阅读说明：本技术 差速装置 (Differential gear ) 是由 森裕之 于 2018-03-20 设计创作，主要内容包括：该差速装置具有差速齿轮机构和差速器壳体,该差速齿轮机构具有多个差速齿轮、支承多个差速齿轮的多个差速齿轮支承体以及与差速齿轮的每一个啮合的一对输出齿轮,该差速器壳体具有多个支承部件、覆盖一个输出齿轮的背面并能够与支承部件结合的第1罩部件以及覆盖另一个输出齿轮的背面并能够与支承部件结合的第2罩部件,该多个支承部件具有支承各个差速齿轮支承体的两端部的两端支承部,在各个两端支承部(8)的外侧支承部(81)形成有面向各个差速齿轮(30)的背面(30f)的凹部(81o),该外侧支承部(81)在输出齿轮(31、32)的径向外侧支承差速齿轮支承体(33)的一个端部,各个外侧支承部(81)的沿着输出齿轮(31、32)的轴向上的一侧被第1、第2罩部件(21、22)覆盖。由此,提高了差速齿轮的背面与差速器壳体之间的旋转滑动面的润滑性能。(The differential gear has differential gear mechanism and differential casing, the differential gear mechanism has multiple differential gears, a pair of of the output gear for supporting multiple differential gear supporting masses of multiple differential gears and being engaged with each of differential gear, the differential casing has multiple bearing parts, cover the back side of an output gear and can the 1st cover member in conjunction with bearing part and cover another output gear the back side and being capable of the 2nd cover member in conjunction with bearing part, multiple bearing part has the two supports portion at the both ends for supporting each differential gear supporting mass, the recess portion (81o) at the back side (30f) towards each differential gear (30) is formed in the outside supporting part (81) of each two supports portion (8), the outside supporting part (81) is in output gear (31, 32) diameter One end of outside side bearing differential gear supporting mass (33), the side in the axial direction along output gear (31,32) of each outside supporting part (81) are covered by the 1st, the 2nd cover member (21,22).The greasy property in the rotational slide face between the back side of differential gear and differential casing is improved as a result,.)

1. a kind of differential gear, with differential casing (16) and the differential gear being accommodated in the differential casing (16) Mechanism (17),

The differential gear mechanism (17) includes

Multiple differential gears (30)；

A pair of of output gear (31,32), engages with each of the multiple differential gear (30)；And

Multiple differential gear supporting masses that each differential gear (30) in the multiple differential gear (30) is supported (33),

The differential casing (16) includes

Bearing part (7) has multiple both ends at the respective both ends for supporting the multiple differential gear supporting mass (33) Supporting part (8)；

1st cover member (21) covers the back side (31f) of an output gear (31), and can be with the supporting part Part (7) combines；And

2nd cover member (22) covers the back side (32f) of another output gear (32), and can be with the bearing Component (7) combines,

The back towards each differential gear (30) is formed in the outside supporting part (81) of each two supports portion (8) The recess portion (81o) in face (30f), the outside supporting part (81) the output gear (31,32) radial outside bearing described in One end of differential gear supporting mass (33),

The position of the axial side positioned at the output gear (31,32) of each outside supporting part (81) is by the described 1st, 2 cover members (21,22) covering.

2. differential gear according to claim 1, wherein

Each outside supporting part (81) has the 1st, the 2nd wall portion (81a, 81b) and the 3rd wall portion (81c), the described 1st, the 2nd Wall portion (81a, 81b) is arranged across interval each other in the circumferential direction of the output gear (31,32), the 3rd wall portion (81c) It is clipped between the described 1st, the 2nd wall portion (81a, 81b), and is located at and leans on the output gear than the 1st, the 2nd wall portion (81a, 81b) The position of the radial outside of (31,32) is taken turns,

The recess portion (81o) is formed by the 1st wall portion (81a), the 2nd wall portion (81b) and the 3rd wall portion (81c).

3. differential gear according to claim 2, wherein

The recess portion (81o) has inclined-plane (81obcc) at least part of the bottom surface (81ob) of the recess portion (81o), described Inclined-plane (81obcc) with the central axis (X2) towards the differential gear supporting mass (33) and to the output gear (31, 32) radial outside inclination.

4. differential gear according to claim 2 or 3, wherein

Each outside supporting part (81) has the 4th wall portion (81d), and the 4th wall portion (81d) is to the described 1st, the 2nd wall portion It is attached between (81a, 81b), the 4th wall portion (81d) forms the recess portion (81o) in the output gear (31,32) Axial direction at least side medial surface.

5. differential gear as claimed in any of claims 1 to 4, wherein

Any one face in bearing surface of each outside supporting part (81) with the described 1st, the 2nd cover member (21,22) On be provided with protruding portion (81t1,81t2), and each outside supporting part (81) with the described 1st, the 2nd cover member (21, 22) be provided on another any face in bearing surface engage with the protruding portion (81t1,81t2) groove portion (21t, 22t)。

6. differential gear as claimed in any of claims 1 to 5, wherein

The bearing part (7) has cavity (O) in central part,

The interior side electrode support (82) of each two supports portion (8) has one end to the cavity (O) opening and the other end To the through hole (82h) of the differential gear (30) side opening, the interior side electrode support (82) is in the output gear (31,32) Radially inner side support another end of the differential gear supporting mass (33).

7. a kind of differential gear, with differential casing (116) and the differential tooth being accommodated in the differential casing (116) It takes turns mechanism (117),

The differential gear mechanism (117) includes

Multiple differential gears (130)；

At least one differential gear supporting mass (133) is supported by the differential casing (116), and to the multiple difference Fast gear (130) is supported；And

A pair of of output gear (131,132), engages with each of the multiple differential gear (130),

In the opposed with the respective back side (130f) of the multiple differential gear (130) interior of the differential casing (116) It is formed on surface (116i) recess portion (200), the radial outside of recess portion (200) the Xiang Suoshu output gear (131,132) is recessed It falls into.

8. differential gear according to claim 7, wherein

The differential gear also has washer (140), and the washer (140) assigns into the recess portion (200) and the differential tooth Between the back side (130f) for taking turns (130), the back side (130f) of the differential gear (130) is opposed with recess portion (200),

The internal diameter of the recess portion (200) is identical as the outer diameter of the washer (140), or bigger than the outer diameter of the washer (140).

Technical field

The present invention relates to the differential gears for being suitable for the vehicle such as automobile.

