JP2008248941A - Automatic transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transmission having a transmission casing molded integrally with a rear wall and capable of increasing the support position accuracy and support rigidity of a counter drive gear. <P>SOLUTION: The automatic transmission comprises a rear wall 2a whose front side is opened and the rear side is closed, a transmission casing 2 molded in a body together with the rear wall 2a, an input shaft 5 provided on the main axis line X1, a counter shaft 15 provided offset to and parallel with the input shaft 5, a counter drive gear 6 provided on the main axis line X1 to transmit a driving force from the input shaft side 5 to the counter shaft side 15, and a running section 2b extending from the rear wall 2a to the front side, wherein the counter drive gear 6 is supported by the running section 2b via a bearing 10. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an automatic transmission suitable for mounting on a vehicle or the like, and in particular, includes a transmission case that has a rear wall that is open at the front side and that closes the rear side, and is integrally molded with the rear wall. About things.

  2. Description of the Related Art Conventionally, an automatic transmission having a transmission case (hereinafter, also simply referred to as a case) having a rear wall that is open on the front side and that closes the rear side has become widespread. In particular, the case body is generally open on the rear side, and the opening is generally closed with a lid called a rear cover, and bolted up to form a rear wall.

  However, there is also known an automatic transmission in which a rear wall is integrally formed with a case, as in an automatic transmission disclosed in Patent Document 1. By adopting such a case as described in Patent Document 1, the following effects can be obtained.

  In general, an automatic transmission intermittently connects a plurality of hydraulic clutches by a hydraulic mechanism. A control valve assembly is provided for adjusting the hydraulic pressure and supplying / discharging hydraulic pressure to / from each clutch. The control valve assembly includes a number of hydraulic valves in a block-shaped valve body. This valve body is attached to the case. An oil passage that connects the valve body and several hydraulic clutches is formed in the case.

  Since it has such a schematic structure, it is advantageous in terms of layout that the attachment surface between the case and the valve body is wide. However, it is difficult for the type including a separate rear wall (rear cover) to extend the attachment surface to the rear side of the mating surface of the case and the rear cover. This is because there are problems in ensuring oil tightness and ease of assembly.

On the other hand, in the case of the case integrated with the rear wall, the attachment surface of the valve body can be secured over almost the entire length of the case. That is, a wider attachment surface can be obtained and the degree of freedom in layout can be increased.
JP 2000-161450 A

  However, the automatic transmission disclosed in Patent Document 1 has the following disadvantages from the viewpoint of gear noise.

  The automatic transmission disclosed in Patent Document 1 has a three-axis structure including a main shaft, a counter shaft, and a differential shaft. Driving force is transmitted from the main shaft side to the counter shaft side by a counter drive gear and a counter driven gear provided on each shaft side. In the automatic transmission shown in Patent Document 1, the counter drive gear is supported by an extending portion that extends from an intermediate wall (corresponding to the support wall 10C of the same document) separate from the case. This intermediate wall is fixed to the case (main body) by bolt-up.

  By the way, conventionally, in the meshing of the counter drive gear and the counter driven gear, it has been regarded as a problem that gear noise is often large. Various measures for reducing gear noise have been proposed, but it is generally important to keep the gear teeth in proper contact, and for this purpose, improvement in gear support position accuracy and support rigidity are important.

  However, the intermediate wall type as described above is disadvantageous in terms of improving the accuracy of the support position of the gear because it is impossible to eliminate variations in the processing positions of the bolt holes for assembling the intermediate wall and the assembly position of the intermediate wall. is there. Further, since the transmission driving force of the gear set is relatively large, the influence of the support rigidity is large. This is because if the support rigidity is low, the tooth contact changes greatly when a large torque is applied. In contrast, a separate intermediate wall cannot be expected to have a very high support rigidity. Increasing the thickness of the intermediate wall, for example, can be considered to increase the support rigidity, but this is also difficult because it goes against the problem of shortening the overall length of an automatic transmission that has recently been demanded.

  The present invention has been made in view of the above circumstances, and provides a transmission capable of enhancing the support position accuracy and the support rigidity of a counter drive gear while adopting a transmission case integrally formed with a rear wall. For the purpose.

  The invention according to claim 1 for solving the above-mentioned problem has a rear wall that is open at the front side, which is one end side of the main axis, and closes the rear side, which is the other end side of the main axis. A transmission case integrally formed with the wall; an input shaft provided on the main axis; a counter shaft provided in parallel with being offset from the input axis; and the input shaft provided on the main axis A counter drive gear that transmits a driving force from the side to the counter shaft side, and an extending portion that is integrally extended from the rear wall to the front side in the main axis direction, the counter drive gear via a bearing The automatic transmission is supported by the extended portion.

