JPH0635726U - Lubrication structure of differential gear - Google Patents

Abstract

(57) [Summary] [Purpose] The inner peripheral surface of the bearing hole formed in the differential case,
Lubrication of the annular gap between the bearing shaft and the outer peripheral surface of the gear shaft, which is fitted in the bearing hole, can be sufficiently performed by a simple configuration without supplying the lubricating oil by the forced lubrication means. [Structure] A gear shaft 16 of a differential side gear 15 is supported in a bearing hole 11 formed in a differential case 6. The gear body 18 is attached to one end 17 of the gear shaft 16, and the surface of the gear body 18 on the side of the bearing hole 11 is brought into sliding contact with the inner surface 26 of the differential case 6. A first oil groove 30 is formed on the inner peripheral surface of the bearing hole 11 so that one end 17 is opened toward the outside of the side portion of the differential case 6 and the other end is extended toward the inside of the differential case 6 above. One end 17 communicates with the inner end of the first oil groove 30 on the inner side of the diff case 6, and the other end has a second oil groove 31 that opens outward in the radial direction of the gear body 18 and has a second oil groove 31.
Is formed on the inner surface 26.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a lubricating structure for a differential device provided in an automobile.

[0002]

[Prior art]

 Conventionally, there is a differential device disclosed in Japanese Utility Model Laid-Open No. 61-28944. According to this, the bearing hole is formed in the side portion of the differential case on the axis passing through the rotation center of the differential case. Further, a gear shaft in which a differential side gear disposed on the shaft center is rotatably fitted in the bearing hole, and a diameter larger than the gear shaft, which is attached to one end of the gear shaft and is installed in the differential case. The gear body is housed, and the surface of the gear body on the bearing hole side is slidably contacted with the inner surface of the differential case. In the above case, generally, the annular gap between the inner peripheral surface of the bearing hole and the outer peripheral surface of the gear shaft and the tooth portion of the differential side gear are each lubricated with lubricating oil.

[0003]

[Problems to be solved by the device]

 By the way, in the above-mentioned conventional structure, since the inner surface of the differential case and the surface of the gear body on the gear shaft side are in sliding contact with each other, a large amount of lubricating oil cannot pass through this sliding contact portion. Therefore, the lubricating oil that has entered the annular gap is blocked by the sliding contact portion and stays there, which may result in insufficient lubrication in the annular gap such that the lubricating oil becomes hot. Therefore, conventionally, there has been a method in which a large amount of lubricating oil is supplied to the annular gap by a large amount of lubricating oil so as to ensure a predetermined lubrication. There is a problem that the configuration of the moving device becomes complicated.

[0004]

[The purpose of the device]

 The present invention has been made in view of the above circumstances, and the ring gap between the inner peripheral surface of the bearing hole formed in the differential case and the outer peripheral surface of the gear shaft fitted in the bearing hole is determined. The purpose of the present invention is to allow sufficient lubrication with a simple structure, without relying on the supply of lubricating oil by forced lubrication means.

[0005]

[Means for Solving the Problems]

 The feature of the present invention for achieving the above-mentioned object is that the gear shaft of the differential side gear is supported in the bearing hole formed in the differential case, the gear body is attached to one end of the gear shaft, and In a differential device in which the surface on the bearing hole side is in sliding contact with the inner surface of the differential case, one end is opened toward the outside of the side of the differential case, and the other end is the same as the first oil groove extending toward the inside of the differential case. Is formed on the inner peripheral surface of the bearing hole, one end communicates with the inner end of the first oil groove on the inside of the differential case, and the other end opens radially outward of the gear body into the differential case. Two oil grooves are formed on the inner surface of the differential case.

[0006]

[Work]

 The operation of the above configuration is as follows. The gear shaft 16 of the differential side gear 15 is supported in a bearing hole 11 formed in the differential case 6, a gear body 18 is attached to one end 17 of the gear shaft 16, and the surface of the gear body 18 on the bearing hole 11 side is attached. In the differential gear 1 slidably contacting the inner surface 26 of the differential case 6, one end 17 is opened toward the outside of the side of the differential case 6, and the other end is extended toward the inside of the differential case 6 as above. The groove 30 is formed on the inner peripheral surface of the bearing hole 11, one end 17 communicates with the inner end of the first oil groove 30 on the inner side of the differential case 6, and the other end faces outward in the radial direction of the gear body 18. A second oil groove 31 opening inside the differential case 6 is formed on the inner surface 26 of the differential case 6.

Therefore, when the differential case 6 is rotated around the shaft center 9 by receiving power from the drive side, the lubricating oil 38 in the second oil groove 31 is centrifugally exerted by the lubricating oil 38 in the second oil groove 31. Is discharged outward from the gear body 18 in the radial direction (arrow B in FIG. 1). With the discharge of the lubricating oil 38 from the inside of the second oil groove 31, the lubricating oil 38 in the first oil groove 30 formed on the inner peripheral surface of the bearing hole 11 is transferred to the side of the second oil groove 31. Is aspirated (arrow C in FIG. 1). Therefore, the lubricating oil 38 is prevented from stagnating in the annular gap between the inner peripheral surface of the bearing hole 11 and the outer peripheral surface of the gear shaft 16 fitted in the bearing hole 11. The above-mentioned lubrication is achieved by simply providing the first oil groove 30 and the second oil groove 31, so that the conventional forced lubrication means for supplying a large amount of the lubricating oil 38 is unnecessary. Is.

