JP2004360807A - Differential - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a differential capable of conducting efficiently and certainly the supply of a lubricating oil to the sliding part between a pinion shaft and a pinion and accomplishing the low cost easily. <P>SOLUTION: The differential is structured so that oil catch pockets 9 capable of reserving the lubricating oil upon capturing are provided over the whole circumference on the pinion revolutional axis side RLS of the sliding part between the pinion 7 and the pinion shaft 5. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a differential that transmits a driving force of a prime mover such as an engine or a motor to a wheel drive shaft, and in particular, lubricating oil is applied to a sliding portion between a pinion shaft and a pinion rotatably supported by the pinion shaft. The present invention relates to a differential that is suitable for efficiently supplying a material.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, in a vehicle such as a three-wheel or four-wheel vehicle, a driving force of an engine or a motor as a prime mover is input to a transmission (transmission) to control the driving force, and the controlled driving force is output from the transmission. A driving force transmission device that inputs the driving force of a prime mover to a wheel drive shaft by inputting the force from a shaft to a differential (differential device) called a differential via a propeller shaft (propulsion shaft) as necessary. Is used. The differential of such a driving force transmission device is rotatably disposed via a bearing inside a transmission transmission case as a housing in, for example, an FF type driving force transmission device.
[0003]
In a conventional differential, a pinion shaft that rotates integrally with the differential case is disposed inside the differential case, and the pinion shaft is rotatably supported by the pinion shaft. In such a differential, it is necessary to lubricate the sliding portion in order to prevent heat, abrasion, galling, seizure and the like in the sliding portion between the pinion shaft and the pinion.
[0004]
Therefore, a differential that can lubricate a sliding portion between the pinion shaft and the pinion has been proposed (for example, see Patent Document 1).
[0005]
FIGS. 3 to 5 show a conventional differential disclosed in Patent Document 1. A conventional differential 100 is a pinion that rotates integrally with the differential cases 101 and 102 inside differential cases 101 and 102 formed in two parts. A pinion 105 that meshes with a side gear 104 is rotatably supported at an end of the pinion shaft 103 located inside the differential cases 101 and 102. Oil grooves 106 are respectively provided at portions of the outer peripheral surface of the pinion shaft 103 located inside the differential cases 101 and 102 at both ends of the rotation axis RL. The oil groove 106 is formed by flattening the outer peripheral surface of the cylindrical pinion shaft 103 by cutting such as milling or plastic working by pressing.
[0006]
In addition, oil supply ports 110 and 111 that communicate the inside and outside of the differential cases 101 and 102 are provided at the seats of the pinion washers 107 on the inner surfaces of the differential cases 101 and 102, that is, at the portions of the spherical seats 108 and 109 behind the pinion washers 107. An oil passage 112 communicating with the oil groove 106 is provided.
[0007]
In the differential 100 having such a configuration, the lubricating oil supplied into the differential cases 101 and 102 through the oil supply ports 110 and 111 flows toward the spherical seats 108 and 109 by centrifugal force, and the pinion washer 107 is provided. Flows into the oil passage 112 provided in the seat portion of the motor. Since the oil passage 112 communicates with the oil groove 106 of the pinion shaft 103, the lubricating oil surely enters the oil groove 106 and lubricates the sliding portion 113 between the pinion shaft 103 and the pinion 105. ing.
[0008]
[Patent Document 1]
Japanese Patent Application Laid-Open No. 8-261313
[Problems to be solved by the invention]
However, in the above-described conventional differential 100, the oil groove 106 of the pinion shaft 105 and the differential cases 101 and 102 communicating with the oil groove 106 serve as a flow path of the lubricating oil to the sliding portion 113 between the pinion shaft 103 and the pinion 105. The oil passage 112 and the oil supply ports 110 and 111 provided in the above are required, the structure is complicated, and there has been a problem that it is not possible to meet the recent demand for cost reduction.
[0010]
In addition, in the conventional differential 100, the sliding surface 114 and the oil surface of the oil groove 106 are prevented from being cut by the edge of the boundary portion 115 between the sliding surface 114 of the pinion shaft 103 and the oil groove 106. The radius of the boundary 115 with the groove 106 is increased by cutting, grinding, barreling, or the like, so that the cost is high.
[0011]
The present invention has been made in view of these points, and it is possible to efficiently and reliably supply lubricating oil to a sliding portion between a pinion shaft and a pinion, and to easily realize cost reduction. The purpose is to provide a differential that can be used.
