JPH022466B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a reduction starter. In particular, the present invention relates to a reduction starter equipped with a planetary gear reduction device that reduces rotational force and transmits it to a pinion. This type of starter is used, for example, as a reduction starter for starting an engine, which is used to reduce the rotational force of an electric motor.

[Background of the invention]

Conventional reduction starters of this type have a problem in that the gears are in uneven contact, resulting in instability in terms of strength. Such uneven contact in gear meshing is largely due to accuracy errors between each component. Furthermore, in the case of a reduction starter having a plurality of planetary gears, irregularities in the mounting dimensions are also a major cause. However, with the prior art, it has been difficult to completely prevent such uneven contact.

Problems of the prior art will be explained below with reference to the drawings.

Figure 5 shows the rotating sun gear a formed on the shaft.
6 shows a general conventional example in which a planetary gear b meshes with a fixed sun gear c, and this planetary gear b meshes with a fixed sun gear c. FIG. 6 shows a ring gear assembly d in which the fixed sun gear is integrated with an intermediate bracket. A conventional example is shown below (see Japanese Utility Model Application No. 58-67977).

In the conventional example shown in Fig. 6, the fixed sun gear (internal gear) is integrally formed with the intermediate bracket, which is a structure, to form a ring gear assembly d, so the fixed sun gear is completely fixed in position. .
In the conventional example shown in Fig. 5 as well, the fixed sun gear a must be fixed to the intermediate bracket e with pins, screws, etc., or fixedly attached to another structure, and must also be fixed mechanically. become. Therefore, if there is even a slight deviation in the mounting method of the planetary gear b, the fixed sun gear a (or the ring gear assembly d integrated with the bracket) cannot be deformed to absorb this deviation, resulting in uneven contact.

A structure in which the internal gear member is arranged on an intermediate bracket via an elastic body (for example, a leaf spring or rubber) to prevent uneven contact may be considered, but in this case, a large transmission force is required for engine starting, etc. In those that do, the structure of the elastic body is complicated and large-scale, and the shape is also large. In addition, when such an elastic body is used, the elastic body changes over time and eventually becomes unstable in terms of strength.

As mentioned above, in the conventional technology, uneven contact occurs due to misalignment, etc., resulting in unstable strength, and extreme stress is generated in the area where uneven contact occurs, so it is necessary to use a material with high strength as a material for fixed sun gears. They had no choice but to use steel or other materials. A structure using an elastic body becomes complicated and large-sized, and strength instability cannot be resolved, so it is not a fundamental solution.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a reduction starter equipped with a planetary gear reduction device in which the gears do not come into uneven contact when the planetary gears and the fixed sun gear mesh. Furthermore, in this case, the power to be transmitted is evenly distributed to multiple planetary gears to stabilize the gear strength, thereby preventing the occurrence of extreme stress caused by uneven application of force, and as a result, The purpose is to enable the use of not only conventional steel but also resin materials for the fixed sun gear.

[Summary of the invention]

In the reduction starter of the present invention, the outer periphery of the rotor-side center bracket that supports the rotating shaft is bent into a substantially L-shape, and the bent tip is brought into contact with the side surface of the pinion-side center bracket that supports the pinion. The fixed sun gear is inserted into the resulting space with a slight side gap, and the internal gear of the fixed sun gear is fitted into the tooth profile protruding from one side of the center bracket on the pinion side. It is equipped with a planetary gear reduction device that is fixed to a gear case by inserting fixing bolts. In this way, the fixed sun gear of the present invention has a gap and is installed by fitting, so it can be stored in a relatively free state, and therefore even if there is misalignment due to dimensional errors or other misalignment, the fixed sun gear can be fixed. This is absorbed by the elastic deformation of , so no uneven contact occurs. In addition, in the case of a structure in which the fixed sun gear is fixed to a bracket, etc., elastic deformation occurs using the fixed part as a fulcrum, so there is a high possibility that uneven force will be applied to the fixed sun gear and extreme stress will occur. However, in the present invention, since the fixed sun gear is not fixed to a bracket or the like, it can be elastically deformed uniformly, and uneven contact can be prevented with stable operation. It is no longer necessary to use a material with high strength for the fixed sun gear.

[Embodiments of the invention]

An embodiment of the present invention will be described below. In this embodiment, the present invention is applied to a starter that decelerates the rotation of an armature 2 of an electric motor 1 and transmits it to a pinion 12, thereby starting an engine.

