JP2000291776A - Differential device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a load from being concentrated to a specific pinion shaft. SOLUTION: This device has a bevel gear type differential gear having a set of pinion shaft 1 rotating integrally with a differential case, a pinion gear supported by a set of pinion shaft 1 and a pair of output side gear meshed with the pinion gear. The set of pinion shaft 1 is composed of a long pinion shaft 3 whose both ends are connected to the differential case through a boss 7 and a short pinion shafts 5, 5 arranged between the differential case and pinion shaft 3 and a recessed part 13 is provided on the center of the pinion shaft 3. The inside ends of respective pinion shaft 5 are penetrated in the recessed part 13 and also the outside end of the pinion shaft 5 is fixed to the differential case by a pin 9.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a differential device.

[0002]

2. Description of the Related Art FIG.
01 is described.

This is a differential device provided with a bevel gear type differential mechanism, and its pinion shaft set 2
Numeral 03 is composed of one long pinion shaft 205 and two short pinion shafts 207, 207.

[0004] The long pinion shaft 205 is connected by engaging both ends thereof with the through holes 211 of the differential case 209. The short pinion shaft 207 has an outer end engaged with the through hole 211 and fixed to the differential case 209 by a pin 213, and an inner end abuts against the long pinion shaft 205.

The pinion shaft 205 is provided with a boss 215
, And each pinion shaft 205 is engaged with the through hole 217 to support the inner end.

The differential case 209 is a pinion shaft set 2
03 is divided into two in the axial direction at the location of
Numeral 11 is formed on the mating surface of this divided part.

A pinion gear 219 is supported on each of the pinion shafts 205 and 207.

FIG. 11 shows another conventional pinion shaft set 221.
Is composed of four short pinion shafts 223.

The outer end of each pinion shaft 223 is engaged with the through hole 211 of the differential case 209 and the pin 213 is engaged.
And the inner tips formed at right angles abut each other. Each of the pinion shafts 223 is engaged with the through hole 217 of the boss 215 to support the inner end.

[0010]

However, in the conventional example of FIG. 10 in which the short pinion shaft 207 is abutted against the long pinion shaft 205, the load tends to concentrate on the high rigidity long pinion shaft 205, and the pinion gear 219
A strong contact occurs at the sliding portion 225 between the first and second sliding members.

Therefore, the pinion shaft 205 needs to be coated with CN or TiN, or to be subjected to a special heat treatment in order to prevent abrasion and improve durability. Ting and heat treatment are expensive.

On the other hand, in the conventional example shown in FIG. 11, since the respective pinion shafts 223 are set to the same condition, the load is not biased to a specific pinion shaft 223.

However, the number of components is increased only by the pin 213 for fixing the pinion shaft 223, and the cost is increased.

Further, the fixing function of the pin 213 may have insufficient reliability.

Therefore, the present invention prevents the load from being concentrated on a specific pinion shaft, eliminates the need for expensive coating, reduces the number of parts, and improves the reliability of the bevel gear type differential device. The purpose is to provide.

[0016]

According to a first aspect of the present invention, there is provided a differential device including a pinion shaft set radially arranged about a boss and rotating integrally with a differential case, and a pinion gear supported on each pinion shaft. A differential mechanism of a bevel gear type having a pair of output side gears meshed with a pinion gear, wherein the pinion shaft set penetrates a boss and has a long pinion shaft having both ends connected to a differential case; and a differential case. A short pinion shaft disposed between the long pinion shaft and a long pinion shaft, a central portion of the long pinion shaft is provided with a concave portion for adjusting rigidity, the short pinion shaft penetrates the concave portion, and the short pinion shaft Is the default case,
Alternatively, a fixing means for fixing to a long pinion shaft is provided.

As described above, in the differential device according to the first aspect, the concave portion is provided at the center portion of the long pinion shaft whose both ends are connected to the differential case, thereby adjusting the rigidity to provide appropriate flexibility and providing the short pinion. The rigidity was evened between the shaft and the shaft.

As a result, unlike the conventional example, the load is evenly distributed to each pinion shaft, and the durability is greatly improved.