[0012]
[Means for Solving the Problems]
In order to achieve the above-mentioned object, the differential according to the present invention according to claim 1 is characterized in that the pinion is rotatably supported on a pinion shaft that rotates integrally with a differential case. An oil catch pocket capable of capturing and storing lubricating oil is provided over the entire circumference on the pinion revolving shaft side of the sliding portion with the shaft. By adopting such a configuration, the lubricating oil can be efficiently and reliably supplied to the sliding portion between the pinion shaft and the pinion, and the cost can be easily reduced.
[0013]
A feature of the differential according to the present invention according to claim 2 is that, in claim 1, a part of an opening end of the oil catch pocket is provided on a pinion rotation shaft side with respect to the sliding portion. By adopting such a configuration, the lubricating oil caught in the oil catch pocket and the lubricating oil stored in the oil catch pocket can efficiently flow into the sliding portion by the centrifugal force accompanying the rotation of the differential case.
[0014]
A feature of the differential according to the present invention according to claim 3 is that, in claim 1 or 2, the oil catch pocket is formed by processing the pinion shaft. And by adopting such a configuration, cost reduction can be realized more easily.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described with reference to embodiments shown in the drawings.
[0016]
1 and 2 show an embodiment of a differential according to the present invention. FIG. 1 is a sectional view of a main part, and FIG. 2 is an enlarged view of the vicinity of an oil catch pocket in FIG.
[0017]
The differential oil supply structure of the present embodiment exemplifies a structure used for an FF type driving force transmission device. Further, the differential of the present embodiment exemplifies a case using a sealed differential case.
[0018]
As shown in FIG. 1, a differential 1 of the present embodiment has a closed differential case 2. The differential case 2 is formed into two parts along a rotation axis RL of the differential case 2 into a case 3 on the right side in FIG. 1 and a cover 4 on the left side in FIG. The inside of the case 3 can be sealed by fastening the cover 4 to the case 3 with fixing bolts (not shown). The differential case 2 is arranged such that the rotation axis RL is substantially horizontal when the vehicle is mounted.
[0019]
A pinion shaft 5 that rotates integrally with the differential case 2 that is rotatable about a rotation axis RL is disposed inside the differential case 2. This pinion shaft 5 is mounted in a shaft mounting groove 6 whose both ends are recessed along the rotation axis RL from the cover 4 side inside the case 3.
[0020]
Pinions 7 are respectively supported on both end portions of the pinion shaft 5 located inside the differential case 2 so as to be rotatable on the outer peripheral surface of the pinion shaft 5 along the circumferential direction. The pinions 7 are rotatable about the rotation axis RL of the differential case 2 with rotation about the rotation axis RL of the pinion shaft 5.
[0021]
That is, the pinion 7 can revolve around the rotation axis RL of the differential case 2 and can rotate about the axis of the pinion shaft 5.
[0022]
Therefore, the revolving axis of the pinion 7 coincides with the rotation axis RL of the differential case 2, and the rotation axis of the pinion coincides with the axis of the pinion shaft 5.
[0023]
As shown in FIG. 2, an oil catch pocket 9 that can capture and store lubricating oil is provided in a rotation direction of the pinion 7 on the pinion revolution axis side RLS of the sliding portion 8 between the pinion 7 and the pinion shaft 5. That is, it is provided over the entire circumference along the rotation direction.
[0024]
The oil catch pocket 9 of this embodiment is provided on the pinion shaft 5 as shown in an enlarged and exaggerated manner in FIG.
[0025]
That is, the pinion shaft 5 of the present embodiment has a large-diameter large-diameter portion 11 on the end side where the pinion 7 is mounted, and a small-diameter portion 12 with a smaller diameter than the large-diameter portion 11 on the pinion revolution axis side RLS. It is formed in a stepped cylindrical shape. The large-diameter portion 11 and the small-diameter portion 12 are connected by a taper or the like, for example, so that the edge of the connecting portion 13 is not generated, that is, the shape of the connecting portion 13 does not suddenly change. A surface of the large-diameter portion 11 facing the inner peripheral surface of the pinion 7 is a sliding surface 14 serving as a bearing for the pinion 7. Further, the pinion 7 is arranged such that the inner end face 15 located on the pinion revolution axis side RLS is located on the pinion revolution axis side RLS from the connection portion 13 between the large diameter portion 11 and the small diameter portion 12 of the pinion shaft 5. Have been. That is, the connection portion 13 is disposed inside the inner peripheral surface of the pinion 7. The oil catch pocket 9 is formed by the space shown by cross-hatching in FIG. 2 formed between the connecting portion 13 side of the small diameter portion 12 of the pinion shaft 5 and the inner end surface 15 side of the inner peripheral surface of the pinion 7. Have been. As shown in FIG. 2, the open end of the oil catch pocket 9 of the present embodiment located on the pinion rotation axis side RLS is a pinion shaft 5 which is a pinion rotation axis when viewed from the pinion revolution axis side RLS. The inner diameter of one end of the open end is smaller than the diameter of the sliding surface 14. Therefore, a part of the opening end of the oil catch pocket 9 is provided on the pinion rotation shaft side from the sliding portion 8.