  The front side and the rear side are names provided for convenience to distinguish one end side and the other end side of the main axis, and do not limit the mounting position of the automatic transmission. For example, the main axis may be mounted in any direction such as front / rear / left / right of the vehicle.

  According to a second aspect of the present invention, in the automatic transmission according to the first aspect, a cylindrical inner peripheral surface is formed on the main axis of the extending portion, and an outer race of the bearing is fixed to the cylindrical inner peripheral surface. It is characterized by being.

  According to a third aspect of the present invention, in the automatic transmission according to the first aspect, a cylindrical outer peripheral surface is formed on the main axis of the extending portion, and an inner race of the bearing is fixed to the cylindrical outer peripheral surface. It is characterized by being.

  According to a fourth aspect of the present invention, in the automatic transmission according to any one of the first to third aspects, a planetary gear is provided adjacent to the extending portion on the main axis, and the counter drive gear is connected to the planetary gear. It is characterized by being integrally joined with a rotating element of the gear.

  According to a fifth aspect of the present invention, in the automatic transmission according to the fourth aspect, the rotating element integrally joined to the counter drive gear is a carrier, and at least one of joint surfaces of the counter drive gear and the carrier. In addition, a lubrication groove communicating with the pinion lubrication hole of the planetary gear is formed.

  A sixth aspect of the present invention is the automatic transmission according to any one of the first to fifth aspects, further comprising a second extending portion integrally extending from the rear wall to the front side in the main axis direction, The input shaft is supported by the second extending portion through a bearing, and the supporting portion is disposed so as to overlap the counter drive gear in the main axis direction.

  The invention of claim 7 is the automatic transmission according to any one of claims 1 to 6, further comprising a third extending portion integrally extending from the rear wall to the front side in the counter axial direction. The counter shaft is supported by the third extension through a bearing, and the support is overlapped with the counter drive gear in the main axis direction.

  The invention according to claim 8 is the automatic transmission according to any one of claims 1 to 7, further comprising a counter driven gear provided on the counter shaft and meshing with the counter drive gear, and the transmission case. Is formed with a cylindrical portion surrounding the counter drive gear in the circumferential direction, and a part of the cylindrical portion is thinned to form a first notch, and the counter drive gear and the counter drive gear are formed through the first notch. The counter driven gear is arranged so as to mesh with the counter driven gear.

  A ninth aspect of the present invention is the automatic transmission according to any one of the first to eighth aspects, further comprising a rotational speed sensor that detects a rotational speed of the counter drive gear, and the transmission case includes the counter. A cylindrical portion that surrounds the drive gear in the circumferential direction is formed, and a part of the cylindrical portion is thinned to form a second notch, and the rotation speed sensor is connected to the counter drive gear through the second notch. It is characterized by being placed in close proximity.

  According to the first aspect of the present invention, as described below, it is possible to increase the support position accuracy and the support rigidity of the counter drive gear while adopting the transmission case integrally formed with the rear wall.

  According to the structure of the present invention, since the transmission case is integrally formed with the rear wall, the attachment surface of the valve body can be widened, and the degree of layout freedom can be increased.

  Further, since the counter drive gear is supported by the extending portion that extends from the rear wall (case), the support position accuracy can be improved as compared with the one that is supported by a separate intermediate wall. This is because the variation in bolt hole position for fixing the intermediate wall to the case and the variation in the assembly position of the intermediate wall can be eliminated.

  Further, since the box shape formed integrally with the side surface of the case and the rear wall is formed, the rigidity of the rear wall is increased. Since the counter drive gear is supported by the rear wall, the support rigidity is increased.

  As a result, it is possible to expect suppression of gear noise in the counter drive-driven gear pair as a result.

  According to the invention of claim 2, the support position accuracy of the outer race of the bearing can be improved, and the support position accuracy of the counter drive gear can be improved accordingly.

  According to the invention of claim 3, it is possible to improve the support position accuracy of the inner race of the bearing, and thereby improve the support position accuracy of the counter drive gear.

  According to the invention of claim 4, since the connecting member that connects the counter drive gear and the rotating element of the planetary gear can be omitted, it is possible to reduce the size (particularly the overall length) and reduce the weight.

  According to the invention of claim 5, by using the fact that the counter drive gear and the rotating element of the planetary gear are integrally joined, lubrication with high oil-tightness can be achieved simply by providing a lubricating groove on at least one of the joint surfaces. An oil passage can be formed. Therefore, the pinion gear can be effectively lubricated with a simple structure.

