JP7086476B2 - Power transmission mechanism - Google Patents

Description

The present invention relates to a power transmission mechanism including a differential gear and a drive shaft.

In vehicles such as automobiles, the power from the drive source is transmitted to the differential gear (differential device) via the transmission (transmission), and the power is converted by the differential gear into the rotation of the left and right drive shafts, and each drive is converted. The rotation of the shaft is transmitted to the drive wheels.

FIG. 5 is a diagram showing a joint portion between the differential gear 101 and the drive shaft 102.

The differential gear 101 includes an outer shell 103 including a differential carrier and a differential cover. Inside the outer shell 103, two pinion gears in which a pinion shaft is supported and rotatably held at both ends of the pinion shaft, and two side gears arranged separately on both sides in a direction orthogonal to the pinion shaft. Is housed. Each side gear meshes with both of the two pinion gears. The outer shell 103 is formed with a cylindrical shaft insertion portion 104 at a position facing each side gear in a direction orthogonal to the pinion shaft.

The drive shaft 102 is inserted into the shaft insertion portion 104 from the outside of the outer shell 103, and the tip portion thereof is coupled to the side gear so as not to rotate relative to each other.

Japanese Unexamined Patent Publication No. 2018-123911

For example, if a part of the drive shaft 102 is damaged, it is necessary to remove the drive shaft 102 from the shaft insertion portion 104 of the outer shell 103 in order to repair or replace the part. In that work, the tip of the bar 105 is inserted into the gap between the drive shaft 102 and the shaft insertion portion 104, the bar 105 is brought into contact with the peripheral edge of the shaft insertion portion 104, and the contact point is used as a fulcrum for the principle of the lever. A force is applied from the bar 105 to the drive shaft 102.

However, while the drive shaft 102 is being displaced, the tip of the bar 105 may come off the drive shaft 102, and it may take time to remove the drive shaft 102.

An object of the present invention is to provide a power transmission mechanism that makes it easy to pull out a drive shaft from a differential gear.

In order to achieve the above object, the power transmission mechanism according to the present invention is a power transmission mechanism including a differential gear and a drive shaft, the differential gear includes an outer shell, and the outer shell has a cylindrical insertion portion. The drive shaft has a shaft portion and an overhanging portion that projects around the outer peripheral surface of the shaft portion, and has a protrusion protruding from the outer shell to the same side as the insertion portion. With the drive shaft assembled, the shaft portion is inserted into the insertion portion, and a gap is provided between the insertion portion and the overhanging portion in the direction of the center line of the insertion portion. The second line that connects the point and the protrusion at the shortest compared to the first line that connects the point on the surface facing the center line in the direction of the center line and the peripheral edge of the tip surface of the insertion part at the shortest. The protrusions are formed so that the length of the minute is large and the inclination of the second line with respect to the direction of the center line is large.

According to this configuration, in the work of pulling out the drive shaft from the differential gear, the operator inserts the tip of a tool such as a bar between the insertion portion of the differential gear and the overhanging portion of the drive shaft, and inserts the tool into a protrusion. The contact point can be used as a fulcrum, and a force can be applied to the overhanging portion by the tip of the tool by the principle of the lever. At this time, the inclination angle of the tool with respect to the direction of the center line of the insertion portion is large and the inclination angle of the tool is large as compared with the conventional configuration in which the tool is in contact with the peripheral edge of the tip surface of the insertion portion and the contact point is used as a fulcrum. Since the distance between the tip of the tool and the fulcrum is long, the tip of the tool does not easily come off the drive shaft, and it is easy to remove the drive shaft from the differential gear.

According to the present invention, a tool such as a crowbar does not easily come off from the drive shaft during the work of removing the drive shaft from the differential gear, and the drive shaft can be easily removed.

It is a side view of the power transmission mechanism which concerns on one Embodiment of this invention. It is a rear view of a power transmission mechanism. It is the figure which looked at the vicinity of the lower side of the insertion part of a differential gear from the front side. It is the figure which looked at the connection part of a differential gear and a drive shaft from the rear side, and shows the state before the start of the extraction work of a drive shaft. It is the figure which looked at the connection part of a differential gear and a drive shaft from the rear side, and shows the state in the process of pulling out a drive shaft. It is the figure which looked at the connection part of the conventional differential gear and a drive shaft from the rear side.

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

<Structure of power transmission mechanism>
FIG. 1 is a side view of the power transmission mechanism 1 according to the embodiment of the present invention. FIG. 2 is a rear view of the power transmission mechanism 1 (a view seen from the rear of the vehicle).

The power transmission mechanism 1 is a mechanism that is arranged at the rear of the vehicle and transmits power from a drive source such as an engine to the left and right rear wheels. As shown in FIG. 2, the power transmission mechanism 1 includes a differential gear 2 and drive shafts 3L and 3R extending to the left and right from the differential gear 2, respectively.

The differential gear 2 includes a differential carrier 11 and a differential cover 12, as shown in FIGS. 1 and 2. The differential carrier 11 and the differential cover 12 form an outer shell of the differential gear 2.