[0026]
Therefore, the oil catch pocket 9 of the present embodiment is formed by processing the pinion shaft 5.
[0027]
The size and shape of the oil catch pocket 9 may be set as required according to a design concept or the like.
[0028]
Note that the oil catch pocket 9 may be formed by processing the pinion 7. Specifically, the oil catch pocket 9 can be provided by forming an annular groove having a larger diameter than the inner peripheral surface on the inner end surface 15 side of the inner peripheral surface of the pinion 7. In this case, it is important that the connecting portion between the inner peripheral surface of the pinion 7 and the annular groove has no edge. In this case, a part of the opening end of the oil catch pocket 9 is provided on the opposite side of the sliding portion 8 from the pinion rotation shaft side. That is, the outer diameter of the opening end of the oil catch pocket 9 is provided on the opposite side of the sliding portion 8 from the pinion rotation shaft side.
[0029]
The oil catch pocket 9 may be formed by processing both the pinion shaft 5 and the pinion 7. In this case, the inner diameter of the open end of the oil catch pocket 9 is provided on the pinion rotation shaft side with respect to the sliding portion 8, and the outer diameter of the open end is provided on the opposite side to the pinion rotation shaft side.
[0030]
In the vicinity of both ends of the outer peripheral surface of the pinion shaft 5, there are formed attachment portions composed of two parallel surfaces that are substantially parallel to each other, and these attachment portions are connected to the inner surface of the shaft mounting groove 6. By inserting the pinion shaft 5 so as to face each other, the pinion shaft 5 can be prevented from rotating around its axis. The width of the shaft mounting groove 6 in the direction in which the two inner surfaces face each other is formed to be slightly larger than the interval between the attachment portions of the pinion shaft 5. As a result, the pinion shaft 5 is disposed inside the case 3 in a free state.
[0031]
The outer surface of the cover 4 of the differential case 2 shown on the left side of FIG. 1 is provided with a lubricating oil discharge hole 17 communicating the outer surface and the inner surface of the cover 4, that is, the inner and outer surfaces of the differential case 2. The lubricating oil discharge hole 17 can discharge a predetermined amount or more of the lubricating oil supplied to the inside of the differential case 2 to the outside of the differential case 2. The supply of the lubricating oil to the inside of the differential case 2 is performed through a small gap formed between the mutually facing surfaces of the axle through holes 18 of the differential case 2 and a wheel drive shaft (not shown). Has become. Further, the lubricating oil supplied to the inside of the differential case 2 slides inside the transmission by forced lubrication using an oil pump driven by the driving force of the driving force transmission device or splash lubrication using lubricating oil droplets. Lubricating oil supplied to the site is used.
[0032]
The other configuration is the same as that of the conventionally known differential, and a detailed description thereof will be omitted.
[0033]
Next, the operation of the present embodiment having the above-described configuration will be described.
[0034]
According to the differential 1 of the present embodiment, the lubricating oil supplied to the inside of the differential case 2 causes the inside of the differential case 2 to move radially outward around the rotation axis RL of the differential case 2 by centrifugal force accompanying the rotation of the differential case 2. Sprays toward and flows. At this time, part of the lubricating oil droplets adheres to the outer peripheral surface of the small diameter portion 12 of the pinion shaft 5. Then, the lubricating oil attached to the small diameter portion 12 of the pinion shaft 5 changes the surface of the small diameter portion 12 by the rotation of the pinion shaft 5 about the rotation axis RL of the differential case 2 as shown by an arrow in FIG. It moves toward the end of the pinion shaft 5 and is caught by the oil catch pocket 9. The lubricating oil trapped in the oil catch pocket 9 flows to the sliding portion 8 between the pinion shaft 5 and the pinion 7 due to the centrifugal force caused by the rotation of the differential case 2 to form a lubricating oil film on the sliding portion 8. The lubrication of the sliding part 8 is properly maintained. At this time, since the lubricating oil flowing from the oil catch pocket 9 to the sliding portion 8 flows from the entire circumference of the pinion shaft 5 to the annular sliding portion 8, the lubricating oil is uniformly distributed over the entire circumference of the sliding portion 8. Can be easily supplied.
