JP2007170440A - Automatic transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an automatic transmission surely preventing rattle of an outer race and occurrence of noise at a time of engagement or disengagement of a one-way clutch, and having a simple and compact structure and good assemblability by preventing increase of the number of components. <P>SOLUTION: An inner race 31 of the one-way clutch 30 is interlocked and connected to a pinion carrier 12c and a ring gear 11d of planetary gear mechanisms 11, 12. The outer race 32 of the one-way clutch 30 is engaged with an inner circumference wall of a transmission case 5 by splines, a plurality of return springs 60 are arranged on a position overlapping a multiple disk brake in an axial direction, and the return springs 60 urges the outer race 35 of the one-way clutch 30 in the axial direction to retain the same in the transmission case 5. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an automatic transmission, and more particularly to an improved structure of a brake mechanism and a one-way clutch mounting structure.

  2. Description of the Related Art Conventionally, an automatic transmission mounted on an automobile or the like is provided with a transmission case, and a plurality of brake mechanisms, clutch mechanisms, gear mechanisms, and the like are accommodated in the transmission case, and these brake mechanisms and clutch mechanisms are controlled respectively. Thus, the shift stage of the automatic transmission is selectively switched to any one of a plurality of forward shift stages and reverse speed stages. A brake mechanism of an automatic transmission normally includes a multi-plate brake, a brake piston that presses the multi-plate brake toward the fastening side, and a plurality of return springs that bias the brake piston toward the brake release side.

  In the automatic transmission of Patent Document 1, a planetary gear mechanism (planetary gear set) is provided radially inward of the multi-plate brake of the brake mechanism (LR / B), and a one-way clutch is provided in the vicinity of the multi-plate brake in the axial direction. The planetary gear mechanism pinion carrier is linked to the inner race of the one-way clutch and the drum of the brake mechanism.

  The outer race of the one-way clutch is spline-engaged with the inner peripheral wall of the transmission case, and is locked and attached in the axial direction by a pair of snap rings. The pair of snap rings are also used to lock the one-way clutch side ends of multi-plate brakes (LR / B and 2.6 / B multi-plate brakes) provided on both sides of the outer race in the axial direction. These snap rings are fitted into annular grooves formed in the inner peripheral wall of the transmission case.

  In the brake mechanism (LR / B), the brake piston is disposed on the side opposite to the one-way clutch with respect to the multi-plate brake, and a spring retainer is provided between the piston portion of the brake piston and the multi-plate brake. A plurality of return springs are disposed between the spring retainer and the piston portion of the brake piston, and these return springs function only to urge the brake piston toward the brake release side.

JP 2003-106406 A

  In the automatic transmission as disclosed in Patent Document 1, the outer race of the one-way clutch is only locked in the axial direction by a pair of snap rings. When the one-way clutch is engaged or released, there is a risk that the outer race will rattle and generate abnormal noise.

  Therefore, although it is conceivable to provide a spring for urging the outer race of the one-way clutch to one of the pair of snap rings, in this case, a separate spring for urging the outer race is required. Since the snap ring is used to lock the one-way clutch side ends of a pair of multi-plate brakes, the snap ring cannot be omitted, so the number of parts increases, the structure becomes complicated, and the assemblability is poor. Become.

  The object of the present invention is to reliably prevent the outer race from rattling due to rattling when the one-way clutch is engaged or released, and to prevent an increase in the number of parts, simplifying and downsizing the structure. It is to provide an automatic transmission that is easy to assemble.

  The automatic transmission according to claim 1 is a transmission case, a planetary gear mechanism, a multi-plate brake for stopping a predetermined rotating member of the planetary gear mechanism with respect to the transmission case, and the multi-plate brake to the fastening side. One-way having a brake piston to be pressed, a plurality of return springs for urging the brake piston toward the brake release side, an inner race linked to the rotating member, and an outer race splined to the inner peripheral wall of the transmission case In the automatic transmission comprising a clutch, the plurality of return springs are disposed at positions overlapping the multi-plate brake in the axial direction of the automatic transmission, and these return springs are arranged in the axial direction of the outer race of the one-way clutch. It is configured to be biased to be received by the transmission case.

