JP2004211769A - Differential - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a differential capable of accurately obtaining a small gap in low costs in order to effectively supply a lubricating oil into a differential case. <P>SOLUTION: A cylindrical projected portion 27 is protrusively arranged on an end face of a first bearing mounting portion 25 at a differential case 3 side so that at least a part of a tip face 27a of the cylindrical projected portion is opposite to a tip face 19a of an oil capturing rib 19. A tip face 19a of the projected portion 19 is formed to locate at a plain surface flush with a mating face 28 between a first case 22 and a second case 23. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a differential for transmitting a driving force of a prime mover such as an engine or a motor to a wheel drive shaft, and more particularly to a differential suitable for reliably supplying lubricating oil to the inside of a differential case.
[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. In such a differential, a differential gear is provided inside the differential case, and lubricating oil is supplied to the inside of the differential case to prevent heat and abrasion of the sliding part inside the differential case. Need to be lubricated. Therefore, a differential that can supply lubricating oil to the inside of a differential case has been proposed (for example, see Patent Document 1).
[0003]
FIG. 3 shows a differential disclosed in Patent Literature 1. In this conventional differential 101, a differential case 103 includes a first bearing (tapered roller bearing) 104 and a second bearing ( A tapered roller bearing (105) is provided so as to be rotatably supported, and a differential gear (106) is provided in the differential case (103). The outer ring of the first bearing 104 is mounted on a first bearing mounting portion 108 which is recessed on the end surface of the first case 107 of the transmission case 102 on the differential case 103 side, and the outer ring of the second bearing 105 is The transmission case 102 is mounted on a second bearing mounting portion 110 that is recessed on the end surface of the second case 109 on the differential case 103 side.
[0004]
A retainer 111 is mounted on a surface of the first bearing mounting portion 108 of the first case 107 opposite to the differential case 103, and the retainer 111 seals a space between one of the wheel drive shafts (not shown). The first seal 112 is mounted. On the right side of the second bearing mounting portion 110, a second seal 113 for sealing between the second bearing mounting portion 110 and the other wheel drive shaft (not shown) is mounted.
[0005]
The first bearing mounting portion 108 has a lubricating oil guide hole 114 formed therein. A guide groove 115 communicating with the guide hole 114 is formed on the inner end surface of the retainer 111. As a result, the lubricating oil in the transmission case 102 is guided from the guide hole 114 to the guide groove 115 and flows into the first space 116 between the first bearing 104 and the first seal 112 in the retainer 111, and the differential case 103 After the first seal 112 and the first bearing 104 are lubricated at the time of the rotation, the gas passes through the first bearing 104 and flows out to the differential case 103 side.
[0006]
The differential case 103 has an annular cylindrical oil catching rib 117 formed on the outer peripheral surface on the left end side along the rotation axis. The inner diameter of the inner peripheral wall of the oil catch rib 117 is slightly larger than the outer diameter of the first bearing 104. An annular recess 118 having a depth substantially parallel to the rotation axis of the differential case 103 is formed inside the oil catching rib 117. A plurality of lubricating oil supply holes (only one is shown in FIG. 3) 119 communicating between the inside and the outside are provided.
[0007]
According to the conventional differential 101 having such a configuration, as shown in FIG. 4, when the differential case 103 rotates, the lubricating oil is supplied by the inner peripheral wall of the oil capturing rib 117 as shown by the arrow in FIG. After being caught, it gathers at the bottom of the concave portion 118 formed inside the oil capturing rib 117, and then is supplied into the differential case 103 through the lubricating oil supply hole 119 formed at the bottom of the concave portion 118. , For lubricating the sliding portion of the differential gear 106.
[0008]
[Patent Document 1]
Japanese Patent No. 2897250
[Problems to be solved by the invention]
However, the above-described conventional differential 101 has a problem that the lubricating oil cannot be efficiently supplied to the inside of the differential case 103.
