JPH08261308A - Differential gear - Google Patents

Abstract

PURPOSE: To provide such a differential gear that uses a bolt as it is, minimizes its change, has a cheap and simple structure, and reduces load applied on the bolt. CONSTITUTION: A diameter in one side facing to the boundary between a gear base 20 and a support base 21a of respective hole parts 30, 31 for bolt insertion which are positioned in the gear base 20 of a differential case 16 and the support base 21a of a ring gear 21 is formed larger than the bolt diameter, a ring recessed part is provided locally only around the boundary, a collar 34 is inserted in this recessed part, a bolt 22 is inserted between the holes 30, 31 through this collar 34, and the gear base 20 and the support base 21a are fastened each other. This constitution provides the bolt with high rigidity, as if the bolt diameter is increased, so that it can withstand repeated load such as bending stress and shear force applied from the boundary between the differential case 16 and the ring gear 21.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a differential device in which a final reducer is integrated.

[0002]

2. Description of the Related Art Normally, a truck is provided with a rear axle 2 connected to rear wheels 1, 1 at the rear portion of the vehicle as shown in FIG. 5, and an output from an engine 3 mounted on the front portion of the vehicle is provided on the rear axle 2. Is being communicated.

More specifically, the power transmission system of this truck will be described. A clutch device 4 and a transmission device 5 are sequentially connected in series to an output portion of an engine 3, and a differential device 6 is incorporated in a central portion of a rear axle 2. Has been.

Then, these transmission devices 5
Between the output part of and the input part of the differential device 6,
They are connected by a propeller shaft 7, and the engine rotation output from the transmission device 5 is transmitted to the rear wheels 1 and 1 at both ends of the rear axle 2 through the propeller shaft 7 and the differential device 6.
In addition, 1a has shown the front wheel which comprises a steering wheel.

In the differential device 5 employed in such a power transmission system, the input rotation is decelerated and then output to a pair of output shafts 9, 9 extending in the vehicle width direction through a differential mechanism 8. , A structure for transmitting power to the rear wheels 1, 1 is used.

That is, the differential device 5 includes a differential housing 10 formed in an intermediate portion of the rear axle 2.
And the differential carrier 1 for closing the opening of the differential housing 10.
It is housed in a machine room 12 formed by 1.

Specifically, a structure as shown in FIGS. 6 and 7 is used. Explaining the structure inside the machine room 12, the input shaft 13 of the differential device 5 will be described.
Is provided so as to penetrate the front portion of the differential carrier 11.

The input shaft 13 is arranged in a front-rear direction which is substantially perpendicular to the output shafts 9 and 9, and both ends thereof are bearings 14.
It is rotatably supported by. The propeller shaft 7 is connected to the end portion of the input shaft 13 protruding outside.

A pinion 15 is provided at the end of the remaining input shaft 13 protruding into the machine chamber 12. Machine room 12
Inside, a differential mechanism 8 employing a bevel gear is provided.

Here, the differential mechanism 8 will be described. Reference numeral 16 is a differential case provided in the machine room 12.
The differential case 16 has, for example, a substantially tubular shape extending in the coaxial direction with the output shaft 9, and both end sides thereof are supported by bearings 17 (only one side is shown) so as to be rotatable in the rotation direction of the output shaft 9.

A pair of side gears 18, 18 is rotatably incorporated in the differential case 16 so as to face the axial direction of the output shafts 9, 9. Further, the differential case 16 is rotatably assembled with a pair of pinion gears 19 meshing with the side gears 18, 18 in a direction perpendicular to the axial direction of the output shafts 9, 9.

The end portions of the output shafts 9, 9 are connected to the side gears 18, 18 through the ends of the case to form a differential mechanism 8 which allows a difference between the inner and outer rings. The differential case 16 is formed with a flange-shaped gear base 20 (seat portion) that projects laterally of the pinion 15.

A ring gear 21 having a large diameter is fixed to a bearing surface 20a formed on the pinion 15 side of the gear base 20. The ring gear 21 is used for the input shaft 1.
The final speed reduction mechanism 24 is constituted by meshing with the pinion 15 of No. 3 and engine rotation output from the propeller shaft 7.

That is, the differential device 6 reduces the engine rotation output from the propeller shaft 7 by the pinion 15 and the ring gear 21 and transmits it to the differential case 16, and the pinion gear 19 to the side gear 18.
To allow the difference between the inner and outer wheels of the rear wheels 1, 1 while driving the output shafts 19, 19.