  According to the sixth aspect of the present invention, the overall length of the automatic transmission can be shortened by the overlap arrangement while increasing the support rigidity of the input shaft.

  According to the seventh aspect of the invention, the overall length of the automatic transmission can be shortened by the overlap arrangement while increasing the support rigidity of the counter shaft.

  According to the eighth aspect of the present invention, the counter drive-driven gear can be easily engaged while securing the rigidity of the case.

  According to the ninth aspect of the present invention, it is possible to efficiently arrange the rotational speed sensor while ensuring the rigidity of the case.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram (skeleton diagram) showing a skeleton structure of an automatic transmission 1 according to a first embodiment of the present invention. The automatic transmission 1 according to this embodiment is connected to an engine and mounted on a vehicle. The automatic transmission 1 is a multistage automatic transmission having six forward speeds and one reverse speed, and is a so-called six-speed automatic transmission.

  The automatic transmission 1 has a three-axis structure in which a main rotating member is disposed around three axes (main axis X1, counter axis X2, and differential axis X3).

  The main axis X1 is an input axis of the automatic transmission 1, and in the present embodiment, coincides with the axis of the crankshaft 90 of the engine. The differential axis X3 is an output axis of the automatic transmission 1, and in this embodiment, coincides with the axis of the drive shaft 80 that drives the drive wheels.

  In the following description, the crankshaft 90 side (the right side in FIG. 1) of the main axis X1 is referred to as a front side, and the opposite side is referred to as a rear side.

  A turbine shaft 4 (first input shaft) and a second input shaft 5 are disposed on the main axis X1, and a torque converter 3, first, second, and third planetary gear sets GS1, GS2 having these as rotating shafts are arranged. , GS3 and counter drive gear 6 are provided.

  A counter shaft 15 is provided on the counter axis X2, and a counter driven gear 12 and a differential drive gear 17 that rotate integrally therewith are provided.

  A differential ring gear 19 and a differential mechanism 50 are provided on the differential axis X3.

  The torque converter 3 includes a transmission-side pump 3a directly connected to the crankshaft 90, a driven-side turbine 3b that rotates integrally with the turbine shaft 4, and a transmission case 2 (more precisely, a transmission). And a stator 3c connected to a member fixed to the case 2. The torque converter 3 includes a lockup damper 3d that rotates integrally with the turbine shaft 4, and a lockup clutch 3e that fastens the pump 3a and the lockup damper 3d. The torque converter 3 is filled with working fluid (ATF).

  With this configuration, the torque converter 3 acts as a fluid coupling having a torque amplifying action when the lockup clutch 3e is released, and directly connects the crankshaft 90 and the turbine shaft 4 when the lockup clutch 3e is engaged.

  Three planetary gear sets (GS1, GS2, GS3) are arranged on the rear side of the torque converter 3.

  The first, second and third planetary gear sets GS1GS2 and GS3 include first, second and third sun gears S1, S2 and S3, first, second and third ring gears R1, R2 and R3, First, second, and third pinions P1, P2, and P3 meshing with the sun gear and each ring gear, and first, second, and third supporting the first, second, and third pinions P1, P2, and P3. A single-pinion type planetary gear set including carriers C1, C2, and C3.

  The first sun gear S1 is connected to the turbine shaft 4 via the clutch drum 4a and rotates integrally therewith. The second sun gear S2 and the third sun gear S3 are provided on a sun gear assembly S23 that rotates integrally with the second input shaft 5, and rotates integrally therewith.

  The first carrier C1 and the second ring gear R2 are connected to each other and rotate integrally. The second carrier C2 and the third ring gear R3 are connected to each other and rotate integrally.

  A counter drive gear 6 supported by the case 2 via a bearing 10 is provided on the rearmost side on the main axis X1. The counter drive gear 6 is fixed to the third carrier C3 and rotates integrally therewith.

  The counter driven gear 12 provided on the counter shaft 15 meshes with the counter drive gear 6 and is driven thereby. A differential drive gear 17 provided on the counter shaft 15 meshes with a differential ring gear 19 to drive it.

  The differential mechanism 50 is a known mechanism that transmits the drive wheels transmitted to the differential ring gear 19 to the pair of drive shafts 80 while distributing the drive wheels according to the rotational difference.