[0008]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings. In the figure, reference numeral 1 is a differential gear for an automobile, and this differential gear 1 has a differential carrier 2 supported by a vehicle body. Circular openings 3 are formed on the left and right sides of the differential carrier 2 coaxially with each other, and one end of an axle tube 4 is fitted and fixed in each opening 3, and the other end of each axle tube 4 is outside. Wheels are respectively supported at the other ends of the wheels.

A differential case 6 is housed in the differential carrier 2. Cylindrical bosses 7 are provided on the left and right sides of the differential case 6 coaxially with each other, and the bosses 7 are fitted in the openings 3 coaxially with the openings 3. The bosses 7 are supported on the inner peripheral surface of the opening 3 by bearings 8, respectively, so that the differential case 6 is rotatable about the shaft center 9 of the bearings 8 and 8 with respect to the differential carrier 2. The shaft center 9 is supported and serves as the center of rotation of the differential case 6. A ring gear 10 is attached to the outer surface of the differential case 6 coaxially with the shaft center 9. A circular bearing hole 11 is formed on each of the bosses 7 on the axis 9.

A pinion shaft 12 having an axis perpendicular to the axis 9 is attached to the differential case 6. A pair of pinion gears 13, 13 are rotatably supported on the pinion shaft 12, respectively.

A pair of differential side gears 15, 15 are arranged on the shaft center 9. Each differential gear 15 has a gear shaft 16 which is rotatably fitted in the bearing hole 11 and is supported on the inner peripheral surface of the bearing hole 11. One end 17 of the gear shaft 16 extends into the differential case 6 to form a spline shaft, and a gear main body 18 is attached to the one end 17 and the gear main body 18 is housed in the differential case 6. Further, one end of an axle 19 is coaxially integrally formed with the other end of the gear shaft 16, and the other end of the axle 19 extends outward in the axle tube 4 and is connected to the wheel.

The gear main body 18 has a boss portion 21 splined to one end 17 of the gear shaft 16, a tooth portion 22 integrally formed at an end of the boss portion 21 on the pinion gear 13 side, and a boss portion 21 of the boss portion 21. It is composed of an annular washer 23 fitted on the middle part in the axial direction. The boss portion 21 has a larger diameter than the gear shaft 16, and the tooth portion 22 has a larger diameter than the boss portion 21. The tooth portion 22 meshes with the pinion gears 13, 13. Furthermore, a large number of small holes 24 are formed in the washer 23.

An annular space 27 is provided on the shaft center 9 between the end surface of the boss portion 21 on the bearing hole 11 side and the inner surface 26 of the differential case 6. A circular hole 28 is formed in the differential case 6 coaxially with the bearing hole 11 so as to be continuous with the bearing hole 11. The inner peripheral surface of the circular hole 28 constitutes a part of the inner surface 26 of the differential case 6. . Then, the boss portion 21 is fitted into the circular hole 28, and the outer peripheral surface of the boss portion 21 which is the surface of the gear body 18 on the bearing hole 11 side is slidably contacted with the inner peripheral surface of the circular hole 28. There is.

The washer 23 is slidably joined to the surface of the tooth portion 22 on the bearing hole 11 side, and the surface of the washer 23 on the bearing hole 11 side is slidably contacted with the inner surface 26 of the differential case 6. There is.

A pair of first oil grooves 30, 30 are formed on the inner peripheral surface of each of the support holes 11, and the first oil grooves 30, 30 are provided at symmetrical positions in the radial direction of the support hole 11. There is. One end of each of the first oil grooves 30 is open toward the outside of the side portion of the differential case 6, and the other end is extended toward the inside of the differential case 6 and is open to the annular space 27.

A second oil groove 31 is formed on the inner surface 26 of the differential case 6 with which the surface of the gear body 18 on the bearing hole 11 side slides. More specifically, the second oil groove 31 is formed on the inner surface 26 of the differential case 6 facing the washer 23 and the axial groove 32 formed on the inner peripheral surface of the circular hole 28 in parallel with the shaft center 9. And the radial groove 33 to be formed. The axial grooves 32 and the radial grooves 33 are connected at one end to each other. The other end of the axial groove 32 communicates with the first oil groove 30 through the annular space 27, and the other end of the radial groove 33 is directed radially outward of the gear body 18 inside the differential case 6. It is open to.

A first baffle plate 35 and a second baffle plate 36 that cover the boss portion 7 and the bearing 8 of the differential case 6 from the outside are mounted in the opening 3 and the axle tube 4. Further, in the opening 3, one end of a supply pipe 39 of the lubricating oil 38 is inserted into a space 37 surrounded by the boss portion 7, the bearing 8 and the first baffle plate 35, and one end of the supply pipe 39 is the above-mentioned. It opens toward the first oil groove 30.