  In this automatic transmission, when the brake piston is driven, the multi-plate brake is pressed against the fastening side by the brake piston and fastened, and the predetermined rotating member of the planetary gear mechanism is stationary with respect to the transmission case. When the driving of the brake piston is stopped, the multi-plate brake is restored and released by a plurality of return springs.

  The inner race of the one-way clutch is interlocked with a predetermined rotating member of the planetary gear mechanism, the outer race of the one-way clutch is spline-engaged with the inner peripheral wall of the transmission case, and a plurality of return springs against the multi-plate brake The automatic transmission is disposed at a position overlapping in the axial direction, and by these return springs, the outer race of the one-way clutch is urged in the axial direction and received by the transmission case.

The following configuration can be adopted in the invention of claim 1.
The multi-plate brake is provided with a retainer plate that contacts the outer race of the one-way clutch and supports the one-way clutch side end of a plurality of return springs at an end portion on the side away from the brake piston. The return spring biases the outer race of the one-way clutch (claim 2).

  The plurality of return springs are disposed outside the outer periphery of the multi-plate brake. One or a plurality of spline teeth of a plurality of brake plates that are spline-engaged with the inner peripheral wall of the transmission case of the multi-plate brake are missing, and a plurality of return springs are disposed in a space including the missing tooth portion. (Claim 4).

  The brake piston has a piston portion and a plurality of arc-shaped brake pressing portions provided on the piston portion at appropriate circumferential intervals and extending toward the multi-plate brake, and the piston portion and the multi-plate brake A spring receiving member that is disposed at an axial position between the pistons and receives end portions of the plurality of return springs on the piston portion side and transmits an urging force of the return springs to the brake piston. The spring receiving member includes a plurality of brakes. A plurality of arc-shaped slits through which the pressing portions are inserted are formed (claim 5).

  The spring receiving member includes an annular portion that is locked to the piston portion of the brake piston, and a protruding portion that protrudes radially outward from the outer peripheral portion of the annular portion and contacts the piston portion side end portions of the plurality of return springs. (Claim 6).

  According to the automatic transmission of claim 1, in particular, a one-way clutch having an inner race linked to a predetermined rotating member of the planetary gear mechanism and an outer race splined to the inner peripheral wall of the transmission case is provided. A plurality of return springs that bias the brake piston toward the brake release side are arranged at positions overlapping the multi-plate brake in the axial direction of the automatic transmission, and the outer race of the one-way clutch is axially arranged by these return springs. It is configured to be urged to be received by the transmission case.

  In other words, the function of urging the brake piston toward the brake release side with multiple return springs and the function of urging the outer race of the one-way clutch in the axial direction are both compatible, and the latter function ensures the one-way clutch in place. In addition, when the one-way clutch is engaged or released, it is possible to reliably prevent the outer race from rattling and generating abnormal noise. In addition, the latter function can be achieved without separately providing a spring other than the return spring, and the snap ring that restricts the movement of the outer race of the one-way clutch in the direction opposite to the biasing direction of the return spring can be omitted. Therefore, the increase in the number of parts can be prevented, the structure can be simplified, the size can be reduced in the axial direction, and the assemblability can be improved.

  According to the automatic transmission of the second aspect, the retainer plate that contacts the outer race of the one-way clutch and supports the one-way clutch side ends of the plurality of return springs at the end of the multi-plate brake on the side away from the brake piston. Since multiple return springs urge the outer race of the one-way clutch through this retainer plate, the retainer plate is applied as the stationary brake plate at the end of the multi-plate brake, and the function of the multi-plate brake is impaired. Without this, the retainer plate can transmit the urging force of the plurality of return springs to the outer race of the one-way clutch, thereby urging the outer race reliably in the axial direction.

  According to the automatic transmission of the third aspect, since the plurality of return springs are disposed outside the outer periphery of the multi-plate brake, the plurality of return springs can be disposed so as not to interfere with the multi-plate brake.