  The automatic transmission 1 includes five engagement elements, that is, a low clutch LC, a high clutch HC, an R35 brake B1, 2/6 brake B2, an L / R brake B3, and a one-way clutch W1. Except for the one-way clutch W1, it is a wet multi-plate type frictional engagement element. The low clutch LC integrally rotates the clutch drum 4a (turbine shaft 4) and the second input shaft 5 by the engagement. The high clutch HC causes the clutch drum 4a (turbine shaft 4) and the second carrier C2 to rotate integrally by being engaged. The R35 brake B1, 2/6 brake B2, and L / R brake B3 fix the first ring gear R1, the second ring gear R2, and the third ring gear R3 to the case 2 by fastening them. The one-way clutch W1 is unlocked when the third ring gear R3 tries to rotate in the same direction as the crankshaft 90, and is allowed when the third ring gear R3 rotates in the opposite direction. (The third ring gear R3 is fixed to the case 2).

  FIG. 2 is a diagram illustrating an intermittent state of each fastening element at each gear position. In this figure, ◯ indicates that the frictional engagement element is engaged, and ● indicates that the one-way clutch W1 is in a locked state. Parentheses indicate that there are cases. No mark indicates that it is released or unlocked. In the automatic transmission 1 according to the present embodiment, the P (parking) range, the R (reverse) range, the N (neutral) range, and the D (travel) are used as shift lever positions (shift ranges) that are not shown in FIG. There is a range. In the D range, the M (manual) mode can be selected according to the driver's intention instead of the normal automatic transmission mode. In the M mode, the driver manually determines the gear position by operating the shift lever.

  At the first speed (1st), the low clutch LC is engaged, and the one-way clutch W1 is locked. This achieves the lowest speed. The L / R brake B3 is engaged (indicated by (◯)) in the M mode and released in the automatic transmission mode. When the L / R brake B3 is engaged, the reverse driving force can be transmitted from the drive shaft 80 side to the turbine shaft 4 side. Therefore, a strong engine brake can be obtained as a vehicle.

  On the other hand, when the L / R brake B3 is released, such a reverse driving force is not transmitted due to the idling of the one-way clutch W1. Therefore, a strong engine brake does not act as a vehicle.

  The automatic transmission mode and the M mode are common to the second speed (2nd) to the sixth speed (6th). At the second speed (2nd), the low clutch LC and the 2/6 brake B2 are engaged to achieve a higher speed than the first speed. At the third speed (3rd), the low clutch LC and the R35 brake B1 are engaged to achieve a higher speed than the second speed. At the fourth speed (4th), the low clutch LC and the high clutch HC are engaged to achieve a higher speed than the third speed. In the fourth speed, the counter drive gear 6 and the turbine shaft 4 are in a directly connected state in which the rotation speeds coincide with each other. At the fifth speed (5th), the high clutch HC and the R35 brake B1 are engaged to achieve a higher speed than the fourth speed. In the sixth speed (6th), the highest speed stage is achieved by engaging the high clutch HC and the 2/6 brake B2.

  In the R range, the drive shaft 80 can be driven in reverse rotation with respect to the crankshaft 90 by engaging the R35 brake B1 and the L / R brake B3. That is, the reverse stage is achieved.

  The supply / discharge of hydraulic pressure to / from each clutch and brake is controlled by a control valve assembly 81 (see FIG. 6). The control valve assembly 81 includes a solenoid valve and a number of hydraulic valves in a block-shaped valve body. The control valve assembly 81 is attached to the transmission case 2 (hereinafter abbreviated as case 2). An oil passage that connects the case 2 to the clutches and brakes is formed in the case 2.

  FIG. 3 is a longitudinal sectional view of the automatic transmission 1. The main axis X1, the counter axis X2, and the differential axis X3 are not actually coplanar, and the plane including the main axis X1 and the counter axis X2 and the plane including the counter axis X2 and the differential axis X3 are about 100 °. Intersect with each other (see FIG. 6). In FIG. 3, it is shown expanded on the same plane (a sandwich angle of 180 °).

  In each element shown in FIG. 1, the torque converter 3 is accommodated in the converter housing 29, and the other elements are accommodated in the case 2. Converter housing 29 and case 2 are bolted up and integrated.

  The case 2 has an opening at the front side and serves as a mating portion with the converter housing 29. The rear side is closed. Accordingly, a rear wall 2a that is integrally formed with the case 2 and closes the rear side is formed.

  Since the rear wall 2 a is integrally formed with the case 2, the attachment surface of the control valve assembly 81 (the valve body) can be secured over almost the entire length of the case 2. That is, a wider attachment surface can be obtained and the degree of freedom in layout can be increased.

  4 is an enlarged partial sectional view showing the vicinity of the rear wall 2a of FIG. 3, particularly the vicinity of the counter drive gear 6 and the counter driven gear 12. FIG.