[0035]
Therefore, according to the differential 1 of the present embodiment, the pinion shaft 5 and the pinion 7 have a simple structure in which the oil catch pocket 9 is provided at the pinion revolution axis side RLS of the sliding portion 8 between the pinion 7 and the pinion shaft 5. The lubricating oil can be efficiently, uniformly and reliably supplied to the sliding portion 8.
[0036]
In addition, the amount of the lubricating oil captured in the oil catch pocket 9 that exceeds the flow amount to the sliding portion 8 is sequentially stored in the oil catch pocket 9. When the lubricating oil stored in the oil catch pocket 9 exceeds the capacity of the space forming the oil catch pocket 9, the excess lubricating oil is moved along the inner end face 15 of the pinion 7 by the rotation of the pinion 7. It scatters as a droplet inside 2.
[0037]
Further, according to the differential 1 of the present embodiment, since a part of the opening end of the oil catch pocket 9 is provided on the pinion rotation shaft side with respect to the sliding portion 8, the lubricating oil captured by the oil catch pocket 9 and The lubricating oil stored in the oil catch pocket 9 can efficiently flow into the sliding portion by the centrifugal force caused by the rotation of the differential case 2.
[0038]
Further, according to the differential 1 of the present embodiment, since the sliding surface 14 of the large-diameter portion 11 of the pinion shaft 5 with respect to the pinion 7 is formed in an annular shape, a conventional oil groove is formed. Since it is not necessary to perform the processing and the rounding processing, the manufacturing cost can be easily reduced, so that the cost can be reduced more easily.
[0039]
The present invention can be applied not only to a differential case having a closed shape but also to a differential using a general differential case having an opening formed on an outer peripheral surface.
[0040]
Further, the present invention can be used for various types of differentials such as a differential used in a FR type driving force transmission device. The differential may have two or more configurations, such as three or four pinions.
[0041]
Further, the present invention is not limited to the above-described embodiment, and can be variously modified as needed.
[0042]
【The invention's effect】
As described above, according to the differential of the present invention, the lubricating oil can be efficiently and reliably supplied to the sliding portion between the pinion shaft and the pinion, and the cost can be easily reduced. It has an extremely excellent effect that it can be performed.
[0043]
Further, according to the differential of the present invention according to claim 2, extremely excellent effects such as the lubricating oil caught in the oil catch pocket and the lubricating oil stored in the oil catch pocket can efficiently flow into the sliding portion. To play.
[0044]
Further, according to the differential of the present invention according to the third aspect, an extremely excellent effect such as lower cost can be realized more easily.
[Brief description of the drawings]
FIG. 1 is a sectional view of a main part of an embodiment of a differential according to the present invention. FIG. 2 is an enlarged view of the vicinity of an oil catch pocket in FIG. 1. FIG. 3 is a sectional view showing an example of a conventional differential. FIG. 5 is a cross-sectional view showing details of a pinion part of FIG. 5; FIG.
DESCRIPTION OF SYMBOLS 1 Differential 2 Differential case 3 Case 4 Cover 5 Pinion shaft 7 Pinion 8 Sliding part 9 Oil catch pocket 11 Large diameter part 12 Small diameter part 13 Connecting part 14 Sliding surface 15 Inner end face RL (Def case) Rotation axis RLS Pinion revolution axis Heart side

Claims (3)

In a differential in which the pinion is rotatably supported on a pinion shaft that rotates integrally with the differential case,
An oil catch pocket capable of catching and storing lubricating oil is provided along the entire circumference on a pinion revolving shaft side of a sliding portion between the pinion and the pinion shaft, the differential being provided on a differential. The differential according to claim 1, wherein a part of an opening end of the oil catch pocket is provided on a pinion rotation shaft side with respect to the sliding portion. The differential according to claim 1, wherein the oil catch pocket is formed by processing the pinion shaft. 4.

Images