JPH0439490Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a device that prevents backlash between gears meshing with each other during power transmission by a gear train.

[Conventional technology]

Although backlash between gears meshing with each other has advantages such as preventing tooth interference, it causes problems such as causing large noise and fluctuations in transmitted torque.

Therefore, as the prior art, Japanese Utility Model Application Publication No. 49-64666 and Japanese Utility Model Publication No. 59-29173, as shown in FIG. The narrow auxiliary gear 22 for preventing crushing is closely attached to the auxiliary gear 22.
A retaining ring 2 is removably fitted into an annular groove 24 on the outer peripheral surface of the shaft 23 into which the one gear 20 is fitted.
Disc spring 2 inserted between 5 and the secondary gear 22
6, the auxiliary gear 22 is engaged with the other gear 21 at the same time as the one gear 20.
It is proposed to eliminate backlash between 0 and 21.

[Problem that the invention attempts to solve]

However, in order to assemble the backlash prevention device in the prior art, the auxiliary gear 22 for backlash prevention is tightly attached to the side surface of one of the gears 20 fitted on the shaft 23, and then the disc-shaped spring 26 is fitted on the shaft 23. This is done by fitting and attaching the retaining ring 25 to the annular groove 24 on the outer circumferential surface of the shaft 23. Next, insert the retaining ring 25 into the annular groove 24.
When the retaining ring 25 is fitted into the annular groove 24, the locking ring 25 is not fully fitted into the annular groove 24, and the secondary gear 22 for preventing backlash cannot be pressed against the side surface of one of the gears 20. In many cases, the assembly was completed without any changes.

In addition, in order to prevent this, when fitting the retaining ring 25 into the annular groove 24, the disc-shaped spring 2
6 must be held so as not to fall into the annular groove 24, and the retaining ring 25 must be fitted into the annular groove 24, resulting in extremely poor assembling performance, which becomes an obstacle to automatic assembly. -ing

In addition, Utility Model Application No. 60-54860 as another prior art
In the publication, a large-diameter annular recess is provided in the side surface of the gear, a small-diameter bush is inserted into the annular recess, and a secondary gear for preventing backlash is fitted into the bush. It is proposed to press the gear against the side surface of the gear using a disc-shaped spring inserted between the secondary gear and a flange formed on the outer periphery of the bush so as to fit over the bush.

However, when assembling this product, when assembling the bush to which the disc spring and secondary gear have been fitted in advance to the gear, there is a risk that the secondary gear and disc spring may fall off from the bush. must be held so that the auxiliary gear and disc-shaped spring fitted thereon do not fall off, which also makes assembly difficult and becomes an obstacle to automatic assembly.Moreover, the disc-shaped spring The spring is configured to press the inner circumferential portion of the annular recess in which the bush fits in the secondary gear, so that the secondary gear easily lifts up from the side surface of the gear, so that the effect of preventing crushing can be sufficiently achieved. I was unable to achieve this goal.

The present invention aims to solve all of the problems of each of these prior art techniques at once.

[Means for solving problems]

For this reason, the present invention provides a backlash prevention device comprising a gear fitted to a shaft, a backlash prevention auxiliary gear in close contact with the side surface of the gear, and a disc-shaped spring that presses the auxiliary gear against the gear. An annular recess surrounding the shaft is provided on the side surface of the gear, and a bush is fitted onto the shaft so that a part of the bush fits into the annular recess, and the auxiliary gear is fitted into the bush. rotatably fitted, and
A flange is formed on the outer periphery of the bush at a portion protruding from the annular recess, and the outer diameter of the disc-shaped spring is larger than the inner diameter of the annular recess,
The disc-shaped spring is inserted into a bush between the collar portion and the secondary gear, and an annular groove is provided in the annular recess on the outer periphery of the bush. The structure is such that a retaining ring is removably fitted into the groove.

〔Example〕

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.The embodiment shown in the drawings is a case in which the rotation of a crankshaft 1 is transmitted to a camshaft 3 for opening and closing intake and exhaust valves via an intermediate shaft 2 in an internal combustion engine. On the intermediate shaft 2, there is a gear 4 fitted on the crankshaft 1.
An idler gear 6 that meshes with both the gear 5 and the gear 5 fitted on the camshaft 3 is rotatably fitted.