Background technique

In the past, as differential gear, it is known to by bearing part to shorter pinion shaft (differential gear supporting mass) The technology of double base is carried out, which supports multiple pinion gears (differential gear) (referring for example to patent document 1) respectively.

Also, it has been known that there is following technologies in differential gear: being provided in the inner surface of differential casing (input part) The lubricating oil reservoir being made of the recess portion of the arc-shaped of the rotation axis around differential casing, is supplied to pinion gear for lubricating oil The peripheral part of (differential gear) and the supported surface of side (referring for example to patent document 2).

Also, it has been known that there is following technologies in differential gear: in differential casing for being packed into side gear (output gear Wheel) and the edge of opening of pinion gear be provided with the lip inwardly for keeping lubricating oil, be maintained at differential to increase The intracorporal lubricants capacity of device shell, and then increase the lubricants capacity (example for being supplied to side gear Yu the mutual engaging section of pinion gear As referring to patent document 3).

Summary of the invention

Subject to be solved by the invention

But in the differential gear of patent document 1, the undisclosed rotation about the back side and differential casing to pinion gear Turn the content of the lubrication of sliding surface.

Also, in the differential gear of patent document 2, although the peripheral part for pinion gear and side can be increased The lubricants capacity of supported surface, but do not propose the lubrication in rotational slide face between the back side and differential casing to pinion gear Countermeasure fully may not can supply lubricating oil to the rotational slide face between the back side of pinion gear and differential casing as a result,.

Also, in the differential gear of patent document 3, although can increase, to be supplied to side gear mutual with pinion gear The lubricants capacity of engaging section, but the countermeasure of the lubrication in rotational slide face to the back side and differential casing of pinion gear is not proposed, Lubricating oil fully may not can be supplied to the rotational slide face between the back side of pinion gear and differential casing as a result,.

The present invention has been made in view of the above-described circumstances, and an object thereof is to provide can be improved pinion gear (differential gear) The differential gear of the greasy property in the rotational slide face between the back side and bearing part or differential casing (input part).

Means for solving the problems

To achieve the goals above, a differential gear according to the present invention has differential casing and is accommodated in described Differential gear mechanism in differential carrier body, the differential gear mechanism include multiple differential gears；A pair of of output gear, It is engaged with each of the multiple differential gear；And multiple differential gear supporting masses, in the multiple differential gear Each differential gear supported, the differential casing includes bearing part, has and supports the multiple differential gear Multiple two supports portions at the respective both ends of supporting mass；1st cover member covers the back side of an output gear, and And it can be in conjunction with the bearing part；And the 2nd cover member, cover the back side of another output gear, and energy Enough in conjunction with the bearing part, the outside supporting part in each two supports portion is formed with towards each differential tooth The recess portion at the back side of wheel, the outside supporting part support the differential gear supporting mass in the radial outside of the output gear One end, the side in the axial direction along the output gear of each outside supporting part is by the described 1st, the 2nd cover portion Part covering.

Preferably, each outside supporting part has the 1st, the 2nd wall portion and the 3rd wall portion, and the described 1st, the 2nd wall portion exists It mutually being arranged across interval in the circumferential direction of the output gear, the 3rd wall portion is clipped between the described 1st, the 2nd wall portion, and And it is located at than the 1st, the 2nd wall portion by the position of the radial outside of the output gear, by the 1st wall portion, the 2nd wall portion And the 3rd wall portion forms the recess portion.

Furthermore it is also preferred that the recess portion at least part of the bottom surface of the recess portion have inclined-plane, the inclined-plane with It is tilted towards the central axis of the differential gear supporting mass to the radial outside of the output gear.

Furthermore it is also preferred that each outside supporting part has the 4th wall portion, the 4th wall portion is to the described 1st, the 2nd wall portion Between be attached, form the medial surface of at least side of the recess portion in the axial direction of the output gear.

Furthermore it is also preferred that it is any one in each outside supporting part and the bearing surface of the described 1st, the 2nd cover member Protruding portion, and appointing in bearing surface of each outside supporting part with the described 1st, the 2nd cover member are provided on a face The groove portion engaged with the protruding portion is provided on meaning another side.

Furthermore it is also preferred that the bearing part has cavity, the interior side bearing in each two supports portion in central part Portion has one end to the cavities open and the other end to the through hole of the differential gear side opening, the interior side electrode support Another end of the differential gear supporting mass is supported in the radially inner side of the output gear.

Also, to achieve the goals above, another differential gear according to the present invention has differential casing and receipts The differential gear mechanism being contained in the differential carrier body, the differential gear mechanism include multiple differential gears；At least one Differential gear supporting mass is supported by the differential casing, and supports the multiple differential gear；And a pair of of output gear Wheel, is engaged with each of the multiple differential gear, in the respective with the multiple differential gear of the input part The opposed inner surface in the back side is formed with recess portion, and the recess portion is recessed to the radial outside of the output gear.

Furthermore it is also preferred that the differential gear also has washer, the washer assigns into the recess portion and the differential tooth Between the back side of wheel, the back side of the differential gear is opposed with the recess portion, the outer diameter phase of the internal diameter of the recess portion and the washer Together, or it is bigger than the outer diameter of the washer.

Invention effect

In accordance with the invention it is possible to improve the greasy property at the back side of differential gear and the rotational slide face of differential casing.

Detailed description of the invention

Fig. 1 is the integrally-built section view for schematically showing differential gear involved in the 1st embodiment of the invention Scheme (the 1-1 line cross-sectional view of Fig. 2).(the 1st embodiment)

Fig. 2 is the 2-2 line cross-sectional view of Fig. 1.(the 1st embodiment)

Fig. 3 is the 3 arrow portion enlarged drawings of Fig. 2.(the 1st embodiment)

Fig. 4 is the perspective view for showing the bearing part of differential gear involved in the 1st embodiment of the invention.(the 1st is real Apply mode)

Fig. 5 is the integrally-built section view for schematically showing differential gear involved in the 2nd embodiment of the invention Figure.(the 2nd embodiment)

Label declaration

O: cavity

X2: the 2 axis (central axis)

7: bearing part (differential casing)

8: supporting mass (two supports portion)

11,111: differential gear

16: differential casing (input part)

17: differential gear mechanism

21, the 22: the 1, the 2nd cover member (differential casing)

21t, 22t: the 1st, 2 groove portions (groove portion)

30f, 31f, 32f, 130f: the back side

30,130: pinion gear (differential gear)

