JP2005106196A - Differential gear - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To surely fix a first case and a second case with a minimum number of parts under a good rigidity condition. <P>SOLUTION: In a differential gear provided with a differential gear case driven and rotated by an engine, a pinion shaft rotating together with the differential gear case, a pinion gear rotatably supported by the pinion shaft, and a pair of side gears meshing with the pinion gear, the differential gear case is provided with the first case including a first boss part in which one end of axle is fitted and the second case including a second boss part in which another end of axle is fitted, a recess part in which a shaft end part of the pinion shaft is fitted is formed on each engagement surface on which the first case and the second case abut, and a load bearing part bearing load in a rotation direction of the differential gear case is provided on a shaft end part of the pinion shaft. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a differential device for a vehicle.

  Generally, in a vehicle such as an automobile, a differential device has been used to appropriately transmit the driving force from the engine to the left and right axles. As shown in FIG. 5, the differential device includes a differential case 102 including a first case 103 and a second case 104 that are divided into two parts, a pinion shaft 107 that is integrally fitted to the differential case 102, and a pinion shaft 107 that is rotatable. And a pair of side gears 106 a and 106 b meshing with the pinion gear 105. A ring gear 144 that meshes with a drive gear that is fixed to an output shaft of a transmission (not shown) is formed on the outer periphery of the second case 104. The first case 103 and the second case 104 are formed in holes formed in the second case 104. The bolt 108 that passes through 145 is screwed into the female screw part 135 formed in the first case 103, so that the bolt 108 is fixed integrally. As shown in FIG. 6, a plurality of bolts 108 are arranged at equal intervals in the circumferential direction.

Next, the operation state of the differential apparatus 101 will be described with reference to FIG. The driving force of the engine (not shown) is input to the ring gear 144 of the second case 104 via the transmission, and the differential case 102 rotates about the axis x. At this time, the driving force is transmitted to the left and right axles (not shown) that are spline-engaged with the inner peripheries of the side gears 106 a and 106 b via the pinion gear 105 and the side gears 106 a and 106 b, and the axle rotates together with the differential case 102. When a difference in rotation occurs between the left and right axles, a rotational force different from the rotation of the differential case 102 is input to the pinion gear 105 and the side gears 106a and 106b from the axle side, and the pinion gear 105 and the side gears 106a and 106b By rotating, the difference in rotation between the left and right axles was absorbed.
JP 2000-266162 A

  Here, the driving force transmitted to the differential device 101 is input to the second case 104 having the ring gear 144 out of the first case 103 and the second case 104 fixed by the bolt 108, and the differential case 102 rotates integrally. . Therefore, in the differential apparatus 101 used for a vehicle equipped with an engine having a particularly large driving force, a large number of bolts 108, for example, 12 pieces as shown in FIG. Bolt 108 was used. That is, in order to receive the load of a rotation direction, many bolts 108 are required, and there exists a problem that the number of parts increases and an assembly man-hour increases.

  Further, as shown in FIGS. 5 and 7, a concave portion 109 for fitting the pinion shaft 107 is formed on the inner periphery of the first case 103, and a female screw portion 135 for screwing the bolt 108 to a position adjacent to the concave portion 109. Is formed. Therefore, the distance d between the concave portion 109 and the female screw portion 135 becomes small, which is not preferable in terms of the rigidity of the differential case 102.

  Furthermore, the first case 103 and the second case 104 need to separately position the hole 145 and the female screw part 135 in order to fix the bolt 108 after matching the hole 145 and the female screw part 135.

  The present invention includes a differential case that includes a differential case that is rotationally driven by an engine, a pinion shaft that rotates integrally with the differential case, a pinion gear that is rotatably supported by the pinion shaft, and a pair of side gears that mesh with the pinion gear. A first case having a first boss portion on which one axle is fitted, and a second case having a second boss portion on which the other axle is fitted, and the first case and the second case abut against each other. The first feature is that a recess for fitting the shaft end portion of the pinion shaft is formed on each engaging surface, and a load receiving portion for receiving a load in the rotational direction of the differential case is provided at the shaft end portion of the pinion shaft.

  In addition to the first feature described above, the present invention has a second feature that the load receiving portion of the pinion shaft has a vertical surface extending in the rotation vertical direction of the differential case.