Therefore, it is not necessary to apply expensive coating or special heat treatment to the long pinion shaft for the purpose of increasing the hardness and durability, so that a large cost increase accompanying these can be avoided.

Further, the short pinion shaft is fixed to the differential case or the long pinion shaft by fixing means.

(1) In addition to inputting the driving force of the engine from the differential case, for example, the driving force of the engine may be input to the boss to drive the pinion shaft.

As described above, in the configuration in which the pinion shaft is on the input side and a large torque is applied, the effect of the present invention for equalizing the load on each pinion shaft and improving the durability is particularly large.

(2) In the case of a free running differential (FRD) in which the outer case and the inner case are connected and disconnected by a clutch, the differential case is replaced by the inner case. Become.

(3) If the pinion shaft can be penetrated or engaged with the boss and the boss from outside, there is no need to divide the defender at the location where the pinion shaft assembly is arranged. This is advantageous in terms of the strength of the differential case, weight, parts cost, and the like.

The same applies to (1) to (3) in the following claims.

According to a second aspect of the present invention, in the differential device according to the first aspect, the fixing means is a fixing member for fixing the short pinion shaft to the differential case. Get the same effect.

In addition, a fixing member such as a pin for fixing the short pinion shaft to the differential case is inexpensive and can be implemented at a lower cost.

According to a third aspect of the present invention, there is provided the differential device according to the first aspect, wherein the fixing means is provided between the short pinion shaft and the long pinion shaft, and the meshing means connects the short pinion shaft in its axial direction. And an effect equivalent to that of the first aspect is obtained.

In addition, the fixing means for connecting the end of the short pinion shaft to the long pinion shaft by the engagement portion has a high fixing function, and has high durability and reliability against centrifugal force.

Further, since a fixing member such as a pin is not used, the number of parts and the cost are reduced, and the reliability is improved.

The invention of claim 4 is the first to third aspects of the present invention.
The differential device according to any one of the above, wherein the concave portion provided in the long pinion shaft, a tapered small diameter portion whose diameter changes in the axial direction, or a cylindrical small diameter portion, or It is a plate-like part with a constant thickness.Select the taper gradient and minimum diameter, or the diameter of the cylindrical part, or the thickness of the plate-like part, respectively, and make the long pinion shaft to the desired rigidity. The present invention is characterized in that it has been adjusted, and an effect equivalent to any one of claims 1 to 3 is obtained.

In addition to this, if the gradient and the minimum diameter of the taper provided on the long pinion shaft, the diameter of the cylindrical small diameter portion, or the thickness of the plate portion are changed, the length of the long pinion shaft is changed. The rigidity can be finely adjusted, the rigidity can be easily adjusted with a short pinion shaft, and the durability of each pinion shaft can be further improved.

The invention of claim 5 is the invention of claims 1 to 4
The differential device according to any one of claims 1 to 3, wherein a recess provided in the long pinion shaft and into which a different short pinion shaft penetrates overlaps in an axial direction of the long pinion shaft. age,
An effect equivalent to any one of claims 1 to 4 is obtained.

In addition to this, the concave portions provided in the long pinion shaft are overlapped in the axial direction, so that the portions connecting the bearing portions of the pinion gear (the portions forming these concave portions) are elongated. Therefore, the rigidity of the long pinion shaft can be sufficiently reduced as required.

Also, similarly to the fourth aspect, by changing the depth of the concave portion and the thickness of the portion forming the concave portion, the rigidity of the long pinion shaft can be finely adjusted. Therefore, the rigidity can be easily adjusted, and the durability of each pinion shaft is further improved.

A differential device according to a sixth aspect of the present invention is a differential device which is radially arranged around a boss, and which is a group of pinion shafts which rotate integrally with the differential case, a pinion gear supported on each pinion shaft, and a pair of gears meshed with the pinion gear. And a bevel gear type differential mechanism having an output side gear of the above, wherein the pinion shaft set includes a plurality of pinion shafts disposed between a differential case and a boss, and the end of each pinion shaft is It is characterized in that it is connected in the respective axial directions by meshing portions provided between each other.

