum 52 side. it can.

Therefore, it is possible to prevent the opening end 53a of the cylindrical portion 53B facing in the axial direction and the radial outer peripheral portion 52d of the clutch drum 52 from coming into contact with each other, thereby causing a rotational difference between the clutch hub 53 and the clutch drum 52. Can do.
In addition, the distance between the hub plate portion 53A of the clutch hub 53 and the radially inner peripheral portion 52c of the clutch drum 52 is smaller than the distance between the opening end 53a of the cylindrical portion 53B and the radially outer peripheral portion 52d of the clutch drum 52. When the length is short, it is possible to prevent the hub plate portion 53A of the clutch hub 53 and the radial inner peripheral portion 52c of the clutch drum 52 from contacting each other.

Therefore, it is possible to eliminate the conventional thrust bearing and reduce the manufacturing cost of the torque limiter 51, and to reduce the axial gap between the clutch hub 53 and the clutch drum 52, and to install the torque limiter 51. Space can be reduced.
As a result, the manufacturing cost of the transaxle 20 can be reduced, and the transaxle 20 can be downsized.

  Further, since the contact surface 53c is brought into contact with the friction plate 55B and the movement of the clutch hub 53 toward the clutch drum 52 can be restricted, the sun gear 23S can move to the left with respect to the pinion gear 23P. Therefore, the meshing between the sun gear 23S and the pinion gear 23P can be maintained.

  When the motor generator MG1 rotates in the other direction and a rightward thrust load is generated on the sun gear 23S due to the meshing of the sun gear 23S and the pinion gear 23P, the friction plates 55A and 55B are snap ringed via the clutch plates 54B and 54C. 58, the movement of the sun gear 23S to the right with respect to the pinion gear 23P can be restricted, and the engagement between the sun gear 23S and the pinion gear 23P can be maintained.

  In the present embodiment, the axial width W of the spline groove 53b is from the contact surface 53c of the cylindrical portion 53B to the contact surface of the radially outer peripheral portion 52d of the clutch drum 52 with which the disc spring 57 contacts. The friction plates 55B, the clutch plates 54B, the friction plates 55A, the clutch plates 54A, and the disc springs 57 provided therebetween are formed to have a thickness smaller than the axial thickness.

  For this reason, when a leftward thrust load in FIG. 2 is generated in the sun gear 23S, the abutment surface 53c is abutted against the friction plate 55B to reliably restrict the clutch hub 53 from moving toward the clutch drum 52 side. be able to.

  Accordingly, it is possible to prevent the opening end 53a of the cylindrical portion 53B and the radial outer peripheral portion 52d of the clutch drum 52 from coming into contact with each other, thereby causing a rotational difference between the clutch hub 53 and the clutch drum 52.

  In the present embodiment, the sun gear 23S, the ring gear 23R, and the pinion gear 23P of the planetary gear mechanism are constituted by bevel gears, but may be constituted by spur gears.

  In this case, when a leftward thrust load in FIG. 2 is generated on the sun gear 23S for some reason, the contact surface 53c is brought into contact with the friction plate 55B and the clutch hub 53 moves to the clutch drum 52 side. Can be regulated.

  Moreover, since the torque limiter 51 can be built in the case 25 by interposing the torque limiter 51 between the sun gear 23S and the motor generator MG1, the torque limiter 51 is rusted by water bounced off the road surface or the like. This can be prevented.

  Further, in the present embodiment, the inner peripheral portion of the friction plate 55B is always in contact with the contact surface 53c in a state where no thrust load is input from the sun gear 23S. However, as shown in FIG. A gap may be formed between the inner peripheral portion of the friction plate 55B and the contact surface 53c in a state where no thrust load is input.

  Even in this case, when the clutch plate 54A, 54B, 54C and the friction plates 55A, 55B are slipped and a leftward thrust load is generated on the sun gear 23S in FIG. The movement of the clutch hub 53 toward the clutch drum 52 can be restricted by contacting the plate 55B.

  In this embodiment, the clutch drum 52 is attached to the rotor shaft 31 and the clutch hub 53 is attached to the sun gear 23S. However, the clutch drum 52 is attached to the sun gear 23S, and the clutch hub 53 is attached to the rotor shaft 31. It may be attached.

