JP2595071Y2 - Non-backlash mechanism - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-backlash mechanism.

[0002]

2. Description of the Related Art A gear mechanism, for example, a gear of a transmission countershaft is always meshed with a drive pinion, so that the gear rattle caused by a gap (backlash) between the two due to a rotational fluctuation on the drive pinion side during idling. Occurs. Therefore, as shown in FIG. 3, a sub gear 4 is provided in close contact with a gear (hereinafter referred to as a "normally meshing gear") 3 of a counter shaft 2 which always meshes with the drive pinion 1 and is rotatable on the counter shaft 2. 4, the normal meshing gear 3 and the sub gear 4
The gear 1 is normally meshed with the teeth 1a of the drive pinion 1 by the spring force of the spring 5 fitted and locked in the holes 3b, 4b.
The non-backlash mechanism is constituted by pressing the teeth 3a of the first and second gears 3a and 3b so as to eliminate the backlash between these two gears and reduce the tooth hitting sound.

[0003]

[Problem to be solved by the invention] Drive pinion 1,
The normally meshing gear 3 is a helical gear in order to carry a high-load, high-speed transmission, and the sub-gear 4 is a spur gear for reasons of cost reduction, ease of manufacture, and the like. Is formed. Therefore, the sub gear 4
Has a small contact area with the drive pinion 1 of the helical gear and is in contact at one point.

By the way, the tooth surface of the sub gear 4 formed by press punching has a smooth surface because a portion where the punch first hits in the punching direction has a sheared surface, but the remaining portion following the sheared surface has a broken surface. Because of the cross section, the surface becomes rough, and the accuracy of the contact surface (engagement) with the teeth 1a of the drive pinion 1 deteriorates. Therefore, if the tooth surface portion of the fractured surface meshes with the helical gear dry pinion 1 in point contact, the tooth contact becomes poor, and the backlash cannot be satisfactorily removed.

[0005] For this reason, conventionally, the sub gear 4 is formed into a smooth surface by machining the tooth surface after press punching, and
To improve the accuracy of meshing and to eliminate backlash well. However, further smoothing of the tooth surface after punching by a press has a problem in that double work is required and the cost of the sub gear is increased.

The present invention has been made in view of the above points, and uses a sub gear formed by press punching as it is, and effectively removes backlash by improving the tooth contact with another meshing gear. An object of the present invention is to provide a non-backlash mechanism as described above.

[0007]

According to the present invention, in order to achieve the above-mentioned object, the first and second helical gears intermeshing with each other mesh with the first helical gear. The second helical gear is rotatably supported coaxially with the second helical gear, and is formed by press punching. The spring is interposed between the sub gear and the second helical gear. 1, the non-backlash mechanism second is given to remove the backlash between the helical gears, the sub gear is the set included so that only part of the shearing surface of the press punching strikes the first of the helical gear A possible installation surface regulating means is provided so that only a portion of the shear surface of the sub- gear contacts the first helical gear.

[0008]

The sub-gear formed by press punching has a smooth surface at the portion where the punch first hits in the press punching direction and has a smooth surface. This shear plane is the first
Assemble so that it contacts the helical gear. Thereby, the sub gear can be used as it is after press punching.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the accompanying drawings. The same members as those in FIG. 3 are denoted by the same reference numerals. FIG. 1 shows a non-backlash mechanism of a drive pinion of a transmission to which the present invention is applied and a normally meshing gear of a counter shaft. A normally meshing gear 3 of a drive pinion 1 and a counter shaft 2 meshing with the drive pinion 1 is provided. In order to carry out high-load high-speed transmission, each is a helical gear, and the sub gear 8 is a spur gear. The tooth width of the drive pinion 1 is slightly wider than the sum of the tooth widths of the normal gear 3 and the sub gear 8.

The sub gear 8 has one end of the tooth surface 8b of each tooth 8a in point contact with the tooth surface of the tooth 1a of the drive pinion 1, and is pressed and pressed in the direction of arrow A by the spring force of a spring (not shown). ing. And the normal gear 3 is
The teeth 3a are pressed against the teeth 1a of the drive pinion 1 in the direction of arrow B by the reaction force of the spring, and the backlash between the teeth 3a and the drive pinion 1 is removed.

The sub-gear 8 is formed by stamping a steel plate (about 1.6 mm) with a press, and has a tooth surface 8b of each tooth 8a.
Are as shown in FIG. That is, assuming that the punching direction of the sub gear 8 by pressing is the direction of arrow C, a small portion 8c first hit by a punch (not shown) in the tooth width direction becomes a shear surface (hereinafter referred to as "shear surface 8c"). A smooth cut surface results. Cutting surface 8d following this shearing surface 8c
Becomes a fracture surface (hereinafter referred to as “fracture surface 8d”), which is a cut surface coarser than the shear surface 8c.

That is, the tooth surface 8b of the tooth 8a of the sub gear 8 is
The first part of the punching in the tooth width direction becomes a smooth shear surface 8c of the surface, and the remaining part from the part following the shear surface to the end of the punching becomes a rough fracture surface 8d of the surface. The sub gear 8
In the punching, a locking hole for locking one end of the spring at the time of punching, a pin hole at the time of assembling, and the like are formed. The sub gear 8 cannot be installed inside the counter shaft upside down due to the positions of the locking holes and the pin holes (both not shown).

As shown in FIG. 1, the sub gear 8 has one end of the shear surface 8c of the tooth surface 8b of the tooth 8a pressed against the tooth 1a of the dry pinion 1, that is, the corner of the shear surface 8c has a drive pinion. The countershaft is incorporated into the countershaft so as to be brought into pressure contact with one tooth 1a by one-point contact, and one end face is in close contact with the opposite end face of the normally meshing gear 3. As a result, the sub gear 8 has a good tooth contact with the dry pinion 1, and the meshing accuracy is improved. As a result,
The backlash between the drive pinion 1 and the normally meshing gear 3 can be effectively removed, and a highly accurate non-backlash mechanism can be constructed even when used without processing the tooth surface after press punching. It is possible to do.

[0014]

As described above, according to the present invention, the contact between the press-punched sub-gear and the helical gear meshing with the sub-gear is improved, and the sub-gear can be used as it is after the press-punching. Thus, there is an effect that the cost of the sub gear can be reduced.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part showing an embodiment of a non-backlash mechanism to which a press punching sub gear according to the present invention is applied.

FIG. 2 is an enlarged view of a portion surrounded by a circle II in FIG.

FIG. 3 is a sectional view of an essential part showing an example of a non-backlash mechanism.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Drive pinion 3 Normal gear 8 Sub gear 8a Teeth 8b Tooth surface 8c Shear surface 8d Break surface

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Makoto Kimura 10-10 Okura-cho, Nakahara-ku, Kawasaki-shi, Kanagawa Prefecture Mitsubishi Motors Engineering Co., Ltd. Tokyo Office (56) References Japanese Utility Model 5-30599 (JP, U)

Claims (1)

(57) [Scope of request for utility model registration] 1. A first helical gear interposed between first and second helical gears meshing with each other and meshed with a first helical gear to be rotatably supported coaxially with a second helical gear. The first and the second gears are formed by a sub gear formed by press punching and a spring interposed between the sub gear and the second helical gear.
In non-backlash mechanism second is given to remove the backlash between the helical gears, the sub gear is capable of pairs included so that only part of the shearing surface of the press punching strikes the first of the helical gear A non-backlash mechanism, wherein a built-in surface restricting means is provided, and only a portion of the sub gear in a shear plane comes into contact with the first helical gear.