JPS6342183Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a partial structure of a manual transmission for an automobile, and more particularly to a spacer for a needle bearing for supporting a gear on a shaft in a manual transmission. In particular, the present invention relates to a spacer that has the function of easily visually confirming whether the snap spring is properly assembled and the function of preventing the snap spring from falling off.

In recent years, as a method of supporting gears on the shaft of manual transmissions, in order to prevent fretting wear, the use of bushes has been abolished and the gears have been widely supported directly on the shaft with or without needle bearings. . For this reason, a snap spring is often used as a means for fixing the needle bearing or clutch hub to the shaft in the axial direction.

For example, in the horizontal transaxle shown in FIG. 1, an input shaft 1 has a first speed gear 2 and a second speed gear 3 integrally molded therein. When assembling other drive gears and clutch hub assemblies, first insert the third speed gear 5 equipped with the needle bearing 4 from the free left end of the input shaft 1, and then
the shoulder 6 of the In this way, the third gear 5
The rightward movement in the axial direction view is restricted by the shoulder portion 6. Next, input shaft 1
The clutch hub 7 is fitted into the clutch hub 7 and brought into pressure contact with the third speed gear 5. Then, with both the clutch hub 7 and the third speed gear 5 pressed tightly toward the shoulder 6, the snap ring 8 is fitted into the groove of the input shaft 1. In this way, the leftward movement of the clutch hub 7 and the third speed gear 5 in the axial direction is restricted by the snap spring 8. Then the fourth bearing 9 is provided with a needle bearing 9.
After the speed gear 10 is inserted and the ball bearing 11 is assembled, it is fixed with a snap spring 12. Note that an annular spacer 13 is interposed between the needle bearing 9 and the snap spring 8. This is a two-piece bearing in which the needle bearing 9 has a vertically divided cage in order to prevent needle impressions that occur on the peripheral surface of the input shaft due to minute displacements between the input shaft and the 4th gear during driving. However, since the cage is divided into two in this way, as the fourth speed gear rotates, a step is created in the longitudinal direction between the two cage halves, and this is pulled into the notch of the snap spring. This is because it interferes with the normal rotation of the bearing.

By the way, when assembling the snap spring 8, it is necessary to mount the snap spring with as little clearance as possible so that the axial displacement of the third speed gear 5 and the clutch hub 7 is minimized. For this reason, conventionally, many types of snap springs with different axial thicknesses are prepared in advance, and then the actual width of the groove into which the snap spring is fitted is measured, and a thickness that matches the measured groove width is determined. I selected a snap spring and installed it in the groove of the input shaft.
However, since the snap spring 8 is press-fitted between the side surface of the groove and the side surface of the clutch hub with no play in the axial direction, the snap spring 8
may not fully snap fit around the input shaft and seat at the bottom of the groove. Conventionally, there is no simple and effective means for checking such an incompletely assembled state during assembly, so that an assembly worker cannot easily discover such an incompletely assembled state. Further, even after being properly assembled, the snap ring may expand in the radial direction and come out of its groove if an abnormally high axial thrust is applied due to fretting wear on the end face during use.

The present invention has been devised in view of the above-mentioned problems of the prior art, and aims to provide a means by which it is possible to easily visually confirm whether the snap spring is properly assembled and to prevent the snap spring from falling off. This is the purpose.

In order to achieve the above object, the present invention utilizes a spacer. The spacer of the present invention has an enlarged diameter portion at the end facing the snap spring, and the inner diameter of this enlarged diameter portion is slightly smaller than the outer diameter of the snap spring. It is characterized by increasing size.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 2 is a partially enlarged view of the transaxle of FIG. 1 to which an embodiment of the spacer of the present invention is installed. Similar to the conventional example shown in FIG. 1, a second speed gear 21 is integrally molded on the input shaft 20. Adjacent to the second speed gear 21, two cage type needle bearings 22 are mounted around the input shaft 20 so as to face inward in the radial direction, and the third speed gear 23 is fitted on the outside of the needle bearings 22. It has been done. The right extreme position of 3rd gear is 2nd gear 21
It is regulated by a shoulder 24 formed by the end surface of. A clutch hub 25 is splined to the input shaft following the third speed gear 23. One side of the clutch hub 25 abuts an annular projection 26 of the input shaft 20. The other side of the clutch hub has a snap spring 2 that is snapped into the annular groove 27 of the input shaft.
8.

Adjacent to the snap ring 28, a spacer 29 of the present invention is inserted through the input shaft. This spacer 29 is attached to the input shaft 2
0, a flange portion extending radially outward from the cylindrical portion, and an enlarged diameter portion extending axially opposite from the outer edge of the flange portion. As is clear from the drawing, the inner diameter of the enlarged diameter portion of this spacer is the same as that of the snap spring 2 when it is properly snapped onto the input shaft 20.
It is made slightly larger than the outer diameter of No. 8. Further, the axial length of the enlarged diameter portion is set to be sufficiently larger than the thickness of the snap spring 28.

A fourth speed gear 30 and a cage two-piece needle bearing 31 supporting the fourth speed gear 30 are attached to the rear of the spacer 29. A notch is provided in the fourth speed gear 30 so as not to interfere with the enlarged diameter portion of the spacer 29.

As mentioned above, in the spacer of the present invention, the inner diameter of the enlarged diameter part is only slightly larger than the outer diameter of the snap spring. If the spacer does not sit on the bottom of the spacer, the end face of the spacer will abut against the snap spring. As a result, the spacer is shifted to the left in the figure by a distance corresponding to the thickness of the snap spring, making it impossible to assemble the needle bearing 31 and, by extension, the fourth speed gear 30. On the other hand, when the snap spring is properly assembled, the enlarged diameter portion of the spacer passes outside the snap spring so as to wrap around the snap spring from the outside and comes into contact with the clutch hub 25. In this case, the needle bearing 31 and the fourth speed gear 30 can be assembled without any problem. In this way, according to the spacer of the present invention, it is possible to indirectly know whether or not the snap spring has been assembled properly by checking whether the fourth speed gear and its bearing have been installed without any problems. . Compared to visually inspecting the assembly condition of a snap spring, it is much easier to visually judge the suitability of the assembly of the 4th gear, etc., so judgments can be made quickly and without errors. be able to. In this manner, the present invention utilizes a conventional spacer and adds an extremely simple shape to it, thereby giving the spacer the function of confirming the suitability of the snap spring assembly.

In addition, once the snap spring is properly assembled, the expanded diameter portion of the spacer surrounds the outer periphery of the snap spring to prevent its expansion, so when abnormal axial thrust is applied to the snap spring due to wear over time, etc. It also has the effect of preventing the snap spring from falling off.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal partial cross-sectional view of a conventional transaxle, and FIG. 2 is a partial cross-sectional view of a transaxle equipped with the spacer of the present invention. 20...Input shaft, 26...Clutch hub, 27...Annular groove for attaching a snap spring, 28...Snat spring, 29...Spacer, 31...4th speed gear needle bearing.

Claims (1)

[Scope of utility model registration request] A cage-split needle bearing that supports the gear freely around the input/output shaft of a manual transmission,
A spacer for a manual transmission interposed between a snap spring that is snapped onto the input/output shaft for axially positioning the clutch hub on the input/output shaft, and an end of the spacer facing the snap ring. A spacer for a manual transmission, characterized in that an enlarged diameter portion is provided, and the inner diameter of the enlarged diameter portion is slightly larger than the outer diameter of the snap spring when contracted.