JPH061849U - Automatic transmission for automobile - Google Patents

Abstract

(57) [Summary] [Purpose] The input shaft can be supported by needle roller bearings,
Reduce the rotation resistance of the input shaft. In an automatic transmission for an automobile, an input shaft 4 is supported on a stator shaft 3 of a torque converter 2 via needle roller bearings 5 and 5. Needle roller bearing 5
A plurality of needle rollers 7 and a cage 8 made of heat-resistant synthetic resin, which rotatably holds each of the needle rollers 7 and which is guided by the needle rollers 7 and has a cutting surface at least at one circumferential position. A shell-shaped outer ring made of a thin steel plate in which the cage 8 and the group of needle rollers 7 are housed in the inner peripheral portion so as not to slip out in the axial direction and are press-fitted into the stator shaft 3 and have a quench hardened layer on the entire surface. It is composed of 9 and.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an automatic transmission for an automobile in which an input shaft is supported by a fixed portion via a so-called shell type needle roller bearing.

[0002]

[Prior art]

 In automatic transmissions for automobiles, in order to rotatably fix an input shaft to which a drive input from the engine is applied to a fixed part, a metal or the like is usually provided between the fixed part and the fixed part. Slide bearings are installed.

By the way, due to structural restrictions such as the type of automobile, conventionally, only a very narrow space can be secured between the input shaft and the fixed portion. They used bearings.

[0004]

[Problems to be solved by the device]

 However, in such a slide bearing, there was a limit in reducing the rotational resistance of the input shaft to obtain high rotation and high output with low fuel consumption, and thus the space between the input shaft and the fixed part is narrow. However, there has been a demand for a transmission that can use, for example, a rolling bearing instead of such a sliding bearing.

However, in the rolling bearing, it is sufficient to manufacture a rolling bearing having a smaller radial dimension according to the space. However, the operating environment of the rolling bearing in the transmission is exposed to the lubricating oil which is high in temperature. In addition, since it is severe that high pressure is applied through this lubricating oil, it is necessary to devise a device to prevent it from becoming unusable by early use, and this device has been difficult so far. Moreover, its practical application has not been successful.

The present invention was devised to solve such a problem, and an object thereof is to enable the input shaft to be supported by a needle roller bearing and to reduce the rotational resistance of the input shaft.

[0007]

[Means for Solving the Problems]

 The present invention has the following configuration in order to achieve such an object.

In the automobile automatic transmission of the present invention, the input shaft of the automatic transmission is supported by the fixed portion via the needle roller bearing, and the needle roller bearing includes a plurality of needle rollers. Needle roller A cage made of a heat-resistant synthetic resin, which holds each of them rotatably and is guided by the needle roller to have a cut surface at least at one position in the circumferential direction, and the cage and the group of needle rollers. It is characterized in that it is composed of a shell-shaped outer ring made of a thin steel plate that is housed in the inner peripheral part so as not to slip out in the axial direction, is press-fitted into the fixed part, and has a quench hardening layer on the entire surface.

[0009]

[Action]

 In the needle roller bearing, the shell-shaped outer ring is press-fitted into the fixed portion of the automatic transmission, so that it is immovable in the axial direction even when subjected to high pressure. Moreover, since the cage is made of heat-resistant synthetic resin, it can prevent expansion and deformation in a high temperature environment and can be made lightweight. Due to such needle roller bearings, it can be used in the part that supports the input shaft of an automatic transmission, and the rotational resistance of the input shaft can be reduced. In addition, since the shell-shaped outer ring made of thin steel sheet has a quench-hardened layer on the entire surface, there is no direction when assembling and work efficiency is improved. Further, since the cage is also divided into one part, it can be assembled to the shell-shaped outer ring that has been hardened.

[0010]

【Example】

 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

1 to 5 show an embodiment of the present invention. In the automatic transmission shown in the figure, 1 is a housing, 2 is a torque converter, 3 is a stator shaft of the torque converter 2 (corresponding to a fixed portion in the claims), 4 is an input shaft, and 4 is an input shaft. Is supported via two needle roller bearings 5 and 5. In the present embodiment, the needle roller bearing 5 is also used for the supporting portion of the reverse clutch 6 with respect to the stator shaft 3.

