JPS622532Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a rotation extraction device for transmitting the rotational speed of a wheel at a predetermined deceleration ratio to a speedometer of a motorcycle or the like.

As an example of this type of rotation take-out device is shown in FIG. 16 and is tightened and fixed with a nut 17. A gear 13 rotatably supported by the center sleeve 11 is
It is connected to a wheel hub 19 via a connector 18 and rotates as the wheel hub 19 rotates.
Pinion gear 14 meshes with this gear 13.
The pinion gear 14 is rotated at a predetermined reduction ratio as the gear 13 rotates, and the rotation is transmitted to the speedometer via a transmission cable or the like.

By the way, when the center sleeve 11 is tightened and fixed together with the fork pipe, a relatively large compressive load acts on it, so it is required to have sufficient compressive strength, and the gear inserted therein is required to have sufficient compressive strength. Since 13 rotates and slides at high speed, it is also required to have good bearing properties. For this reason, in the past, expensive sintered alloys or cast iron for bearings were formed into relatively thick walls, resulting in increased weight and high cost. Furthermore, the gear housing 12 has generally been made of light alloy casting, but in recent years, gear housings made of synthetic resin have been adopted to reduce the weight of the device. A gear housing made of synthetic resin in which the center sleeve is molded as an insert has the advantage of not only making the device lighter but also reducing manufacturing costs, but on the other hand, it has the problem of low bonding strength between the center sleeve and the gear housing. It was hot.

The present invention was developed in view of these points, and the gear housing is made of synthetic resin, which provides good bearing properties for the gear without using a bearing material as the center sleeve, and has high bonding strength between the gear housing and the center sleeve. The object of the present invention is to provide a rotation take-out device for a traveling speedometer made by a manufacturer.

The present invention will be described in detail below based on embodiments shown in the drawings.

FIG. 2 shows a longitudinal cross-sectional view of one embodiment of the present invention. In the drawing, 1 is a center sleeve that is fitted onto the wheel shaft and tightened and fixed. When this center sleeve 1 is insert-molded, Center sleeve 1 is made of synthetic resin that forms the gear housing.
forming a synthetic resin layer 5 that covers the center sleeve 1 and is integral with the gear housing 2;
I inserted gear 3 here. FIG. 3 shows a cross-sectional view of a main part of an example of a mold for molding the gear housing of the rotary take-out device of the present invention. A cylindrical cavity 8 is formed that communicates with a cavity 7 that molds the housing. The synthetic resin injected through the introduction hole 9 of the mold forms the gear housing 2, and at the same time forms a synthetic resin layer 5 that covers the center sleeve 1 and is integral with the gear housing 2. In the drawing, 4 is a pinion gear that meshes with the gear 3 to rotate at a predetermined reduction ratio and transmits the rotation to the outside, and 20 is a pinion gear that is being pulled out to form an inner hole for accommodating the pinion gear 4 in the gear housing 2. It is a child.

As mentioned above, in this invention, the synthetic resin that forms the gear housing is guided to the outer periphery of the center sleeve, and a synthetic resin layer is formed that covers the center sleeve and is integrated with the gear housing, and the gear is inserted therein. Since the supported gear slides on this synthetic resin layer, good sliding properties can be obtained without using a bearing material such as a sintered alloy for bearings or cast iron as the center sleeve. Furthermore, since the center sleeve is not required to have any bearing performance, it is possible to use materials that are cheaper and have higher compressive strength than sintered alloys or cast iron, such as ordinary steel or steel pipes, which can reduce the weight by reducing the wall thickness. It is possible to reduce the cost and reduce the cost. Further, since the synthetic resin layer that is integral with the synthetic resin forming the gear housing covers the center sleeve with a wide contact area, an extremely high bonding strength between the center sleeve and the gear housing can be obtained.

As mentioned above, the present invention has the advantage of reducing the weight and cost of the speedometer rotation extractor, as well as significantly increasing the strength of the connection between the gear housing and the center sleeve.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a conventional example, FIG. 2 is a longitudinal sectional view of an embodiment of the present invention, and FIG. 3 is a sectional view of essential parts of an example of a mold for molding a gear housing. Explanation of symbols: 1...Center sleeve, 2...Gear housing, 3...Gear, 4...Pinion gear, 5...Synthetic resin layer.

Claims (1)

[Scope of utility model registration request] It has a gear housing 2 made of synthetic resin, in which a center sleeve 1 is insert-molded, which is inserted into the wheel shaft and fixed by tightening, and inside the gear housing,
rotatably supported by the center sleeve 1;
Gear 3 connected to the wheel hub and rotated
and a pinion gear 4 that meshes with the gear 3 to rotate at a predetermined reduction ratio and transmits the rotation to the outside. A rotation take-out device for a traveling speedometer, characterized in that a synthetic resin layer 5 is formed which is guided to the outer periphery of a sleeve 1, covers the center sleeve 1, and is integrated with a gear housing 2, into which the gear 3 is inserted.