  As shown in FIG. 4, a boss-like extending portion 2 b that is integrally extended from the rear wall 2 a to the front side in the main axis X <b> 1 direction is formed. The extending portion 2b is formed with a cylindrical inner peripheral surface 2bb on the main axis X1. On the other hand, a flange portion 6a extending to the rear side in the main axis X1 direction is formed on the inner peripheral side of the counter drive gear 6. The outer diameter of the flange portion 6a is smaller than the diameter of the cylindrical inner peripheral surface 2bb, and these are overlapped with each other in the axial direction. A bearing 10 is interposed in the annular gap.

  The bearing 10 is a radial ball bearing and mainly includes an inner race 10a, a large number of balls 10b, and an outer race 10c. The outer peripheral portion of the flange portion 6a of the counter drive gear 6 is fixed (press-fitted) to the inner peripheral portion of the inner race 10a. Further, the outer peripheral portion of the outer race 10c is fixed to the cylindrical inner peripheral surface 2bb of the extending portion 2b (stopped by a snap ring 27 as shown in FIG. 5). Thus, the counter drive gear 6 is supported by the extending portion 2b via the bearing 10.

  Thus, since the counter drive gear 6 is supported by the extended portion 2b extending from the case 2 (the rear wall 2a), the support position of the counter drive gear 6 is compared with the conventional structure supported by the separate intermediate wall. Accuracy can be improved. This is because the variation in bolt hole position for fixing the intermediate wall to the case and the variation in the assembly position of the intermediate wall can be eliminated. In addition, since the box shape is formed integrally with the side surface of the case 2 and the rear wall 2a, the rigidity of the rear wall 2a is increased. Since the counter drive gear 6 is supported by the rear wall 2a, the support rigidity is increased.

  As shown in FIG. 1, the counter drive gear 6 is an output section on the main axis X1, and its transmission torque is relatively large. For example, at low speed (first speed to third speed), the transmission torque is higher than the torque of the turbine shaft 4 (first input shaft). In general, when a large torque is applied, the gear support portion is likely to be deformed, and the tooth contact of the gear is changed to easily cause gear noise. In that respect, gear noise in the counter drive gear 6 -counter driven gear 12 is a portion that is relatively problematic. Therefore, by improving the support position accuracy and the support rigidity as in this embodiment, it is easy to stably maintain an appropriate tooth contact, so that effective gear noise suppression can be expected.

  Further, a boss-like second extending portion 2c that is integrally extended from the rear wall 2a to the front side in the main axis X1 direction is formed further on the inner peripheral side than the flange portion 6a. The second extending portion 2c is formed with an inner peripheral cylindrical surface, and the rear end of the second input shaft 5 is overlapped on the inner peripheral side. The second input shaft 5 is supported by the second extending portion 2 c via a bearing 9.

  With such a structure, it is possible to shorten the overall length of the automatic transmission 1 by overlapping arrangement while increasing the support rigidity of the second input shaft 5.

  Also, a boss-like third extending portion 2d is formed integrally extending from the rear wall 2a to the front side of the counter axis X2 direction. The third extending portion 2d is formed with an inner peripheral cylindrical surface, and the rear end of the counter shaft 15 is disposed on the inner peripheral side in an overlapping manner. The counter shaft 15 is supported by the third extending portion 2 d via the bearing 11. The bearing 11 is a radial roller bearing and mainly includes an inner race 11 a, a large number of rollers 11 b, and an outer race 11.

  With such a structure, the overall length of the automatic transmission 1 can be shortened by the overlapping arrangement while increasing the support rigidity of the counter shaft 15.

  By the way, on the further inner peripheral side of the flange portion 6a of the counter drive gear 6, a flange portion C3a formed on the inner peripheral side of the third carrier C3 and extending rearward in the main axis X1 direction is disposed so as to overlap. The flange portion 6a and the flange portion C3a are spline-fitted, whereby the counter drive gear 6 and the third carrier C3 are integrally rotated. The flange portion 6a, the flange portion C3a, and the bearing 10 (the inner race 10a thereof) are fixed by the nut 25. When the nut 25 is tightened, the counter drive gear 6 and the third carrier C3 are joined in a state where the axial vertical surfaces facing each other are in close contact with each other.

  With such a structure, there is no need to separately provide a connecting member for connecting the counter drive gear 6 and the third carrier C3, so that it is possible to achieve a small size (especially a reduction in the overall length) and a reduction in weight.