  According to the differential device of the first feature of the present invention, the first case and the first case to be divided are formed on the respective engaging surfaces where the first case and the second case come into contact with each other in order to rotate integrally as a differential case. The pinion shaft provided with a load receiving part is fitted in the recess to be received, and the load receiving part receives the load in the rotational direction input to the case, so the number of bolts for fixing the first case and the second case is reduced. And the number of assembly steps can be reduced. Further, by reducing the number of bolts, it is possible to increase the interval between the female screw portion and the concave portion into which the bolt is screwed, which is preferable in terms of the rigidity of the differential case. Furthermore, since a recess is formed in each of the engaging surfaces of the first case and the second case, and the pinion shaft is fitted so that the both recesses coincide with each other, it is necessary to position the first case and the second case separately. Absent.

  According to the differential device of the second feature of the present invention, the load in the rotation direction of the differential case can be reliably received by the vertical surface of the pinion shaft extending in the rotation vertical direction of the differential case.

  The first case and the second case are securely fixed with a minimum number of parts and in a good state in terms of rigidity.

  1 to 4 show an embodiment of a differential apparatus according to the present invention. FIG. 1 shows the differential apparatus, and is a partial cross-sectional front view taken along line BB of FIG. 2, FIG. 2 is a side view thereof, and FIG. AA sectional view, FIG. 4 shows the pinion shaft used for a differential apparatus, (A) is a top view, (A) is a front view.

  First, the differential device will be described.

  A differential apparatus 1 shown in FIG. 1 includes a differential case 2 in which a first boss portion 31 and a second boss portion 41 formed at both ends in an axle direction are rotatably supported in a differential carrier (not shown) by bearings. A pinion shaft 7 that is integrally fitted, a pinion gear 5 that is rotatably supported by the pinion shaft 7, and a pair of side gears 6 a and 6 b that mesh with the pinion gear 5 are provided.

  The differential case 2 is divided into a first case 3 having a first boss portion 31 and a second case 4 having a second boss portion 41 and having a ring gear 44 formed on the outer periphery, and both cases 3 and 4 abut against each other. Recesses 9 for fitting the pinion shafts 7 arranged in the direction perpendicular to the axles are formed on the respective engagement surfaces. As shown in FIG. 3, the concave portion 9 matches a first half concave portion 33 formed on the inner peripheral side of the first case 3 with a second half concave portion 43 formed on the inner peripheral side of the second case 4. In the concave portion 9 formed by matching, the planar engagement surface 9a extending in the rotation vertical direction of the differential case 2 is formed.

  As shown in FIG. 4, the pinion shaft 7 fitted into the recess 9 of the differential case 2 is fitted into a cylindrical shaft portion 72 into which the pinion gear 5 is fitted at the center, and into the recess 9 of the differential case 2 at both ends. A shaft end portion 70 is formed. The shaft end portion 70 is opposed to the contact surface 9 a of the recess 9, and a load receiving portion 71 having a vertical surface 71 a extending in the rotation vertical direction of the differential case 2 is formed. As shown in FIG. 1, the pinion gear 5 rotatably supported by the shaft portion 72 of the pinion shaft 7 meshes with the pair of side gears 6a and 6b. Here, a right axle (not shown) that is inserted into the through hole 32 of the first boss portion 31 of the first case 3 is spline-engaged with the inner periphery of the one side gear 6a, and the second periphery of the other side gear 6b is A left axle (not shown) fitted into the through hole 42 of the second boss portion 41 of the case 4 is spline-engaged.

  As described above, the first case 3 and the second case 4 in which the pinion shaft 7, the pinion gear 5, and the side gears 6a and 6b are arranged are provided with holes 45 formed in the second case 4, as shown in FIGS. The bolt 8 to be inserted is fixed integrally by being screwed into a female screw portion 35 formed in the first case 3. Eight bolts 8 are arranged at equal intervals in the circumferential direction.

  Next, a method for assembling the differential apparatus 1 configured as described above will be described.

  First, the one side gear 6a is arranged in the first case 3 so that the axial center of the first boss portion 31 coincides with the axial center, and then the shaft end portion 70 of the pinion shaft 7 fitted with the pinion gear 5 is attached. The pinion gear 5 and the one side gear 6a are engaged with each other by fitting in the first half recess 33 of the first case 3. Subsequently, the other side gear 6 b is arranged in the other second case 4 so that the axis of the second boss portion 41 coincides with the axis, and then fitted into the second half recess 43 of the second case 4. Thus, the second half recess 43 of the second case 4 is fitted to the shaft end portion 70 of the pinion shaft 7 projecting substantially half, and the pinion gear 5 and the other side gear 6b are engaged. Finally, the eight bolts 8 are sequentially screwed together to complete the assembly of the differential device 1.