By the way, in order to fix the differential case 16 and the ring gear 21 of the differential device 6, the structure is simple and the cost is low. Therefore, the bolts 2 are usually provided at a plurality of points as shown in FIG.
2 (fastening member) is penetrated and a nut 23 is screwed into these bolt ends.

[0016]

However, the bolt 22
With the operation of the differential device 6, a load such as a bending stress and a shearing force, which is caused by a shift in the rotational direction between the differential case 16 and the ring gear 21 (relative rotation shift), is repeatedly applied to the.

Therefore, the load on the bolt 22 is considerably large, and the bolt 22 may be overloaded. Therefore, it is conceivable to increase the number of bolts 22 or use a stepped bolt having a partially increased outer diameter so as to withstand each stress.

However, with the former structure, since the differential case 16 and the ring gear 21 are fastened with a considerably large number of bolts 22 as compared with the conventional case, it is difficult to secure a space for fastening with the bolts 22 separately.

Moreover, even if the space is secured, the overall layout of the bolt positions up to now is inevitably changed, so that there is a problem that the cost is also high.

Further, in the latter structure, the stepped bolt itself is considerably expensive, so that there is a problem that if it is adopted, the cost will be considerably high. Therefore, neither was adopted.

The present invention has been made in view of the above circumstances, and an object thereof is to use the fastening member as it is, with a simple structure in which the change is minimal, the cost is low, and the fastening is the same. An object of the present invention is to provide a differential device that can reduce the burden on members.

[0022]

In order to achieve the above object, the invention described in claim 1 is the ring gear through which the fastening member is inserted and the inner surface of each hole formed in the seat of the differential case and the inner surface thereof. The pipe member is interposed between the outer peripheral surface of the fastening member and the ring member so that the boundary between the ring gear and the seat portion is continuous.

According to a second aspect of the invention, in addition to the above object, in order to reduce the load on the fastening member which is a short-length tubular member and looks good, each ring gear and seat facing the boundary between the ring gear and the seat portion. By forming the diameter of one side of the hole portion of the portion to be larger than that of the fastening member, it is provided in the annular recess around the boundary, and the pipe member is inserted into this recess.

According to the invention described in claim 3, in addition to the above-mentioned object, in order to make a simpler modification, by forming all of the respective holes of the ring gear and the seat portion to have a larger diameter than the fastening member, The structure is such that a gap is provided on the outer peripheral surface of the fastening member, and the pipe member is inserted into the entire gap.

[0025]

According to the invention described in claim 1, the tubular member receives the repeated load such as the bending stress and the shearing force applied from the boundary between the seat portion of the differential case and the ring gear due to the operation of the differential device.

Here, since the pipe member is provided on the outer peripheral surface of the fastening member and provides high rigidity as if the rigidity of the fastening member is increased, the pipe member withstands the above-mentioned load and the relative case between the differential case and the ring gear. It prevents the deviation of the rotational direction.

As a result, the load on the fastening member is reduced. That is, the fastening member is protected from overload. Moreover, since the existing fastening member is used as it is and the pipe member is provided between the outer peripheral surface of the fastening member and the inner surface of the hole, the layout of the entire hole can be kept unchanged. , There are few changes and the structure is simple.

In addition, since the pipe member is a component that can be used as it is as a general-purpose component, it has a cost-effective reinforcing structure. According to the invention described in claim 2, the pipe member is
The differential case is locally embedded in a portion corresponding to the boundary between the seat portion and the ring gear and is invisible from the outside, so that the appearance is improved.

In addition, since the pipe member is provided only in a necessary place, the total length is short and the unnecessary increase in weight can be prevented.
According to the invention described in claim 3, the pipe member can be installed only by changing the overall diameter of the seat portion of the differential case and each hole portion of the ring gear.

[0030]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on the first embodiment shown in FIGS. In the drawings, the same parts as those of the differential device 6 described in the above-mentioned "Prior Art" are denoted by the same reference numerals and the description thereof will be omitted.
In this section, different parts (essential parts of the invention) will be described.

That is, in the present embodiment, the boundary between the differential case 16 and the ring gear 21 is formed between the inner surface of each hole formed in the differential case 16 and the ring gear 21 and the outer peripheral surface of the bolt 22 facing the hole. The difference is that the collar 34 is provided so as to be continuous.

