JPH04341650A - Rotating member supporting structure in transmission - Google Patents

Abstract

PURPOSE:To equalize each thermal expansion coefficient of a bearing and a flange member as well as to prevent any lost motion from occurring by casting the flange member consisting of a ferrous material, thereby forming a wall part supporting a rotating member in a housing consisting of an aluminum material. CONSTITUTION:An output gear 12 or a rotating member of a transmission mechanism is supported by a wall part 20 formed in a central housing 2 free of rotation via an angular ball bearing 16. In this case, the wall part 20 forms a disklike flange member 21, consisting of a ferrous material, by way of casting it at the time of casting the housing 2 consisting of an aluminum material. In brief, the flange member 21 is cast together with the housing 2 and joined with it through an external tooth spline part 33a formed on a joined surface of the flange member 21. In addition, an inner race 16a is inserted into a bearing setting hole 23a of an inner circumferential boss part 23 formed in the flange part 21, holding it, and the bearing 16 is attached to it. With this constitution, both thermal expansion coefficients of the bearing 16 and the flange member 21 are equalized.

Description

[Detailed description of the invention]

0001

[Industrial Field of Application] The present invention relates to a transmission in which a transmission mechanism is disposed within a housing made by casting an aluminum material, in which rotating members such as gears and shafts constituting the transmission mechanism are Concerning supporting structures.

0002

[Prior Art] A transmission is usually constructed by disposing a transmission mechanism consisting of gears, shafts, clutches, etc. in a cast housing. Rotating members such as gears, shafts, etc. are equipped with bearings. It is rotatably supported by the wall of the housing via the housing.

[0003] An example of such a structure for supporting a rotating member using a housing is a structure disclosed in Japanese Patent Laid-Open No. 1-98736. For example, a structure is shown in which a shaft having an output gear on one end is rotatably supported, and in this structure, two tapered roller bearings are placed back to back on the outer periphery of the shaft to which the output gear is attached. The shaft (rotating member) is rotatably supported by the wall of the housing via this bearing. In this case, the outer race of the tapered roller bearing is integrally formed and is press-fitted into the bearing mounting hole formed in the wall of the housing. On the other hand, the inner race is attached to the shaft with one end abutting the output gear at the end of the shaft and the other end tightened with a preload nut to apply a preload.

0004

Transmission housings are sometimes made by casting iron-based materials, but recently they are often made by casting aluminum-based materials to reduce weight. When such an aluminum-based material is used, the following problems arise if the above-mentioned rotating member support structure remains unchanged.

First of all, when the bearing outer race is press-fitted into the bearing mounting hole formed in the wall of the housing, the outer race is made of iron-based material such as steel, and aluminum-based material is different from heat-resistant material. Since the expansion coefficients are different, there is a problem in that play (gap) occurs in this press-fit portion during hot operation. This causes problems such as unstable support of the shaft, and gears attached to the shaft tilting due to the influence of this play, which reduces gear meshing accuracy and increases noise, vibration, etc. be.

Second, since aluminum-based materials have lower strength and rigidity than iron-based materials, it is necessary to increase the thickness of the housing wall that supports the shaft. When a gear is attached to the end of the shaft as described above, it is desirable to have the meshing point of the gear as close to the center of the support action points of the two bearings in the axial direction as possible, but the thickness of the housing wall If it is thick, there is a problem in that the wall becomes an obstacle and forces the meshing point of the gear to be moved away from the center of the support point. Thirdly, when the shaft is supported using two tapered roller bearings as described above, the tapered roller bearings are tightened with a preload nut and installed on the shaft with a preload applied. ,
There is also the problem that friction resistance increases in the tapered roller bearing portion.

[0007] Furthermore, Japanese Unexamined Patent Publication No. 188854/1983 discloses that a sleeve made of an iron-based material is cast or press-fitted into the wall of an aluminum housing, and a bearing insertion hole is formed in this sleeve. ing. Although this sleeve is made from a material with high vibration damping performance and is provided to suppress vibration and noise,
Since it is made of iron-based material, the difference in coefficient of thermal expansion from that of the bearing is small, and it is thought that the first problem mentioned above can be overcome by using this sleeve. However, this sleeve is provided only around the bearing mounting hole, and even if it is used, it is not possible to increase the rigidity of the wall, and even in this case, the wall thickness must be increased. , it is not possible to solve the second and third problems above.