  Further, with respect to the process of assembling the counter drive gear 6 and the third carrier C3 to the case 2, the third carrier C3 (including the third pinion P3), the counter drive gear 6 and the bearing 10 are fixed to each other with a nut 25 in advance as a subassembly. In addition, it is possible to set a process in which the subassembly is assembled to the case 2 by inserting the bearing 10 into the cylindrical inner peripheral surface 2bb of the extending portion 2b and stopping with the snap ring 27. This is a suitable process for mass production with an automatic machine because a relatively large number of members can be assembled to the case 2 at once (by subassembly).

  FIG. 5 is a further enlarged view of FIG. 4 and shows the vicinity of the counter drive gear 6 and the third planetary gear set GS3. The lubricating oil passage of the third pinion P3 will be described with reference to this figure. The third pinion P3 is supported by the pinion shaft 45, and the pinion shaft 45 is fixed to the third carrier C3. The pinion shaft 45 is formed with a pinion lubricating hole 45a that communicates the rear end of the pinion shaft 45 and the inner peripheral surface of the third pinion P3.

  On the other hand, a lubricating oil passage 5 b is formed in the axial direction on the inner peripheral portion of the second input shaft 5. Lubricating holes 5a penetrating the outer peripheral portion are formed radially from the lubricating oil passage 5a. Further, a lubrication hole C3b penetrating the inner and outer peripheries is formed in the flange portion C3a of the third carrier C3. Further, radial lubrication grooves 6b are formed on the axis vertical surface of the counter drive gear 6 which is in contact with the third carrier C3. The lubrication groove 6b communicates with the rear opening of the pinion lubrication hole 45a.

  With such a configuration, the lubricating oil (ATF) guided from the lubricating oil passage 5b is guided to the pinion lubricating hole 45a via the lubricating hole 5a, the lubricating hole C3b, and the lubricating groove 6b (arrows A1, A2, A3). ). Here, since the mutually perpendicular axis surfaces of the counter drive gear 6 and the third carrier C3 are in close contact with each other, there is little lubricating oil leaking from the lubricating groove 6b. That is, the lubricating oil can be supplied from the lubricating hole C3b to the pinion lubricating hole 45a without waste without using a separate sealing member or the like. The lubrication groove 6b may be provided on the third carrier C3 side or both.

  6 is a cross-sectional view taken along the line VI-VI in FIG. 4, and in particular, a cross section of the case 2 is extracted. In this cross-sectional position, the case 2 is formed with a cylindrical portion 2f that surrounds the counter drive gear 6 in the circumferential direction. As shown in FIG. 3, the cylindrical portion 2f fixes the fixed side plates of the R35 brake B1, 2/6 brake B2, and L / R brake B3 to the case 2 by spline fitting.

  The cylindrical portion 2f is formed so as to surround the entire circumference of the main axis X1 in principle over the range where the R35 brakes B1 to L / R brakes B3 are arranged in the direction of the main axis X1. However, as shown in FIG. 6, a part thereof is thinned in the vicinity of the cross-sectional position, and a first notch 2g and a second notch 2h are formed.

  The first notch 2g is formed in the vicinity of a line connecting the main axis X1 and the counter axis X2. By passing the counter driven gear 12 through the first notch 2g, the counter drive gear 6 and the counter driven gear 12 are engaged. As shown in FIG. 4, the axial length of the first notch 2g extends to the L / R brake B3. For this reason, the fixed side plate of the L / R brake B3 is not fixed to the case 2 at the location corresponding to the first notch 2g, but it is fixed at other locations and the fixed side plate rotates. Because it is a plate that does not, there is no problem. In other words, the overall length can be shortened by arranging the L / R brake B3 and the counter driven gear 12 in the main axis X1 direction so as not to cause such trouble.

  In addition, since the said cross-sectional position is a rear side from L / R brake B3, the cylindrical part 2f is not necessarily required on the function of fixing a stationary-side plate. However, although the first notch 2g and the second notch 2h are provided, the rigidity of the case 2 is enhanced by extending the cylindrical portion 2f to the rear side up to this position.

  By the way, as indicated by a two-dot chain line in FIG. 6, a control valve assembly 81 is provided inside the case 2 and outside the cylindrical portion 2f.

  A control unit 82 is attached to the side of the control valve assembly 81 close to the cylindrical portion 2f. The control unit 82 is an electric control unit incorporating a microprocessor having a CPU, a memory, and the like. The control unit 82 performs calculation based on various sensor signals and sends a control signal to a solenoid valve (not shown) (duty solenoid or on / off solenoid) mounted on the control valve assembly 81. In the control valve assembly 81, the operation of the solenoid valve adjusts the hydraulic pressure (line pressure) supplied to each friction engagement element, or switches the oil path so as to realize the engagement pattern as shown in FIG. Or do.