FIG. 1 shows a sectional view of a fastening structure using the collar 34, and FIG. 2 shows an exploded view thereof. If this fastening structure is explained, 30 is a gear base 20.
Bolt insertion holes (first through holes) formed in the (differential case 16), and 31 are holes (second through holes) formed in the support base 21a of the ring gear 21 corresponding to the holes 31. Hole), both hole portions 30 arranged in series,
A bolt insertion passage 32 is formed at 31.

Each of the holes 30 and 31 has a gear base 2
The end on one side facing the boundary between 0 and the ring gear 21 has a diameter larger than the diameter of the other portion, that is, the bolt diameter. The large-diameter portions 30a and 31a of the holes 30 and 31 have the same diameter, and an annular recess 33 is formed in the intermediate portion of the bolt insertion passage 32 where the boundary between the gear base 20 and the ring gear 21 exists.

In the annular recess 33 which continues this boundary,
A tubular collar 34 (tube member) formed of a member having high rigidity is fitted and housed. The collar 34 is formed in the shape of a short cylinder whose inner diameter has a diameter corresponding to the bolt diameter and whose overall length is short according to the length of the recess 33, and which is formed from the boundary between the gear base 20 and the ring gear 21. The structure is such that the bending stress and shear stress applied are effectively received by as small a part as possible.

The bolt 22 is inserted into the bolt insertion passage 32 from one side through the gear base 20 and the collar 34. Then, a nut 23 is screwed into the bolt end, and the differential case 16 and the ring gear 21 are fastened as in the conventional case.

Next, the operation of the differential device 6 thus constructed will be described. The engine rotation output from the propeller shaft 7 to the input shaft 13 is first decelerated by the pinion 15 and the ring gear 21.

Then, in response to this rotation, the pair of pinion gears 19 move around the side gears 18 together with the differential case 16 to drive the output shafts 19 and 19, while the difference between the inner and outer rear wheels 1 and 1. Allow.

With the operation of the differential device 6, the collar 34 receives repeated loads such as bending stress and shearing force applied from the boundary between the gear base 20 of the differential case 16 and the support base 21a of the ring gear 21.

Here, since the collar 34 is provided on the outer peripheral surface of the bolt 22, it can be seen that the collar 34 provides high rigidity as if the outer diameter of the bolt 22 was increased and the rigidity was increased. .

Therefore, the relative load between the differential case 16 and the ring gear 21 in the rotational direction can be prevented by withstanding the load. As a result, the load on the bolt 22 that fastens the differential case 16 and the ring gear 21 can be reduced.

In other words, the bolt 22 is protected from overload and can always ensure reliable operation of the differential device 6. Moreover, the existing bolt 2
2 as it is, the outer peripheral surface of the bolt 22 and the hole 3
Since the structure is such that only the collar 34 is provided between the inner surface of 0 and 31, the layout of the entire hole can be kept unchanged, and the number of changes is small and the structure is simple.

In addition, since the collar 34 is a component which can be used as it is as a general-purpose product, it has a reinforced structure which is excellent in cost. Further, if a structure is adopted in which an annular recess 33 is formed in a portion corresponding to the boundary between the gear base 20 of the differential case 16 and the support base 21a of the ring gear 21 and the collar 34 is embedded locally, the collar 34 can be seen from the outside. Since it does not exist, it has the effect of improving the appearance.

Moreover, with this structure, since the collar 34 is provided only in a necessary place, the collar 34 has an advantage that the total length is short and an unnecessary increase in weight can be prevented. 3 and 4
Shows a second embodiment of the present invention.

In the second embodiment, the collar 34 is not provided only at the boundary portion as in the first embodiment, but the collar 34 is provided over the entire bolt insertion hole 32 including the boundary.

That is, in the second embodiment, the entire holes 30, 31 of the gear base 20 of the differential case 16 and the support base 21a of the ring gear 21 are formed to have a larger diameter than the bolt diameter, and the bolt 22 is Outer peripheral surface and hole 3
A gap 35 is provided in the entire space between the inner surfaces of 0 and 31, and the collar 34 is fitted in the entire gap.

Even in this case, as in the first embodiment,
It is possible to protect the bolt 22 from overload with a simple structure that uses the bolt 22 as it is, requires a minimum change, and is inexpensive.