In the differential device according to the sixth aspect, the ends of the respective pinion shafts constituting the pinion shaft assembly are connected in the respective axial directions by meshing portions provided between each other.

As described above, since each pinion shaft is made substantially equal in length, unlike the conventional example in which the rigidity becomes uneven between the long pinion shaft and the short pinion shaft due to the use of each pinion shaft, No unevenness in rigidity occurs between the pinions, the load is evenly distributed to the pinion shafts, and the durability is greatly improved.

Accordingly, it is not necessary to apply expensive coating or special heat treatment to the pinion shaft for the purpose of increasing the hardness and durability, and it is possible to avoid a large increase in cost accompanying this.

Further, if the shape of the meshing portion provided at the end of each pinion shaft is made the same, it is possible to use a common pinion shaft, so that the pinion shaft set can be replaced by the same pinion shaft. Because it can be configured, the type and cost of parts are greatly reduced.

According to a seventh aspect of the present invention, there is provided the differential device according to the sixth aspect, wherein at least one of the plurality of pinion shafts constituting the pinion shaft set includes:
The present invention is characterized in that it penetrates into a concave portion provided in another pinion shaft and is fixed to a differential case by a fixing member.

In addition, by fixing at least one pinion shaft to the differential case with a fixing member such as a pin, the function of fixing to the differential case and the durability of each pinion shaft are improved accordingly.

[0043]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A bevel gear type differential device according to a first embodiment of the present invention will be described with reference to FIG.

FIG. 1 shows a pinion shaft set 1 used in this differential device. This differential device has the features of claims 1, 2 and 4.
In addition, members and the like without reference numerals are not shown.

The differential device of the first embodiment is
It comprises a differential case to which the driving force of the engine is input, a bevel gear type differential mechanism for receiving rotation of the differential case, and the like.

This bevel gear type differential mechanism comprises a pinion shaft set 1, a pinion gear supported by the pinion shaft set 1, a pair of output side gears meshing with the pinion gear, and the like.

The pinion shaft set 1 is composed of a long pinion shaft 3, two short pinion shafts 5, 5, and a boss 7, and a pinion gear is supported on each of the pinion shafts 3, 5.

The differential case is divided into two parts in the axial direction at the position where the pinion shaft set 1 is disposed, and the following through holes with which the pinion shafts 3 and 5 are engaged are formed on the mating surfaces of the divided parts. .

The long pinion shaft 3 is connected by engaging both ends with through holes of the differential case.

Each of the short pinion shafts 5 has an outer end engaged with a through hole of the differential case, is fixed in a differential case by a pin 9 (fixing means: fixing member), and receives centrifugal force.

The central portion of the long pinion shaft 3 is provided with a concave portion 1 radially inward of the support portion 11 of the pinion gear.
3 and 13 are formed, and the inner end of the short pinion shaft 5 penetrates these recesses 13.

The boss 7 is provided with through holes 15, 15 at right angles to each other. The long pinion shaft 3 passes through one of the through holes 15, and the short pinion shaft 5 is connected to the other of the other. The inner end is supported by engaging with the through hole 15.

Each output side gear is connected to each wheel via an axle.

The driving force of the engine for rotating the differential case is distributed from the pinion shaft set 1 and the respective pinion gears to the respective wheels via the side gears.

When a difference in driving resistance occurs between the wheels on a bad road or the like, the driving force of the engine is differentially distributed to each wheel due to the rotation of the pinion gear.

The long pinion shaft 3 is
Is provided, the rigidity is reduced, moderate flexibility is given, and the rigidity between the short pinion shafts 5 and 5 is adjusted to be uniform.

The recess 13 of the long pinion shaft 3
May be formed in a plate shape or a circular cross section. In any case, recess 1
The inner end of the short pinion shaft 5 penetrating into 3 is shaped to match the shape of the recess 13.

When the concave portion 13 provided on the long pinion shaft 3 has a circular cross section, the diameter of the concave portion 13
Is a plate shape, the pinion shaft 3 is made to have a desired rigidity by selecting its thickness to an appropriate value.

Thus, the differential device according to the first embodiment is configured.