[0010]
That is, as shown in FIG. 4, an end surface 108 a of the first bearing mounting portion 108 of the first case 107 on which the outer ring of the first bearing 104 is mounted is located on the differential case 103 side shown on the right side of FIG. It is formed in such a manner that a tip end surface 117a of a cylindrical oil catching rib 117 formed on an outer peripheral surface is opposed to the tip end surface 117a in a non-contact state. Therefore, in consideration of manufacturing variations and assembly variations of the transmission case 102 and the differential case 103, the gap g between the end face 108a of the first bearing mounting portion 108 and the tip end face 117a of the oil catching rib 117 must be increased. I can't get it. As a result, as shown by the arrow in FIG. 4, the lubricating oil to be supplied to the inside of the differential case 103 through the lubricating oil supply hole 119 formed at the bottom of the concave portion 118 by being captured by the oil capturing rib 117. There is a problem that a large amount of the lubricating oil escapes from the gap g due to the centrifugal force, and the lubricating oil cannot be efficiently supplied to the inside of the differential case 103.
[0011]
Efficiently supplying the lubricating oil into the differential case 103 is particularly important when the differential case 103 is formed in a closed state.
[0012]
Further, in the conventional differential 101, when the first bearing 104 and the lubricating oil supply hole 119 are separated from each other due to design reasons or the like, the end face 108a of the first bearing mounting portion 108 and the oil catching rib 117 The gap g between the tip surface 117a and the tip surface 117a becomes larger, and a part of the lubricating oil to be captured by the oil capturing rib 117 and supplied to the inside of the differential case 103 through the lubricating oil supply hole 119 is removed by centrifugal force. There is also a problem in that the amount of oil that escapes from the g increases and lubricating oil cannot be efficiently supplied to the inside of the differential case 103.
[0013]
Therefore, there is a demand for a differential that can accurately and inexpensively obtain a small gap for efficiently supplying the lubricating oil to the inside of the differential case.
[0014]
The present invention has been made in view of such a point, and an object of the present invention is to provide a differential that can accurately and inexpensively obtain a small gap for efficiently supplying lubricating oil to the inside of a differential case. .
[0015]
[Means for Solving the Problems]
In order to achieve the above-mentioned object, a differential feature of the present invention according to claim 1 of the present invention has a housing and a differential case disposed in the housing via a bearing, wherein the housing is A first case including a first bearing mounting portion to which an outer ring of a first bearing rotatably supports one end of the differential case along a rotation axis; and a second end of the differential case in which the differential case is stored. And a second case provided with a second bearing mounting portion to which an outer ring of a second bearing rotatably supports the differential case, wherein the differential case has a differential gear disposed therein and rotates the differential case. A lubricating oil formed so as to communicate between the inside and the outside of the differential case with an oil catching rib protruding in a cylindrical shape about the axis and a concave portion formed inside the oil catching rib; In a differential in which a supply hole is formed on the outer peripheral surface on the first case side, a cylindrical convex portion protrudes from an end surface on the differential case side of the first bearing mounting portion, and at least a distal end surface of the convex portion is provided. A part is formed so as to face the tip surface of the oil catching rib, and the tip surface of the projection is formed so as to be located on the same plane as the mating surface of the first case with the second case. It is in that being. By employing such a configuration, a small gap for efficiently supplying the lubricating oil to the inside of the differential case can be obtained accurately and at low cost.
[0016]
Further, a feature of the differential of the present invention according to claim 2 is that, in claim 1, the front end surface of the convex portion and the mating surface of the first case with the second case are formed by the same processing. On the point. And by adopting such a configuration, it is possible to simultaneously process the tip surface of the cylindrical convex portion and the mating surface, so that a small gap for efficiently supplying the lubricating oil to the inside of the differential case is provided. It can be obtained more accurately and at lower cost.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described with reference to embodiments shown in the drawings.
[0018]
1 and 2 show an embodiment of a differential according to the present invention. FIG. 1 is a sectional view showing a main part, and FIG. 2 is a partially enlarged view of the main part in FIG.
