JP2021089058A - Thrust receiving structure of rotor - Google Patents

Abstract

To provide a thrust receiving structure of a rotor capable of preventing generation of noise and vibration, and abrasion wear of a retainer by preventing falling-down of needle rollers of a thrust needle bearing by centrifugal force.SOLUTION: In a thrust receiving structure of a rotor (2) constituted by disposing a thrust needle bearing (7) and a ring plate-like shim (8) applying an axial preload to the thrust needle bearing (7) in an axial clearance between a fixed body (1) and the rotor (2) relatively rotatable to the fixed body (1) in a state of being axially kept into contact with each other, an oil groove (8a) opened to an inner peripheral surface of the shim (8) is formed on an axial end surface at a side opposite to the thrust needle bearing (7), of the shim (8), an axial oil passage (2a) and a radial oil passage (2b) linearly extended from the axial oil passage (2a) toward a radial outer part, are formed on the rotor (2), and the radial oil passage (2b) is communicated to the oil groove (8a) of the shim (8).SELECTED DRAWING: Figure 2

Description

The present invention relates to a thrust receiving structure of a rotating body on which a thrust force acts.

For example, a vehicle power transmission device is provided with a rotation shaft, gears, and the like that transmit rotational power from a drive source such as an engine to drive wheels. Here, when the gear fixed to the rotating shaft is, for example, a helical gear, an axial thrust force generated by the engagement of the helical gears acts on the rotating shaft. For this reason, thrust bearings are used to receive the thrust force acting on the rotating shaft.

As the thrust bearing, a plurality of needle-shaped rollers as rolling elements are interposed between the ring plate-shaped outer race and the inner race, and the plurality of needle-shaped rollers are equally spaced in the circumferential direction by a retainer. Thrust needle bearings constructed by holding may be used.

As a thrust receiving structure of a rotating shaft using a thrust needle bearing, a thrust needle bearing and the thrust needle bearing are provided in an axial gap between a case that is a fixed body and a rotating shaft that is a rotating body that can rotate relative to the case. In some cases, a configuration is adopted in which ring plate-shaped shims that apply preload in the axial direction are interposed in a state where they are in contact with each other in the axial direction. In such a thrust receiving structure, when the rotating shaft rotates at high speed when there is no load, the needle-shaped roller of the thrust needle bearing collapses due to the large centrifugal force acting on it, which causes abnormal noise or vibration. The retainer may wear.

Therefore, as a measure to prevent the needle-shaped rollers of the thrust needle bearing from falling over, it is conceivable to insert a spring washer with a large spring constant into the ring plate-shaped shim. However, if such a configuration is adopted, the spring washer even at low rotation speeds. Since pressure is applied to the thrust needle bearing, the life of the thrust needle bearing is shortened and friction is increased. In addition, since the number of parts increases, there is a problem that the weight of the thrust needle bearing increases and the cost increases.

By the way, in Patent Document 1, a plurality of radial oil grooves and an annular protrusions protruding in the axial direction toward the rollers of the roller bearing are provided on the side surface of the thrust washer on the bearing side for receiving the thrust force in the transmission of the vehicle. The lubrication structure of the transmission that formed the above has been proposed. According to this, lubricating oil is supplied to the radial oil groove of the thrust washer via the axial oil passage and the radial oil passage formed in the shaft, and this lubricating oil is supplied along the annular protrusion of the thrust washer. By supplying to the rollers of the roller bearing, it is possible to suppress the scattering of the lubricating oil and prevent the roller bearing from seizing.

Japanese Unexamined Patent Publication No. 2017-025985

However, even with the lubrication structure proposed in Patent Document 1, it is impossible to solve the problem that occurs in the thrust receiving structure.

The present invention has been made in view of the above problems, and an object of the present invention is to prevent the thrust needle bearing from collapsing due to the centrifugal force of the needle-shaped rollers to prevent abnormal noise, vibration, wear of the retainer, and the like. The purpose is to provide a thrust receiving structure for the body.

In order to achieve the above object, the present invention presents the thrust needle bearing (7) and the thrust needle bearing (7) in the axial gap between the fixed body (1) and the rotating body (2) that can rotate relative to the fixed body (1). It is a thrust receiving structure of the rotating body (2) formed by interposing ring plate-shaped shims (8) that apply a preload in the axial direction to the thrust needle bearing (7) in a state of being in contact with each other in the axial direction. An oil groove (8a) that opens to the inner peripheral surface of the shim (8) is formed on the axial end surface of the shim (8) opposite to the thrust needle bearing (7), and the rotating body (8a) is formed. An axial oil passage (2a) and a radial oil passage (2b) extending linearly outward from the axial oil passage (2a) are formed in 2), and the radial oil passage (2b) is formed. Is communicated with the oil groove (8a) of the shim (8).