  According to the automatic transmission of the fourth aspect, one or a plurality of spline teeth of a plurality of brake plates that are spline-engaged with the inner peripheral wall of the transmission case among the multi-plate brakes are missing, and the missing teeth portion is included. Since multiple return springs are arranged in the space, multiple return springs can be securely placed outside the outer periphery of the multi-plate brake without complicating the structure of the multi-plate brake, and large in the radial direction. Can be suppressed.

  According to the automatic transmission of the fifth aspect, the brake piston has a piston portion and a plurality of brake pressing portions having an arcuate cross section provided on the piston portion at appropriate circumferential intervals and extending toward the multi-plate brake. A spring receiving member that is disposed at an axial position between the piston portion and the multi-plate brake, receives the piston portion side end portions of the plurality of return springs, and transmits the urging force of the return springs to the brake piston; Since the spring receiving member is formed with slits on a plurality of arcs through which a plurality of brake pressing portions are respectively inserted, the plurality of return springs disposed on the outer periphery of the multi-plate brake are not impaired without impairing the function of the brake piston. The urging force can be reliably transmitted to the brake piston.

  According to the automatic transmission of claim 6, the spring receiving member includes an annular portion that is locked to the piston portion of the brake piston, and a plurality of return spring piston portions that project radially outward from the outer peripheral portion of the annular portion. Since the projecting part has a projecting part with which the side end part abuts, the projecting part reliably receives the piston part side end part of the plurality of return springs, and the annular part reliably transmits the urging force of the plurality of return springs to the brake piston. be able to.

  The automatic transmission according to the present invention includes a transmission case, a planetary gear mechanism, a multi-plate brake for stopping a predetermined rotating member of the planetary gear mechanism with respect to the transmission case, and pressing the multi-plate brake toward the fastening side. One-way clutch comprising: a brake piston that urges, a plurality of return springs that urge the brake piston toward the brake release side, an inner race that is interlocked with the rotating member, and an outer race that is splined to the inner peripheral wall of the transmission case A plurality of return springs are disposed at positions overlapping the multi-plate brake in the axial direction of the automatic transmission, and these return springs bias the outer race of the one-way clutch in the axial direction to change the speed. It is configured to be received by the machine case.

  As shown in FIGS. 1 and 3, an automatic transmission 1 mounted on a vehicle such as an automobile includes an input shaft 2 to which engine output is input, an output gear 3 that outputs driving force to the wheels, and these A transmission mechanism 4 interposed between the input shaft 2 and the output gear 3 and a transmission case 5 for housing the transmission mechanism 4 are provided.

  The transmission mechanism 4 includes first to fourth planetary gear mechanisms 10 to 13, LCL14 (low clutch), HCL15 (high clutch), 35RCL16 (35 reverse clutch), OWCL17 (one-way clutch), LRBrk18 (low reverse brake), 26Brk19 (26 brakes).

  In the first planetary gear mechanism 10, the sun gear 10 a is fixed to the transmission case 5, the pinion carrier 10 c of the pinion 10 b is connected to the clutch drum 14 a on the outer peripheral side of the LCL 14, and the ring gear 10 d is connected to the outer peripheral side of the input shaft 2 and the HCL 15. It is connected to the clutch drum 15a.

  In the second planetary gear mechanism 11, the sun gear 11a is connected to the clutch hub 14b on the inner peripheral side of the LCL 14, the pinion carrier 11c of the pinion 11b is connected to the output gear 3 and the ring gear 12d of the third planetary gear mechanism 12, and the ring gear 11d. Is connected to the drum 18a on the inner peripheral side of the LRBrk 18, and the OWCL 17 is interposed between the drum 18a (ring gear 11d) and the transmission case 5.

  In the third planetary gear mechanism 12, the sun gear 12a is connected to the inner drum 19a of the 26Brk19 and the inner clutch hub 16b of the 35RCL16, and the pinion carrier 12c of the pinion 12b is connected to the drum 18a of the LRBrk18 and the inner circumference of the HCL15. Is connected to the clutch hub 15b.

  In the fourth planetary gear mechanism 13, the sun gear 13 a is fixed to the transmission case 5, the pinion carrier 13 c of the pinion 13 b is connected to the clutch drum 16 a on the outer peripheral side of the 35 RCL 16, and the ring gear 13 d is connected to the input shaft 2.