[0019]
The differential of the present embodiment exemplifies the differential used in the FF type driving force transmission device. Further, the differential of the present embodiment exemplifies a case using a sealed differential case.
[0020]
As shown in FIG. 1, in a differential 1 of the present embodiment, a differential case 3 is rotatably disposed by a first bearing 4 and a second bearing 5 inside a transmission case 2 as a housing. These bearings 4 and 5 can be selected from various types of bearings as required according to a design concept or the like. In this embodiment, a tapered roller bearing is used. Further, inside the differential case 3, as is conventionally known, a plurality of pinions (pinion gears) 7 rotatably disposed on one or more pinion shafts 6 and a pair of left and right side gears 8 with which the pinions 7 mesh. A differential gear 9 is provided.
[0021]
The differential case 3 of the present embodiment is formed into two parts along a rotation axis RL into a cover 11 shown on the left side in FIG. 1 and a case 12 shown on the right side in FIG. By fixing the cover 11 to the case 12 by means of one (only one is shown) 13, the interior can be sealed and integrated.
The differential case 3 has a large diameter at the center along the rotation axis RL and small diameters at both ends. Further, at a connection portion between the cover 11 and the case 12 of the differential case 3, a ring gear 14 is fixed to the outer side surface of the cover 11 shown on the left side in FIG. It should be noted that a known fastening member such as a rivet (not shown) may be used instead of the differential fixing bolt 13.
Further, the number of the differential fixing bolts 13 to be used can be increased or decreased as necessary such as strength.
[0022]
An inner ring of the first bearing 4 is mounted on an outer peripheral surface of a small diameter portion 15 provided at a left end portion of the cover 11 shown on the left side of FIG. 1 of the differential case 3, and inside the small diameter portion 15, One of the wheel drive shafts 16, for example, the base end of the left wheel drive shaft is inserted therethrough. The base end of the wheel drive shaft 16 is coupled to the inner peripheral surface of the side gear 8 shown on the left side of FIG. 1 so as to be integrally rotatable by coupling means such as a spline.
[0023]
The inner ring of the second bearing 5 is mounted on the outer peripheral surface of the small diameter portion 17 provided at the right end of the case 12 shown on the right side of FIG. 1 of the differential case 3, and inside the small diameter portion 17, The base end of the other wheel drive shaft 18, for example, the right wheel drive shaft, is inserted therethrough. The base end of the wheel drive shaft 18 is coupled to the inner peripheral surface of the side gear 8 shown on the right side of FIG. 1 so as to be integrally rotatable by coupling means such as a spline.
[0024]
An oil catching rib 19 is formed on the outer surface of the cover 11 of the differential case 3 shown on the left side in FIG. The height of the oil catch rib 19 is substantially parallel to the rotation axis RL of the differential case 3, and the oil capture rib 19 is formed in a cylindrical shape with the rotation axis RL of the differential case 3 as a center. Further, the inner diameter of the oil capturing rib 19 is formed slightly larger than the outer dimension of the first bearing 4. An annular recess 20 having a depth direction substantially parallel to the rotation axis RL of the differential case 3 is formed inside the oil catching rib 19. A plurality of lubricating oil supply holes (only one is shown in FIG. 1) 21 communicating between the outer surface and the inner surface of the eleventh, that is, the inside and outside of the differential case 3 are provided.
[0025]
The transmission case 2 has a first case 22 shown on the left side of FIG. 1 and a second case 23 shown on the right side of FIG. The first case 22 and the second case 23 are each formed by casting. The first case 22 and the second case 23 are fixed and integrated by a plurality of case fixing bolts (only one is shown in FIG. 1) 24.