As described above, in this differential device, the long pinion shaft 3 is provided with the concave portion 13 to provide flexibility, and the rigidity between the short pinion shafts 5 and 5 is equalized.

As a result, unlike the conventional example, the load is evenly distributed to the pinion shafts 3, 5, and 5, and the durability is greatly improved.

Accordingly, it is not necessary to apply expensive coating or special heat treatment to the long pinion shaft 3 for the purpose of increasing hardness and durability, thereby avoiding a large cost increase.

The pins 9 for fixing the pinion shaft 5 to the differential case are inexpensive, and can be implemented at a lower cost.

As described above, the recess 13 (portion 16)
By changing the diameter and thickness of the pinion shaft 3
Since the rigidity of the pinion shafts 3 and 5 can be finely adjusted, the rigidity can be easily adjusted between the pinion shafts 5 and 5 and the durability of each of the pinion shafts 3 and 5 can be greatly improved.

Further, the long pinion shaft 3 is made to penetrate through the through holes 15 of the boss 7 from outside the differential case, and then the short pinion shaft 5 is formed through the through hole 15 of the boss 7 and the pinion shaft from outside the differential case. When the pinion 3 is engaged with the recess 13, it is not necessary to divide the differential case at the position where the pinion shaft set 1 is arranged, which is advantageous in terms of the strength, weight, parts cost and the like of the differential case.

Further, the boss 7 may be formed integrally,
Alternatively, a two-part structure may be used depending on the conditions for assembling the pinion shafts 3 and 5.

In addition to the input of the driving force of the engine from the differential case, the driving force of the engine may be input to the boss 7 to drive the pinion shaft set 1 to rotate.

As described above, in the configuration in which a large torque is applied to the directly driven pinion shaft set 1, the effect of the present invention for equalizing the loads on the pinion shafts 3, 5, and 5 and improving the durability is particularly large.

Further, a free running differential (FR.R.) in which the outer case and the inner case are connected and disconnected by a clutch.
In the case of D), the differential case may be changed to the inner case.

Next, a bevel gear type differential device according to a second embodiment will be described with reference to FIGS.

Each of the figures shows a pinion shaft set 17 used in the differential device, and the differential device has the features of claims 1, 2 and 4. In addition, members and the like without reference numerals are not shown.

Hereinafter, members having the same functions as those of the differential device according to the first embodiment are given the same reference numerals and quoted.

The pinion shaft set 17 includes a long pinion shaft 3, two short pinion shafts 5, 5,
And a boss 7.

A concave portion 19 is formed in the center of the long pinion shaft 3, and the concave portion 19 forms a plate-like portion 21 having a constant thickness.

The inner end of the short pinion shaft 5 penetrates the recess 19.

The pinion shaft 3 is given a desired rigidity by making the plate portion 21 have an appropriate thickness.

As described above, the long pinion shaft 3 is given appropriate flexibility, and the rigidity between the long pinion shaft 3 and the short pinion shafts 5 is adjusted to be equal.

FIGS. 3 and 4 show an example in which a small-diameter cylindrical portion 23 is provided at the center of the long pinion shaft 3, and a concave portion 25 is formed by the cylindrical portion 23.

The inner end 27 of the short pinion shaft 5 penetrates the recess 25 and is in contact with the cylindrical portion 23.

The long pinion shaft 3 is given an appropriate flexibility by the concave portion 25, and is adjusted so that the rigidity is equal to that of the short pinion shaft.

At this time, the diameter of the cylindrical portion 23 of the long pinion shaft 3 is selected so that the pinion shaft 3 has a desired rigidity.

Thus, the differential device according to the second embodiment is configured.

As described above, in this differential device, the long pinion shaft 3 is provided with the concave portions 19 and 25,
Since the rigidity is equalized between the short pinion shafts 5, 5, the load is evenly distributed to the pinion shafts 3, 5, 5 unlike the conventional example, and the durability is greatly improved.

The rigidity of the pinion shaft 3 can be finely adjusted by changing the thickness of the plate portion 21 and the diameter of the cylindrical portion 23.
Since the adjustment of the rigidity is easier, the effect of improving the durability of each of the pinion shafts 3 and 5 is great.