  LCL14, HCL15, 35RCL16, LRBrk18, and 26Brk19 are controlled by a control device such as an ECU, respectively, so that the gear position of the transmission mechanism 4 is selectively switched to any one of the first to sixth gears and the reverse gear. FIG. 2 shows the states of LCL14, HCL15, 35RCL16, LRBrk18, 26Brk19, and OWCL17 at each gear position, and “◯” indicates the engaged state. Note that the OWCL 17 in the first speed is engaged only when accelerating, and the LRBrk 18 is engaged only when engine braking such as manual mode is required.

  Next, the transmission case 5, the OWCL 17, and the LRBrk 18 will be described in detail. The direction of arrow a in FIG. 3 is the axial direction, and the right side of FIG.

  As shown in FIG. 3, the transmission case 5 includes a main body case 20 and a case cover 25 that covers the opening 20 a at the rear end of the main body case 20. It is fixed to the case 20. A spline groove 20c is formed in the rear half of the inner peripheral wall 20b of the main body case 20, and LRBrk18, OWCL17, and 26Brk19 are arranged in this order along the spline groove 20c from the front side to the rear side.

  As shown in FIG. 3, the OWCL 17 includes an annular inner race 30, an annular outer race 31, and a locking mechanism 32 interposed between the inner race 30 and the outer race 31. The inner race 30 is spline-engaged in a spline groove 45 a formed on the outer peripheral portion of the drum 45 (18 a) of the LRBrk 18 so as to be integrally rotated, and the second planetary gear mechanism 11 is rotated via the drum 45. The ring gear 11d and the pinion carrier 12c of the third planetary gear mechanism 12 are coupled to each other. At least one of the ring gear 11d and the pinion carrier 12c corresponds to a predetermined rotating member.

  The outer race 31 is spline-engaged with the spline groove 20c of the inner peripheral wall 20b of the transmission case 5 so as to be fitted inside, and the outer race 31 is fitted with an annular plate 33 that contacts the rear end surface and the rear end surface of the inner race 30. Has been. An annular groove 20d is formed in the inner peripheral wall 20b of the transmission case 5 on the rear side of the outer race 31, and a snap ring 34 is fitted into the annular groove 20d. The outer ring 31 and the inner race 30 are attached by the snap ring 34. (OWCL17) is locked from the front side via the annular plate 33.

  As shown in FIGS. 3 to 8, the LRBrk 18 is a multi-plate brake 40 for stopping the ring gear 11 d of the second planetary gear mechanism 11 and the pinion carrier 12 c of the third planetary gear mechanism 12 with respect to the transmission case 5. A brake piston 50 that presses the multi-plate brake 40 toward the fastening side (rear), a plurality of (for example, nine) return springs 60 that bias the brake piston 50 toward the brake release side (forward), and a plurality of returns A spring receiving member 70 that receives the piston portion side end (rear end portion) of the spring 60 and transmits the urging force of the return spring 60 to the brake piston 50 is provided.

  As shown in FIG. 3, the multi-plate brake 40 includes a plurality of (for example, six) brake plates 41 that are spline-engaged in the spline grooves 20 c of the transmission case 5 and the diameters of the brake plates 41. And a plurality of (for example, five) brake disks 42 that are spline-engaged with the spline grooves 45a of the drum 45 disposed on the inner side in the direction.

  The plurality of brake plates 41 and the plurality of brake disks 42 are alternately arranged in the axial direction so that the brake plates 41 are positioned at both front and rear ends. The outer race 31 of the OWCL 17 is spline-engaged with the spline groove 5c of the transmission case 5, and the plurality of brake plates of the 26Brk19 multi-plate brake are also spline-engaged.

  As shown in FIGS. 3 to 8, the brake piston 50 is disposed on the front side of the multi-plate brake 40, and is provided with a piston portion 51 and a plurality of piston portions 51 provided at appropriate circumferential intervals (equal intervals). A plurality of (for example, three) cross-section arc-shaped brake pressing portions 55 extending toward the plate brake 40 side (rear) are provided. For example, when the number of brake pressing parts 55 is three, each brake pressing part 55 is provided over about 55 degrees with respect to the center of the brake piston 50.