According to the present invention, the oil flowing in the axial oil passage of the rotating shaft flows outward in the radial direction by centrifugal force, and flows from each radial oil passage into each oil groove of the shim. Then, the oil that has flowed into each oil groove is pressurized by centrifugal force to become a high pressure, so that the thrust needle bearing is pressed through the shim. Therefore, the tipping of the needle-shaped roller of the thrust needle bearing due to the centrifugal force is prevented, and abnormal noise and vibration due to the falling of the needle-shaped roller, wear of the retainer, and the like are effectively prevented.

Here, a plurality of the oil grooves (8a) are formed radially outward from the inner peripheral surface of the shim (8), and the same number of the radial oil passages (8a) as the oil grooves (8a) are formed. 2b) may be communicated with each oil groove (8a). Then, the plurality of oil grooves (8a) and the radial oil passages (2b) may be formed at equiangular pitches in the circumferential direction.

According to the above configuration, the pressing force of the oil pressurized in the plurality of oil grooves acts uniformly on the thrust needle bearing over the entire circumference, so that all the needle-shaped rollers of the thrust needle bearing are uniformly pressed. The bearing is surely prevented from falling.

Further, the oil groove (8a) is formed in the inner peripheral portion of the axial end surface of the shim (8) opposite to the thrust needle bearing (7), and the ring-shaped first one is formed over the entire circumference. It is composed of an oil groove (8a1) and a plurality of second oil grooves (8a2) extending linearly outward from the first oil groove (8a1), and the first oil groove (8a2). At least one radial oil passage (2b) may be communicated with 8a1).

According to the above configuration, it is not necessary to form the same number of radial oil passages as the second oil groove of the shim on the rotating shaft, so that the man-hours required for drilling holes in the rotating shaft can be reduced.

Further, the oil groove (8a) is formed in a ring shape over the entire circumference on the axial end surface of the shim (8) opposite to the thrust needle bearing (7), and the oil groove (8a) is formed. At least one of the radial oil passages (2b) may be communicated with each other.

According to the above configuration, the formation of oil grooves in the shim is simplified, and it is not necessary to form a large number of radial oil passages communicating with each of the plurality of oil grooves of the shim on the rotating shaft. The machining man-hours for the rotating shaft can be reduced.

According to the present invention, it is possible to prevent the thrust needle bearing from falling due to the centrifugal force of the needle-shaped roller, and to prevent the generation of abnormal noise and vibration, the wear of the retainer, and the like.

It is sectional drawing of the transmission main part for a vehicle which shows the thrust receiving structure of the rotating body which concerns on this invention. It is an enlarged detailed view of part A of FIG. It is an enlarged perspective view of part A of FIG. FIG. 2 is a cross-sectional view taken along the line BB of FIG. It is a perspective view of the shim used for the thrust receiving structure of the rotating body which concerns on this invention. It is the same figure as FIG. 4 which shows another form 1 of a shim. It is the same figure as FIG. 4 which shows another form 2 of a shim.

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

1 is a cross-sectional view of a main part of a vehicle transmission showing a thrust receiving structure of a rotating body according to the present invention, FIG. 2 is an enlarged detailed view of part A of FIG. 1, and FIG. 3 is an enlarged perspective view of part A of FIG. 4 is a sectional view taken along line BB in FIG. 2, and FIG. 5 is a perspective view of the shim.

In the vehicle transmission, as shown in FIG. 1, a rotating shaft 2 which is a rotating body is supported by a transmission case 1 which is a fixed body so as to be relatively rotatable. Specifically, the rotating shaft 2 is rotatably supported by the transmission case 1 by supporting both ends in the axial direction (both left and right ends in FIG. 1) by ball bearings 3 and needle bearings 4. .. Here, the ball bearing 3 is between the inner race (inner ring) 3a fixed to the outer circumference of the rotating shaft 2 and rotating integrally with the rotating shaft 2 and the outer race (outer ring) 3b fixed to the transmission case 1. A plurality of balls (steel balls) 3c are arranged so as to be rotatable. Further, in the needle bearing 4, a plurality of rollable needle-shaped rollers 4b are arranged between the outer circumference of the axial end portion (right end portion in FIG. 1) of the rotating shaft 2 and the outer race 4a fixed to the transmission case 1. It is composed of.