In addition, the differential device according to the second embodiment has the same effect as the first embodiment except for the features of the first embodiment.

Next, a bevel gear type differential device according to a third embodiment will be described with reference to FIG.

FIG. 5 shows a pinion shaft set 29 used in this differential device. This differential device has the features of claims 1, 2 and 4. In addition, members and the like without reference numerals are not shown.

Hereinafter, members having the same functions as those of the differential devices of the first and second embodiments are given the same reference numerals and quoted.

The pinion shaft set 29 includes a long pinion shaft 3, two short pinion shafts 5, 5,
And a boss 7.

At the center of the long pinion shaft 3, a tapered small-diameter portion 31 is formed.
1 forms a recess 33. The inner end of the short pinion shaft 5 penetrates this recess 33.

The long pinion shaft 3 is given an appropriate flexibility by the concave portion 33, and the rigidity between the short pinion shaft 5 and the short pinion shaft 5 is evenly adjusted.

At this time, the gradient and the minimum diameter of the tapered small diameter portion 31 are selected so that the pinion shaft 3 has a desired rigidity.

Thus, the differential device according to the third embodiment is configured.

As described above, in this differential device, the concave portion 33 is provided in the long pinion shaft 3 and the rigidity between the short pinion shafts 5 and 5 is equalized.
Unlike the conventional example, the load is applied to each of the pinion shafts 3, 5,
5, and the durability is greatly improved.

Further, the rigidity of the pinion shaft 3 can be finely adjusted by changing the gradient and the minimum diameter of the tapered small-diameter portion 31, so that the rigidity adjustment with the short pinion shaft 5 is only accordingly. It is easy and the effect of improving the durability of each of the pinion shafts 3 and 5 is great.

In addition, the differential device of the third embodiment has the same effects as those of the first and second embodiments except for the features of the first and second embodiments.

Next, a bevel gear type differential device according to a fourth embodiment will be described with reference to FIG.

FIG. 6 shows a pinion shaft set 35 used in this differential device. This differential device has the features of claims 1, 2, 4, and 5. In addition, members and the like without reference numerals are not shown.

Hereinafter, members having the same functions as those of the differential devices of the first, second, and third embodiments are given the same reference numerals and quoted.

The pinion shaft set 35 includes a long pinion shaft 3, two short pinion shafts 5, 5,
And a boss 7.

In the center of the long pinion shaft 3, recesses 37, 37 into which the short pinion shaft penetrates are provided in opposite directions, and are provided so as to overlap in the axial direction of the pinion shaft 3. ing.

The inner ends of the short pinion shafts 5 penetrate into the recesses 37, respectively.

The long pinion shaft 3 is provided with appropriate flexibility by these concave portions 37, and is adjusted so that the rigidity between the long pinion shaft 3 and the short pinion shaft 5 becomes equal.

At this time, the concave portion 3 of the long pinion shaft 3
7 and the thickness of the portion 39 forming the concave portion 37 are selected so that the pinion shaft 3 has a desired rigidity.

Thus, the differential device according to the fourth embodiment is configured.

As described above, in this differential device, the long pinion shaft 3 is provided with the concave portions 37, 37,
Since the rigidity is equalized between the short pinion shafts 5, 5, the load is evenly distributed to the pinion shafts 3, 5, 5 unlike the conventional example, and the durability is greatly improved.

Further, the rigidity of the pinion shaft 3 can be finely adjusted by changing the depth of the concave portion 37 and the thickness of the portion 39 forming the concave portion 37.
The adjustment of the rigidity with the short pinion shaft 5 is easier, and the effect of improving the durability of each of the pinion shafts 3 and 5 is great.

Also, since the concave portion 37 is overlapped, the portion 39 forming the concave portion 37 becomes longer.
If necessary, the rigidity of the long pinion shaft 3 can be sufficiently reduced.

In addition to this, the differential device according to the fourth embodiment is different from the first, second, and third embodiments except for the features.
An effect equivalent to these is obtained.

