JPH028121Y2 - - Google Patents

Description

[Detailed explanation of the invention] (a) Industrial application field The present invention relates to an automatic transmission for vehicles using a planetary gear transmission, and more specifically, it is installed in a front engine/front drive vehicle and is The present invention relates to an automatic transmission having a first shaft and a second shaft arranged in the same direction, the rear ends of which are connected by a gear.

(b) Conventional technology Conventionally, automatic transmissions for vehicles have been configured in a uniaxial configuration from a torque converter to an extension shaft, and the uniaxial shaft is equipped with an overdrive planetary gear mechanism, a Simpson system, etc. A main transmission planetary gear mechanism consisting of:

For this reason, the structure is long in the axial direction, making it difficult to install it in a front engine/front drive vehicle.

Therefore, a first shaft and a second shaft are arranged in parallel, a torque converter and a main transmission planetary gear mechanism are arranged on the first shaft, and an output gear is arranged on the second shaft. An automatic transmission has been proposed in which a first shaft and a second shaft are connected by a counter drive gear and a counter driven gear.

(c) Problems to be solved by the invention By the way, in the above-mentioned automatic transmission, since the planetary gear mechanism is disposed in the center of the first shaft, the counter drive gear and the driven gear are not connected to the first shaft. and disposed at the respective tips of the second shaft,
In addition, when assembling the drive gear and driven gear, which are large-diameter gears, they are disposed outside of the bearing portions supported by the transaxle cases of the first and second shafts.

For this reason, these gears are supported in a cantilever structure, and the first and second shafts are controlled based on the unbalanced load due to the meshing of both gears and the axial force due to the fact that these gears are generally helical gears. This causes deviation in the gear direction, which causes uneven wear on the gear tooth surfaces of the planetary gear mechanism, and also causes defects in the contact surfaces of the counter drive gear and driven gear, causing noise generation.

In particular, the first shaft consists of two shafts: the front shaft, which serves as the input shaft of the main transmission planetary gear mechanism, and the rear shaft, which serves as the output shaft. As a result, the gap of the driven gear itself becomes large, and the above-mentioned problems occur conspicuously.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an automatic transmission for a vehicle that improves the support structure of a countershaft drive gear and eliminates the above-mentioned problems.

(d) Means for Solving the Problems The present invention has been developed in view of the above-mentioned circumstances. For example, as shown in FIG. A front shaft 31 connected to the output part of the fluid coupling, a rear shaft 32 disposed concentrically with the front shaft, a planetary gear transmission mechanism 3 disposed on these front and rear shafts, and the front shaft and a countershaft 4 disposed parallel to the rear shaft, a countershaft drive gear 33 mounted on the end of the rear shaft opposite to the engine, and a counter meshed with the countershaft drive gear and mounted on the countershaft 4. comprising a shaft driven gear 41 and an output gear 52 coaxially disposed on the engine side of the countershaft,
In the automatic transmission for a vehicle, in which the rotation appropriately changed by the planetary gear transmission mechanism 3 is transmitted to the countershaft 4 via the rear shaft 32, the countershaft drive gear 33, and the countershaft driven gear 41, the planetary The gear transmission mechanism 3 is housed in the transaxle case 12, the countershaft drive gear 33 and the countershaft driven gear 4 are housed in the rear cover 13 fixed to the side of the transaxle case 12 opposite to the engine, and The countershaft drive gear 3
3 has a hub part 34 protruding on both sides, and a bearing 35 is attached to the support wall 15 formed on the transaxle case 12 with the engine side part of the hub part.
A bearing 36 is attached to the rear cover 13 on the opposite side of the hub portion from the engine.
Become a supporter through.

Furthermore, the countershaft drive gear 3
The hub portion 34 of No. 3 is fitted with the rear shaft 32 at its central inner circumferential surface, and has a spline 34a formed on the engine-side inner circumferential surface of the hub portion 34, and is connected to the rear shaft 32 by the spline. and the inner circumferential surface of the hub portion 34 on the side opposite to the engine side and the rear shaft 3
There is a predetermined distance 321 between the outer circumferential surface of 2 and the outer circumferential surface of 2.

(E) Effect Based on the above configuration, the rotation from the engine is transmitted to the front shaft 31 via the fluid coupling 2, and then the speed is appropriately changed by the planetary gear transmission mechanism 3 and transmitted to the rear shaft 32, and then to the countershaft drive. The signal is transmitted to the gear 33. Furthermore,
The rotation of the drive gear 33 is transmitted to the countershaft 4 via a countershaft driven gear 41.
and is transmitted from the output gear 52 to the front differential device 6.