In FIG. 1, the output of an armature 2 of an electric motor 1 is transmitted from an armature pinion (rotating sun gear) 4 formed on an armature shaft 3 to an internal gear ( The signal is transmitted to a plurality of planetary gears 7 which are meshed with the fixed sun gear (fixed sun gear) 6 and the gears of the armature pinion 4 and are arranged at substantially equal positions on the circumference.

The power transmitted to the planetary gear 7 is then transmitted to the planetary arm 9, which has a support pin 8 that rotatably supports the planetary gear 7 and rotates as the planetary arm 9 revolves, and a pinion formed integrally with the planetary arm 9. Shaft 1
transmitted to 0. Below, pinion shaft 10
The signal is then transmitted to the roller clutch 11 and pinion 12 to crank the engine.

The armature shaft 3 is supported by bearings 15 and 16 provided on the rear cover 13 and the center bracket 14 on the armature side, respectively, and the pinion shaft 10 is supported on bearings 19 and 20 provided on the gear case 17 and the center bracket 18 on the pinion side, respectively. ing. The fixing bolts 21 are for fixing the yoke 22 and the rear cover 13 to the gear case 17.

The armature side center bracket 14 is constructed by bending its outer periphery into an L-shape. And, attach the bent end to the pinion side center bracket 1.
The structure is such that the fixed sun gear 4 is sandwiched in the space obtained by abutting against the side surface of the fixed sun gear 8 with a slight side gap.

Specifically, in this embodiment, the armature side center bracket 14 is formed of an iron plate or the like, and is structured into a two-stage structure having a first cylindrical portion 23 that accommodates the bearing 16 and a second cylindrical portion 24 that accommodates the internal gear 6. It is made into an L-shape by press forming into an L-shape. Also, the depth H and inner diameter D of this second cylindrical portion 24 are as follows:
There is a small gap (0.2
mm).

Also, the internal gear (fixed sun gear) in this example
6 is as shown in Fig. 2, and this has an internal gear 2 on the inner periphery.
5 is formed as an annular cylinder 26. This internal gear 26 can be formed from metal such as steel or aluminum, or from resin, by cold molding or resin molding. As will be described later, it is not necessarily made of steel, but may be made of resin. As in this example, the fixed sun gear 6 can be formed in a symmetrical shape and is therefore easy to manufacture, and since it can be assembled from either side, it is easy to assemble, and since position detection is not required, it can be assembled automatically.

As shown in FIG. 3, the pinion side center bracket 18 is formed with a toothed portion 27 protruding from one side thereof. The internal gear 25 (FIG. 2) of the fixed sun gear 6 is fitted into this toothed portion 27.

In this example, the details are as follows. That is, the pinion side center bracket 18 of this example is cold-formed or precision cast into a shape having a tooth profile 27 protruding from one side, as shown in FIG. Tooth profile 2
7 is designed to have the same number of teeth so that it can be inserted through the internal gear 25 of the internal gear through an optimal gap (backlash of about 0.1 module), and the inside of the rim 28 of the tooth profile 27 is designed to have the same number of teeth. The planetary arm 9 explained in can be stored. The bearing 20 is press-fitted into the center. A fixing bolt 21 is inserted into the hole 29 to fix the pinion side center bracket so that it does not spin idly.

Pinion side center bracket 1 as shown above.
8 and the fixed sun gear 6 are separate bodies, and instead of fixedly attaching both, the internal gear 25 of the fixed sun gear 6 is attached to the toothed portion 27 of the bracket 18.
It is configured to be installed by fitting it. As a result, the fixed sun gear 6 can be elastically deformed to a certain extent.
Moreover, this elastic deformation is performed uniformly because a part of the fixed sun gear 6 is not fixed to any part.

The effect of preventing uneven contact due to this will be described next. That is, it will be explained in detail below that the planetary gear reduction device configured as described above can effectively prevent uneven contact of gears, which is an object of the present invention.

As mentioned above, uneven contact in gear meshing is largely due to accuracy errors between each part, but in products with multiple planetary gears such as this reduction starter, irregularities in the mounting dimensions are also a large factor. account for the cause.

Now, if one of the planetary gears 7 has a large irregularity in the mounting dimensions, the fixed sun gear 6 will move into the annular space 5 created by each center bracket 14, 18 as described above.
Tooth profile 2 of the pinion side center bracket 18
7 and the internal gear 25 of the fixed sun gear 6 are inserted in the assembly in a relatively free state, so the fixed sun gear 6 easily eccentrically responds to the revolution of the planetary gear 7 and becomes a planetary gear. 7 powers are equally distributed.