Next, a bevel gear type differential device according to a fifth embodiment will be described with reference to FIG.

FIG. 7 shows a pinion shaft set 41 used in this differential device. This differential device has the features of claims 1, 2 and 7. In addition, members and the like without reference numerals are not shown.

Hereinafter, members having the same functions as those of the differential devices of the first, second, third, and fourth embodiments are given the same reference numerals and are quoted, and redundant description of these same members is omitted.

The pinion shaft set 41 is composed of two pinion shafts 43, a pinion shaft 45, a pinion shaft 47, and the boss 7.

Each of the pinion shafts 43, 45, 47 supports a pinion gear.

A pair of output side gears meshing with the pinion gears are connected to the respective wheels via an axle. The driving force of the engine for rotating the differential case is as follows.
It is distributed to the wheel side from the pinion shaft set 41 and each pinion gear via each side gear. Further, when a driving resistance difference occurs between the wheels on a bad road or the like, the driving force of the engine is differentially distributed to each wheel side by the rotation of the pinion gear.

At the end of the pinion shaft 43, there are provided a meshing portion 49 (fixing means) meshing with the mating side and a meshing portion 51 (fixing means) meshing with the mating side.

The pinion shaft 45 has a meshing portion 53 meshing with the meshing portion 51 of the pinion shaft 43.
(Fixing means) is provided.

The pinion shaft 47 has a meshing portion 55 with which the meshing portion 49 of the pinion shaft 43 meshes.
(Fixing means) is provided.

One pinion shaft 43 is fixed in the radial direction of the differential case by meshing between a meshing portion 49 and a meshing portion 55 of the pinion shaft 47.
The other pinion shaft 43 is fixed in the radial direction of the differential case by the engagement of the engagement portion 49 with the engagement portion 51 of the one pinion shaft 43.

The pinion shaft 45 is fixed in the radial direction by meshing between the meshing portion 53 and the meshing portion 51 of the pinion shaft 43.

The pinion shaft 47 is fixed in a differential case by the pins 9 and receives a centrifugal force.

Further, each of the pinion shafts 43, 43, 4
5 and 47 are engaged with the through holes 15 of the boss 7 to support the inner ends.

Thus, the differential device according to the fifth embodiment is configured.

As described above, this differential device is different from the conventional example in which the rigidity is uneven between the long and short pinion shafts, and the respective pinion shafts 43, 43, 4
By making the lengths of the pinion shafts 43, 43, 4 and 4 equal, the rigidity between the pinion shafts 43, 43, 4
The loads are evenly distributed to 5, 47, and the durability is greatly improved.

Therefore, in order to increase hardness and durability, expensive pinion shafts 43, 43, 45, 47 are used.
Therefore, it is not necessary to perform a heating and a special heat treatment, thereby avoiding a large increase in cost.

Each of the pinion shafts 43, 43, 4
A structure is adopted in which the ends 5 and 47 are connected at each end, and two identical pinion shafts 43 are used, so that the type and cost of parts are reduced accordingly.

Further, since the pinion shaft 47 is fixed to the differential case with the pin 9, the pinion shaft set 41 is fixed.
The fixing function for the differential case is improved accordingly.

Next, a bevel gear type differential device according to a sixth embodiment will be described with reference to FIG.

FIG. 8 shows a pinion shaft set 57 used in this differential device. This differential device has the features of the first, second and sixth aspects. In addition, members and the like without reference numerals are not shown.

In the following, members having the same functions as those of the differential device of the fifth embodiment are given the same reference numerals and are quoted, and redundant description of these same members will be omitted.

The pinion shaft set 57 is composed of four identical pinion shafts 59 and the boss 7.

Each of the pinion shafts 59 supports a pinion gear, and a pair of output side gears meshing with the pinion gear are connected to the respective wheels via axles.

The driving force of the engine for rotating the differential case is distributed to each wheel side from the pinion shaft set 57 and each pinion gear via the side gears. By rotation,
The driving force of the engine is differentially distributed to each wheel side.

At the end of each pinion shaft 59, there are provided a meshing portion 61 (fixing means) meshing with the mating side and a meshing portion 63 (fixing means) meshing with the mating side.