31,131: the 1 side gears (output gear, another output gear, output gear)

32,132: the 2 side gears (another output gear, output gear, an output gear)

33,133: pinion shaft (differential gear supporting mass, differential gear bearing part)

81: the 1 supporting parts (outside supporting part)

81o: recess portion

81ob: bottom surface

81obcc: circular conical surface (inclined-plane)

81a, 81b, 81c, 81d: the 1st, the 2nd, the 3rd, the 4th wall portion

81t1,81t2: the 1st, 2 protrusions (protrusion, protruding portion)

82: the 2 supporting parts (interior side electrode support)

82h: support holes (through hole)

116: differential casing (input part)

117: differential gear mechanism

116i: inner surface

140: pinion gear is with washer (washer)

200: recess portion

Specific embodiment

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

1st embodiment

Firstly, referring to Fig.1~Fig. 4 is illustrated differential gear 11 involved in the 1st embodiment of the invention.Automobile With gear box casing 12, which is configured in the engine (not shown) as the power source for being equipped on automobile Side, and store gearbox (not shown) and differential gear 11.Inserted with being connect simultaneously with axle respectively in gear box casing 12 And can around the left and right that the 1st axis X 1 rotates the 1st, the inner end of the 2nd output shaft 13a, 13b.1st, the 2nd output shaft 13a, The inner end of 13b and a pair of of output section (the aftermentioned 1st, the 2nd side gear 31,32) of differential gear 11 combine.

For example be equipped between gear box casing 12 and the 1st, the 2nd output shaft 13a, 13b cricoid seal member 14a, 14b.The the 1st, the 2nd output of seal member 14a, 14b in the close mode of liquid to relative rotation is carried out relative to gear box casing 12 It is sealed between axis 13a, 13b and gear box casing 12.In the present embodiment, the bottom of gear box casing 12 with towards The mode of the inner space of gear box casing 12 is formed with the food tray (not shown) of the lubricating oil of storage specified amount.It is stored in food tray In rotation or reducing gear turbine of the lubricating oil in the inner space of gear box casing 12 through aftermentioned differential casing 16 Rotation of movable element of structure 15 etc. and raise and disperse to periphery, the power in reduction gear ultromotivity in the 15 future source passes It is delivered to differential casing 16.Then, by the lubricating oil that disperses in gear box casing 12 to being present in aftermentioned differential carrier The inside and outside mechanical moving parts of body 16 are lubricated.

Differential gear 11 for example includes differential casing (input part) 16, by the 1st, the 2nd bearing 61,62 around the 1st Axis X 1 is rotatably freely supported on gear box casing 12；Differential gear mechanism 17 is accommodated in differential casing 16；And Ring component (slave unit) 20 is connected in a manner of covering the periphery of differential casing 16 with the peripheral end of differential casing 16 It connects.

Differential casing 16 for example includes the 1st, the 2nd cover member 21,22, along the direction of the 1st axis X 1, i.e. in differential Differential gear mechanism 17 is clamped in the axial direction (axial direction of aftermentioned side gear 31,32) of device shell 16；And cricoid bearing Component 7, configure between the 1st, the 2nd cover member 21,22, and be configured to by ring component 20 cover and can be with the 1st, the 2nd Cover member 21,22 connects.

Thus, the 1st cover member 21, the 2nd cover member 22 and bearing part 7 have respectively formed one of differential casing 16 Point.

1st cover member 21 for example includes the 1st flat sidewall portion 21a, is formed as the circle centered on the 1st axis X 1 Shape is cyclic annular；And the 1st boss portion 21b, from the inner peripheral end thereof of the 1st sidewall portion 21a to the axial direction of aftermentioned side gear 31,32 Outside (that is, side opposite with the face towards the 2nd cover member 22) extends.

2nd cover member 22 for example includes the 2nd flat sidewall portion 22a, is formed as the circle centered on the 1st axis X 1 Shape is cyclic annular；And the 2nd boss portion 22b, from the inner peripheral end thereof of the 2nd sidewall portion 22a to the axial direction of aftermentioned side gear 31,32 Outside (that is, side opposite with the face towards the 1st cover member 21) extends.

Also, the 1st cover member 21 and the 2nd cover member 22 for example respectively from the axial side of differential casing 16 and The other side covers differential gear mechanism 17.Also, at least one party in the 1st, the 2nd cover member 21,22 is for example provided with perforation Hole (not shown), the through hole can make to circulate in differential casing 16 with the lubricating oil being connected in gear box casing 12.And And the 1st, the 2nd boss portion 21b, 22b is supported in gear box casing 12 by the 1st, the 2nd bearing 61,62 respectively.

Ring component 20 is for example configured to the radial outside (radial direction of aftermentioned side gear 31,32 from differential casing 16 Outside) bearing part 7 is covered, which is connected with the peripheral end of the 1st, the 2nd cover member 21,22 respectively by welding It connects.Also, ring component 20 is for example provided with gear teeth 20g outwardly in outer peripheral surface.Also, gear teeth 20g and reducing gear turbine The driving gear 23 of structure 15 engages.Therefore, the power of engine is transmitted to differential casing via ring component 20 from gearbox 16。

In addition, in the present embodiment, the combination of ring component 20 and the 1st, the 2nd cover member 21,22 uses welding, still The present invention is not limited thereto, other engagement means (such as be screwed, be pressed into) also can be used.In addition, ring component 20 is An example of input part.

Differential gear mechanism 17 for example includes multiple (such as four) pinion gears (differential gear) 30, be supported to around 2nd axis X 2 vertical with the 1st axis X 1, X2 ' are rotated freely；A pair of of side gear (output gear) 31,32 is (that is, the 1st side Gear (output gear, another output gear) the 31 and the 2nd side gear (another output gear, an output gear Wheel) 32), and it is supported to rotate freely around the 1st axis X 1, and engage with multiple pinion gears 30 respectively；And multiple pinion gears Axis (differential gear supporting mass, differential gear bearing part) 33, by the bearing of each pinion gear 30 for around the 2nd axis X 2, X2 ' rotation Turn freely.

1st side gear 31 for example includes the 1st flat sidewall portion 31a, is formed as centered on the 1st axis X 1 Circular annular form；And the 1st boss portion 31b, from the inner peripheral end thereof of the 1st sidewall portion 31a to the axially external of the 1st side gear 31 (that is, side opposite with the face towards the 2nd side gear 32) extends.