(Second Embodiment)
FIG. 4 is a diagram showing a second embodiment of the power transmission device according to the present invention. The same components as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted.

In FIG. 4, the sun gear 23 </ b> S is connected to the rotor shaft 31 via the torque limiter 61.
The torque limiter 61 includes a clutch drum 52 attached to the rotor shaft 31 and a clutch hub 62 as an inner cylindrical member attached to the sun gear 23S by welding or the like.

  The clutch hub 62 includes a hub plate portion 62A extending radially outward from the sun gear 23S, an axial direction projecting from the hub plate portion 62A toward the clutch drum 52, and an opening at an axial end facing the clutch drum 52. And a cylindrical portion 62B having a spline groove (second spline groove) 62b formed on the outer peripheral surface thereof and facing the spline groove 52b. The clutch drum 52 is disposed on the same axis.

  The spline groove 52b of the clutch drum 52 is fitted with spline portions 64a and 64b provided on the outer periphery of friction plates 64A and 64B as outer plates, and the friction plates 64A and 64B move in the axial direction. It is free to rotate integrally with the clutch drum 52.

  Further, spline portions 63a, 63b, 63c provided on inner peripheral portions of clutch plates 63A, 63B, 63C as inner plates are spline-fitted into the spline grooves 62b of the cylindrical portion 62B, and this clutch plate 63A 63B and 63C are movable in the axial direction and rotate integrally with the clutch hub 62.

  Note that the spline grooves 52b and 62b are formed of concave and convex portions continuous in the circumferential direction of the clutch drum 52 and the clutch hub 62, respectively, and the spline portions 63a, 63b and 63c of the clutch plates 63A, 63B and 63C and the friction plates 64A and 64B. , 64a, 64b are constituted by concave and convex portions continuous in the circumferential direction of the clutch plates 63A, 63B, 63C and the friction plates 64A, 64B.

  The friction plates 64A, 64B are alternately arranged with the clutch plates 63A, 63B, 63C, and a pair of friction plates 64A, 64B opposite to the clutch plates 63A, 63B, 63C have a predetermined friction coefficient. Friction materials 65a and 65b are affixed.

  Further, a disc spring 66 as an urging member is interposed between the clutch hub 62 and the clutch plate 63C positioned at the right end in the axial direction, and the disc spring 66 is adjacent to the clutch plates 63A, 63B, 63C. The friction plates 64A and 64B are urged in the axial direction to be frictionally engaged.

  Further, a snap ring 67 is provided on the inner peripheral portion of the clutch drum 52, and the snap ring 67 is fitted to the convex portion of the spline groove 62b.

  The snap ring 67 abuts against the clutch plate 63A at the right end to prevent the clutch plates 63A, 63B, 63C from coming out of the clutch drum 52, and the disc spring 66 is applied so as to apply a biasing force to the disc spring 66. I try to bend it.

  Further, the spline groove 52b extends from the open end 52a of the cylindrical portion 52B of the clutch drum 52 to the middle of the inner peripheral portion of the cylindrical portion 52B in the axial direction, and is a cylinder at the end of the extending direction of the spline groove 52b. The wall surface in the axial direction of the inner peripheral portion of the shaped portion 52B constitutes a contact surface 52e.

That is, the spline groove 52b is not formed on the plate portion 52A side, and therefore is not formed over the entire axial direction of the cylindrical portion 52B.
The inner peripheral portion of the friction plate 64A located at the left end in the axial direction is in contact with the contact surface 52e of the spline groove 52b.

  Also, the axial width W of the spline groove 52b is such that the friction plate 64A and the clutch plate installed between the contact surface 52e of the cylindrical portion 52B and the contact surface of the hub plate portion 62A with which the disc spring 66 contacts. 63B, the friction plate 64B, the clutch plate 63C and the disc spring 66 are formed to be smaller than the axial thickness.

  The plate spring 66 may have a plate thickness that may be such that the disc spring 66 is maximally contracted in the axial direction or may be maximally extended.

  In the present embodiment, the spline groove 52b formed in the cylindrical portion 52B of the clutch drum 52 extends from the open end 52a of the cylindrical portion 52B to the middle of the outer peripheral portion of the cylindrical portion 52B, and the spline groove 52b extends. The axial wall surface of the outer peripheral portion of the cylindrical portion 52B formed at the end in the current direction forms a contact surface 52e with which the friction plate 64A positioned at the end portion in the axial direction contacts.