The gear 4 on the crankshaft 1 is provided with an annular recess 7 on its side surface for processing the crankshaft 1,
A bush 8 is fitted onto the crankshaft 1 so that a part of the bush 8 fits into the annular recess 7.

This bush 8 has one more tooth than the gear 4.
A secondary gear 9 for backlash prevention having an increased number of teeth is rotatably fitted, the secondary gear 9 is brought into close contact with the side surface of the gear 4, and the gear 4 is meshed with the idler gear 6 at the same time.

Further, a flange 10 is formed on the outer periphery of the bush 8 at a portion that protrudes from the annular recess 7, and a flange 10 is formed between the flange 10 and the auxiliary gear 9 from the inner diameter of the annular recess 7. A disc-shaped spring 11 formed to have a large diameter is inserted into the bushing, and an annular groove 12 is carved in the outer periphery of the bush at a portion that fits into the annular recess 7, and a stop ring 13 is inserted into this annular groove 12. After attaching and detaching, fit it into the sitting position.

With this structure, before the bush 8 is fitted onto the crankshaft 1, the disc spring 11 and the secondary gear 9 for preventing backlash are fitted onto the bush 8, and then the annular groove 12 in the bush 8 is fitted. By fitting and attaching the retaining ring 13 to the bush 8, the secondary gear 9 and the disc-shaped spring 11 can be assembled to the bush 8, and the bush with the secondary gear 9 and disc-shaped spring 11 assembled in this way is 8 is the crankshaft 1 on which the gear 4 is fitted in advance.
By fitting into the gear 4, the backlash prevention auxiliary gear 9 can be assembled in a state where it is pressed against the side surface of the gear 4 by the plate spring 11.

As a result, the disc-shaped spring as in the prior art,
It is possible to prevent the retaining ring for supporting the disc-shaped spring from falling into the annular groove for fitting and mounting the disc-shaped spring, resulting in incomplete fitting of the retaining ring, and also to prevent the disc-shaped spring from falling into the annular groove. It is also possible to avoid the trouble of fitting and attaching a retaining ring in this state.

Furthermore, assembling the disc spring 11, the secondary gear 9, and the retaining ring 13 to the bush 8 as described above is possible regardless of the crankshaft 1 and the gear 4.
While it can easily be done elsewhere,
Belleville spring 11 fitted into bush 8 and secondary gear 9
The bushing 8 with the auxiliary gear 9 and the disc-shaped spring 11 assembled thereon is held in place by the retaining ring 13 fitted into the annular groove 12 of the bushing 8 so that it cannot be removed. Since it is possible to reliably prevent the disc spring 11 and the secondary gear 9 from falling off the bush 8 during the process, the secondary gear 9 and the disc spring 1
This allows the bushing 8 with a 1-piece to be easily fitted onto the crankshaft 1.

Furthermore, when the bush 8 is fitted onto the crankshaft 1, the retaining ring 1 is attached to the bush 8.
Since the part of the annular groove 12 with the 3-rings is configured to fit into the annular recess 7 of the gear 4, the dish-shaped spring 11 and the secondary gear 9, which are fitted into the bush 8 as described above, are prevented from coming off. In order to do this, the bush 8 is provided with an annular groove 12 and a retaining ring 13 that is fitted into the annular groove 12, thereby making it possible to avoid an increase in the length in the axial direction, and thus an increase in size. It is.

Moreover, a disc-shaped spring 11 fitted into the bush
By making the outer diameter of the annular recess 7 larger than the inner diameter of the annular recess 7, the portion of the disc spring 11 that presses the secondary gear 9 against the gear 4 is made to have a larger outer diameter than the outer circumference of the secondary gear 9. Therefore, it is possible to reliably reduce the floating of the auxiliary gear 9 from the side surface of the gear 4.

On the other hand, in an internal combustion engine, when power is transmitted from the crankshaft 1 to the camshaft 3 for opening and closing the intake/exhaust valves via the intermediate shaft 2, the idler gear 6 on the intermediate shaft 2 and the gear on the camshaft 3 Since there is also a backlash between the intermediate shaft 2 and the idler gear 6, a backlash prevention device configured in the same manner as described above is provided for the idler gear 6 on the intermediate shaft 2 as well.