Also, the 1st sidewall portion 31a is for example in the axially inner side of the side gear of peripheral part 31,32 (with the 2nd side gear 32 opposed opposed surface sides) it is formed with gear teeth 31ag.Gear teeth 31ag is for example made of bevel gear.Also, as the 1st side wall The side gear 31,32 of portion 31a it is axially external (relative to the opposed opposed faces of the 2nd side gear 32 and opposite side) The back side 31f of the 1st sidewall portion 31a covered by the 1st cover member 21 (more specifically the 1st sidewall portion 21a), and via side Face gear washer (washer) 41 and be supported to being capable of rotational slide.

Also, the peripheral part of the 1st boss portion 31b by relative rotation freely in a manner of be fitted into be supported on the 1st cover member 21 The inner peripheral portion of 1st boss portion 21b.Also, the inner peripheral portion of the 1st boss portion 31b by can not in a manner of relative rotation with the 1st output shaft The periphery of the inner end of 13a is fitted into (such as being spline fitted S1 in the present embodiment).

2nd side gear 32 for example includes the 2nd flat sidewall portion 32a, is formed as centered on the 1st axis X 1 Circular annular form；And the 2nd boss portion 32b, from the inner peripheral end thereof of the 2nd sidewall portion 32a to the axially external of the 2nd side gear 32 (that is, side opposite with the face towards the 1st side gear 31) extends.

Also, the 2nd sidewall portion 32a is for example in the axially inner side of the side gear of peripheral part 31,32 (with the 1st side gear 31 opposed opposed surface sides) it is formed with gear teeth 32ag.Gear teeth 32ag is for example made of bevel gear.Also, as the 2nd side wall The side gear 31,32 of portion 32a it is axially external (relative to the opposed opposed faces of the 1st side gear 31 and opposite side) The back side 32f of the 2nd sidewall portion 32a covered by the 2nd cover member 22 (more specifically the 2nd sidewall portion 22a), and via side Face gear washer (washer) 42 and be supported to being capable of rotational slide.

Also, the peripheral part of the 2nd boss portion 32b by relative rotation freely in a manner of be fitted into be supported on the 2nd cover member 22 The inner peripheral portion of 2nd boss portion 22b.Also, the inner peripheral portion of the 2nd boss portion 32b by can not in a manner of relative rotation with the 2nd output shaft The periphery of the inner end of 13b is fitted into (such as being spline fitted S2 in the present embodiment).

Alternatively, it is also possible to omitting side gear washer 41,42, make the 1st, the 2nd side gear 31,32 back side 31f, 32f by can directly be supported in a manner of rotational slide corresponding 1st, the 2nd cover member 21,22 (the more specifically the 1st, 2nd sidewall portion 21a, 22a) medial surface.

Each pinion gear 30 for example includes gear body portion 30m, has axis hole 30mh, pinion shaft 33 in central part Relative rotation is inserted freely in axis hole 30mh；And gear tooth 30mg, it is formed in the periphery of gear body portion 30m Face, and attenuate with towards the 1st axis X 1.Gear teeth 30mg is for example made of bevel gear.

Also, the back side 30f (diameter by side gear 31,32 of more specifically gear body portion 30m of pinion gear 30 End face outward) be formed as the cricoid plane vertical with the rotation axis of pinion gear 30 (i.e. the 2nd axis X 2, X2 ').Separately Outside, the back side 30f of pinion gear 30 can not also be formed by cricoid plane, and be on the rotation axis of pinion gear 30 by center Spherical surface a part or tapered surface formed.

Bearing part 7 for example includes multiple supporting masses (two supports portion) 8, supports the respective of multiple pinion shafts 33 Both ends, and arranged at equal intervals in the circumferential direction of side gear 31,32；And the union body 9 of multiple substantially arc-shapeds, Be formed as thinner than supporting mass 8 in the axial direction of side gear 31,32, and by the circumferential direction of side gear 31,32 adjacent two A supporting mass 8 is bonded to each other integrally.

Multiple supporting masses 8 and union body 9 are alternately arranged into the annular shape centered on the 1st axis X 1 respectively.Therefore, it props up Bearing portion part 7 is integrally formed into ring-type.Thus, bearing part 7 is formed in central part and is surrounded by multiple supporting masses 8 and union body 9 Made of cavity O.

In addition, in the present embodiment, supporting mass 8 is equipped with four in the circumferential direction of side gear 31,32 at equal intervals, But the present invention is not limited thereto.In the present invention, it such as can also be consistently equipped with the quantity of aftermentioned pinion gear 30 Two or three or five or more.

Each supporting mass 8 for example includes the 1st supporting part (outside supporting part) 81, have the 1st support holes 81h, the 1st Support holes 81h is passed through for the end (end, another end) of the radial outside by side gear 31,32 of pinion shaft 33 It inserts, to be supported to pinion shaft 33；And the 2nd supporting part (interior side electrode support) 82, there is the 2nd support holes 82h, it should End (the other end, an end) of the 2nd support holes 82h for the radially inner side by side gear 31,32 of pinion shaft 33 It inserts, to be supported to pinion shaft 33.

The space 90 that can store pinion gear 30 is formed between the 1st supporting part 81 and the 2nd supporting part 82.Also, it is empty Between 90 two axial end sides by side gear 31,32 be opened.Therefore, inside of the space 90 directly with differential casing 16 Connection.In addition, the 2nd support holes 82h be central part from one end to bearing part 7 cavity O opening and the other end to pinion gear 30 An example of the through hole of side (i.e. space 90) opening.

In addition, can also form following through hole in the 2nd supporting part 82 seperatedly with the 2nd support holes 82h and (not scheme Show), one end of the through hole is open to cavity O, and the other end is open to 30 side of pinion gear (i.e. space 90).