  The piston portion 51 is formed relatively thick in the front-rear direction, and annular grooves 51a and 51b are formed in the outer peripheral portion and the inner peripheral portion of the piston portion 51. The annular seal members 52a and 52b are respectively formed in the annular grooves 51a and 51b. Is installed. A cylindrical portion 56 extending rearward is formed integrally with the piston portion 51, and the plurality of brake pressing portions 55 are integrally formed with the cylindrical portion 56 so as to protrude rearward from the cylindrical portion 56.

  The main body case 20 is formed with a cylinder portion 20e on the front side of the multi-plate brake 40, and a piston portion 51 is fitted into the piston cylinder portion 20e via annular seal members 52a and 52b, and hydraulic pressure is applied to the piston cylinder portion 20e. When supplied, the brake piston 50 is driven rearward. A pin-shaped restricting portion 53 is formed in the piston portion 51 so as to protrude forward, and the restricting portion 53 is fitted into a hole (not shown) formed in the bottom portion of the piston cylinder portion 20e. (Brake piston 50) is prevented from rotating.

  As shown in FIGS. 3 to 6, the plurality of return springs 60 are composed of compression coil springs, are disposed outside the outer periphery of the multi-plate brake 40, and are positioned so as to overlap the multi-plate brake 40 in the axial direction. These return springs 60 are configured to urge the outer race 31 of the OWCL 17 in the rearward direction in the axial direction so as to be engaged with the snap ring 34 and received by the transmission case 5.

  The plurality of return springs 60 are arranged with respect to the plurality of brake pressing portions 55 between the retainer plate 41 </ b> A and the spring receiving member 70 at the end (rear side) of the multi-plate brake 40 away from the brake piston 50. The outer race 31 of the OWCL 17 is urged through the retainer plate 41A. For example, when the number of return springs 60 is nine, three return springs 60 are disposed between two brake pressing portions 55 adjacent in the circumferential direction.

  A plurality of spline teeth 41a are formed on the outer periphery of the plurality of brake plates 41. The plurality of spline teeth 41a are missing to form a plurality of (for example, three) missing tooth portions 41b. A plurality of (for example, three) concave grooves 20f that are wider in the circumferential direction than the spline teeth 41a are formed in the inner peripheral wall 20b of the main body case 20 corresponding to the tooth portions 41b. A plurality of return springs 60 are disposed in a space including 20f. For example, when the number of the missing tooth portions 41b and the recessed grooves 20f is three, the missing tooth portions 41b and the recessed grooves 20f are formed at three equal positions in the circumferential direction.

  In the retainer plate 41A, instead of the plurality of spline teeth 41a, a plurality of (for example, three) spring receiving portions 41c wider in the circumferential direction than the spline teeth 41a are provided at positions corresponding to the plurality of missing tooth portions 41b. The plurality of spring receiving portions 41c are respectively engaged with the plurality of concave grooves 20f, and the one-way clutch side end portions (rear end portions) of the plurality of return springs 60 are supported by the spring receiving portions 41c. Yes.

  As shown in FIGS. 3 to 7, the spring receiving member 70 is disposed at an axial position between the piston portion 51 of the brake piston 50 and the multi-plate brake 40 and is locked to the piston portion 51 of the brake piston 50. And a plurality of (for example, three) projecting portions 75 projecting radially outward from the outer peripheral portion of the annular portion 71 and contacting the piston portion side end portions (front end portions) of the plurality of return springs 60. And have.

  A plurality of (for example, three) arc-shaped slits 71 a into which the plurality of brake pressing portions 55 of the brake piston 50 are inserted are formed in the annular portion 71. In a state where the plurality of brake pressing portions 55 are inserted into the plurality of slits 71 a, the annular portion 71 urged forward by the plurality of return springs 60 comes into contact with the front end portion of the tubular portion 56 of the brake piston 50. The urging forces of the plurality of return springs 60 are stopped and input to the brake piston 50 from the cylindrical portion 56 via the spring receiving member 70.

