JPS626535Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a rotation take-out device for a traveling speedometer of a motorcycle or the like, in which a gear housing is molded of synthetic resin.

As shown in FIG. 1, this type of device consists of a gear housing 1 fixedly attached to a wheel shaft 11, and a gear device 2 provided within the gear housing 1. The gear housing 1 has an oil seal engaging cylinder. The cylindrical portion fits into the oil seal 5 provided on the wheel hub 4, and the gear housing 1
Gear device 2 parts and wheel hub bearing 6
This prevents dust, muddy water, etc. from entering the area. or,
The gear device 2 includes a gear 2a that is connected to and rotates with the wheel hub 4, and a pinion gear 2b that meshes with the gear 2a, rotates at a desired reduction ratio, and transmits the rotation to the outside.

By the way, when the gear housing 1 of this type of device is molded from synthetic resin, as shown in FIG. 2, the gear housing 1 consists of a substantially central cylindrical part that houses the gear 2a and a knob part that houses the pinion gear 2b. Shrinkage during molding of the portion affects the oil seal engaging cylindrical portion 3, and the roundness of the oil seal engaging cylindrical portion 3 is significantly reduced, causing the oil seal 5 to deteriorate.
Therefore, the gear device 2 and the wheel hub bearing 6 could not be smoothly rotated and slid, resulting in the inconvenience that dust, muddy water, etc. could enter the gear device 2 and the wheel hub bearing 6. If the gear housing 1 is made thicker in order to improve its strength, this phenomenon becomes more noticeable. This problem has been considered unavoidable in the gear housing 1 made of synthetic resin.

The present invention was developed in consideration of these points, and the gear housing is made of synthetic resin, which improves the sealing performance between the oil seal and the oil seal engaging cylindrical part, and reliably prevents the intrusion of dust and muddy water. The object of the present invention is to provide a rotary take-out device for measuring instruments, and the present invention will be explained below based on the accompanying drawings.

Figures 3 and 4 show examples of the present invention.
In the drawing, a groove 8 is provided in a flange end surface 7 extending radially from the oil seal engaging cylindrical portion 3 of the gear housing 1 . For this reason, when the gear housing 1 is molded from synthetic resin, shrinkage and warpage of the synthetic resin can be alleviated by widening or narrowing the width of this groove 8, so that the oil seal engaging cylinder The part 3 is not affected by the shrinkage during molding of the pinion gear built-in part and can obtain extremely high roundness, and improves the sealing performance between the oil seal and the oil seal engaging cylindrical part 3.
It is possible to reliably prevent the intrusion of dust, muddy water, etc. Furthermore, if the annular groove 8 is formed around the entire circumference as in the illustrated embodiment, the warping of the flange end surface 7 can be alleviated, and the annular groove 8 can also provide the effect of a labyrinth seal. .

Further, although the continuous annular groove is provided in the above embodiment, the groove may be provided intermittently or locally on the end surface of the flange adjacent to the pinion gear built-in portion. In this case as well, the oil seal engaging cylindrical portion can achieve extremely high roundness without being affected by the shrinkage during molding of the bump portion that houses the pinion gear, and the oil seal and the oil seal engaging cylindrical portion It is possible to improve the sealing performance between the two and reliably prevent the intrusion of dust, muddy water, etc.

As mentioned above, the present invention is a speedometer rotation take-out device in which the gear housing is made of synthetic resin, and a groove is provided in the end face of the flange extending radially from the oil seal engaging cylindrical part of the gear housing. ,
When molding gear housings from synthetic resin, shrinkage and warping of the synthetic resin can be alleviated by widening or narrowing the width of this groove.
The oil seal engaging cylindrical part can obtain extremely high roundness without being affected by the shrinkage during molding of the knob part that houses the pinion gear, and the sealing property between the oil seal and the oil seal engaging cylindrical part is improved. This has the effect of being able to reliably prevent the intrusion of dust, muddy water, etc.

[Brief explanation of the drawing]

Fig. 1 is a vertical cross-sectional view of a rotation take-out device for a traveling speedometer showing a conventional example, Fig. 2 is a side view of a gear housing, Fig. 3 is a longitudinal cross-sectional view of a gear housing showing an embodiment of the present invention, and Fig. 4 FIG. 3 is a side view of the gear housing of FIG. Explanation of the symbols 1...Gear housing, 2...Gear device, 3...Oil seal engaging cylindrical portion, 4...Wheel hub, 5...Oil seal, 7...Flame end face, 8...Groove.

Claims (1)

[Scope of utility model registration request] A gear housing 1 made of synthetic resin has an oil seal engaging cylindrical portion 3 that is fixedly attached to a wheel shaft 11 and that engages with an oil seal 5 provided on a wheel hub 4; In a speedometer rotation extractor comprising a gear device 2 for transmitting rotation of a hub 4, a groove 8 is formed in a flange end surface 7 extending radially from an oil seal engaging cylindrical portion 3 of the gear housing 1. A rotation take-out device for a traveling speedometer.