A transmission gear 5 is integrally formed in an axially intermediate portion of the rotating shaft 2 near the needle bearing 4, and another transmission gear 6 is meshed with the transmission gear 5. Further, an axial oil passage 2a is formed along the axial direction at the center of the rotating shaft 2.

By the way, when the transmission gears 5 and 6 that mesh with each other are composed of, for example, helical gears, the thrust force F in the direction of the arrow in FIG. 1 acts on the rotating shaft 2 due to the engagement between the transmission gears 5 and 6. The thrust force F is received by the thrust receiving structure according to the present invention.

That is, as shown in detail in FIG. 2, there is a thrust needle in the axial gap between the outer race 4a of the needle bearing 4 forming the fixed body together with the transmission case 1 and the transmission gear 5 integrally formed on the rotating shaft 2. A ring plate-shaped shim 8 that applies a preload in the axial direction to the bearing 7 and the thrust needle bearing 7 is interposed in a state of being in contact with each other in the axial direction.

The thrust needle bearing 7 allows rotation of the rotating shaft 2 while receiving a thrust force F acting on the rotating shaft 2, and is an axial end surface of the outer race 4a of the needle bearing 4 (left end surface in FIG. 2). A plurality of rollable needle-shaped rollers 7c are arranged between the ring-shaped outer race 7a fixed to the wheel and the ring-shaped inner race 7b fixed to the outer periphery of the rotating shaft 2, and these needle-shaped rollers 7c are arranged. Is configured by holding the retainer 7d at predetermined intervals in the circumferential direction. In the present embodiment, the outer race 7a of the thrust needle bearing 7 constitutes a fixed body together with the transmission case 1.

The shim 8 is a member that is fitted into a ring-shaped concave groove 5a formed on the axial end surface (right end surface of FIG. 2) of the transmission gear 5 and rotates integrally with the transmission gear 5 and the rotation shaft 2. On the axial end surface (left end surface in FIG. 2) opposite to the thrust needle bearing 7, a plurality of (8 in the illustrated example) oil grooves 8a opening on the inner peripheral surface of the shim 8 are arranged in the circumferential direction. They are formed radially at an equal pitch (45 ° pitch) (see FIGS. 4 and 5). Here, each oil groove 8a extends linearly outward in the radial direction from the inner peripheral surface of the shim 8, and its radial outer end is closed.

By the way, as shown in FIGS. 1 to 4, from the axial oil passage 2a formed at the center of the rotating shaft 2, the same number of radial oils (8 in the illustrated example) as the oil grooves 8a of the shim 8 are used. The roads 2b are formed radially outward in a diagonal straight line, and each radial oil passage 2b communicates with each oil groove 8a formed in the shim 8.

In a vehicle transmission having the thrust receiving structure as described above, when the rotating shaft 2 rotates, the transmission gear 5 integrally formed with the rotating shaft 2 and the transmission gear 6 meshing with the rotating shaft 2 rotate. A thrust force F in the direction shown in FIG. 1 is generated on the rotating shaft 2 by meshing the transmission gears 5 and 6 with each other. This thrust force F is received by the thrust needle bearing 7 (more specifically, the transmission case 1 finally via the thrust needle bearing 7 and the outer race 4a of the needle bearing 4) via the shim 8.

By the way, when the rotating shaft 2 rotates at a high speed (for example, 19,000 rpm) when there is no load or the like, a large centrifugal force acts on the plurality of needle-shaped rollers 7c of the thrust needle bearing 7, so that the needle-shaped rollers 7c have a large centrifugal force. As mentioned above, a fall may occur.

However, in the present embodiment, as shown in FIGS. 2 to 4, the oil flowing in the axial oil passage 2a of the rotating shaft 2 flows outward in the radial direction by centrifugal force, and each of them It flows from the radial oil passage 2b into each oil groove 8a of the shim 8. Then, since the oil flowing into each oil groove 8a is pressurized by centrifugal force to become a high pressure, the thrust needle bearing 7 is pushed through the shim 8 in the direction of the arrow shown by the pressing force f as shown in FIG. Press on. Therefore, the tipping of the needle-shaped roller 7c of the thrust needle bearing 7 due to the centrifugal force is prevented, and abnormal noise and vibration due to the falling of the needle-shaped roller 7c, wear of the retainer 7d, and the like are effectively prevented. In this case, since a plurality of (8 in the present embodiment) oil grooves 8a are formed radially in the circumferential direction at an equal angle pitch (45 ° pitch) in the shim 8, the oil grooves 8a are added. The pressing force f due to the pressed oil acts uniformly on the thrust needle bearing 7 over the entire circumference thereof. Therefore, all the needle-shaped rollers 7c of the thrust needle bearing 7 are uniformly pressed, and their fall is surely prevented. In the present embodiment, the number of the oil grooves 8a formed in the shim 8 and the radial oil passages 2b formed in the rotating shaft 2 is eight, but these oil grooves 8a and the radial oil passages 2b The number is not limited to eight and is arbitrary.