  The front end portions of the plurality of return springs 60 are fixed in advance to the plurality of protruding portions 75 of the spring receiving member 70, and the spring receiving members 70 are assembled together with the plurality of return springs 60. In addition, the annular portion 71 of the spring receiving member 70 is integrally formed with a cylindrical portion 72 that protrudes rearward from the inner peripheral portion thereof, thereby increasing the strength.

The effects of the automatic transmission 1 described above are exhibited.
When the brake piston 50 is driven in the LRBrk 18, the multi-plate brake 40 is pressed and fastened to the engagement side, the ring gear 11d and the pinion carrier 12c are stationary with respect to the transmission case 5, and the brake piston 50 is stopped driving. Then, the brake piston 50 is returned by the plurality of return springs 60, the multi-plate brake 40 is released, and the ring gear 11d and the pinion carrier 12c can rotate.

  According to the automatic transmission 1, the inner race 30 linked to the ring gear 11 d of the second planetary gear mechanism 11 and the pinion carrier 12 c of the third planetary gear mechanism 12 and the inner peripheral wall 20 b of the transmission case 5 are connected to the spline. The OWCL 17 having the joined outer race 31 is provided, and a plurality of return springs 60 for urging the brake piston 50 toward the brake release side (forward) are disposed at positions overlapping the multi-plate brake 40 in the axial direction. The return spring 60 urges the outer race 31 of the OWCL 17 rearward in the axial direction so as to be received by the transmission case 5.

  That is, the function of urging the brake piston 50 toward the brake release side by the plurality of return springs 60 and the function of urging the outer race 31 of the OWCL 17 in the axial rearward direction are both compatible, and the OWCL 17 is moved to a predetermined position by the latter function. In addition, the outer race 31 can be reliably prevented from rattling due to the outer race 31 when the OWCL 17 is fastened or released. The latter function can be achieved without providing a spring other than the return spring 60, and the outer race 31 of the OWCL 17 is controlled to move in the direction opposite to the urging direction of the return spring 60 (forward). Since the ring can be omitted, the increase in the number of parts can be prevented, the structure can be simplified, the size can be reduced in the axial direction, and the assemblability can be improved.

  A retainer that abuts the outer race 31 of the OWCL 17 and supports the one-way clutch side ends (rear end portions) of the plurality of return springs 60 at the end portion (rear end portion) on the side away from the brake piston 50 of the multi-plate brake 40. Plate 41A, and a plurality of return springs 60 urge the outer race 31 of the OWCL 17 through the retainer plate 41A. Therefore, the retainer plate 41A is applied as the stationary brake plate 41 at the rear end of the multi-plate brake 40, Without damaging the function of the multi-plate brake 40, the retainer plate 41A can transmit the urging forces of the plurality of return springs 60 to the outer race 31 of the OWCL 17, thereby reliably urging the outer race 31 rearward in the axial direction.

  Since the plurality of return springs 60 are disposed outside the outer periphery of the multi-plate brake 40, the plurality of return springs 60 can be disposed so as not to interfere with the multi-plate brake 40. One or a plurality of spline teeth 41a of a plurality of brake plates 41 that are spline-engaged with the inner peripheral wall 20b of the transmission case 5 in the multi-plate brake 40 are missing, and a plurality of returns are made in a space including the missing tooth portion 41b. Since the spring 60 is disposed, the plurality of return springs 60 can be reliably disposed outside the outer periphery of the multi-plate brake 40 without complicating the structure of the multi-plate brake 40, and the size in the radial direction is increased. Can be suppressed.

  The brake piston 50 includes a piston portion 51 and a plurality of arc-shaped brake pressing portions 55 provided on the piston portion 51 at appropriate circumferential intervals and extending toward the multi-plate brake 40. A spring receiving member 70 disposed at an axial position between the multi-plate brakes 40 and receiving the piston portion side end portions of the plurality of return springs 60 to transmit the urging force of the return springs 60 to the brake piston 50; Since the spring receiving member 70 is formed with slits 71a on a plurality of arcs through which the plurality of brake pressing portions 55 are inserted, they are disposed outside the outer periphery of the multi-plate brake 40 without impairing the function of the brake piston 50. The urging forces of the plurality of return springs 60 can be reliably transmitted to the brake piston 50.