[0026]
A first bearing mounting portion 25 to which the outer ring of the first bearing 4 is mounted is recessed on an end surface of the first case 22 facing the differential case 3. The first bearing mounting portion 25 has an opening at the end surface on the differential case 3 side, and a first bottom made of an oil seal or the like at the center of the bottom for sealing the space between the first bearing mounting portion 25 and the wheel drive shaft 16. A sealing device 26 is mounted. Further, a cylindrical convex portion 27 is protruded from an end surface of the first bearing mounting portion 25 on the differential case 3 side. As shown in a partially enlarged view of FIG. 2, the convex portion 27 is formed such that at least a part of the distal end surface 27 a thereof faces the distal end surface 19 a of the oil capturing rib 19. In addition, the tip surface 27a of the convex portion 27 is formed so as to be located on the same plane as the mating surface 28 of the first case 22 and the second case 23 shown in FIG.
[0027]
In the present embodiment, by forming the distal end surface 27a of the convex portion 27 and the mating surface 28 of the first case 22 by the same processing, the distal end surface 27a of the convex portion 27 and the mating surface 28 of the first case 22 are formed. Are located on the same plane.
That is, the distal end surface 27a of the projection 27 and the mating surface 28 of the first case 22 are formed flush.
[0028]
The first bearing mounting portion 25 of the first case 22 is formed with a guide groove 29 which is an opening for lubricating oil and has an opening on the second case 23 side. The lubricating oil can be supplied to the first space 30 between them. The supply of the lubricating oil to the guide groove 29 is performed by forcing the lubricating oil stored in the transmission case 2, specifically, the bottom of the second case 23, using an oil pump driven by the driving force of a driving force transmission device. It is performed by using lubricating oil or a lubricating oil droplet spraying alone or in combination.
[0029]
A second bearing mounting portion 31 to which the outer ring of the second bearing 5 is mounted is recessed on an end surface of the other second case 23 facing the differential case 3. The second bearing mounting portion 31 has an end surface with an opening at the end surface on the differential case 3 side, and has a second center made of an oil seal or the like at the center of the bottom portion for sealing between the second bearing mounting portion 31 and the wheel drive shaft 18. A sealing device 32 is mounted.
[0030]
The other configuration is the same as that of the conventionally known differential, and a detailed description thereof will be omitted.
[0031]
Next, the operation of the present embodiment having the above-described configuration will be described.
[0032]
According to the differential 1 of the present embodiment, the cylindrical projection 27 is projected from the end surface of the first bearing mounting portion 25 on the differential case side, and at least a part of the distal end surface 27 a is formed by the oil catching rib 19. Is formed so as to face the distal end surface 19a of the oil trap rib 19, the gap G formed between the distal end surface 27a of the cylindrical convex portion 27 and the distal end surface 19a of the oil catch rib 19 (FIG. 2). Can be easily and reliably made smaller than before. Since the gap G can be made smaller than before, a part of the lubricating oil to be supplied to the inside of the differential case 3 through the lubricating oil supply hole 21 formed at the bottom of the concave portion 20 by being captured by the oil capturing rib 19. Can be surely reduced by a centrifugal force from the gap G by much less than before. As a result, the efficiency of capturing the lubricating oil by the oil capturing ribs 19 during rotation of the differential case 3 is improved, and the lubricating oil can be more efficiently supplied to the inside of the differential case 3.
[0033]
Further, according to the differential 1 of the present embodiment, since the tip end surface 27a of the projection 27 and the mating surface 28 of the first case 22 are formed on the same plane, the lubricating oil is provided inside the differential case. A small gap for efficiently supplying the water can be obtained accurately and at low cost.
[0034]
Further, according to the differential 1 of the present embodiment, since the distal end surface 27a of the convex portion 27 and the mating surface 28 of the first case 22 are formed by the same processing, the distal end surface 27a of the convex portion 27 and the first surface Positioning the mating surface 28 of the case 22 with the same plane can be performed more accurately and at lower cost.
[0035]
That is, when the mission case 2 is manufactured by casting, it is possible to simply reduce the variation of the gap G due to the manufacturing accuracy of the transmission case 2 by improving the manufacturing accuracy of the casting. Has the disadvantage that the cost is extremely high because of the need for expensive casting molds and molding machines and complicated processing steps. In particular, when the position of the mating surface 28 and the distal end surface 27a of the convex portion 27 are different from each other, it is necessary to perform the processing of the mating surface 28 and the distal end surface 27a of the convex portion 27 in a separate step. Become. On the other hand, in the differential 1 of the present embodiment, the distal end surface 27a of the convex portion 27 and the mating surface 28 of the first case 22 can be easily positioned on the same plane. And the processing steps are simple and the cost can be reduced.