If there is a large mounting irregularity, the power will not be distributed evenly due to the eccentricity of the fixed sun gear 6 alone, but in this case, the force will be due to the elastic deformation of the fixed sun gear 6.

In this case, according to the present structure, since the annular tube 26 of the fixed sun gear 6 has a uniform cross-sectional shape as shown in FIG. 4, its elastic deformation is uniformly distributed as shown by the broken line 34. As a result, the internal stress generated in the fixed sun gear 6 is also distributed over the whole and becomes small. Therefore, no extreme stress or excessive force is applied to the fixed sun gear 6.
Therefore, it is possible to form this not only from a strong material such as steel but also from resin or the like. Moreover, this allows uneven contact of the gears to be effectively absorbed, and the plurality of planetary gears 7 accurately distributes the transmitted power evenly.

If the fixed sun gear 6 is not configured to be free with respect to the center bracket 18 in this way, for example, one end (the right side in the figure) of the fixed sun gear 6 in FIG. 4 is restrained by engaging the center bracket 18 or otherwise. When configured, this constraint point becomes the fulcrum,
This fulcrum portion does not deform, and portions away from it deform sequentially, resulting in a lack of uniformity in elastic deformation. This prevents the occurrence of extreme stress,
Precise prevention of uneven contact and equal distribution of transmitted power between multiple planetary gears cannot be fully expected. Therefore, this configuration can be said to have solved this problem.

〔Effect of the invention〕

As mentioned above, the reduction starter of the present invention includes:
It has various effects as listed below.

(1) The structure allows the fixed sun gear to be stored freely without being restrained by the center bracket, so uneven contact between the gears can be effectively absorbed. Therefore, it is highly durable and has a long lifespan. The noise during operation can also be reduced. Of course, it also has the effect of stable operation. In addition, the plurality of planetary gears accurately distribute the transmitted power evenly, which further ensures the stability of operation.

(2) The elastic deformation of the fixed sun gear is uniform and distributed almost throughout the gear, resulting in less internal stress and stable strength.

(3) As a result of (1) and (2) above, there is a margin in gear strength, so the fixed sun gear does not necessarily have to be strong. For example, resin can be used as the material, and the material Greater freedom in selection.

(4) As a result of the above, lightweight materials such as resin can be used, so weight can be reduced. Even when steel or the like is used, it is easy to reduce the size and weight by making the wall thinner.

(5) A special elastic body for absorbing uneven contact is not required, and a reduction starter with a simple structure can be provided.

As described above, the present invention has great practical effects.

It should be noted that, as a matter of course, the present invention is not limited to the illustrated embodiments.

[Brief explanation of drawings]

1 to 4 show a reduction starter according to an embodiment of the present invention, FIG. 1 is a partial sectional view thereof, FIG. 2 is a perspective view of its fixed sun gear, and FIG.
The figure is a perspective view of the pinion side center bracket, and FIG. 4 is a sectional view of the main part to show the function. 5 and 6 are sectional views of conventional examples, respectively. 3... Armature shaft (rotating shaft),
4... Armature pinion (rotating sun gear), 5
... Annular space, 6 ... Internal gear (fixed sun gear), 7 ... Planetary gear, 10 ... Pinion shaft, 14 ... Armature side center bracket (rotor side center bracket), 17 ... Gear case, 18 ... Pinion side center bracket, 21 ... Fixing bolt, 25 ... Internal gear, 27
...protruding teeth.

Claims (1)

[Claims] 1. A rotating sun gear formed on a rotating shaft, a fixed sun gear installed on this rotating sun gear via an annular space, and a plurality of gears meshing with each of the above gears and disposed at approximately equal positions on the circumference. A planetary gear having a planetary gear, a pinion shaft that rotatably supports the planetary gear and rotates as it revolves, and a rotor-side center bracket and a pinion-side center bracket that support the rotating shaft and the pinion shaft, respectively. In a reduction starter equipped with a gear reduction device, the outer periphery of the rotor side center bracket is bent and the bent end is brought into contact with the side surface of the pinion side center bracket, thereby creating a space with a slight side gap and fixing it. In addition to sandwiching the sun gear, the internal gear of the fixed sun gear is fitted into the toothed part protruding from one side of the pinion side center bracket, and each center bracket is fixed to the gear case by inserting a fixing bolt. A reduction starter equipped with a planetary gear reduction device.