By the way, in the above embodiment, a plurality of (8 in the illustrated example) oil grooves 8a are formed on the axial end surface of the shim 8 so as to linearly extend from the inner circumference of the shim 8 in the radial direction outward. However, a configuration was adopted in which a plurality of (8) radial oil passages 2b formed on the rotating shaft 2 were communicated with each oil groove 8a of the shim 8, but the configuration as shown in FIG. 6 or FIG. 7 was adopted. You may.

That is, as shown in FIG. 6, the oil groove 8a formed in the shim 8 is formed in the inner peripheral portion of the axial end surface of the shim 8 with a ring-shaped first oil groove 8a1 formed over the entire circumference. It is composed of a plurality of second oil grooves 8a2 extending linearly outward from the first oil groove 8a1 and formed in the first oil groove 8a1 on the rotating shaft 2. At least one of the roads 2b may be communicated. According to such a configuration, it is not necessary to form the same number of radial oil passages 2b as the second oil groove 8a2 of the shim 8 on the rotating shaft 2, and the man-hours required for drilling holes in the rotating shaft 2 are reduced. be able to. Also in this case, the number of the second oil grooves 8a2 is not limited to eight and is arbitrary.

Alternatively, as shown in FIG. 7, an oil groove 8a is formed in a ring shape over the entire circumference on the axial end surface of the shim 8, and a radial oil passage 2b formed on the rotating shaft 2 is formed in the oil groove 8a. At least one may be communicated. According to such a configuration, the formation of the oil groove 8a in the shim 8 is simplified, and it is not necessary to form a large number of radial oil passages 2b in the rotating shaft 2, so that the shim 8 and the rotating shaft 2 are not formed. The processing man-hours can be reduced.

The present invention is not limited to the embodiments described above, and various modifications can be made within the scope of claims and the technical ideas described in the specification and drawings.

1 Transmission case (fixed body)
2 Rotating shaft (rotating body)
2a Axial oil passage 2b Radial oil passage 3 Ball bearing 4 Needle bearing 4a Needle bearing outer race (fixed body)
4b Needle-shaped roller of needle bearing 5,6 Speed change gear 7 Thrust needle bearing 7a Outer race of thrust needle bearing 7b Inner race of thrust needle bearing 7c Needle-shaped roller of thrust needle bearing 7d Retainer of thrust needle bearing 8 shim 8a Oil groove of shim 1st oil groove of 8a1 shim 2nd oil groove of 8a2 shim F Thrust force f Pressing pressure

Claims (5)

A ring plate-shaped shims that apply axial preload to the thrust needle bearing and the thrust needle bearing are axially abutted against each other in the axial gap between the fixed body and the rotating body that can rotate relative to the fixed body. It is a thrust receiving structure of the rotating body which is interposed in the state of being made to move.
An oil groove that opens on the inner peripheral surface of the shim is formed on the axial end surface of the shim opposite to the thrust needle bearing.
An axial oil passage and a radial oil passage extending linearly outward from the axial oil passage were formed in the rotating body, and the radial oil passage was communicated with the oil groove of the shim. The thrust receiving structure of the rotating body is characterized by this. The feature is that a plurality of the oil grooves are formed radially outward from the inner peripheral surface of the shim, and the same number of the radial oil passages as the oil grooves are communicated with each oil groove. The thrust receiving structure of the rotating body according to claim 1. The thrust receiving structure for a rotating body according to claim 2, wherein the plurality of oil grooves and the radial oil passages are formed at equal angles in the circumferential direction. The oil groove is formed from a ring-shaped first oil groove formed over the entire circumference on the inner peripheral portion of the axial end surface of the shim opposite to the thrust needle bearing, and the first oil groove. Claim 1 is composed of a plurality of second oil grooves extending linearly outward in the radial direction, and at least one of the radial oil channels is communicated with the first oil groove. The thrust receiving structure of the rotating body described in. The oil groove is formed in a ring shape over the entire circumference on the axial end surface of the shim opposite to the thrust needle bearing, and at least one radial oil passage is communicated with the oil groove. The thrust receiving structure of a rotating body according to claim 1, which is characterized.

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