The differential carrier 11 extends in the front-rear direction and is open to both front and rear sides. A drive pinion shaft is housed in the front portion of the differential carrier 11. The drive pinion shaft extends in the front-rear direction and is rotatably held around its center line by the differential carrier 11. A propeller shaft extending in the front-rear direction is connected to the front end of the drive pinion shaft via a constant-velocity universal joint 13. A drive pinion gear composed of bevel gears is attached to the rear end of the drive pinion shaft so that it cannot rotate relative to each other. A differential case is housed in the rear portion of the differential carrier 11. The differential case is rotatably held around a rotation axis extending in the left-right direction by the differential carrier 11. An annular ring gear centered on the rotation axis of the differential case is fixed to the differential case. A drive pinion gear is meshed with the ring gear. Inside the differential case, a differential pinion shaft extending in a direction orthogonal to the left-right direction is supported, and two differential pinion gears rotatably held at both ends of the differential pinion shaft and two separately arranged on the left and right sides. Side gear and is housed. Each side gear meshes with both of the two diff pinion gears.

The differential cover 12 is fixed to the rear end of the differential carrier 11 with a plurality of bolts 14, and closes the opening at the rear end of the differential carrier 11 from the rear. The space between the rear end surface of the differential carrier 11 and the differential cover 12 is sealed by a gasket 15. The gasket 15 may be, for example, a cured liquid gasket applied to the rear end surface of the differential carrier 11.

As shown in FIG. 2, a semi-cylindrical wall portion 16 that is opened rearward is formed at the right end portion of the differential carrier 11. Further, a semi-cylindrical wall portion 17 that is opened forward is formed at the right end portion of the differential cover 12. The wall portions 16 and 17 have the same curvature, and the ends thereof are abutted against each other to form a flat cylindrical insertion portion 18R. Similarly, as shown in FIG. 1, a flat cylindrical insertion portion 18L is formed at the left end portion of the differential carrier 11 and the differential cover 12.

FIG. 3 is a view of the vicinity of the lower side of the insertion portion 18R as viewed from the front side.

Projections 21 and 22, respectively, are provided side by side on the lower side of the wall portions 16 and 17 constituting the insertion portion 18R. The protrusion 21 on the front side is formed in a plate shape having a side 23 extending downward from the lower end of the wall portion 16 and a side 24 extending to the left from the lower end of the side 23. The rear projection 22 is formed in a plate shape having a side 25 extending downward from the lower end of the wall portion 17, a side 26 extending rearward and downward from the lower end of the side 25, and a side 27 extending forward from the lower end of the side 26. .. The protrusion 22 is larger in size than the protrusion 21, and as shown in FIG. 3, the sides 25, 26, and 27 are exposed without being hidden behind the protrusion 21 when viewed from the front side.

As shown in FIG. 2, the drive shaft 3L on the left side includes a shaft portion 31 and a constant velocity universal joint 32. The shaft portion 31 extends to the right from the constant velocity universal joint 32, is inserted into the insertion portion 18L, and is connected to the side gear in the differential case so as not to rotate relative to each other. The constant velocity universal joint 32 has a 360 ° rotationally symmetric outer shape, and projects around the outer peripheral surface of the shaft portion 31. A space is provided in the left-right direction between the insertion portion 18L and the constant velocity universal joint 32.

The drive shaft 3R on the right side includes a shaft portion 33 and a constant velocity universal joint 34. The shaft portion 33 extends to the left from the constant velocity universal joint 34, is inserted into the insertion portion 18R, and is connected to the side gear in the differential case so as not to rotate relative to each other. The constant velocity universal joint 34 has a 360 ° rotationally symmetric outer shape, and projects around the outer peripheral surface of the shaft portion 33. A space is provided in the left-right direction between the insertion portion 18R and the constant velocity universal joint 34.

Power from a drive source such as an engine is transmitted to the drive pinion shaft housed in the differential carrier 11 via the propeller shaft. The power transmitted to the drive pinion shaft is transmitted from the drive pinion gear to the ring gear to rotate the differential case. The rotation of the differential case is transmitted to the drive shafts 3L and 3R via the differential pinion shaft, the differential pinion gear and the side gear. As a result, the drive shafts 3L and 3R rotate, and the left and right rear wheels rotate, so that the vehicle moves forward or backward.

<Use of protrusions>
4A and 4B are views of the vicinity of the protrusion 22 as viewed from the rear side.

The protrusion 22 is used as a fulcrum of the bar 41 when the drive shaft 3R is pulled out from the differential gear 2. Specifically, the tip of the bar 41 is inserted between the insertion portion 18R of the differential gear 2 and the constant velocity universal joint 34 of the drive shaft 3R, and the tip of the bar 41 is the insertion portion 18R of the constant velocity universal joint 34. It comes into contact with the surfaces 42 facing each other in the left-right direction. Then, the intermediate portion of the bar 41 is brought into contact with the tip of the protrusion 22, that is, the angle formed by the side 26 and the side 27, and the bar 41 is rotated around the contact point as a starting point. A force is applied to the constant velocity universal joint 34.