End i.e. the 1st supporting part 81 of the radial outside by side gear 31,32 of supporting mass 8 for example includes the 1st, the 2nd Wall portion 81a, 81b is mutually arranged across interval in the circumferential direction of the radially inner side laterally gear 31,32 of side gear 31,32 Column；3rd wall portion 81c, is clamped between the 1st, the 2nd wall portion 81a, 81b, and is located at than the 1st, the 2nd wall portion 81a, 81b By the position of the radial outside of side gear 31,32；And the 4th, the 5th wall portion 81d, 81e, in the axis of side gear 31,32 It is mutually arranged upwards across interval, and clamps the 3rd wall portion 81c between the 4th, 5 wall portion 81d, 81e.Moreover, by 1st, the 2nd, the 3rd wall portion 81a, 81b, 81c formation recess portion 81o.Also, the 4th, the 5th wall portion 81d, 81e forms recess portion 81o in side Medial surface in the axial direction of face gear 31,32.In addition, at least one of the 4th, the 5th wall portion 81d, 81e can be omitted.That is, In In the present invention, at least one medial surface of recess portion 81o in the axial direction of side gear 31,32 can not also be formed.That is, in recess portion In 81o, bottom surface 81ob is formed by the 3rd wall portion 81c, side gear 31,32 is formed in the circumferential by the 1st, the 2nd wall portion 81a, 81b Side.Also, the bottom surface 81ob of recess portion 81o is supported the back side 30f of pinion gear 30 with washer (washer) 40 across pinion gear For being capable of rotational slide.Alternatively, it is also possible to omit pinion gear washer 40, by the bottom surface 81ob of recess portion 81o directly by small tooth The back side 30f bearing of wheel 30 is being capable of rotational slide.

Also, at least part of the bottom surface 81ob in recess portion 81o (is the central portion of bottom surface 81ob in the present embodiment 81obc) place is for example formed with circular conical surface (inclined-plane) 81obcc, and circular conical surface 81obcc is with the central axis towards pinion shaft 33 Line (the 2nd axis X 2, X2 ') and to the radial outside of side gear 31,32 inclination (central axis towards pinion shaft 33 is lateral Lower inclination).

In addition, in the present embodiment, showing and being set to the internal diameter of the open end of circular conical surface 81obcc to compare pinion gear The small situation of the outer diameter of 30 back side 30f (more specifically pinion gear washer 40), but the present invention is not limited thereto.In In the present invention, for example, the outer diameter of the back side 30f of pinion gear 30 can also be set to in the open end of circular conical surface 81ob cc Diameter is same or about.In this case, it is desirable to which the gradient of circular conical surface 81obcc is for example set such that circular conical surface The 81obcc and back side 30f of pinion gear 30 is substantially the small skew degree of face contact.

Also, the 1st supporting part 81 is clamped in the axial direction of side gear 31,32 by the 1st, the 2nd cover member 21,22.That is, the Two sides of 1 supporting part 81 in the axial direction of side gear 31,32 respectively with the peripheral end of the 1st, the 2nd cover member 21,22 Medial surface abuts, and the medial surface and the 1st supporting part 81 of the peripheral end of the 1st, the 2nd cover member 21,22 are in side gear 31,32 Axial direction on two sides it is opposite.

Also, the either side in the 1st supporting part 81 and the mutual bearing surface of the 1st cover member 21 is (in present embodiment In be the 1st supporting part 81 another side) be for example integrally formed with the 1st protrusion (protrusion, protruding portion) 81t1, the 1st is convex Portion 81t1 is extended in circular arc along the circumferential direction of side gear 31,32.Also, the 1st supporting part 81 and the 1st cover member 21 each other Bearing surface in any another (being the medial surface of the peripheral end of the 1st cover member 21 in the present embodiment) be for example arranged There is the 1st groove portion (groove portion) 21t, the 1st groove portion 21t and the 1st protrusion 81t1 of channel-shaped to engage and by the 1st cover member 21 in same heart shaped Ground be positioned at the 7, the 1st groove portion 21t of bearing part along side gear 31,32 circumferential direction in arc-shaped (in the present embodiment It is circular) extend.

Also, the either side in the 1st supporting part 81 and the mutual bearing surface of the 2nd cover member 22 is (in present embodiment In be the 1st supporting part 81 another side) be for example integrally formed with the 2nd protrusion (protrusion, protruding portion) 81t2, the 2nd protrusion 81t2 is extended in circular arc along the circumferential direction of side gear 31,32.Also, it is mutual in the 1st supporting part 81 and the 2nd cover member 22 Any other party (being the medial surface of the peripheral end of the 2nd cover member 22 in the present embodiment) in bearing surface is for example provided with The 2nd groove portion (groove portion) 22t, the 2nd groove portion 22t and the 2nd protrusion 81t2 of channel-shaped engage and by the 2nd cover member 22 in concentrically The 7, the 2nd groove portion 22t of bearing part is positioned at along the circumferential direction of side gear 31,32 (is in the present embodiment in arc-shaped It is circular) extend.

Supporting mass 8 is for example by the perforation screwed bolt 50 in the 1st supporting part 81 of the 1st cover member 21 and with the 1 cover member 21 combines.Also, such as prevent pinion shaft 33 from the abjection of the 1st supporting part 81,51 lateral direction penetrating of pin by pin 51 1st supporting part 81 and pinion shaft 33.Also, due to the medial surface pair at the both ends of pin 51 and the 1st, the 2nd cover member 21,22 It sets, therefore in the state that the 1st, the 2nd cover member 21,22 is combined with supporting mass 8, is prevented by the 1st, the 2nd cover member 21,22 Pin 51 is deviate from from the 1st supporting part 81.

Then, the effect of present embodiment is illustrated.In the differential gear 11 of present embodiment, in differential carrier In the case that body 16 receives rotary force via reduction gear 15 and ring component 20 from engine, pinion gear 30 is not around small 33 rotation of gear shaft, but revolve together around i.e. the 1st axis X 1 of the central axis of differential casing 16 with differential casing 16, this When, rotation driving is carried out with identical speed to the 1st, the 2nd side gear 31,32 from differential casing 16 via pinion gear 30, So that the driving force of the 1st, the 2nd side gear 31,32 is equably transmitted to the 1st of left and right the, the 2nd output shaft 13a, 13b.In addition, In turning driving due to automobile etc. when the 1st, the 2nd output shaft 13a, 13b generates rotational speed difference, 30 one side rotation of pinion gear, On one side around the 1st axis X 1 revolve, be as a result, while allowing differential speed rotation from pinion gear 30 to the 1st, the 2nd side gear 31, 32 transmitting rotary driving forces.More than, it is identical as the previous work of well-known differential gear.