  From the control unit 82, a turbine rotation speed sensor 85 and an intermediate rotation speed sensor 86 indicated by a two-dot chain line are erected in the direction of the main axis X1. These circumferential positions are the same as shown in FIG. 6 (in FIG. 6, they overlap in a direction perpendicular to the paper surface). As shown in FIG. 3, the turbine rotational speed sensor 85 is in the vicinity of the clutch drum 4 a, and the intermediate rotational speed sensor 86 is in the vicinity of the counter drive gear 6.

  The turbine rotation speed sensor 85 uses a number of holes or grooves provided in the circumferential direction on the outer periphery of the clutch drum 4a that rotates integrally with the turbine shaft 4, and is proportional to the turbine rotation speed (rotation speed of the turbine shaft 4) by electromagnetic induction. Inductive electromotive force having the above frequency is generated and the sensor information is transmitted to the control unit 82. Similarly, the intermediate rotational speed sensor 86 detects the rotational speed of the counter drive gear 6 (the output rotational speed on the main axis X1) by electromagnetic induction using the unevenness of the tooth surface of the counter drive gear 6.

  Control based on the sensor information enables high-precision shift control by the control unit 82. However, the rotational speed sensors 85 and 86 that are separated in the axial direction are directly placed from the control unit 82 at the same circumferential position. By installing the control unit 82 (control valve assembly 81) in the case 2, the rotational speed sensors 85 and 86 can also be assembled in the case 2. Moreover, since the lead wire which connects each rotation speed sensor 85 and 86 and the control unit 82 becomes unnecessary, concerns, such as a disconnection and a noise, can be eliminated.

  As shown in FIG. 3, the turbine rotational speed sensor 85 is installed on the front side of the front end face of the cylindrical portion 2f, so that there is no problem. However, the intermediate rotational speed sensor 86 is installed in the axial direction. It overlaps with 2f. Therefore, as shown in FIG. 6, a second notch 2h is provided in the vicinity of the position of the cylindrical portion 2f, and an intermediate rotational speed sensor 86 is passed there.

  Thus, by providing the cylindrical portion 2f and the second notch portion 2h, efficient arrangement of the intermediate rotational speed sensor 86 is facilitated while ensuring the rigidity of the case 2.

  FIG. 7 is a diagram corresponding to FIG. 4 according to the second embodiment of the present invention. In this figure, members having the same or the same functions as those in the first embodiment are denoted by the same reference numerals, and redundant description thereof is omitted. In addition, the present embodiment is different from the first embodiment in the support structure of the counter drive gear 106, and the others are the same, so that point (difference from the first embodiment) will be particularly described.

  A boss-like extending portion 102b extending integrally from the rear wall 102a formed integrally with the case 102 toward the front side in the main axis X1 direction is formed. In addition, a cylindrical outer peripheral surface 102bb is formed on the main axis X1 in the installation portion 102b. On the other hand, the inner peripheral surface 106a of the counter drive gear 106 has a larger diameter than the cylindrical outer peripheral surface 102bb, and these are overlapped with each other in the axial direction. A bearing 10 is interposed in the annular gap.

  The inner race 10a of the bearing 10 is fixed (press-fitted) to the cylindrical outer peripheral surface 102bb of the extending portion 102b and fixed with a nut 125. Further, the outer race 10 c of the bearing 10 is fitted on the inner peripheral surface 106 a of the counter drive gear 106 and is stopped by a snap ring 127.

  Similarly to the first embodiment, since the counter drive gear 106 is supported by the extended portion 102b extending from the case 102 (the rear wall 102a), the present embodiment can improve the support position accuracy and the support rigidity. It can be expected to suppress gear noise.

  Regarding the process of assembling the counter drive gear 106 to the case 102, first, the bearing 10 is assembled to the first extending portion 102b, the nut 125 is tightened, and then the counter drive gear 106 and the third carrier C3 (including the third pinion P3); It is possible to set a process in which the sub-assembly is inserted into the outer race 10 c of the bearing 10 and stopped by the snap ring 127. The structure of this embodiment is suitable for setting a process for sequentially incorporating members in this way.

  As mentioned above, although embodiment of this invention was described, these embodiment can be suitably changed in the range which does not deviate from the summary of this invention. For example, the automatic transmission 1 is a 6-speed automatic transmission with 6 forward speeds and 1 reverse speed, but is not limited to this, and may be other types such as 5 forward speeds and 4 speeds. Further, instead of the torque converter 3, an electromagnetic clutch or the like may be provided.