The constant velocity universal joint 34 has a surface 42 facing the insertion portion 18R in the left-right direction, and connects a point 43 on the surface 42 and a peripheral edge portion of the tip surface 44 of the insertion portion 18R in the shortest time. Compared with the one line segment 45, the length of the second line segment 46 connecting the point 43 and the tip of the protrusion 22 at the shortest is large, and the inclination of the second line segment 46 with respect to the left-right direction is large. Therefore, when the protrusion 22 is used as the fulcrum of the bar 41, the inclination angle of the bar 41 with respect to the left-right direction is large as compared with the case where the peripheral edge of the tip surface 44 of the insertion portion 18R is used as the fulcrum of the bar 41. Since the distance between the tip of the bar 41 and the fulcrum becomes long, the tip of the bar 41 does not easily come off from the constant velocity universal joint 34.

Further, the protrusion 22 is used as a tapping surface when the differential cover 12 is removed from the differential carrier 11. Specifically, the protrusion 22 is larger in size than the protrusion 21, and the sides 25 to 27 are exposed without being hidden behind the protrusion 21 when viewed from the front side, so that the front surface of the exposed portion is exposed. Is hit with a hammer. When the protrusion 22 is hit, a stress wave is generated, and the stress wave propagates to the joint surface between the differential carrier 11 and the differential cover 12.

<Action effect>
As described above, the differential cover 12 is provided with the protrusion 22. Therefore, in the work of extracting the drive shaft 3R from the differential gear 2, the operator inserts the tip of the bar 41 between the insertion portion 18R of the differential gear 2 and the constant velocity universal joint 34 of the drive shaft 3R, and inserts the bar 41. A force can be applied to the constant velocity universal joint 34 at the tip of the bar 41 by abutting on the protrusion 22 and using the contact point as a fulcrum. At this time, the inclination angle of the bar 41 with respect to the direction of the center line of the insertion portion 18R is larger than that in the case where the bar 41 is in contact with the peripheral edge of the tip surface 44 of the insertion portion 18R and the contact point is used as a fulcrum. Since it is large and the distance between the tip of the bar 41 and the fulcrum is long, the tip of the bar 41 does not easily come off from the drive shaft 3R, and the drive shaft 3R can be easily pulled out from the differential gear 2.

Further, in the work of removing the differential cover 12 from the differential carrier 11, the operator can hit the protrusion 22 with a hammer from the front side. When the protrusion 22 is hit, a stress wave is generated, and the stress wave propagates to the joint surface between the differential carrier 11 and the differential cover 12. Therefore, even if the differential carrier 11 and the differential cover 12 are joined via a gasket 15 made of a liquid gasket, the differential cover 12 can be easily removed from the differential carrier 11.

<Modification example>
Although one embodiment of the present invention has been described above, the present invention can also be implemented in other embodiments.

For example, in the above-described embodiment, a case where a protrusion 22 is formed on the differential cover 12 and the protrusion 22 is used for pulling out the drive shaft 3R and removing the differential cover 12 is taken as an example. However, the present invention is not limited to this, and the protrusion 21 of the differential carrier 11 may be formed larger than the protrusion 22 of the differential cover 12, and the protrusion 21 may be used for pulling out the drive shaft 3R and removing the differential cover 12.

Further, in the above-described embodiment, the configuration that facilitates the extraction of the drive shaft 3R on the right side from the differential gear 2 is taken as an example, but the protrusion 22 is used to facilitate the extraction of the drive shaft 3L on the left side from the differential gear 2. May be provided with a left-right inverted configuration.

In addition, various design changes can be made to the above-mentioned configuration within the scope of the matters described in the claims.

1: Power transmission mechanism 2: Differential gear 3L, 3R: Drive shaft 11: Differential carrier (outer shell)
12: Diff cover (outer shell)
18L, 18R: Insertion part 22: Protrusion 31, 33: Shaft part 32, 34: Constant velocity universal joint 42: Surface 44: Tip surface 45: 1st line segment 46: 2nd line segment

Claims (1)

A power transmission mechanism that includes a differential gear and a drive shaft.
The differential gear has an outer shell and has an outer shell.
The outer shell has a cylindrical insertion portion and a protrusion protruding from the outer shell to the same side as the insertion portion.
The drive shaft has a shaft portion and an overhanging portion that projects around the outer peripheral surface of the shaft portion.
With the differential gear and the drive shaft assembled, the shaft portion is inserted into the insertion portion, and the gap between the insertion portion and the overhanging portion is in the direction of the center line of the insertion portion. Is provided,
Compared with the first line segment connecting the point on the surface facing the insertion portion in the overhanging portion in the direction of the center line and the peripheral edge portion of the tip surface of the insertion portion at the shortest, the point and the point. A power transmission mechanism in which the protrusion is formed so that the length of the second line segment connecting the protrusion at the shortest length is large and the inclination of the second line segment with respect to the direction of the center line is large.

Images