In the work of such differential gear 11, the lubricating oil to disperse in gear box casing 12 for example passes through the 1st, Spline-fitting portion S1, S2 of 2 output shaft 13a, 13b and the 1st, the 2nd side gear 31,32 and it is set to the 1st, the 2nd cover member 21,22 through hole (not shown) and in the inside and outside circulation of differential casing 16.Then, enter the 1st, the 2nd side gear 31, A part of the lubricating oil of (such as cavity O of bearing part 7) is by centrifugal force towards side gear between 32 opposed faces 31,32 radial outside flowing, such as supporting mass 8 the 2nd supporting part 82 support holes 82h and pinion shaft 33 chimeric surface Between or pinion gear 30 and the chimeric surface of pinion shaft 33 between flow, near the back side 30f for reaching pinion gear 30, and lodge in In the recess portion 81o of 1st supporting part 81.Also, it is flowed into the lubricating oil between the opposed faces of the 1st, the 2nd side gear 31,32 Another part is for example flowed towards the 1st, the 2nd side gear 31,32 and the engaging section of pinion gear 30 by centrifugal force, then Near the back side 30f for reaching pinion gear 30, and lodge in the recess portion 81o of the 1st supporting part 81.

When assembling the differential gear 11 of present embodiment, such as firstly, the son for wanting pre-assembly to obtain as follows Assembly (that is, the case where state shown in Fig. 4): pinion gear 30 and pinion gear washer 40 are encased in bearing part 7 Each supporting mass 8 the 1st, the 2nd supporting part 81,82 between in the space 90 that is formed, and insert pinion shaft 33 in small tooth Wheel 30, pinion gear washer 40 and the 1st, the 2nd supporting part 81,82, and prevent pinion shaft 33 from deviating from by pin 51.

Then, it is used with configuration structure appropriate arrangement sub-assemblies, the 1st, the 2nd side gear 31,32 and side gear Washer 41,42.Then, pass through the 1st, the 2nd cover member 21,22 pairs of sub-assemblies suitably arranged, the 1st, the 2nd side gears 31,32 and side gear clamped with washer 41,42.Then, by bolt 50 to the 1st cover member 21 and bearing part 7 (more specifically the 1st supporting part 81) is combined.

Also, the 2nd cover member 22 and bearing part 7 (more specifically the 1st supporting part 81) are welded.As a result, Form the combination of differential gear mechanism 17 and the 1st, the 2nd cover member 21,22.Then, ring component 20 is embedded into differential gear In the combination of mechanism 17 and the 1st, the 2nd cover member 21,22.Then, to the outer peripheral surface and ring portion of the 1st, the 2nd cover member 21,22 Part 20 is welded.Differential gear 11 is produced as a result,.

According to the present embodiment, the recess portion 81o of the 1st supporting part 81 is open to the radially inner side of side gear 31,32, towards The back side 30f (being pinion gear washer 40 in the present embodiment) of pinion gear 30, and two of the axial direction from side gear 31,32 Side is covered by the 1st, the 2nd cover member 21,22.Therefore, when differential gear 11 works, lubricating oil easily accumulates the 1st bearing It, can be by the lubricating oil of accumulation efficiently to the back side 30f of pinion gear 30 and pinion gear washer 40 in the recess portion 81o in portion 81 It is lubricated.That is, back side 30f and pinion gear washer 40 can sufficiently be supplied to the lubricating oil lodged in recess portion 81o Mutual rotational slide face, so as to improve the lubricity of differential gear 11.Thereby, it is possible to improve the back side of pinion gear 30 The greasy property in the rotational slide face between 30f and bearing part 7.

In addition, even if making bottom surface of the back side 30f of pinion gear 30 directly with recess portion 81o in omission pinion gear washer 40 In the case that 81ob is contacted, also the lubricating oil lodged in recess portion 81o can sufficiently be supplied to back side 30f and bottom surface 81ob Mutual rotational slide face, so as to improve the lubricity of differential gear 11.Thereby, it is possible to improve the back side of pinion gear 30 The greasy property in the rotational slide face of 30f and bearing part 7.

Also, according to the present embodiment, at least part of the bottom surface 81ob of recess portion 81o is (in being in the present embodiment Centre portion 81obc) it is formed by circular conical surface (inclined-plane) 81obcc, circular conical surface 81obcc is with the central axis towards pinion shaft 33 (the 2nd axis X 2, X2 ') and to the radial outside of side gear 31,32 inclination (towards pinion shaft 33 central axis line side and to Lower inclination).Thereby, it is possible to before the bottom surface 81ob for not damaging recess portion 81o substantially is to bearing strength of the pinion gear with washer 40 Put the storage capacity for substantially ensuring the lubricating oil in recess portion 81o.

Also, according to the present embodiment, by being respectively arranged at the 1st supporting part 81 and the mutual abutting of the 1st cover member 21 The 1st protrusion 81t1 of a side and another party in face with the 1st groove portion 21t is mutual engages, can be easily by the 1st cover member 21 Bearing part 7 is positioned in same heart shaped.Thereby, it is possible to improve the bond strength between bearing part 7 and the 1st cover member 21.

Also, the side by being respectively arranged in the 2nd supporting part 82 and the mutual bearing surface of the 2nd cover member 22 and another 2nd protrusion 81t2 of side with the 2nd groove portion 22t is mutual engages, can be in easily that same heart shaped be positioned at branch by the 2nd cover member 22 Bearing portion part 7.Thereby, it is possible to improve the bond strength between bearing part 7 and the 2nd cover member 22.

Thus, according to the present embodiment, it can to easily and reliably carry out clamping between the 1st, the 2nd cover member 21,22 Positioning operation when sub-assemblies.Therefore, it can be improved the assembling operation of differential gear 11.

2nd embodiment

Then, differential gear 111 involved in the 2nd embodiment of the invention is illustrated referring to Fig. 5.It is real the 1st Apply in mode, show by make the two sidewalls as differential casing 16 the 1st, the 2nd cover member 21,22 distinguish flattening and The case where realizing the flattening of differential casing 16 in the axial direction, but differential casing is formed as in the 2nd embodiment Differential gear 111 when substantially spherical is illustrated.

Differential gear 111, which for example includes, is shaped generally as spherical differential casing 116；It is accommodated in differential casing Differential gear mechanism 117 in 116；And gear ring (driven gear, ring component, the follower being connect with differential casing 116 Part) 120.

In addition, differential casing 116 can be formed as one type as shown in the 2nd embodiment, or can also lead to It is excessively cut into multiple housing elements and housing element is fastened each other and is constituted.Also, differential casing 116 to In the case where being one-piece type less, the element (example for making differential gear mechanism 117 is formed on the peripheral wall of differential casing 116 Such as, the aftermentioned 1st, the 2nd side gear 131,132 or pinion gear 130 etc.) through hole of assembling operation of disengaging (do not scheme Show).