That is, a bush 8a is fitted onto the intermediate shaft 2 so that a part thereof fits into an annular recess 7a provided on the side surface of the idler gear 6, and the gear 5 on the camshaft 3 is fitted onto the bush 8a. A auxiliary gear 9a for preventing backlash that meshes with the bushing 8a is rotatably fitted therein, and a flange 10a is formed on the outer periphery of the bush 8a at a portion protruding from the annular recess 7a. and the secondary gear 9a,
A disc-shaped spring 11a having a diameter larger than the inner diameter of the annular recess 7a is inserted, and an annular groove 12 is formed on the outer periphery of the bush 8a in a portion inside the annular recess 7a.
a, and the stop ring 13a is removably fitted into this annular groove 12a.

In the above embodiment, a backlash prevention device is installed on one of the gears 4 on the crankshaft 1 and the idler gear 6 on the intermediate shaft 2 in an internal combustion engine, and on the idler gear 6 and the camshaft 3. One idler gear 6 of both gears with the upper gear 5
The case is shown in which the gears 4 and 6 are provided respectively, but the idler gear 4 of the other gear 4 and the idler gear 6 is
In addition, the idler gear 6 and the gear 5 on the camshaft 3 may each be provided on the other gear 5, and may be provided on the other gear 5 of the idler gear 6 and the gear 5 on the camshaft 3. Needless to say, the present invention can also be applied to various gear transmission parts.

[Functions and effects of the idea]

As described above, according to the present invention, before the bushing is fitted onto the shaft, a secondary gear for preventing backlash against the gear on the shaft and a disc-shaped spring for pressing the secondary gear against the gear are attached to the bushing.
These can be assembled so that they do not come off and fall off the bushing, and after this assembly, simply by fitting the bushing onto the shaft, the secondary gear for preventing crashing can be attached to the side of the gear with a disc-shaped spring. Since it can be assembled so that it can be pressed with This significantly improves performance and makes it easy to fully automate the assembly.

Moreover, by making the outer diameter of the disc-shaped spring that fits into the bushing larger than the inner diameter of the annular recess in the gear, the part of the disc-shaped spring that presses the auxiliary gear against the gear can be brought close to the outer periphery of the auxiliary gear, and it is possible to reliably reduce the protruding gear from floating up from the side surface of the gear, which also has the effect of greatly promoting the anti-backlash effect of the auxiliary gear.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention; FIG. 1 is a longitudinal sectional front view of the end portion of a crankshaft in an internal combustion engine;
The figure is an enlarged exploded view of the main parts of FIG. 1, and FIG. 3 is a diagram showing a conventional device. 1... Crankshaft, 2... Intermediate shaft, 3... Camshaft, 4, 5... Gear, 6... Idler gear, 7,
7a... Annular recess, 8, 8a... Bush, 9,
9a... Secondary gear for preventing backlash, 10,1
0a... Tsuba, 11, 11a... Belleville spring, 12,
12a... annular groove, 13, 13a... retaining ring.

Claims (1)

[Scope of utility model registration request] Gears 4 and 6 fitted onto shafts 1 and 2;
The secondary gears 9, 9a are closely attached to the side surfaces of the gears 4, 9a for preventing backlash, and the secondary gears 9, 9a are connected to the gears 4, 6.
In the anti-backlash device consisting of disc springs 11 and 11a that press against gears 4 and 6,
Annular recesses 7, 7 surrounding the shafts 1, 2 are provided on the side surfaces of the shafts 1, 2.
A is provided on the shafts 1 and 2, while bushes 8 and 8 are provided on the shafts 1 and 2.
a, so that a part of the bushes 8, 8a fit into the annular recesses 7, 7a, and the auxiliary gears 9, 9a are rotatably fitted into the bushes 8, 8a, Moreover, on the outer periphery of the bushes 8, 8a,
A flange portion 1 is provided at a portion protruding from the annular recesses 7 and 7a.
0, 10a, while the disc springs 11,
The outer diameter of 11a is made larger than the inner diameter of the annular recesses 7, 7a, and the disc-shaped springs 11, 11a are
The bushings 8, 8a are inserted between the flange portions 10, 10a and the secondary gears 9, 9a, and further,
On the outer periphery of the bushes 8, 8a, annular grooves 12, 12a are provided in the annular recesses 7, 7a, and retaining rings 13, 13 are provided in the annular grooves 12, 12a.
A device for preventing a gear from collapsing, characterized in that a is removably fitted.