When the differential device 1 is operated by the traveling of the automobile, the ring gear 10 receives power from the engine side and rotates about the shaft center 9, and together with this, the differential case 6, the pinion shaft 12, and each pinion gear 13 are rotated. Rotates around the axis 9. Then, the respective diff side gears 15 meshing with the respective pinion gears 13 are rotated about the same shaft center 9, and the torques are substantially evenly distributed to the left and right wheels via the axles 19, respectively.

As the vehicle runs, the lubricating oil 38 discharged from the supply pipe 39 is supplied into the first oil groove 30 (arrow A in FIG. 1). Further, a part of this lubricating oil 38 lubricates the bearing 8. The first baffle plate 35 and the second baffle plate 36 prevent a part of the lubricating oil 38 from passing through the axle tube 4 toward the wheel.

When the differential case 6 rotates about the shaft center 9 as described above, the lubricating oil 38 in the second oil groove 31 is centrifugally moved from the inside of the second oil groove 31 into the gear main body 18. Is discharged radially outward (arrow B in FIG. 1). Then, as the lubricating oil 38 is discharged from the inside of the second oil groove 31, the lubricating oil 38 inside the first oil groove 30 formed on the inner peripheral surface of the bearing hole 11 is transferred to the side of the second oil groove 31. Is aspirated (arrow C in FIG. 1). Therefore, the lubricating oil 38 is prevented from stagnating in the annular gap between the inner peripheral surface of the bearing hole 11 and the outer peripheral surface of the gear shaft 16, and the lubrication in the annular gap is favorably performed.

The lubricating oil 38 discharged from the second oil groove 31 into the differential case 6 lubricates the pinion shaft 12 and the pinion gear 13 and the meshing portion between the pinion gear 13 and the differential side gear 15, and then the differential case 6 is fed into the differential carrier 2 through the opening 40 (arrow D in FIG. 1), and this lubricating oil 38 is forcibly returned to the supply pipe 39 side by a hydraulic pump or the like. Repeated.

[0022]

[Effect of device]

 According to this invention, the gear shaft of the differential side gear is supported in the bearing hole formed in the differential case, the gear body is attached to one end of the gear shaft, and the surface of the gear body on the bearing hole side is the inner surface of the differential case. In the slidingly contacted differential device, one end is opened toward the outside of the side of the differential case, and the other end is provided with a first oil groove extending toward the inside of the differential case on the inner peripheral surface of the bearing hole. A second oil groove is formed and has one end communicating with the inner end of the first oil groove on the inner side of the diff case and the other end opening outward in the radial direction of the gear body to the inside of the diff case. Is formed on the above inner surface.

Therefore, when the differential case rotates about the shaft center, the centrifugal force of the lubricating oil in the second oil groove causes the lubricating oil to be discharged from the second oil groove to the outside in the radial direction of the gear body. Be done. Then, with the discharge of the lubricating oil from the second oil groove, the lubricating oil in the first oil groove formed on the inner peripheral surface of the bearing hole is sucked toward the second oil groove. Therefore, it is possible to prevent the lubricating oil from stagnating in the annular gap between the inner peripheral surface of the bearing hole and the outer peripheral surface of the gear shaft fitted in the bearing hole, and the lubrication in the annular gap can be satisfactorily performed. Will be seen.

The above-mentioned lubrication is achieved simply by providing the first oil groove and the second oil groove, and the conventional forced lubrication means for supplying a large amount of lubricating oil is unnecessary. Is. Therefore, the lubrication for the annular gap can be obtained with a simple structure.

[Brief description of drawings]

FIG. 1 is a plan sectional view of a differential device.

FIG. 2 is a sectional view taken along the line 2-2 of FIG.

3 is a sectional view taken along the line 3-3 of FIG.

[Explanation of symbols]

 1 Differential device 6 Differential case 9 Shaft center 11 Bearing hole 15 Differential side gear 16 Gear shaft 18 Gear body 26 Inner surface 30 First oil groove 31 Second oil groove 38 Lubricating oil 39 Supply pipe

Claims (1)

[Scope of utility model registration request] 1. A gear in which a bearing hole is formed in a side portion of the differential case on an axis passing through the center of rotation of the differential case, and a differential side gear disposed on the same axis is rotatably fitted in the bearing hole. A shaft, and a gear main body having a diameter larger than that of the gear shaft and attached to one end of the gear shaft and accommodated in the differential case. The surface of the gear main body on the bearing hole side is the inner surface of the differential case. In the differential device in sliding contact with the differential case, a first oil groove is formed on the inner peripheral surface of the bearing hole, the first oil groove having one end open toward the outside of the side of the differential case and the other end extending toward the inside of the differential case. And a second oil groove, one end of which communicates with the inner end of the first oil groove on the inner side of the diff case, and the other end of which opens radially outward of the gear body to the inside of the diff case. The lubrication structure of the differential gear formed on the.