Gear ring 120 is for example threadably secured and connect with the peripheral part of differential casing 116.Also, gear ring 120 engages In the driving gear 123 for the reduction gear 115 being connect with engine.Therefore, rotary force is from engine via reduction gearing Mechanism 115 and gear ring 120 and be input to differential casing 116.Alternatively, it is also possible to which gear ring 120 is integrally formed in differential Device shell 116.In addition, gear ring 120 is an example of input part.

Differential casing 116 for example includes main part 116a, and differential gear mechanism can be stored in inside by being formed with 117 space, and inner surface 116i is formed as dome shape；1st boss 116b is integrally provided projectingly on main part 116a Right-hand end, and be formed in the 1st axis X 1；And the 2nd boss 116b ', integrally it is provided projectingly on main part The left end of 116a, and be formed in the 1st axis X 1.Also, the 1st, the periphery of the 2nd boss 116b, 116b ' are by bearing 161,162 gear box casing 112 is rotatably freely supported on around the 1st axis X 1.Also, the of the left and right being connect respectively with axle 1, the 2nd output shaft 113a, 113b is rotatably freely fitted into around the 1st axis X 1 and is supported in the 1st, the 2nd boss 116b, 116b ' Week.

Also, in the 1st, inner peripheral surface of the outer peripheral surface of the 2nd output shaft 113a, 113b and the 1st, the 2nd boss 116b, 116b ' Chimeric surface at least one party's (being the inner peripheral surface of the 1st, the 2nd boss 116b, 116b ' in the present embodiment) be formed with spiral Slot 116s, the 116s ' of shape.Slot 116s, 116s ' with automobile advance when driving the 1st, the 2nd output shaft 113a, 113b and the 1st, 2nd boss 116b, 116b ' relative rotation and play screw rod pumping action.Thereby, it is possible to by the lubrication in gear box casing 112 Oil is introduced into differential casing 116.In addition, differential casing 116 is an example of input part.

Differential gear mechanism 117 for example include the 1st arranged in pairs in the 1st axis X 1 in differential casing 116, 2nd side gear (output gear, an output gear, another output gear) 131,132；Vertical with the 1st axis X 1 Single pinion shaft (the differential gear branch being configured in 2nd axis X 2 between the opposed faces of the 1st, the 2nd side gear 131,132 Hold body, differential gear bearing part) 133；And supported in a manner of being rotatably freely embedded in pinion shaft 133, and point Multiple (such as the two) pinion gears (differential gear) 130 that do not engaged with the 1st, the 2nd side gear 131,132.Pinion gear 130 with And the 1st, the 2nd gear teeth 130g, 131g, 132g of side gear 131,132 be for example made of bevel gear.

In addition, in Fig. 5, about differential gear mechanism 117 and the 1st, the 2nd output shaft 113a, 113b, across the 1st axis Line X1 and illustrate only top half, and the diagram of lower half portion is omitted, differential casing is illustrated for ease of judgement The shape of the inner peripheral surface of the shape and the 1st, the 2nd boss 116b, 116b ' of 116 inner surface 116i.In addition, being omitted figure The structure of the differential gear mechanism 117 of the lower half portion shown and the 1st, the 2nd output shaft 113a, 113b about the 1st axis X 1 with Top half is symmetrical.

1st, the outer peripheral surface of the 2nd output shaft 113a, 113b in a manner of relative rotation can not be fitted into (in the present embodiment It is spline fitted S1 ', S2 ') in the inner peripheral surface of the 1st, the 2nd side gear 131,132.As a result, the 1st, the 2nd side gear 131, 132 are rotatably freely supported on differential casing 116 around the 1st axis X 1 by the 1st, the 2nd output shaft 113a, 113b.

The back side 131f of 1st side gear 131 and the back side 132f of the 2nd side gear 132 copy differential casing 116 The inner surface 116i for being formed as dome shape and be formed as cricoid spherical surface around the 1st axis X 1.Moreover, in differential casing 116 The back side side 131f by the 1st side gear 131 inner surface 116i and differential casing 116 lean on the 2nd side gear 132 The back side side 132f inner surface 116i, be formed with recess portion in the form of the axially external recess to side gear 131,132 201,202, the recess portion 201,202 is towards the 1st, the 2nd side gear 131, the 132 respective back side 131f, 132f.Recess portion 201, 202 respective bottom surface 201b, 202b are across side gear with washer (washer) 141,142 by the corresponding back side 131f, 132f branch It holds as being capable of rotational slide.

It, directly will be right by recess portion 201,202 respective bottom surface 201b, 202b alternatively, it is also possible to omit washer 141,142 The back side 131f, 132f bearing for the 1st, the 2nd side gear 131,132 answered for can rotational slide need but in this case The back side 131f, 132f are formed as directly contacting with bottom surface 201b, 202b.

Also, in the present embodiment, recess portion 201,202 respective internal diameters be configured to the back side 131f, 132f (because This, roughly same outer diameter for side gear washer 141,142) respective, but the present invention is not limited thereto.In the present invention In, such as recess portion 201,202 respective internal diameters can also be set to than back side 131f, 132f (therefore, side gear washer 141,142) respective outer diameter big.

Also, in the present embodiment, recess portion 201,202 respective bottom surface 201b, 202b curvature be configured to and carry on the back Face 131f, 132f (therefore, side gear washer 141,142) respective curvature is identical, but the present invention is not limited thereto.In In the present invention, such as it can also be formed at least part of recess portion 201,202 respective bottom surface 201b, 202b with towards the 1, the rotation axis (i.e. the 1st axis X 1) of the 2nd side gear 131,132 and the axially external inclination to side gear 131,132 (being tilted down towards 1 side of the 1st axis X) circular conical surface (inclined-plane).In this case, it is desirable to the gradient of circular conical surface (inclined-plane) Such as it is set so that circular conical surface and the back side 131f, 132f (therefore for side gear washer 141,142) are substantially that face connects The small skew degree of touching.

Also, both ends (the end of the radial outside of the side gear 131,132 of pinion shaft 133 of pinion shaft 133 Portion) it inserts in a pair of of support holes 116h and is supported respectively, which is arranged in the 2nd axis X 2 and is arranged In differential casing 116.Pinion shaft 133 is prevented by the pin 151 of perforation pinion shaft 133 and differential casing 116 One end abjection.Also, the one end of pin 151 in conjunction with the pin mounting hole 116c of differential casing 116 (such as indentation, riveting Deng).