Each of the pinion shafts 59 is
1 engages with the mating portion 63 on the other side, and thus each is fixed to each other in the radial direction of the differential case.

Further, each of the pinion shafts 59 is engaged with the through hole 15 of the boss 7 to support the inner end.

Thus, the differential device according to the sixth embodiment is configured.

As described above, this differential device is different from the conventional example in that the pinion shaft set 57 is constituted by four identical pinion shafts 59,
The rigidity becomes uniform among them, the load is evenly distributed to each pinion shaft 59, and the durability is greatly improved.

Accordingly, it is not necessary to apply expensive coating or special heat treatment to each pinion shaft 59 in order to increase the hardness and durability, thereby avoiding a large increase in cost.

In addition, a structure is adopted in which the pinion shafts 59 are connected at their respective ends, and the pinion shaft set 57 is composed of four identical pinion shafts 59 as described above. It is greatly reduced.

In addition to this, the differential device of the sixth embodiment has the same effect except for the features of the fifth embodiment.

FIG. 9 shows another boss 65.

The boss 65 is ring-shaped and has a differential
Placed coaxially with the The boss 65 has four through holes 67
Are provided at equal intervals in the circumferential direction, and in each of the above embodiments, the pinion shaft penetrates or engages with each through hole 67.

According to the third aspect of the present invention, the short pinion shaft is connected in the radial direction of the differential case by a meshing portion provided between the short pinion shaft and the long pinion shaft.
It is fixed.

As described above, the fixing means for connecting the short pinion shaft to the long pinion shaft by the engagement portion has a high fixing function and a high durability against centrifugal force.

Further, since a fixing member such as a pin is not used, the number of parts and the cost are reduced, and the reliability is improved.

[0147]

According to the differential device of the first aspect, a concave portion is provided in a long pinion shaft and rigidity is equalized with a short pinion shaft.
The load is evenly distributed to each pinion shaft, and the durability is greatly improved.

Therefore, it is not necessary to apply expensive coating or special heat treatment to the long pinion shaft, and it is possible to avoid a large increase in cost accompanying this.

According to the second aspect of the invention, the same effect as that of the first aspect can be obtained, and the short pinion shaft can be deflected.
A fixing member such as a pin for fixing to a wire is inexpensive and can be implemented at a lower cost.

According to the third aspect of the present invention, the same effect as that of the first aspect is obtained, and the fixing means for fixing the short pinion shaft by meshing it with the long pinion shaft has a high fixing function and is durable against centrifugal force. Is high.

Further, since a fixing member such as a pin is not used, the number of parts and the cost are reduced, and the reliability is improved.

The invention of claim 4 is the invention of claims 1 to 3
In addition to obtaining the same effect as any one of the above, the rigidity of the long pinion shaft can be finely adjusted by changing the gradient and minimum diameter of the small diameter portion of the taper, the diameter of the cylindrical small diameter portion, and the thickness of the plate portion, respectively. Therefore, the rigidity can be easily equalized between the short pinion shafts and the durability of each pinion shaft is greatly improved.

The invention of claim 5 is the invention of claims 1 to 4
In addition to obtaining the same effect as any one of
By wrapping, the rigidity of the long pinion shaft can be sufficiently reduced as necessary.

The rigidity of the long pinion shaft can be finely adjusted by changing the depth of the concave portion and the thickness of the portion forming the concave portion, and the rigidity can be easily equalized with the short pinion shaft. And the effect of improving the durability of each pinion shaft is great.

In the differential device according to the sixth aspect, since each pinion shaft is made equal in length, unlike the conventional example using the long and short pinion shafts, the load is evenly distributed to each pinion shaft, and the durability is greatly improved. This eliminates the need for expensive coating and special heat treatment on each pinion shaft, thereby avoiding a large increase in cost.

Further, since the pinion shaft set can be constituted by the same pinion shaft, the type and cost of parts are greatly reduced.

According to the seventh aspect of the present invention, the same effect as that of the sixth aspect is obtained, and at least one pinion shaft is fixed to the differential case with a pin or the like, so that the fixing function for the differential case and each pinion can be achieved. The durability of the shaft is further improved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a pinion shaft set used in a first embodiment of the present invention.