  The frame structure (skeleton) of the speed change mechanism is not limited to that shown in FIG. Further, the combination and arrangement of the frictional engagement elements (clutch and brake) are not limited to those shown in FIGS. For example, a type using a friction brake band for a part or all of the brake may be used.

  Although a preferred installation position of the control unit 82 and the control valve assembly 81 is shown in FIG. 6, the present invention is not limited to this, and the control valve assembly 81 may be provided at any position in the case 2. Further, the control unit 82 may be provided outside the case 2.

It is a figure which shows the frame | skeleton structure of the automatic transmission which concerns on 1st Embodiment of this invention. It is a figure which shows the intermittent state of each friction fastening element. It is a longitudinal cross-sectional view of the automatic transmission. FIG. 4 is an enlarged partial sectional view of FIG. 3. FIG. 5 is an enlarged view of FIG. 4. FIG. 6 is a sectional view taken along line VI-VI in FIG. 4. It is a figure corresponding to Drawing 4 concerning a 2nd embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Automatic transmission 2 Transmission case 2a Rear wall 2b Extension part 2bb Cylindrical inner peripheral surface 2c 2nd extension part 2d 3rd extension part 2f Cylindrical part 2g 1st notch part 2h 2nd notch part 5 2nd input Axis (input shaft)
6 Counter drive gear 6b Lubrication groove 9 Bearing 10 Bearing 10a Inner race 10c Outer race 11 Bearing 12 Counter driven gear 15 Counter shaft 45a Pinion lubrication hole 86 Intermediate rotation speed sensor (rotation speed sensor)
102 Transmission case 102a Rear wall 102b Extension portion 102bb Cylindrical outer peripheral surface C3 Third carrier (planetary gear rotating element)
GS3 3rd planetary gear set (planetary gear)
X1 Main axis X2 Counter axis

Claims (9)

A transmission case that has a rear wall that is open at a front side that is one end side of the main axis and closes a rear side that is the other end side of the main axis, and is integrally formed with the rear wall;
An input shaft provided on the main axis,
A counter shaft provided in parallel to be offset with respect to the input shaft;
A counter drive gear provided on the main axis and transmitting a driving force from the input shaft side to the counter shaft side;
An extending portion integrally extending from the rear wall to the front side in the main axis direction,
The automatic transmission, wherein the counter drive gear is supported by the extended portion via a bearing. A cylindrical inner peripheral surface is formed on the main axis of the extending portion,
2. The automatic transmission according to claim 1, wherein an outer race of the bearing is fixed to the cylindrical inner peripheral surface. A cylindrical outer peripheral surface is formed on the main axis of the extending portion,
2. The automatic transmission according to claim 1, wherein an inner race of the bearing is fixed to the cylindrical outer peripheral surface. A planetary gear is provided adjacent to the extending portion on the main axis,
The automatic transmission according to any one of claims 1 to 3, wherein the counter drive gear is integrally joined to a rotating element of the planetary gear. The rotating element integrally joined with the counter drive gear is a carrier,
The automatic transmission according to claim 4, wherein a lubricating groove communicating with a pinion lubricating hole of the planetary gear is formed on at least one of the joint surfaces of the counter drive gear and the carrier. A second extending portion integrally extending from the rear wall to the front side in the main axis direction;
6. The input shaft according to claim 1, wherein the input shaft is supported by the second extending portion via a bearing, and the supporting portion is disposed so as to overlap the counter drive gear in the main axis direction. The automatic transmission according to item 1. A third extending portion integrally extending from the rear wall to the counter axial direction front side;
7. The counter shaft according to claim 1, wherein the counter shaft is supported by the third extending portion via a bearing, and the supporting portion is disposed so as to overlap the counter drive gear in the main axis direction. The automatic transmission according to item 1. A counter driven gear provided on the counter shaft and meshing with the counter drive gear;
In the transmission case, a cylindrical portion that surrounds the counter drive gear in the circumferential direction is formed, and a part of the cylindrical portion is thinned to form a first notch,
The automatic transmission according to any one of claims 1 to 7, wherein the counter drive gear and the counter driven gear are arranged to mesh with each other through the first cutout portion. A rotation speed sensor for detecting the rotation speed of the counter drive gear;
In the transmission case, a cylindrical portion that surrounds the counter drive gear in the circumferential direction is formed, and a part of the cylindrical portion is thinned to form a second notch,
The automatic transmission according to any one of claims 1 to 8, wherein the rotation speed sensor is disposed in proximity to the counter drive gear through the second cutout portion.

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