[0036]
Further, according to the differential 1 of the present embodiment, since the mating surface 28 and the front end surface 27a of the convex portion 27 are formed by the same processing, the processing of the mating surface 28 and the front end surface 27a of the convex portion 27 can be performed simultaneously. It can be carried out. As a result, a small gap G for efficiently supplying the lubricating oil to the inside of the differential case 3 can be obtained more accurately and at a lower cost.
[0037]
Further, according to the differential 1 of the present embodiment, since the convex portion 27 is formed on the end face of the first bearing mounting portion 25, the first bearing 4 and the lubricating oil supply hole 20 are separated from each other for design reasons or the like. Even in the case of being separated, the gap G formed between the distal end surface 27a of the convex portion 27 and the distal end surface 19a of the oil capturing rib 19 can be reduced.
[0038]
Therefore, according to the differential 1 of the present embodiment, the lubricating oil can be efficiently supplied to the inside of the differential case 3. As a result, the function of the differential 1 can be reliably maintained for a long period of time.
[0039]
The present invention can be used for various types of differentials such as a differential used for a FR type driving force transmission device. The differential may have two or more configurations, such as three or four pinions.
[0040]
Further, the present invention can be applied not only to a closed differential case but also to a differential using a general differential case having an opening formed on the outer peripheral surface of the differential case.
[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 first aspect of the present invention, an extremely excellent effect is obtained such that a small gap for efficiently supplying the lubricating oil to the inside of the differential case can be obtained accurately and at low cost. Play.
[0043]
Further, according to the differential of the present invention according to claim 2, since the front end surface of the convex portion and the mating surface of the first case with the second case can be easily and easily located on the same plane, the differential case An extremely excellent effect is obtained such that a small gap for efficiently supplying the lubricating oil to the inside of the device can be obtained more accurately and at a lower cost.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a main part of an embodiment of a differential according to the present invention. FIG. 2 is a partially enlarged view of a main part of FIG. 1. FIG. 3 is a cross-sectional view of a main part of a conventional differential. Partial enlarged view of the main part of [Description of symbols]
Reference Signs List 1 differential 2 transmission case 3 differential case 4 first bearing 5 second bearing 11 cover 12 case 19 oil catching rib 19a tip end surface 20 concave portion 21 lubricating oil supply hole 22 first case 23 second case 25 first bearing mounting hole 27 convex portion 27a Tip surface 28 Mating surface 29 Guide groove 31 Second bearing mounting portion G Clearance RL (of differential case)

Claims (2)

A housing, and a differential case disposed in the housing via a bearing,
The housing includes a first case having a first bearing mounting portion to which an outer ring of a first bearing rotatably supporting one end portion of the differential case along a rotation axis thereof is mounted, and the differential case accommodating the differential case. A second case provided with a second bearing mounting portion to which an outer ring of a second bearing rotatably supporting the other end of the second bearing is mounted,
The differential case has a differential gear disposed therein, an oil catching rib protruding in a cylindrical shape around the rotation axis of the differential case, and a concave formed inside the oil catching rib. And a lubricating oil supply hole formed to communicate between the inside and outside of the differential case and a differential formed on the outer peripheral surface of the first case side,
A cylindrical projection is projected from an end surface of the first bearing mounting portion on the differential case side, and at least a part of a tip surface of the projection is formed so as to face a tip surface of the oil catching rib. A differential, characterized in that a tip surface of the projection is formed so as to be located on the same plane as a mating surface of the first case with the second case. 2. The differential according to claim 1, wherein a tip end surface of the projection and a mating surface of the first case with the second case are formed by the same processing.

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