The present invention has been developed in view of the above-mentioned problems.The present invention prevents the generation of looseness (gap) in the press-fitted portion of the bearing during hot operation, allows the thickness of the wall portion to be made thinner, and makes it possible to reduce the thickness of the bearing. An object of the present invention is to obtain a rotating member support structure configured such that it is possible to reduce the rotational resistance of the rotating member.

[0009]

[Means for Solving the Problems] In order to achieve the above object, a rotating member support structure for a transmission according to the present invention includes a transmission housing made by casting an aluminum material, and
The rotating member is supported by the wall portion of this housing, and this wall portion is formed by casting a flange member made of iron-based material, and the bearing attached to the inner peripheral boss portion of this flange member. The rotary member is rotatably supported via the rotary member. Note that the flange member has spline teeth on its outer periphery, and the flange member is cast through at least the portion having the spline teeth. When the rotating member has a gear portion at its end with teeth located on the side of the flange member, a ring-shaped recess is formed on the side surface of the gear portion facing the flange member on the inner diameter side of the teeth, and It is preferable that the inner circumferential boss portion of the member is formed so as to protrude into the ring-shaped recess,
Further, it is preferable that the rotary member is rotatably supported via an angular ball bearing attached to the inner circumferential boss portion.

0010

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 2 shows the overall structure of a transmission having a rotating member support structure according to the present invention, and the transmission mechanism portion of this transmission is configured as shown in FIG. Furthermore, the power transmission of this transmission is as shown in the skeleton of FIG. 4. The following description will be made with reference to these three figures.

This transmission meshes with a torque converter 5 connected to an output shaft 6 of an engine, a transmission mechanism 10 having an input shaft 11 connected to a turbine of the torque converter 5, and an output gear 12 of this transmission mechanism 10. It consists of a counter shaft 51 having a gear 52 and a differential mechanism 57 having a gear 56 that meshes with a gear 55 formed integrally with the counter shaft 51. It is located inside. The housings 1, 2, and 3 are all cast from an aluminum-based material. Note that the differential mechanism 57 is connected to left and right axle shafts 58a and 58b that extend separately into left and right sides.

The engine output is transmitted from the output shaft 6 to the input shaft 11 of the transmission mechanism 10 via the torque converter 5, and after being shifted in the transmission mechanism 10, the output gear 1
2 to the counter shaft 51 via the gear 52. Further, the signal is transmitted from the counter shaft 51 to the differential mechanism 57 via the gears 55 and 56, and the differential mechanism 57 causes the left and right axle shafts 5
It is distributed and transmitted to 8a and 58b.

The transmission mechanism 10 includes first, second and third planetary gear trains G1, G2, which are arranged in parallel on an input shaft 11.
Has G3. Each planetary gear train has first to third sun gears S1, S2, and S3 located in the center, and these first to third sun gears S1, S2, and S3.
~First to third planetary pinions P1, P2, P3 that mesh with the third sun gear and revolve around it while rotating, and first to third planetary pinions that rotatably hold this pinion and rotate at the same time as the pinion revolves. 3 carriers C1, C2, C3,
It is composed of first to third ring gears R1, R2, and R3 having internal teeth that mesh with the pinion. The first planetary gear train G1 and the second planetary gear train G2 are double pinion type planetary gear trains, and the first pinion P1 and the second pinion P2 each have two pinion gears P11, P12 and P21, as shown in FIG. , P22.

The first sun gear S1 is always connected to the input shaft 11, and the first carrier C1 is always fixed. The first ring gear R1 is connected to the second sun gear S2 via the third clutch K3, and the second sun gear S2 can be held fixed by the first brake B1. The second carrier C2 is directly connected to the third carrier C3 and also connected to the output gear 12, and the rotation of the second carrier C2 and the third carrier C3 becomes the output rotation of the transmission mechanism. The second ring gear R2 is directly connected to the third ring gear R3, and these two ring gears R2 and R3 are integrally connected to the second brake B.
2, and is detachably connected to the transmission input shaft 8a via the second clutch K2. The third sun gear S3 is connected to the input shaft 1 via the first clutch K1.
It is detachably connected to 1. In addition, the second brake B
A one-way brake B3 is arranged in parallel with the brake 2.