  For this reason, when the input torque or the reverse input torque is transmitted to the planetary gear mechanism that constitutes the power distribution device 22, the clutch gears 63A, 63B, 63C and the friction plates 64A, 64B are slipped to the sun gear 23S. In FIG. 4, when a leftward thrust load is generated, the contact surface 52e can be brought into contact with the friction plate 64A to restrict the clutch hub 62 from moving toward the clutch drum 52.

For this reason, the opening end 62a of the cylindrical portion 62B facing in the axial direction and the radial outer peripheral portion 52d of the clutch drum 52 are prevented from coming into contact with each other, causing a rotational difference between the clutch hub 62 and the clutch drum 52. be able to.
Further, the hub plate portion 62A of the clutch hub 62 and the radially inner peripheral portion of the clutch drum 52 with respect to the distance between the opening end 62a of the cylindrical portion 62B facing the axial direction and the radially outer peripheral portion 52d of the clutch drum 52. When the distance between the clutch hub 62 and the clutch drum 52 is short, contact between the hub plate portion 62A of the clutch hub 62 and the radially inner peripheral portion 52c of the clutch drum 52 is prevented. Can be generated.

Therefore, it is possible to eliminate the conventional thrust bearing and reduce the manufacturing cost of the torque limiter 61, and reduce the axial clearance between the clutch hub 62 and the clutch drum 52 to install the torque limiter 61. Space can be reduced.
As a result, the manufacturing cost of the transaxle 20 can be reduced, and the transaxle 20 can be downsized.

  Further, in the present embodiment, the axial width W of the spline groove 52b is set between the contact surface 52e of the cylindrical portion 52B and the contact surface of the hub plate portion 62A with which the disc spring 66 contacts. The friction plates 64 </ b> A, the clutch plates 63 </ b> B, the friction plates 64 </ b> B, the clutch plates 63 </ b> C, and the disc springs 66 are formed to be smaller than the axial thickness.

  For this reason, when a leftward thrust load in FIG. 4 is generated in the sun gear 23S, the contact surface 52e is brought into contact with the friction plate 64B, thereby reliably restricting the clutch hub 62 from moving toward the clutch drum 52. be able to.

  For this reason, it is possible to prevent the opening end 62a of the cylindrical portion 62B and the radial outer peripheral portion 52d of the clutch drum 52 from coming into contact with each other, thereby generating a rotational difference between the clutch hub and the clutch drum 52.

  Further, in the present embodiment, the inner peripheral portion of the friction plate 64A is always in contact with the contact surface 52e in a state where no thrust load is input from the sun gear 23S, but the state where no thrust load is input from the sun gear 23S. Thus, a gap may be formed between the inner peripheral portion of the friction plate 64B and the contact surface 52e.

  Even in this case, when a leftward thrust load is generated on the sun gear 23S in a state where the clutch plates 63A, 63B, 63C and the friction plates 64A, 64B are slipped, the contact surface 52e is applied to the friction plate 64B. It is possible to restrict the movement of the clutch hub 62 toward the clutch drum 52 by being brought into contact therewith.

  In this embodiment, the clutch drum 52 is attached to the rotor shaft 31 and the clutch hub 62 is attached to the sun gear 23S. However, the clutch drum 52 is attached to the sun gear 23S, and the clutch hub 62 is attached to the rotor shaft 31. It may be attached.

  As described above, the torque limiter and the power transmission device according to the present invention eliminate the need to provide a thrust bearing between the inner cylindrical member and the outer cylindrical member, thereby reducing the manufacturing costs of the torque limiter and the power transmission device. The effect of reducing the axial space between the inner cylindrical member and the outer cylindrical member and reducing the installation space for the torque limiter and the power transmission device can be reduced. The present invention is useful as a torque limiter interposed between the first component of the gear mechanism and the rotating shaft of the rotating electrical machine, a power transmission device having the torque limiter, and the like.

