JP2008185090A - Automatic transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an automatic transmission with a PTO mounted thereon preventing the breakage of a gear element while suppressing an increase in the outer diameter of a housing. <P>SOLUTION: The automatic transmission comprises a C2 front drum 31 to be rotated when a shift lever is selected into a N-range or a P-range, and having an inner spline portion 31a on the inner periphery, a PTO driving gear member 6 having a PTO gear portion 6a on the outer periphery, an outer spline portion 6b on the outer periphery at another than the gear portion 6a, to be fitted to the inner spline portion 31a, and an inner spline portion 6c on the inner periphery, and a sun gear drum 41 connected to the sun gear of a planetary set, and having an outer spline portion 41a on the outer periphery, to be fitted to the inner spline portion 6c. A first clearance in the radial direction between the inner spline portion 31a and the outer spline portion 6b is smaller than a second clearance in the radial direction between the inner spline portion 6c and the outer spline portion 41a. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an automatic transmission, and more particularly to an automatic transmission equipped with a power take-off (hereinafter referred to as PTO).

  In general, special vehicles (crane cars, pump cars, dump trucks, snow plows, etc.) equipped with automatic transmissions (hereinafter referred to as ATs) are used to operate mechanical devices (crane, pumps, dump trucks, rotary machines, etc.) at ATs. It has a PTO.

  An example of a three-clutch two-brake type automatic transmission equipped with a PTO is shown in FIG. The rotational force of the engine (not shown) is transmitted to the input shaft 102 via the torque converter 101. The rotational force of the input shaft 102 is transmitted from the C2 drum 103 to the sun gear drum 104. A PTO drive gear 105 is attached to a step on the outer periphery of the sun gear drum 104, and an external PTO driven gear 106 is driven by the PTO drive gear 105.

  Here, in general, mechanical devices (crane, pump, dumper, rotary, etc.) are operated in the AT shift range in the N range and P range, so the PTO drive gear is applied to the rotating element that transmits the rotational force in both ranges. 105 needs to be attached. When torque acts on the PTO drive gear 105, a gear meshing reaction force F1 is generated. If the gear meshing reaction force F1 continues to act inside the AT when the AT shift range is in the N range or P range, the gear element (for example, the sun gear 111) may be damaged. Therefore, in order to prevent such damage, the meshing reaction force F1 of the PTO drive gear 105 is desirably supported by a fixing element such as the case 107. Also in the automatic transmission of FIG. 5, the meshing reaction force F <b> 1 of the PTO drive gear 105 is supported by needle bearings 109 and 110 that are press-fitted into the inner periphery of the carrier 108 fixed to the case 107.

  As described above, the following restrictions must be satisfied with respect to the mounting position of the PTO drive gear. The first condition is that the rotational force is transmitted with the AT shift range in the N range and P range. As a second condition, the meshing reaction force of the PTO drive gear must be a member that can be supported by a fixed element.

  With regard to a three-clutch three-brake type automatic transmission, in Patent Document 1 (see FIG. 6), the PTO drive gear 202 is spline-fitted 228 at the outer peripheral step portion 201b of the front drum 201, and the front drum 201 is in the N range. Since the PTO drive gear 202 and the input shaft 208 rotate together as a result of being connected to the input shaft 208 that rotates in the P range, the first condition is satisfied. Further, the input shaft 208 is rotatably supported by a housing 237 serving as a fixed element, and the meshing reaction force of the PTO drive gear 202 is related to the housing 237 via the front drum 201 and the input shaft 208 without affecting the gear element. Therefore, the second condition is satisfied.

No. 7-23645

  By the way, the two-clutch three-brake type automatic transmission (see FIG. 7) has an advantage that the axial width can be reduced. In the two-clutch three-brake type automatic transmission, as in Patent Document 1, when the PTO drive gear 303 is spline-fitted to the outer peripheral step portion of the front drum 302, the PTO drive gear 303, the N range, the P Since the input shaft 301 that rotates even in the range rotates integrally, the first condition is satisfied, but the PTO drive gear 303 rotates integrally with the sun gear 308 as a gear element via the front drum 302 and the follow shaft 307. Since the meshing reaction force of the PTO drive gear 303 is related to the sun gear 308, the second condition is not satisfied. Further, when the PTO drive gear 303 is attached to the outer peripheral step of the front drum 302, the outer diameter of the housing (not shown) increases, leading to an increase in size. This significantly deteriorates the manufacturability of the housing and significantly deteriorates the vehicle mountability of the automatic transmission.