In particular, this structure is easy to realize because the collar 34 can be installed only by changing the overall diameters of the holes 30 and 31 in the gear base 20 and the support base 21a.

However, in the second embodiment, the same parts as those in the first embodiment are designated by the same reference numerals and the description thereof is omitted. In addition, in the first and second embodiments, the collar 34 includes the differential case 16 and the ring gear 2.
It goes without saying that it may be provided on all the bolts 22 that fasten 1 to each other, or may be provided on some of the bolts 22 if the reinforcement is sufficient.

[0049]

As described above, according to the invention described in claim 1, the use of the pipe member brings about high rigidity as if the rigidity of the fastening member is increased, and the boundary between the differential case and the ring gear is provided. It withstands repeated loads such as bending stress and shearing force, and prevents relative displacement between the differential case and ring gear in the direction of rotation.

As a result, the fastening member can be protected from overload. Moreover, since the existing fastening member is used as it is, and the pipe member is provided between the outer peripheral surface of the fastening member and the inner surface of the hole, the layout of the entire hole is not changed. In addition, there are few changes and the structure is simple. In addition, since the pipe member is a component that can be used as it is as a general-purpose component, it has a cost-effective reinforcement structure.

As a result, the fastening member is used as it is,
With a simple structure that requires minimal changes and is inexpensive,
It is possible to reduce the load on the fastening member that fastens the differential case and the ring gear.

According to the second aspect of the invention, in addition to the effect of the first aspect of the invention, the appearance of the pipe member is improved because the pipe member cannot be seen from the outside. Moreover, since the pipe member is provided only in a necessary place, the overall length can be short, and it is possible to prevent an unnecessary increase in weight.

According to the third aspect of the present invention, in addition to the effect of the first aspect of the invention, the change in the diameter of the pipe member of the differential case is made only by increasing the overall diameters of the seat portion of the differential case and the holes of the ring gear. Since it can be installed, it has the advantage of being easy to implement.

[Brief description of drawings]

FIG. 1 is a cross-sectional view illustrating a differential device according to a first embodiment of the present invention.

FIG. 2 is an exploded view for explaining a fastening structure of a differential case and a ring gear using a collar of the same device.

FIG. 3 is a sectional view for explaining a differential device according to a second embodiment of the present invention.

FIG. 4 is an exploded view for explaining a fastening structure of a differential case and a ring gear using a collar of the same device.

FIG. 5 is a diagram for explaining a power transmission system of a truck.

FIG. 6 is a cross-sectional view for explaining the structure of a differential device incorporated in a rear axle of the power transmission system.

FIG. 7 is an exploded view for explaining a final reduction gear mechanism and a differential mechanism that constitute the differential device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Rear wheel 2 ... Rear axle 6 ... Differential device 8 ... Differential mechanism 9 ... Output shaft 12 ... Machine room 13 ... Input shaft 15 ... Pinion 16 ... Differential case 18 ... Side gear 19 ... Pinion gear 20 ... Gear base (seat part) 21 ... Ring gear 21a ... Support base 22 ... Bolt (fastening member) 23 ... Nut 24 ... Final reduction mechanism 30,3
DESCRIPTION OF SYMBOLS 1 ... Hole part 33 ... Annular recessed part 34 ... Collar (tube member) 3
5 ... Gap.

Claims (3)

[Claims] 1. A ring-shaped gear that meshes with an input shaft is arranged so as to overlap a flange-shaped seat portion formed in a differential case, and the ring gear and the seat portion are shaft-shaped fastening members that pass through each other. In the differential device that is fastened, the ring gear is provided between the inner surface of each hole formed in the ring gear and the seat through which the fastening member is inserted and the outer peripheral surface of the fastening member that faces the hole. A differential device characterized in that a pipe member is interposed so that the boundary of the seat portion is continuous. 2. The ring member provided around the boundary by forming the ring gear facing the boundary and the diameter of one side of the hole of the seat portion larger than the fastening member. The differential gear according to claim 1, wherein the differential gear is fitted in the recess. 3. The pipe member is fitted into the entire gap provided on the outer peripheral surface of the fastening member by forming the ring gear and the hole portion of the seat portion to have a larger diameter than the fastening member. The differential gear according to claim 1, wherein the differential gear is provided.