As described above, each element (first to third sun gears S1 to S3, first to third carriers C1 to C3, and first to third ring gears S1 to S3), input shaft 11 and output gear 12 are connected. In the connected transmission mechanism, by controlling the engagement and disengagement of the first to third clutches K1 to K3 and the first and second brakes B1 and B2, it is possible to set the gear stage and control the speed change. Specifically, as shown in Table 1 below, if the engagement/disengagement control is performed, the forward speed of 5 (1S
T, 2ND, 3RD, 4TH and 5TH) and reverse 1st speed (REV) can be set. Note that the reduction ratio (ratio) in each speed range varies depending on the number of teeth of each gear, but Table 1
An example of this ratio is shown below for reference.

[0016] In Table 1, the second brake B2 in the 1ST is shown in parentheses, but this means that the one-way brake B3 can be activated even if the second brake B2 is not engaged.
This is because power is transmitted on the driving side. That is, if the first clutch K1 is engaged, the second brake B
Even if 2 is not engaged, it is possible to transmit power on the drive side at a gear ratio of 1ST, and 1ST is set. However, power cannot be transmitted in the opposite direction to the drive side, so 1ST when the second brake B2 is not engaged is a speed stage where the engine brake is not effective, and when the second brake B2 is engaged, the engine brake is not applied. It becomes an effective speed stage.

[0017]

[Table 1]

The output gear 12 of the transmission mechanism 10 configured as described above is rotatably supported by a wall portion 20 formed in the housing 2 located at the center via an angular ball bearing 16. This support structure of the output gear 12 by the housing 2 is the structure according to the present invention, and will be explained in detail based on FIG. 1.

The wall portion 20 is made by casting a disc-shaped flange member 21 made of iron-based material when the housing 2 is cast. For this reason, the housing 2 is cast from an aluminum material, and this wall portion 20
Only the portion a (more precisely, the portion consisting of the flange member 21) is made of iron-based material. The flange member 21 has a cylindrical joint 22 on its outer periphery, and an external spline part 22a formed on the outer periphery of the joint 22.
, the flange member 21 is joined to the housing 2 by casting. By casting through the external spline portion 22a in this way, the enclosing property during casting is improved, and the flange member 21 made of iron-based material is firmly cast and joined to the housing 2 made of aluminum-based material. . Further, the inner circumferential portion of the flange member 21 is swollen into a cylindrical shape to form an inner circumferential boss portion 23.
A bearing mounting hole 23a is formed in the bearing mounting hole 23a. The inner race 16a is inserted into the bearing mounting hole 23a and is held by a retaining ring, so that the angular ball bearing 16 is mounted.

On the other hand, the output gear 12 has external teeth 13 on its outer periphery.
The gear part 13 is formed of a disc-shaped gear part 13 having a shape a formed therein, and a cylindrical shaft part 14 extending laterally in the axial direction from the inner peripheral part of the gear part 13. An internal spline 14a is formed on the inner periphery of the shaft portion 14.
The output gear 12 is connected to a second carrier C2 forming a second planetary gear train G2 via a. Shaft part 14
is the inner race 16 of the angular ball bearing 16 attached to the flange member 21 as described above.
As a result, the output gear 12 is rotatably supported by the flange member 21 (that is, the wall portion 20 of the housing 2) via the bearing 16.

Note that the lock nut 17 attached to the threaded portion 14b formed on the outer periphery of the shaft portion 14 allows
The inner race 16b is attached and held in a locked state on the shaft portion 14. However, this lock nut 17 only tightens and holds the inner race 16b, which is an integral structure having a lubricating hole 16c in the center, fixed, and this tightening does not apply a preload to the ball. That is, bearing 16
is simply attached in an assembled state with the two balls sandwiched between the outer and inner races 16a and 16b. Therefore, the friction resistance in this bearing 16 is small.