  The main subject of this invention is providing the automatic transmission carrying PTO which can prevent damage to a gear element, suppressing the increase in the outer diameter of a housing.

  In one aspect of the present invention, there is provided an automatic transmission that has a plurality of friction engagement elements and a plurality of planetary gear sets, and that changes a gear ratio by a combination of engagement of the plurality of friction engagement elements. A front drum that constitutes one of the friction engagement elements, rotates when the shift lever of the automatic transmission is selected to the N range or the P range, and has an inner spline on the inner periphery; A PTO gear member having an outer spline fitted to the inner spline of the front drum at a portion other than the PTO gear portion on the outer periphery, and an inner spline on the inner periphery, An outer spline that is connected to one of the plurality of planetary gear sets and fits with the inner spline of the PTO gear member on the outer periphery. A first radial clearance between the inner spline of the front drum and the outer spline of the PTO gear member, the first spline of the PTO gear member and the outer spline of the gear drum. It is comprised smaller than the 2nd radial clearance in between.

  In the automatic transmission according to the present invention, the engagement length between the inner spline of the PTO gear member and the outer spline of the gear drum is determined by the engagement length between the inner spline of the front drum and the outer spline of the PTO gear member. Longer than the length is preferred.

  In the automatic transmission according to the aspect of the invention, it is preferable that the front drum is connected to an input shaft.

  In the automatic transmission according to the present invention, a groove portion is formed at a fitting portion between the front drum and the PTO gear member, and the front drum and the PTO gear member cannot be moved in the axial direction at the groove portion. A snap ring is preferably provided.

  According to the present invention, the first clearance of the spline fitting between the PTO gear member and the front drum is configured to be smaller than the second clearance in the radial direction of the spline fitting between the PTO gear member and the gear drum. For example, a reaction force due to an external force acting on a member, such as a winch device, a crane device, or a hydraulic device, first acts on a front drum having a small radial clearance with respect to the PTO gear member. Therefore, since the meshing reaction force of the PTO is transmitted only to the front drum side and not to the gear drum side, an input of an excessive reaction force to the gear element (planetary gear set) is suppressed. Further, in the PTO gear member arranged at the outermost periphery in the housing, the PTO gear portion and the outer spline are formed at different positions in the axial direction on the outer periphery, so that the radial direction of the meshing portion of the PTO gear portion and the outer spline is formed. The overlap can be eliminated, the outer diameter of the automatic transmission can be reduced, and the mountability of the vehicle can be improved.

(Embodiment 1)
An automatic transmission according to Embodiment 1 of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view schematically showing the configuration of the automatic transmission according to the first embodiment of the present invention. FIG. 2 is a plan view schematically showing the configuration of the PTO drive gear member in the automatic transmission according to the first embodiment of the present invention. FIG. 3 is a partial cross-sectional view schematically showing a combination of a PTO drive gear member, a C2 front drum, and a sun gear drum in the automatic transmission according to the first embodiment of the present invention. FIG. 4 is a gear train diagram schematically showing the configuration of the automatic transmission according to the first embodiment of the present invention.

  The automatic transmission 1 is a two-clutch three-brake type automatic transmission equipped with a power take-off (hereinafter referred to as PTO). A rotational force of an output shaft (not shown) of an engine (not shown) is input to the automatic transmission 1 via a torque converter 2 and an input shaft 3.

  The torque converter 2 is connected to the housing 4 via a pump impeller 11 connected to the output shaft of the engine, a turbine runner 12 facing the pump impeller 11 and connected to the input shaft 3, and a one-way clutch 14. And a stator 13.

  The input shaft 3 is connected to the C1 front drum 21 and is connected to the C2 front drum 31 via the C1 front drum 21. The input shaft 3 also rotates in the N range and P range.

  A C1 hub 23 is disposed on the inner peripheral side of the C1 front drum 21, and a multi-plate C1 frictional engagement element is provided between the C1 front drum 21 (inner spline portion) and the C1 hub 23 (outer spline portion). 22 is disposed, and a C1 piston 24 is disposed on one axial side of the C1 friction engagement element 22. Each plate of the C1 friction engagement element 22 is spline-engaged with the C1 front drum 21 and the C1 hub 23 alternately so as to be axially movable but not relatively rotatable. The C1 piston 24 is operated by a balance between the hydraulic pressure and the spring. The C1 front drum 21, the C1 friction engagement element 22, the C1 hub 23, and the C1 piston 24 constitute a C1 clutch. The C1 hub 23 is connected to the intermediate shaft 5.