FIG. 2 is a sectional view showing a pinion shaft set used in a second embodiment.

FIG. 3 is a perspective view showing a state where another pinion shaft set according to the second embodiment is disassembled.

FIG. 4 is a view showing a state where the pinion shaft sets of FIG. 3 are connected.

FIG. 5 is a sectional view showing a pinion shaft set used in a third embodiment.

FIG. 6 is a sectional view showing a pinion shaft set used in a fourth embodiment.

FIG. 7 is a sectional view showing a pinion shaft set used in a fifth embodiment.

FIG. 8 is a sectional view showing a pinion shaft set used in a sixth embodiment.

FIG. 9 is a front view showing a boss used in each embodiment.

FIG. 10 is a sectional view showing a pinion shaft set used in the first conventional example.

FIG. 11 is a cross-sectional view illustrating a pinion shaft set used in a second conventional example.

[Explanation of symbols]

1, 17, 29, 35, 41, 57 Pinion shaft set 3 Long pinion shaft 5 Short pinion shaft 7, 65 Boss 9 Pin (fixing means: fixing member) 11 Pinion gear support portion of long pinion shaft 13, 19, 25, 33 Depressed portion provided on long pinion shaft 21 Plate-shaped portion provided on long pinion shaft with constant thickness 23 Cylindrical small diameter portion provided on long pinion shaft 31 Tapered shape provided on long pinion shaft The small diameter portion of 37 is provided on a long pinion shaft and
Depressed portions 43, 45, 47 Pinion shafts 49, 51 Meshing portions (fixing means) provided on pinion shaft 43 53 Meshing portions (fixing means) provided on pinion shaft 45 55 Meshing portions provided on pinion shaft 47 (Fixing means) 59 Same pinion shafts 61 and 63 Meshing portions provided on pinion shaft 59 (Fixing means)

Claims (7)

[Claims] 1. A pinion shaft set radially arranged about a boss and rotating integrally with a differential case, a pinion gear supported on each pinion shaft, and a pair of output side gears meshed with the pinion gear. A long pinion shaft penetrating the boss and having both ends connected to a differential case, and a short pinion shaft disposed between the differential case and the long pinion shaft. The long pinion shaft is provided with a concave portion for adjusting rigidity at a central portion thereof. The short pinion shaft penetrates the concave portion, and the short pinion shaft is deflected.
Or a fixing device for fixing to a long pinion shaft. 2. The differential device according to claim 1, wherein the fixing means is a fixing member for fixing the short pinion shaft to the differential case. 3. The invention according to claim 1, wherein the fixing means is a meshing portion provided between the short pinion shaft and the long pinion shaft and connecting the short pinion shaft in the axial direction. Differential device. 4. The tapered small-diameter portion according to claim 1, wherein the concave portion provided in the long pinion shaft has a tapered shape whose diameter changes in the axial direction. ,
Alternatively, select a cylindrical small diameter part or a plate part with a constant thickness, and select the taper gradient and minimum diameter, or the diameter of the cylindrical part or the thickness of the plate part, respectively. And
A differential device wherein a long pinion shaft is adjusted to a desired rigidity. 5. The invention according to claim 1, wherein the recess provided in the long pinion shaft and through which a different short pinion shaft penetrates is provided.
A differential device characterized by being overlapped in the axial direction of a long pinion shaft. 6. A pinion shaft set radially arranged about a boss and rotating integrally with a differential case, a pinion gear supported on each pinion shaft, and a pair of output side gears meshed with the pinion gear. A differential mechanism of a bevel gear type, wherein the pinion shaft set includes a plurality of pinion shafts disposed between a differential case and a boss, and ends of the respective pinion shafts are provided between each other. A differential device characterized by being connected in the respective axial directions by a mating portion. 7. The fixing member according to claim 6, wherein at least one of the plurality of pinion shafts constituting the pinion shaft set penetrates into a recess provided in another pinion shaft. A differential device fixed to the differential case by means of