The needle roller bearing 5 includes a plurality of needle rollers 7, a cage 8 made of a heat-resistant resin that rotatably holds the needle rollers 7 and is guided by the needle rollers 7 to rotate. A cage 8 and a group of needle rollers 7 are housed in the inner peripheral portion of the stator shaft 3 such that they cannot be slid out in the axial direction and are press-fitted into the stator shaft 3. In this needle roller bearing 5, the needle roller 7 has a diameter of 1 mm and the cage 8 has a wall thickness of 0. The thickness of the shell-shaped outer ring 9 is set to 7 mm and the thickness of the shell-shaped outer ring 9 is set to 0.5 mm, and the radial thickness L in the assembled state is set to 1.5 to 2.0 mm, for example.

The cage 8 is provided with pockets 10 for accommodating the needle rollers 7 at several circumferential positions thereof, and facilitates shaft insertion on the inner peripheral surfaces at both ends in the axial direction. Taper-shaped guide surfaces 11, 11. In addition, a recess (reference numeral omitted) is provided at an axial intermediate portion of two surfaces facing each other in the circumferential direction in the pocket 10 in order to reduce the weight and the contact area with the needle roller 7, and the pocket 10 has a recess. Two surfaces facing each other in the circumferential direction are formed into tapered surfaces 12, 12. The cage 8 is separated at one location on its circumference (column between the adjacent pockets 10), and the projection 13 provided on one of the separation surfaces and the recess 14 provided on the other side are fitted together. It is designed to be combined by combining. The shape of the unevenness is not limited to the one shown in the figure, and various shapes such as a round shape are conceivable.

The shell-shaped outer ring 9 is provided with flanges 15 and 16 projecting inward in the radial direction at both ends in the axial direction, and the retainer 8 is rotatable on the inner peripheral portion thereof so that it cannot be pulled out in the axial direction. It will be stored like.

By the way, the cage 8 is made of synthetic resin having high strength and high heat resistance so that expansion and deformation are hard to occur, for example, 46 nylon, PES (polyether sulfone), PPS (polyphenylene sulfide) and the like. It is manufactured. Specifically, as shown in FIG. 5, by arranging a plurality of rod-shaped molds B having a projection C for forming a pocket radially around the cylindrical mold A, the cylindrical mold A Molding is performed by injecting the above-mentioned synthetic resin into a cavity D formed of an annular space formed between the outer peripheral surface of the mold A and the inner end surfaces of the rod-shaped molds B. The retainer 8 is formed so as to form a substantially perfect circle when it is not connected, but in addition to this, for example, when it is not connected, the retainer 8 is formed in a C-shape so that the split portion spreads apart. I don't mind.

The shell-shaped outer ring 9 is obtained by, for example, deep-drawing a substrate made of a thin steel plate into a cylindrical shape with a bottom using a cylindrical mold, then punching the bottom of this processed product, and finally processing. It is manufactured by making the opening side of the object thin and bending this thin portion inward in the radial direction. After this manufacturing, the entire surface is hardened by carburizing.

In the needle roller bearing 5 of this embodiment, since the shell-shaped outer ring 9 is hardened after being molded and then the cage 8 is assembled in the cage-shaped outer ring 9, the cage 8 is not assembled. It has a split structure. When the cage 8 is assembled to the cured shell-shaped outer ring 9, the diameter of the cage 8 is reduced by shrinking one end of the cage 8 that separates into the inner diameter side of the other end. The outer ring 9 is inserted into the inner peripheral portion of the shell-shaped outer ring 9 in a state of being smaller than the inner diameter dimension of the one flange 15 of the outer ring 9. In this way, the cage 8 put in the shell-shaped outer ring 9 expands by its own elastic restoring force so that the diameter size returns to the size before the assembling, so that the cage 8 comes off from the shell-shaped outer ring 9. It will not come out. Further, the elastic return force due to the bulging of the retainer 8 itself floats up from the input shaft 4 into which the inner peripheral surface of the retainer 8 is inserted, and is not in contact with the outer peripheral surface of the input shaft 4. To help. Moreover, when the cage 8 floats, the tapered surfaces 12, 12 of the pocket 10 of the cage 8 are pressed against the needle rollers 7 and the expansion of the cage 8 is limited, so that the outer peripheral surface of the cage 8 is It is not in contact with the inner peripheral surface of the shell-shaped outer ring 9. Therefore, the cage 8 floats between the shell-shaped outer ring 9 and the input shaft 4 and is guided by the needle rollers 7 to rotate.