  An inner spline portion 31a is formed inside the outer peripheral front end portion of the C2 front drum 31, and the inner spline portion 31a and the outer spline portion 6b of the PTO drive gear member 6 are spline-fitted so as not to rotate relative to each other ( (See FIG. 3). A groove portion is formed in the spline fitting portion between the C2 front drum 31 and the PTO drive gear member 6, and a snap ring 7 is disposed in the groove portion so that both cannot move in the axial direction and both can be disassembled. (See FIGS. 2 and 3). An outer gear portion 6a is formed in a portion of the outer peripheral portion of the PTO drive gear member 6 where the spline is not fitted. The gear portion 6a of the PTO drive gear member 6 is engaged with the PTO driven gear 8 (see FIG. 4). An inner spline portion 6c is formed on the inner peripheral portion of the PTO drive gear member 6, and the inner spline portion 6c and the outer spline portion 41a of the sun gear drum 41 of the first row double pinion planetary gear set cannot be rotated relative to each other. The spline is engaged (see FIG. 3). The first clearance in the radial direction of spline fitting between the outer spline of the PTO drive gear member 6 and the spline of the C2 front drum 31 is the spline fitting between the inner spline of the PTO drive gear member 6 and the outer spline of the sun gear drum 41. Is configured to be smaller than the second clearance in the radial direction. As a result, the meshing reaction force of the PTO is transmitted only to the C2 front drum 31 side and not to the sun gear drum 41 side. Further, by fitting the PTO drive gear member 6 to the inner diameter side of the C2 front drum 31, it is possible to suppress a protrusion margin of the outer diameter of the gear portion 6a of the PTO drive gear member 6 from the outer diameter of the C2 front drum 31. The increase in the outer diameter can be suppressed. The C2 front drum 31, the PTO drive gear member 6, the sun gear drum 41, and the sun gear 42 rotate in the N range and the P range together with the input shaft 3.

  A C2 hub 33 is disposed between the C2 front drum 31 and the C1 front drum 21, and a multi-plate C2 friction is provided between the C2 front drum 31 (inner spline portion) and the C2 hub 33 (outer spline portion). An engagement element 32 is disposed, and a C2 piston 34 is disposed on one axial side of the C2 friction engagement element 32. Each plate of the C2 frictional engagement element 32 is spline-engaged with the C2 front drum 31 and the C2 hub 33 alternately so as to be axially movable but not relatively rotatable. The C2 piston 34 is operated by a balance between the hydraulic pressure and the spring. The C2 front drum 31, the C2 friction engagement element 32, the C2 hub 33, and the C2 piston 34 constitute a C2 clutch. The C2 hub 33 is connected to the carrier 51 of the second row single planetary gear set.

  A sun gear 42 is connected to the outer periphery of the sun gear drum 41. The sun gear 42 meshes with the inner pinion gear 43. The carrier 44 rotatably supports the inner pinion gear 43 and the outer pinion gear 45. The outer pinion gear 45 meshes with the ring gear 46, and the ring gear 46 is connected to the ring gear 53 of the second row single pinion planetary gear set via the first row flange 47. The sun gear drum 41, the sun gear 42, the inner pinion gear 43, the carrier 44, the outer pinion gear 45, the ring gear 46, and the first row flange 47 constitute a first row double pinion planetary gear set.

  A multi-plate B1 friction engagement element 48 is arranged between the outer peripheral portion (outer spline portion) of the carrier 44 and the inner wall portion 4a (inner spline portion) of the housing 4, and the shaft of the B1 friction engagement element 48 is arranged. A B1 piston 49 is arranged on one side of the direction. Each plate of the B1 frictional engagement element 48 is spline-engaged with the carrier 44 and the inner wall 4a alternately in an axially movable manner and in a relatively non-rotatable manner. The B1 piston 49 is operated by a balance between the hydraulic pressure and the spring. The carrier 44, the B1 friction engagement element 48, and the B1 piston 49 constitute a B1 brake.