The back side 130f of pinion gear 130 copies the inner surface 116i for being formed dome shape of differential casing 116, around 2 axis Xs 2 are formed as cricoid spherical surface.Moreover, the inner surface in the back side side 130f by pinion gear 130 of differential casing 116 On 116i, it is formed with recess portion 200 in the form of to the radial outside of side gear 131,132 recess, the recess portion 200 is towards small tooth The back side 130f of wheel 130.Also, the bottom surface 200b of recess portion 200 is across pinion gear with washer (washer) 140 by pinion gear 130 130f bearing in the back side is being capable of rotational slide.

Alternatively, it is also possible to omit pinion gear washer 140, by the bottom surface 200b of recess portion 200 directly by pinion gear 130 Back side 130f bearing for can rotational slide need to be formed as back side 130f into the bottom surface with recess portion 200 but in this case 200b is directly contacted.

Also, in the present embodiment, the internal diameter of recess portion 200 is configured to and back side 130f (therefore, pinion gear washer 140) roughly same outer diameter, but the present invention is not limited thereto.It in the present invention, such as can also be by the internal diameter of recess portion 200 It is set to bigger than the outer diameter of back side 130f (therefore, pinion gear washer 140).

Also, in the present embodiment, the curvature of the bottom surface 200b of recess portion 200 is configured to (therefore, small with back side 130f Gear washer 140) curvature it is identical, but the present invention is not limited thereto.It in the present invention, such as can also be in recess portion 200 Bottom surface 200b at least part at formed as the rotation axis (i.e. the 2nd axis X 2) towards pinion gear 130 is to side tooth Wheel 131,132 radial outside it is inclined (towards pinion gear 130 rotary shaft line side and tilt down) circular conical surface (inclined-plane). In this case, it is desirable to which the gradient of circular conical surface (inclined-plane) is for example set such that circular conical surface and back side 130f (therefore are small Gear washer 140) be substantially face contact small skew degree.

In the 2nd embodiment, differential casing 116 and pinion gear 130 and the 1st, the 2nd side gear 131, On the 132 corresponding inner surface 116i of each back side 130f, 131f, 132f, be formed with specific inner surface 116i recess recess portion 200, 201,202.Also, each back side 130f, 131f, 132f are across corresponding pinion gear washer 140 or side gear washer 141,142 can be supported on recess portion 200,201,202 respective bottom surface 200b, 201b, 202b in a manner of rotational slide.

Also, when differential gear 111 works, pinion gear 130 is reached along the inner surface 116i of differential casing 116 And the 1st, the 2nd side gear 131,132 each back side 130f, 131f, 132f near lubricating oil easily accumulate in phase For in the recess portion 200,201,202 of the inner surface 116i recess of differential casing 116.

Therefore, the lubricating oil lodged in recess portion 200,201,202 can sufficiently be supplied to each back side 130f, 131f, 132f and corresponding pinion gear washer 140 and side gear washer 141,142 mutual rotational slide faces. Thereby, it is possible to efficiently use each back side 130f, 131f, 132f and corresponding pinion gear washer 140 and side gear Washer 141,142 is lubricated.

Thus, according to the 2nd embodiment, can be improved between the back side 130f of pinion gear 130 and differential casing 116 The greasy property in rotational slide face.Further, it is possible to improve the back side 131f, 132f and differential of the 1st, the 2nd side gear 131,132 The greasy property in the rotational slide face between device shell 116.

In addition, even if making pinion gear 130 in omission pinion gear washer 140 and side gear washer 141,142 And the 1st, the 2nd side gear 131,132 the back side 130f, 131f, 132f directly with the bottom of corresponding recess portion 200,201,202 In the case that face 200b, 201b, 202b are contacted, also the lubricating oil lodged in recess portion 200,201,202 can fully be supplied It is given to the back side 130f, 131f, 132f and the corresponding mutual rotational slide face bottom surface 200b, 201b, 202b.Thereby, it is possible to Improve the greasy property in the rotational slide face between the back side 130f and differential casing of pinion gear 130.Further, it is possible to improve 1, the greasy property in the rotational slide face between the back side 131f, 132f and differential casing of the 2nd side gear 131,132.

More than, embodiments of the present invention are illustrated, but the present invention is not limited to above-mentioned embodiment, It is able to carry out various design alterations within the scope of its spirit.

For example, differential gear is accommodated in the transmission housing body of automobile in the first and second embodiments, but this hair It is bright to be not limited to this.Differential gear of the invention is not limited to the differential gear of automobile, can be used as various machines The differential gear of tool device is implemented.

Also, in the first and second embodiments, the transmission system that differential gear is applied to the left and right wheels of vehicle is shown And the case where distributing power to the drive shaft of left and right while allowing differential speed rotation, but the present invention is not limited thereto.At this In invention, such as differential gear applied to the transmission system of the front and back wheel in the vehicle of front and back wheel drive and can also allowed Power is distributed to the driving wheel of front and back while differential speed rotation.

Also, in the 1st embodiment, as bearing part 7 and the 1st, the 2nd cover member 21,22 respectively between combination Means instantiate while applying the means of bolt and welding, but the present invention is not limited thereto.In the present invention, it such as props up Bearing portion part 7 and the 1st, the 2nd cover member 21,22 respectively between can all be combined by bolt, or can also all pass through welding To combine.Furthermore be also possible to bearing part 7 and the 1st, the 2nd cover member 21,22 respectively between all by bolt or except welding with Outer engagement means combine.

Also, in the 2nd embodiment, the present invention is made of single pinion shaft, but be not restricted to that this.In the present invention In, multiple pinion shafts can also be arranged according to the quantity of pinion gear.

Also, in the first and second embodiments, the peripheral part instantiated in differential casing 16,116 has in outer peripheral surface Be provided with gear teeth ring component (slave unit) 20 or gear ring (driven gear) 120 using as receive the power from power source The case where being entered portion, but the present invention is not limited thereto.It in the present invention, such as can also be by the driven wheel other than gear ring (such as driven sprocket, driven pulley etc.) is combined as the portion that is entered and differential casing (input part).Also, in the present invention In, such as can also be by the various power transfer mechanisms and reduction gear that are connect with power source (such as planet Gear type deceleration mechanism) output block and the 1st embodiment the 1st, the 2nd cover member 21,22 in any one cover member Lateral surface combine.