  The spring receiving member 70 has an annular portion 71 that is locked to the piston portion 51 of the brake piston 50, and projects radially outward from the outer peripheral portion of the annular portion 71 so that the end portions on the piston portion side of the plurality of return springs 60 are in contact with each other. Since the plurality of projecting portions 75 are in contact with each other, the plurality of projecting portions 75 reliably receive the end portions on the piston portion side of the plurality of return springs 60 and the annular portion 71 applies the urging force of the plurality of return springs 60 to the brake piston 50. Can be transmitted reliably.

  In addition, you may comprise the brake piston 50 and the spring receiving member 70 fixedly. In addition, the number and arrangement of the return springs 60 may be changed, and the shape of the brake plate 41, the shape of the spring receiving member 70, and the like may be changed according to the change. In addition, the present invention can be applied with various modifications other than the above-described disclosure without departing from the spirit of the present invention, and the present invention can be applied to various automatic transmissions.

1 is a skeleton diagram schematically showing an automatic transmission according to an embodiment. FIG. It is a chart which shows the state of a plurality of friction engaging elements about a plurality of gear stages of a speed change mechanism. It is a longitudinal cross-sectional view of the principal part of an automatic transmission. It is the IV-IV sectional view taken on the line of FIG. It is a disassembled perspective view of a brake piston, a spring receiving member, and a retainer plate. It is a disassembled side view of a brake piston, a spring receiving member, and a retainer plate. It is a rear view of a brake piston, a spring receiving member, and a retainer plate. It is a perspective view of a brake piston.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Automatic transmission 5 Transmission case 11 2nd planetary gear mechanism 11d Ring gear 12 3rd planetary gear mechanism 12c Pinion carrier 17 One-way clutch 30 Inner race 31 Outer race 40 Multi-plate brake 41A Retainer plate 41a Spline tooth 41b Missing part 50 Brake piston 51 Piston part 55 Brake pressing part 60 Return spring 70 Spring receiving member 71 Annular part 71a Slit 75 Projection part

Claims (6)

A transmission case, a planetary gear mechanism, a multi-plate brake for stopping a predetermined rotating member of the planetary gear mechanism with respect to the transmission case, a brake piston for pressing the multi-plate brake toward the fastening side, and a brake piston In an automatic transmission comprising a plurality of return springs biased toward a brake release side, a one-way clutch having an inner race linked to the rotating member and an outer race splined to the inner peripheral wall of the transmission case ,
The plurality of return springs are disposed at positions overlapping the multi-plate brake in the axial direction of the automatic transmission, and these return springs urge the outer race of the one-way clutch in the axial direction to form a transmission case. An automatic transmission configured to be received.   The multi-plate brake is provided with a retainer plate that contacts the outer race of the one-way clutch and supports the one-way clutch side end of a plurality of return springs at an end portion on the side away from the brake piston. The automatic transmission according to claim 1, wherein the return spring biases the outer race of the one-way clutch.   The automatic transmission according to claim 1 or 2, wherein the plurality of return springs are disposed on the outer periphery of the multi-plate brake.   One or a plurality of spline teeth of a plurality of brake plates that are spline-engaged with the inner peripheral wall of the transmission case of the multi-plate brake are missing, and a plurality of return springs are disposed in a space including the missing tooth portion. The automatic transmission according to claim 3. The brake piston has a piston part and a plurality of arc-shaped brake pressing parts provided on the piston part at appropriate intervals in the circumferential direction and extending to the multi-plate brake side,
A spring receiving member that is disposed at an axial position between the piston portion and the multi-plate brake, receives the piston portion side end portions of the plurality of return springs, and transmits the urging force of the return springs to the brake piston;
The automatic transmission according to claim 1, wherein a plurality of arc-shaped slits through which a plurality of brake pressing portions are inserted are formed in the spring receiving member. The spring receiving member includes an annular portion that is locked to the piston portion of the brake piston, and a protruding portion that protrudes radially outward from the outer peripheral portion of the annular portion and contacts the piston portion side end portions of the plurality of return springs. 6. The automatic transmission according to claim 5, further comprising:

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