  The sun gear portion 5a formed on the intermediate shaft 5 meshes with the pinion gear 52, the pinion gear 52 is rotatably supported by the second row flange 54, the pinion gear 52 meshes with the ring gear 53, and the second row. The flange 54 is connected to the ring gear 62 of the third row single pinion planetary gear set, and the ring gear 53 is connected to the ring gear 46 via the first row flange 47. The carrier 51, the sun gear portion 5a, the pinion gear 52, the ring gear 53, and the second row flange 54 constitute a second row single pinion planetary gear set.

  A multi-plate B2 friction engagement element 55 is disposed between the outer peripheral portion (outer spline portion) of the ring gear 53 and the inner wall portion 4b (inner spline portion) of the housing 4. A B2 piston 56 is arranged on one side of the direction. Each plate of the B2 frictional engagement element 55 is spline-engaged with the ring gear 53 and the inner wall portion 4b alternately in an axial direction and in a relatively non-rotatable manner. The B2 piston 56 is operated by a balance between the hydraulic pressure and the spring. The ring gear 53, the B2 friction engagement element 55, and the B2 piston 56 constitute a B2 brake.

  The sun gear portion 5b formed on the intermediate shaft 5 meshes with the pinion gear 61, the pinion gear 61 is rotatably supported by the carrier 63, the pinion gear 61 meshes with the ring gear 62, and the carrier 63 is coupled to the output shaft 9 The ring gear 62 is connected to the one-way clutch 65 via the third row flange 64. The sun gear part 5b, the pinion gear 61, the ring gear 62, the carrier 63, and the third row flange 64 constitute a third row single pinion planetary gear set.

  A multi-plate B3 friction engagement element 66 is disposed between the outer peripheral portion (outer spline portion) of the ring gear 62 and the inner wall portion 4c (inner spline portion) of the housing 4. A B3 piston 67 is arranged on one side of the direction. Each plate of the B3 frictional engagement element 66 is spline-engaged with the ring gear 62 and the inner wall portion 4c alternately in an axially movable and non-rotatable manner. The B3 piston 67 is operated by a balance between the hydraulic pressure and the spring. The ring gear 62, the B3 friction engagement element 66, and the B3 piston 67 constitute a B3 brake.

  The shifting operation of the automatic transmission according to the first embodiment is the same as the shifting operation of the conventional two-clutch three-brake type automatic transmission.

  According to the first embodiment, the spline fitting between the PTO drive gear member 6 and the C2 front drum 31 has a stronger fitting force in the radial direction than the spline fitting between the PTO drive gear member 6 and the sun gear drum 41. By configuring, the meshing reaction force of the PTO is transmitted only to the C2 front drum 31 side and not to the sun gear drum 41 side, so that damage to the gear elements (sun gear 42, inner pinion gear 43) can be prevented. . In the two-clutch, three-brake type automatic transmission, the outer diameter of the PTO drive gear member 6 from the outer diameter of the C2 front drum 31 is obtained by fitting the PTO drive gear member 6 to the inner diameter side of the C2 front drum 31. Can be suppressed, the increase in the outer diameter of the device can be suppressed, and the merchantability of the automatic transmission can be improved.

  In the first embodiment, the two-clutch three-brake type automatic transmission has been described. However, in the present invention, the gear element rotates integrally with the input shaft via the front drum and the gear drum, and the gear is also used in the N range and P range. This is also effective for an automatic transmission having a structure in which the element rotates.