When such a needle roller bearing 5 is interposed between the stator shaft 3 and the input shaft 4 of the automatic transmission, the shell-shaped outer ring 9 of the needle roller bearing 5 is attached to the inner peripheral surface of the stator shaft 3. By press-fitting into the shaft, it becomes immovable in the axial direction even if high pressure is applied through the internal lubricating oil. In this press-fitting work, since the flanges 15 and 16 at both axial ends of the shell-shaped outer ring 5 are both hardened, the flanges 15 and 16 may be deformed by the built-in pressing force regardless of which direction they are installed. Absent. Also, when the input shaft 4 is inserted into the inner peripheral portion of the needle roller bearing 5 mounted on the stator shaft 3, the tapered guide surfaces 11, 11 on the inner peripheral surfaces of both axial ends of the cage 8 are used. While being guided, the elastic return force of the cage 8 pushes the needle roller group 7 outward in the radial direction, so that the input shaft 4 can be easily inserted. Further, since the cage 8 is made of heat-resistant synthetic resin, it does not have to expand or deform even in an environment where high temperature lubricating oil comes into contact, and the cage 8 can be used with respect to the shell-shaped outer ring 9 and the input shaft 4. It is kept almost untouched.

If such a needle roller bearing 5 is interposed between the stator shaft 3 and the input shaft 4 of the automatic transmission, the rotation resistance of the input shaft 4 will be reduced when the conventional slide bearing is used. The power transmission efficiency of the automatic transmission is improved.

The present invention is not limited to the needle roller bearing 5 in the above embodiment. For example, a needle roller bearing using a cage having a non-separated structure may be used. In this case, as the shell-shaped outer ring, the flange at one end in the axial direction may be bent after the non-separable cage is assembled.

[0021]

[Effect of device]

 As described above, according to the present invention, the shell-shaped outer ring of the needle roller bearing is axially immovable so that it can be press-fitted into the fixed portion of the automatic transmission, and the cage is made of heat-resistant resin to prevent expansion and expansion in high-temperature environments. It is designed to prevent deformation and to be lightweight. Such needle roller bearings can be used for supporting the input shaft of an automatic transmission, and as a result, the rotational resistance of the input shaft can be reduced. Therefore, the power transmission efficiency of the automatic transmission is improved, which leads to lower fuel consumption and higher rotation and output.

[Brief description of drawings]

FIG. 1 is a partially broken sectional view of an embodiment of an automatic transmission for an automobile of the present invention.

FIG. 2 is a vertical cross-sectional view of the upper half of the needle roller bearing.

FIG. 3 is a perspective view of a cage of the needle roller bearing.

FIG. 4 is a sectional view taken along line (4)-(4) of FIG.

FIG. 5 is an explanatory view showing a manufacturing state of a cage.

[Explanation of symbols]

 3 Stator shaft 4 Input shaft 5 Needle roller bearing 7 Needle roller 8 Cage 9 Shell outer ring

Claims (1)

[Scope of utility model registration request] 1. An input shaft of an automatic transmission is supported by a fixed portion via needle roller bearings, and the needle roller bearings rotatably hold a plurality of needle rollers and individual needle rollers. And is guided by the needle rollers to rotate in at least the circumferential direction 1
A cage made of heat-resistant synthetic resin having a cut surface at a place, and the cage and the needle roller group are housed in the inner peripheral part so as not to slip out in the axial direction, press-fitted into the fixed part, and baked on the entire surface. An automatic transmission for an automobile, comprising: a shell-shaped outer ring made of a thin steel plate having an insertion hardening layer.