JPS5854254A - Reduction gear mechanism - Google Patents

Abstract

PURPOSE:To both reduce generation of a gear noise and improve transmission efficiency, in the captioned mechanism used for a counter and the like of automobile odometer, by both constituting a gear train only with spur gears and forming an input side gear to a small module with a soft material. CONSTITUTION:Rotation of a rotor 5 is output to a gear 11 from a gear 7 via gears 8, 8a, gears 9, 9a and gears 10, 10a. The gear 8 in an input side is meshed to the driving gear 7, and formed to a small module, further prepared by a soft material of polyurethane, nylon or rubber, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a reduction gear mechanism that has good transmission efficiency, is easy to assemble, and generates little gear noise.

Conventionally, for example, an automobile mileage counter and a step motor (which electrically detects the number of revolutions of the wheel of a shoulder-driven vehicle and is rotated by the detected output) are used as its drive source. Since the reduction gear mechanism was mainly composed of a worm gear, there were problems in that the transmission efficiency was poor and assembly and manufacturing were troublesome. Therefore, a reduction gear mechanism composed of spur gears was considered as a solution to these problems, but this had the problem of generating significant gear noise as a drawback of spur gears. Furthermore, when a lubricant or a damper is attached to muffle the sound, there is a problem in that the transmission efficiency decreases and the assembly process becomes complicated.

In view of the above-mentioned problems, the present invention aims to provide a reduction gear mechanism in which only a plurality of spur gears are assembled together, and the input gear is a gear made of a small module made of soft material. This will be explained below based on an example shown in the drawings. 2 is an outer frame made of a ferromagnetic material and has a U-shaped cross section, and 2 and 3 are each fixed at one end to the end of the outer frame 1. Also, semicircular notches 2a facing each other at each tip
and 3a are formed respectively, and a yoke and a core constitute a stator at the front end of the image, and 4 is a coil wound around the core 3 and connected to a wheel rotation speed detecting device (not shown), etc. , 5 is a rotor which is rotatably inserted into the notches 2a and 3a, is pivotally supported by a bearing 6, and has a drive gear 7 fixed to its shaft portion, and these constitute a stepping motor. are doing. 8 is a small soft material (polyurethane, nylon, ZAM, etc.) of the module that meshes with the drive gear 7 and has a binion 8a integrally formed on its upper surface.
9 is a first intermediate gear that meshes with the pinion 8a and has a pinion 9a integrally formed on its lower surface; 10 is a second intermediate gear that meshes with the pinion 9a and has a pinion 10a integrally formed on its lower surface; Reference numeral 11 denotes an output side gear that meshes with the binion 10a and also meshes with an input side gear such as a mileage counter (not shown), and these are all configured as spur gears and are pivotally mounted on the inner bottom surface of the outer frame 1. Along with being there,
The whole constitutes a reduction gear mechanism.

As described above, the reduction gear mechanism according to the present invention is composed of only a plurality of spur gears, so it has high transmission efficiency and is easy to assemble and manufacture. In addition, since the input gear 8, which has a high rotational speed and tends to generate the loudest gear noise, has a smaller module, the speed at which the teeth collide between the drive gear 7 and the input gear 8 decreases, reducing the gear noise and reducing the overall noise. This also reduces gear noise. Furthermore, since the input gear 8 is made of a soft material, the generation of gear noise is further reduced due to its own buffering effect.

As described above, the reduction gear mechanism according to the present invention has important practical advantages of high transmission efficiency, easy assembly, and little gear noise, and is particularly suitable for driving automobile mileage counters, etc. It can be used very suitably as a device.

[Brief explanation of the drawing]

FIG. 1 is a front view of an embodiment of a reduction gear mechanism according to the present invention, and FIG. 2 is a plan view of the above embodiment. 7... Drive gear, 8... Input side gear, 9... First intermediate gear, 10... Second intermediate gear, 11... Output gear.

Claims (1)

[Claims] A reduction gear mechanism constructed by combining only a plurality of spur gears, and characterized in that the input gear is a small modular gear made of a soft material.