At this time, countershaft drive gear 33
Although the drive gear 33 is supported by bearings 35 and 36 in a double-supported structure, unbalanced loads and shaft extensions due to engagement with the driven gear 41 act on the rear shaft 32, so that there is no possibility of adverse effects such as gearing on the rear shaft 32. There isn't.

Furthermore, due to installation errors of the rear cover 13, etc.
Even if the concentricity of the bearing 35 of the case support wall 15 and the bearing 36 of the rear cover 13 is slightly distorted, the drive gear hub part 34 only has its central inner circumferential surface fitted tightly to the rear shaft 32. The inner circumferential surfaces of the left and right end portions have a predetermined play relationship due to the gap 321 and the spline 34a, so that the rotation of the drive gear 33 does not greatly affect the rotation of the rear shaft 32, and the rear shaft 3
2 functions in a self-aligning manner due to its sliding contact with the front shaft 31 at its tip, and the parallelism is maintained.

Note that the symbols inside brackets do not limit the structure in any way.

(F) Example Next, the present invention will be explained based on an example shown in the drawings.

Reference numeral 1 designates an automatic transmission case, which in this embodiment includes a transaxle housing 11 provided with a fastening surface 101 to the engine, a transaxle case 12 in which a planetary gear transmission mechanism is housed, and a countershaft drive gear and a countershaft. It is composed of a rear cover 13 in which the driven gear is housed. An engine-side support wall 14 is provided on an end surface of the transaxle case 12 on the engine side, and is fastened to the case 12, and a support wall 15 is provided on the end surface of the case 12 on the side opposite to the engine. The rear cover 13 constitutes the side wall of the transaxle case 12 opposite to the engine, and is attached to the case 12 by a spigot part 13a and bolts 20.
Positioned and fixed. Further, an oil pump 16 is provided within the engine-side support wall 14 of the transaxle case 12, and an oil pump cover 17 is fastened thereto.

Reference numeral 2 designates a hydraulic torque converter provided within the transaxle housing, which is comprised of a pump impeller connected to the engine crankshaft, a turbine liner serving as an output member, and a lock-up clutch 2a. 3 is a first planetary gear transmission mechanism provided in the transaxle case 12, and the planetary gear transmission mechanism 3 is of the Simpson type having a front planetary gear 3a and a rear planetary gear 3b, and has a clutch and a brake as appropriate. Based on the operation, three forward speeds and one reverse speed are obtained. Reference numeral 31 denotes a front shaft rotatably supported by the engine side support wall 14 of the transaxle case 12, and serves as the output shaft of the torque converter 2 as well as the input shaft of the first planetary gear transmission mechanism 3; The rear shaft is the output shaft of the planetary gear transmission mechanism, and the front shaft 31 and the rear shaft 32 are arranged concentrically and constitute a first shaft. Reference numeral 33 denotes a countershaft drive gear mounted on the end of the rear shaft opposite to the engine, and the countershaft drive gear 33 has a sleeve-shaped hub portion 34 projecting on both sides, which is connected to bearings 35 and 36, respectively.
It is rotatably supported by the rear support side wall 15 and rear cover 13 of the transaxle case. The inner peripheral surface of the countershaft drive gear hub portion 34 has a central portion closely fitted to the rear shaft 32, and a spline 34a is formed on the engine side and is spline-fitted to the rear shaft 32. , furthermore, there is a predetermined distance between the rear side and the shaft 32 =321
have.

Reference numeral 4 denotes a countershaft constituting a second shaft arranged in parallel with the front shaft 31 and rear shaft 32 of the first planetary gear transmission mechanism, which constitutes an input shaft of the second planetary gear transmission mechanism 5, and which is connected to the engine. A countershaft driven gear 41 that meshes with the countershaft drive gear 33 is spline-fitted to the opposite end, and a hollow second planetary gear that also serves as a drive gear for the differential mechanism 6 is fitted to the engine side end. A transmission mechanism output shaft 52 is rotatably supported. The second planetary gear transmission mechanism 5 is composed of one single planetary gear, and acts as a reduction gear in normal times, and is directly connected in overdrive.
Together with the countershaft drive gear 33 and the driven gear 41, which serve as speed increasing devices, overdrive is achieved.

The rear shaft 32 has a hollow part 30 at its center, and the end of the hollow part 30 on the side opposite to the engine has a plug 30.
1 for supplying lubricating oil to bearings 35 and 36 that rotatably support the bearings of the planetary gear transmission mechanism, the one-way clutch, the planetary gear set, and the countershaft drive gear. Radial holes 32A, 32B, 32C, 32D, 32E, 3
2F, 32G, and 32H are formed.