It is sectional drawing which showed typically the structure of the automatic transmission (2 clutch 3 brake type) which concerns on Embodiment 1 of this invention. It is the top view which showed typically the structure of the PTO drive gear member in the automatic transmission which concerns on Embodiment 1 of this invention. It is the fragmentary sectional view which showed typically the combination of the PTO drive gear member, C2 front drum, and sun gear drum in the automatic transmission which concerns on Embodiment 1 of this invention. 1 is a gear train diagram schematically showing the configuration of an automatic transmission (2-clutch 3-brake type) according to Embodiment 1 of the present invention. FIG. It is sectional drawing which showed typically the structure of the automatic transmission (3 clutch 2 brake type) which concerns on the prior art example 1. FIG. It is sectional drawing which showed typically the structure of the automatic transmission (3 clutch 3 brake type) which concerns on the prior art example 2. FIG. It is the gear train figure which showed typically the structure of the automatic transmission (2 clutch 3 brake type) which concerns on a comparative example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Automatic transmission 2 Torque converter 3 Input shaft 4 Housing 4a, 4b, 4c Inner wall part 5 Intermediate shaft 5a, 5b Sun gear part 6 PTO drive gear member 6a Gear part 6b Outer spline part 6c Inner spline part 7 Snap ring 8 PTO Driven gear 9 Output shaft 11 Pump impeller 12 Turbine runner 13 Stator 14 One-way clutch 21 C1 front drum 22 C1 friction engagement element 23 C1 hub 24 C1 piston 31 C2 front drum 31a Inner spline portion 32 C2 friction engagement element 33 C2 hub 34 C2 Piston 41 Sun gear drum 41a Outer spline portion 42 Sun gear 43 Inner pinion gear 44 Carrier 45 Outer pinion gear 46 Ring gear 47 First row franc 48 B1 friction engagement element 49 B1 piston 51 carrier 52 pinion gear 53 ring gear 54 second row flange 55 B2 friction engagement element 56 B2 piston 61 pinion gear 62 ring gear 63 carrier 64 third row flange 65 one-way clutch 66 B3 friction engagement element 67 B3 piston 101 Torque converter 102 Input shaft 103 C2 drum 104 Sun gear drum 105 PTO drive gear 106 PTO driven gear 107 Case 108 Carrier 109, 110 Needle bearing 111 Sun gear 112 Pinion gear 113 Ring gear 201 Front drum 201a Hub part 201b Step part 201c Hub part 202 PTO Drive gear 203 C3 clutch piston 205 Friction plate 20 C3 flange 207 hub 208 input shaft 209 friction plate 214 intermediate shaft 215 output shaft 216 center support 217 C2 drum 218 C2 piston 219 torque converter 219a pump impeller 219b turbine impeller 219c stator 228 spline fitting 230 ring gear 231 sun gear 232 carrier 233 Ring gear 234 Follow shaft 235 Follow shaft 236 One-way clutch 237 Housing 238 Friction engagement element 239 C1 clutch 240 Carrier 241 Planetary pinion 242 Carrier 243 Planetary pinion 244 Ring gear 245 Planetary pinion 246 Flange member 247 Friction engagement element 248 C3 H 249 Friction engagement element 250 C2 clutch 251 B1 brake 252 B2 brake 253 B3 brake 254 Spring 255 C3 hub 256 Spring 301 Input shaft 302 Front drum 303 PTO drive gear 304 PTO driven gear 305 Intermediate shaft 306 Follow shaft 307 Follow shaft 308 Sun gear 309 Pinion gear 310 Pinion gear 311 Ring gear 312 Carrier 313 Carrier 314 Sun gear 315 Pinion gear 316 Ring gear 317 Carrier 318 Carrier 319 Sun gear 320 Pinion gear 321 Ring gear 322 Carrier 323 Output shaft

Claims (4)

An automatic transmission that has a plurality of friction engagement elements and a plurality of planetary gear sets, and that changes a gear ratio by a combination of engagement of the plurality of friction engagement elements,
A front drum that constitutes one of the plurality of friction engagement elements, rotates when the shift lever of the automatic transmission is selected to the N range or the P range, and has an inner spline on the inner periphery When,
A PTO gear member having a PTO gear portion on the outer periphery, an outer spline that fits with the inner spline of the front drum at a portion other than the PTO gear portion on the outer periphery, and an inner spline on the inner periphery; ,
A gear drum coupled to one of the plurality of planetary gear sets and having an outer spline fitted to the inner spline of the PTO gear member on the outer periphery;
With
A first radial clearance between the inner spline of the front drum and the outer spline of the PTO gear member is a radial clearance between the inner spline of the PTO gear member and the outer spline of the gear drum. An automatic transmission configured to be smaller than the second clearance.   The meshing length of the inner spline of the PTO gear member and the outer spline of the gear drum is longer than the meshing length of the inner spline of the front drum and the outer spline of the PTO gear member. Item 2. The automatic transmission according to Item 1.   3. The automatic transmission according to claim 1, wherein the front drum is connected to an input shaft. A groove portion is formed in a fitting portion between the front drum and the PTO gear member,
The automatic transmission according to any one of claims 1 to 3, wherein a snap ring for disabling axial movement of the front drum and the PTO gear member is disposed in the groove portion.

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