  The differential device 1 assembled in this way has a load receiving portion in the first half recess 33 formed in the engagement surface of the first case 3 and the second half recess 43 formed in the engagement surface of the second case 4. Since the shaft end portion 70 of the pinion shaft 7 provided with 71 is fitted, the circumferential positions of the female screw portion 35 of the first case 3 and the hole 45 of the second case 4 are simultaneously performed. There is no need to perform directional positioning.

  Next, the operating state and operation of the differential device 1 configured as described above will be described.

  The driving force of the engine (not shown) is input to the ring gear 44 of the second case 4 via the transmission, and the differential case 2 rotates about the axis X. At this time, the driving force is transmitted to the left and right axles (not shown) that are spline-engaged with the inner peripheries of the side gears 6 a and 6 b via the pinion gear 5 and the side gears 6 a and 6 b, and the axle rotates together with the differential case 2. When a difference in rotation occurs between the left and right axles, a rotational force different from the rotation of the differential case 2 is input to the pinion gear 5 and the side gears 6a and 6b from the axle side, and the pinion gear 5 and the side gears 6a and 6b are separately provided from the differential case 2. By rotating, the rotation difference between the left and right axles is absorbed.

  Here, the driving force transmitted to the differential device 1 is input to the second case 4 having the ring gear 44, and the differential case 2 rotates integrally, but the first half recess 33 of the first case 3 and the second case 4 Due to the structure in which the load receiving portion 71 of the pinion shaft 7 is fitted into the second half recess 43, the load receiving portion 71 of the pinion shaft 7 receives the rotational load generated in the first case 3 and the second case 4 due to the rotation. . Thereby, the load of the rotation direction concerning the volt | bolt 8 can be reduced, and the number of the volt | bolts 8 can be reduced with respect to the conventional differential apparatus with the same input from an engine.

  Further, by reducing the number of bolts 8, the gap D between the recess 9 into which the pinion shaft 7 is fitted and the female screw portion 35 (or the hole 45) can be set large.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and various design changes can be made without departing from the scope of the present invention. For example, the load receiving portion 71 of the pinion shaft 7 of the above embodiment is the vertical surface 71a extending in the rotation vertical direction of the differential case 2, but is not limited to the vertical surface 71a extending in the rotation vertical direction. Etc.

FIG. 3 is a partial cross-sectional front view taken along the line B-B of FIG. 2, illustrating a differential device according to an embodiment of the present invention. It is a left view of the differential apparatus of the Example of this invention. It is AA sectional drawing of FIG. The pinion shaft is represented, (A) is a plan view, and (A) is a front view. It represents the conventional differential apparatus, and is the FF partial cross section front view of FIG. FIG. 7 shows a conventional differential device and is a left side view of FIG. 6. It is CC sectional drawing of FIG.

Explanation of symbols

2 differential case 3 first case 4 second case 5 pinion gear 6a side gear 6b side gear 7 pinion shaft 31 first boss portion 41 second boss portion 70 shaft end portion 71 load receiving portion 71a vertical surface

Claims (2)

  A differential case (2) driven to rotate by an engine, a pinion shaft (7) rotating integrally with the differential case (2), a pinion gear (5) rotatably supported by the pinion shaft (7), and the pinion gear (5) In the differential including a pair of side gears (6a, 6b) meshing with the differential case (2), the first case (3) having a first boss portion (31) on which one axle is fitted. A second case (4) having a second boss portion (41) to which the other axle is fitted, and each engaging surface on which the first case (3) and the second case (4) abut. A recess (9) for fitting the shaft end (70) of the pinion shaft (7) is formed, and the shaft end (70) of the pinion shaft (7) receives a load in the rotational direction of the differential case (2). Receiver ( Differential gear and providing a 1).   The differential device according to claim 1, wherein the load receiving portion (71) of the pinion shaft (7) has a vertical surface (71 a) extending in a direction perpendicular to the rotation of the differential case (2).

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