JPS6133299Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a center nut rotation prevention structure, for example, a center nut rotation prevention structure for a flange connecting a propeller shaft of an automobile and a drive pinion of a final drive.

The conventional center nut rotation prevention structure is as follows:
For example, the one shown in Figure 1 is known (Nitsun Service Bulletin No. 453, Showa
57th edition, p. 73). First, to explain the structure of this anti-rotation structure, reference numeral 1 is a final drive placed at the rear of the automobile, and this final drive 1 is connected to a gear carrier 2 and a drive rotatably supported by the gear carrier 2 via a bearing. It has a pinion 3 and a drive gear 4 that meshes with the tribe pinion 3. This drive pinion 3 is formed with a spline portion 5a and a threaded portion 5b, and a companion flange 6 meshes with the spline portion 5a. Therefore, the companion flange 6 and the drive pinion 3 are restricted from rotating relative to each other, but are slidable in the axial direction. A hole 7 is formed in the companion flange 6, and the companion flange 6 is fixed to the drive pinion 3 by screwing a center nut 8 into a threaded portion 5b protruding into the hole 7. Further, by adjusting the tightening torque of the center nut 8, the bridle of the bearing interposed between the gear carrier 2 and the drive pinion 3 can be adjusted to a predetermined value. A hole 9 is formed at a predetermined position in the threaded portion 5b, and a groove 10 is also formed in the center nut 8. Therefore, by aligning the groove 10 of the center nut 8 with the hole 9 and inserting and bending the split pin 11, the center nut can be prevented from rotating.

However, in the case of such a conventional center nut rotation prevention structure, the split pin 11 is inserted into the groove 1.
Since the center nut 8 was intended to be prevented from rotating by inserting it into the center nut 8 and the hole 9, there was a problem in that if an excessive torque was applied to the center nut 8, the split pin 11 would be damaged and the center nut 8 would become loose. Such loosening of the center nut 8 will cause abnormal noise in the bearing.

This invention was made by focusing on such conventional problems, and includes a first flange connected to the first shaft via a spline, and a first flange that is screwed to the first shaft and extends in the axial direction of the first flange. a central nut with a non-circular cross section that regulates sliding; and a second shaft that is connected to a second shaft that extends along the axis of the first shaft, that is connectable to the first flange, and that is formed with a hole that encloses the nut so that it can be stored therein. It is an object of the present invention to solve the above-mentioned problems by providing a rotation prevention structure for a center nut, which is provided with a flange and an engaging portion that allows the center nut to engage with a hole in the second flange.

This invention will be explained below based on the drawings.

Figures 2 and 3 are diagrams showing the first automobile of this invention, and the configuration will be explained first. Reference numeral 13 denotes a final drive mounted at the rear of the automobile, and this final drive 13 meshes with a gear carrier 14, a drive pinion 17 supported by the gear carrier 14 via bearings 15 and 16, and a differential. allencial case 1
8, a pinion mate shaft 20 supported by the differential case 18, and a pinion mate gear 21 rotatably supported by the pinion mate shaft 20.
and a side gear 22 that meshes with the pinion mate gear 21. A flexible collapsible spacer 24 is interposed on the outer periphery of the shaft portion 23 of the drive pinion 17 between the bearings 15 and 16, and the spacer 24 adjusts the preload applied to the bearings 15 and 16. The shaft portion 23 of the drive pinion 17 protrudes from the gear carrier 14, and the space between the shaft portion 23 and the gear carrier 14 is sealed by an oil seal 25. Shaft 23
A spline 26 and a screw 27 are formed in the flange 26, and a companion flange 28 is splined to the spline 26. A hole 29 is formed in the companion flange 28, and the screw 27 of the shaft portion 23 projects into the hole 29.
A hexagonal nut 30 is screwed onto this screw 27 with a predetermined tightening torque, and as a result, the bearing 1
A predetermined briload is added to 5 and 16. The companion flange 28 can be fixed to the flange yoke 32 of the universal joint 31 with bolts and nuts.
2 is formed with a hole 35 in which a nut 30 can be accommodated. As shown in detail in FIG. 4, this hole 35 has a shape in which a part of a circle projects in a crescent shape, and this projecting engagement portion 36 is connected to the hexagonal nut 3.
It is possible to engage with the side surface of 0. The universal joint 31 is fixed to one end of a propeller shaft 50, which is a second shaft, and the other end of the propeller shaft is connected to an engine via a transaxle (not shown).

Next, the effect will be explained. First, to connect the final drive 13 to the universal joint 31, the shaft portion 23 is inserted into the companion flange 28, and the hexagonal nut 30 is tightened on the screw 27 with a predetermined tightening torque. As a result, a preload is applied to the bearings 15 and 16, and the companion flange 28 is fixed to the shaft portion 23. Next, the companion flange 28 and the flange yoke 32 are fixed with bolts and nuts. At this time, the hexagonal nut 30 is inserted into the hole 35, so the companion flange 28 and the flange yoke 31 can be connected, and the hexagonal nut 30
Even if the bearing 15,
The preload applied to 16 can be maintained at approximately a predetermined value.

Next, if the hexagonal nut 30 tries to rotate for some reason while driving the car, the hexagonal nut 30
0 contacts the engaging portion 36, rotation of the nut 30 is restricted. Furthermore, since the engaging portion 36 has much greater rigidity than the conventional split pin 11, the engaging portion 36 will not be damaged.

Note that the shape of the engaging portion may be formed by two crescent-shaped protrusions 37 formed at positions 180° apart from each other as shown in FIG. The protrusion 39 may be provided so that the hole 38 has a shape similar to that of the hole 38 .

As explained above, according to this idea,
The rotation prevention structure of the center nut includes: a first flange connected to the first shaft via a spline; a center nut having a non-circular cross section that is screwed onto the first shaft and restricts sliding of the first flange in the axial direction; A rotation prevention mechanism for a center nut, which includes a second flange connected to a second shaft extending in the axial direction of the first shaft, connectable to the first flange, and formed with a hole surrounding the nut so as to accommodate the nut. Since the hole of the second flange is provided with an engaging portion that can be engaged with the center nut, it is possible to prevent the rotation prevention structure from being damaged even when excessive torque is applied to the center nut.

[Brief explanation of the drawing]

Fig. 1 is a front sectional view showing the rotation prevention structure of a conventional center nut, Fig. 3 is an exploded perspective view of Fig. 2,
4 is a sectional view taken along the - arrow in FIG. 2, and FIGS. 5 and 6 are sectional views at the same position as FIG. 4, showing other examples of the engaging portion. 23...First shaft (shaft part), 26...Spline, 28...First flange (companion flange), 30... Center nut (hexagonal nut), 32
...Second flange (flange yoke), 35,3
8... Hole, 36, 37, 39... Engaging portion (protrusion), 50... Second shaft.

Claims (1)

[Scope of utility model registration request] a first flange connected to the first shaft via a spline; a center nut having a non-circular cross section that is screwed onto the first shaft and restricts sliding of the first flange in the axial direction; a second flange that is connected to a second shaft located in the center, is connectable to the first flange, and is formed with a hole surrounding the nut so as to accommodate the nut; A center nut rotation prevention device characterized in that an engaging portion with which the center nut can engage is provided, and after the first flange and the second flange are connected, rotation of the center nut is regulated to prevent the center nut from loosening. structure.