A ring-shaped recess 13a is formed on the side surface of the gear portion 13 of the output gear 12 facing the flange member 21, and the side portion of the inner peripheral boss portion 23 of the flange member 21 is inserted into this ring-shaped recess 13a. I'm getting into it. In this way, the external teeth 13a of the gear portion 13 approach the angular ball bearing 16 in the axial direction, and the external teeth 13a approach the angular ball bearing 16 in the axial direction.
The meshing point between the gear 3a and the external teeth of the gear 52 is the bearing 16.
approaches the center point B of the support action points A1 and A2 of both balls. Note that by making the flange member 21 from iron-based material with high rigidity and strength, its thickness, that is,
Since the thickness of the wall portion 20 of the housing 21 can be made thinner, the center point B is set closer to the meshing point of the external teeth 13a. Furthermore, by forming the wall portion 20 from a flange member having high rigidity and strength, the support rigidity and strength of the bearing 16 by the wall portion 20 are improved, and vibrations of the wall portion 20 can be suppressed.

The flange member 21 of this example has a cylindrical cylinder chamber 21a formed on the side opposite to the side facing the gear portion 13, and a piston is slidably slidable in the axial direction within this cylinder chamber 21a. 28 is inserted. This piston 28 is used to control the operation of the second brake B2, and when hydraulic pressure is supplied into the cylinder chamber 21a, the piston 28 that has received this hydraulic pressure presses the friction plate of the second brake B2, and the piston 28 presses the friction plate of the second brake B2. 2. Engage brake B2.

[0024]

[Effects of the Invention] As explained above, according to the present invention,
The transmission housing is made by casting an aluminum-based material, and the rotating member is supported by the walls of this housing.This wall is formed by casting a flange member made of an iron-based material. Since the rotating member is rotatably supported via a bearing attached to the inner circumferential boss portion of the flange member, both the bearing and the flange member supporting it are made of iron-based materials, and the coefficient of thermal expansion of both is low. almost equal. Therefore, it is possible to prevent play from occurring between the inner circumferential boss portion of the flange member and the bearing even when the rotating member is hot, and to reduce the meshing accuracy of the gears that constitute or are attached to this rotating member. This can prevent the increase in noise and vibration. Here, spline teeth are formed on the outer periphery of the flange member, and the flange member is cast through at least the portion having the spline teeth, so the flange member made of iron-based material is replaced with aluminum-based material. It can be firmly molded into the housing.

[0025] When the rotating member has a gear portion at its end with teeth located on the side of the flange member,
It is preferable to form a ring-shaped recess on the side surface of the gear portion facing the flange member on the inner diameter side of the teeth, and to form the inner peripheral boss portion of the flange member to protrude into the ring-shaped recess. By doing so, the meshing point of the gear can be brought closer to the center of the supporting point of the bearing. In this case, since the flange member is made of iron-based material with high rigidity and strength, its thickness, that is, the thickness of the wall of the housing, can be made thinner.
The center point B can be brought closer to the meshing point of the gears.

[0026] Furthermore, it is preferable that the rotating member is rotatably supported via an angular ball bearing attached to the inner circumferential boss portion, and in the case of an angular ball bearing, it is necessary to apply a preload at the time of installation. Since there is no friction, the friction resistance of the bearing can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a rotating member support structure according to the present invention.

FIG. 2 is a sectional view showing a transmission having the rotating member support structure described above.

FIG. 3 is a sectional view showing a transmission mechanism that constitutes the transmission.

FIG. 4 is a skeleton diagram showing a power transmission path of the transmission.

[Explanation of symbols]

1, 2, 3 Housing 5 Torque converter 10 Transmission mechanism 11 Input shaft 12 Output gear 13 Gear part 16 Angular ball bearing 17 Lock nut 20 Wall part 21 Flange member 28 Piston 57 Differential mechanism

Claims (2)

[Claims] 1. A structure in which a rotating member is supported by a wall of a transmission housing made by casting an aluminum-based material, wherein the wall has a flange member made of an iron-based material and having spline teeth on the outer periphery. The rotary member is formed by casting through at least a portion having the spline teeth, and is configured to rotatably support the rotary member through a bearing attached to an inner circumferential boss portion of the flange member. A rotating member support structure for a transmission. 2. The rotary member has a gear portion provided with teeth located on a side of the flange member at one end thereof, and faces the flange member on the inner diameter side of the teeth of the gear portion. A ring-shaped recess is formed on a side surface, and the inner peripheral boss of the flange member is formed to protrude into the ring-shaped recess, and the inner peripheral boss of the flange member is formed to protrude into the ring-shaped recess through an angular ball bearing attached to the inner peripheral boss. The rotating member support structure for a transmission according to claim 1, characterized in that the rotating member is rotatably supported.