20 Transaxle (Power transmission device)
21 Engine (Internal combustion engine)
23S Sungear (first component)
23C carrier (second component)
23R ring gear (third component)
28 Input shaft (input shaft)
31 Rotor shaft (rotation axis, first rotation axis)
33 Rotor shaft (second rotating shaft)
35 Counter drive gear 36 Gear train (power transmission part)
37 Drive shaft (axle)
51, 61 Torque limiter 52 Clutch drum (outer cylindrical member)
52b, 62b Spline groove (first spline groove)
52e, 53c Contact surface 53, 62 Clutch hub (inner cylindrical member)
53b, 62b Spline groove (second spline groove)
54A, 54B, 54C Clutch plate (outer plate)
55A, 55B Friction plate (inner plate)
57, 66 Disc spring (biasing member)
63A, 63B, 63C Clutch plate (inner plate)
64A, 64B Friction plate (outer plate)
MG1 motor generator (rotary electric machine, first rotating electric machine)
MG2 motor generator (second rotating electrical machine)

Claims (4)

A rotating shaft of a rotating electrical machine having a planetary gear mechanism having a plurality of components attached so as to be differentially rotatable and a rotating shaft connected to a first component of the plurality of components of the planetary gear mechanism. A torque limiter that transmits torque between the first component and the rotating electrical machine within a preset torque range,
An outer cylindrical member attached to one of the first component and the rotating shaft and having an inner circumferential portion formed with an opening end opened at an axial end and a first spline groove; and A plurality of outer plates that are spline-fitted to the spline grooves in the axial direction so as to be slidable in the axial direction, and are attached to the other one of the first component or the rotary shaft, and open at the axial end to open the outer cylinder An inner cylindrical member having an open end facing the cylindrical member and an outer peripheral portion formed with a second spline groove facing the inner peripheral portion of the outer cylindrical member, and an axial direction in the second spline groove A plurality of inner plates which are slidably fitted to the outer plate and arranged alternately with the outer plates, and are provided between the outer cylindrical member and the outer plate or between the inner cylindrical member and the inner plate. Et , And a biasing member and the said outer plate adjacent the inner plate is the bias the outer plate and the inner plate in the axial direction so as to frictionally engage,
The first spline groove or the second spline groove is an inner peripheral portion of the outer cylindrical member or an outer periphery of the inner cylindrical member from the opening end of the outer cylindrical member or the opening end of the inner cylindrical member. An axial wall surface of the inner peripheral portion of the outer cylindrical member or the inner cylinder formed at the end in the extending direction of the first spline groove or the second spline groove and extending partway in the axial direction of the portion A torque limiter, characterized in that an axial wall surface of an outer peripheral portion of the cylindrical member constitutes a contact surface with which the inner plate or the outer plate positioned at an end portion in the axial direction contacts.   The axial width of the first spline groove or the second spline groove is such that the urging member abuts from the axial wall surface of the outer cylindrical member or the axial wall surface of the inner cylindrical member. The axial thickness of the inner plate, the outer plate, and the biasing member installed between the outer cylindrical member and the contact surface of the inner cylindrical member is smaller than the plate thickness in the axial direction. The torque limiter according to 1.   3. The torque limiter according to claim 1, wherein the second component of the planetary gear mechanism that meshes with the first component and the first component is a bevel gear. A power transmission device having a torque limiter according to any one of claims 1 to 3,
An input shaft to which power is transmitted from the internal combustion engine;
A first rotating electric machine having the first rotating shaft composed of the rotating shaft connected to the input shaft via the planetary gear mechanism, and constituting the rotating electric machine;
A second rotating electrical machine having a second rotating shaft provided in parallel with the first rotating shaft;
The planetary gear mechanism includes a sun gear constituting the first component attached to a first rotating shaft and a pinion gear meshing with the sun gear, and constitutes a second component connected to the input shaft. And a ring gear that constitutes a third component that is coupled to the axle and the second rotating electrical machine via a power transmission unit and meshes with the pinion gear,
Either the inner cylindrical member or the outer cylindrical member is provided on the sun gear, and either the inner cylindrical member or the outer cylindrical member is provided on the first rotating shaft. The torque limiter is interposed between the sun gear and the first rotating shaft,
The power transmission device, wherein the ring gear is provided integrally with a counter drive gear, and the counter drive gear is coupled to the second rotating shaft and the axle via the power transmission unit.

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