The rear shaft 32 and the rotating and sliding portion of the first planetary gear transmission mechanism around it are connected to the oil pump 16.
The lubricating oil passage 3 is discharged from the front shaft 31 and is regulated by the hydraulic pressure control device 18 provided at the lower part or side of the transaxle case, and is formed in the front shaft 31 via the oil passage provided in the transaxle case.
The lubricating oil discharged into the rear shaft 32
A radial hole 32A provided at a predetermined position in the shaft 32 through a hollow portion 30 formed in the center of the shaft 32.
The bearing 36 has a gap formed between the outer periphery of the rear shaft 32 and the inner periphery of the hub portion 34 of the countershaft drive gear from the radial hole 32H.
Lubricating oil is supplied through step 1.

(g) Effects of the invention As explained above, according to the invention, the countershaft 4 is provided parallel to the front shaft 31 and the rear shaft 32 that are arranged concentrically, and these shafts are connected to the countershaft drive gear 33 and the driven gear 41. Although it is an automatic transmission that is connected to the countershaft drive gear 33 and shortened in the axial direction, it can be mounted on front engine/front drive vehicles.
is supported by the transaxle case support wall 15 and the rear cover 13 via bearings 35 and 36, respectively, in a double-sided structure. The gear 33 is supported reliably and accurately, preventing improper meshing with the driven gear 41 and preventing the generation of noise. Furthermore, the biasing force acting on the drive gear 33 is applied to the rear shaft 32 by a gear or the like. It is possible to prevent uneven contact or the like from occurring in the gears of the planetary gear transmission mechanism 3 without causing any adverse effects, thereby improving reliability and durability.

In addition, the inner circumferential surface of the countershaft drive gear hub portion 34 is connected to the rear shaft 3 so that the center portion thereof
2, and spline-fits with the rear shaft 32 on the engine side, and forms a gap 321 between the rear shaft 32 and the rear shaft 32 on the opposite side. Even if a slight deviation occurs in the concentricity accuracy, the deviation will not amplify and greatly affect the rear shaft 32, and the rear shaft 32 will be supported in a self-aligning manner and its parallelism will be maintained. As a result, although the portion of the hub portion 34 of the drive gear opposite to the engine is supported by the rear cover 13 via the bearing 36, it is possible to prevent uneven contact or the like from occurring in the gears of the planetary gear transmission mechanism 3.
Reliability and durability can be improved.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an automatic transmission according to the present invention. 1... Automatic transmission case, 2... Fluid coupling (torque converter), 3... Planetary gear transmission mechanism, 4
... Countershaft, 15 ... Supporting wall, 13
...Rear cover, 31 ...Front shaft, 3
2... Rear shaft, 33... Counter drive gear, 34... Hub portion, 34a... Spline, 35, 36... Bearing, 41... Counter driven gear, 52... Output gear, 321...
...Pause〓.

Claims (1)

[Claims for Utility Model Registration] A fluid coupling connected to the output shaft of the engine, a front shaft coupled to the output part of the fluid coupling, a rear shaft disposed concentrically with the front shaft, and a front a planetary gear transmission mechanism disposed on a shaft and a rear shaft; a countershaft disposed parallel to the front and rear shafts; and a countershaft drive gear mounted on an end of the rear shaft opposite to the engine; a countershaft driven gear that meshes with the countershaft drive gear and is attached to the countershaft;
and an output gear disposed coaxially on the engine side of the countershaft, and the rotation appropriately changed by the planetary gear transmission mechanism is transmitted to the counter via the rear shaft, the countershaft drive gear, and the countershaft driven gear. In the automatic transmission for a vehicle, the planetary gear transmission mechanism is housed in a transaxle case, and the countershaft drive gear and countershaft driven gear are fixed to a side of the transaxle case opposite to the engine. The countershaft drive gear is housed inside the rear cover, and the countershaft drive gear is
It has a hub part protruding on both sides, and the engine side part of the hub part is supported via a bearing on a support wall formed on the transaxle case, and the side part of the hub part opposite to the engine is attached to the rear cover. The hub portion of the countershaft drive gear is supported via a bearing, and the inner circumferential surface of the central portion of the hub portion is closely fitted to the rear shaft, and a spline is formed on the inner circumferential surface of the hub portion on the engine side. An automatic transmission for a vehicle, wherein the hub portion is spline-fitted with the rear shaft, and has a predetermined distance between an inner circumferential surface of the hub portion on the side opposite to the engine side and an outer circumferential surface of the rear shaft.