JPH0631590B2 - Reduction starter - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a starter having a reduction mechanism between a rotation shaft of a starter motor and a pinion, and particularly, the rotation shaft of the motor and the rotation shaft of the pinion are coaxial. It relates to the reduction starter that is designed to

[Background of the Invention]

As a starter for an internal combustion engine for automobiles, a pinion held on a shaft of a starter motor is meshed with a ring gear mounted on the outer circumference of a flywheel of the internal combustion engine only when necessary, and it has been widely used from the past. It was

In recent years, however, so-called reduction starters, which have a reduction mechanism between the shaft of the starter motor and the pinion, have been used as in Japanese Utility Model Publication No. 49-130237. However, since the conventional reduction starter uses the spur gear reduction device as the reduction mechanism, the rotation shaft of the motor and the pinion shaft are not on the same center line and are parallel to each other. Since the structures are separated by a distance, the structure is complicated, the cost is increased, and the size is increased.

Therefore, in order to eliminate the drawbacks of the reduction gear starter by using this conventional spur gear reducer, a reduction starter using a planetary gear unit as a reduction mechanism is proposed, for example, in Japanese Patent Application No. 57-22637. According to this method, since the shaft of the motor and the pinion can be configured coaxially and the reduction mechanism can be downsized, a reduction starter having almost the same size and shape as a conventional direct-coupled starter can be obtained as a whole. be able to.

However, in the conventional reduction starter using this planetary gear device, manufacturing of the planetary gear device,
High precision is required for assembly, and therefore, there is a drawback that the cost up in this respect is remarkable and sufficient cost reduction cannot be obtained as a whole. That is, the planetary gear device often requires a plurality of planetary gears in view of its balance and necessary torque transmission characteristics.In this case, the accuracy between the planetary gears and their mounting position accuracy are This is because an extremely high level is required, otherwise, there is a characteristic that one-sided contact occurs between gears, resulting in a decrease in performance, particularly a marked decrease in life.

[Object of the Invention]

An object of the present invention is to provide a reduction starter using a planetary gear device that is low in cost and has sufficient performance, except for the above-mentioned drawbacks of the prior art.

[Outline of Invention]

In order to achieve this object, the present invention provides an outer sun gear of a planetary gear device used as a reduction mechanism of a reduction starter at a right angle to the axis of the central sun gear and the center line of the revolution axis of the planetary gear. It is characterized in that it is held so that it can be displaced in a predetermined range over a predetermined range.

Example of Invention

Embodiments of the reduction starter according to the present invention will be described below with reference to the drawings.

1 to 4 show one embodiment of the present invention, in which 1 is a starter motor, 2 is an armature, 3 is an armature shaft, 4 is an armature pinion, 5 is an annular space, and 6 is Internal tooth ring gear, 7 is a planetary gear, 8 is a support pin, 9 is a planetary arm,
10 is a pinion shaft, 11 is a roller clutch, 12 is a pinion, 13 is a rear cover, 14 is an armature side center bracket, 15 and 16 are bearings, 17 is a gear case, 18
Is a pinion side center bracket, 19 and 20 are bearings,
21 is a fixing bolt, 22 is a yoke, 23 is an internal gear, 24
Is an annular member, 25 is a concave portion, 26 is a V-shaped groove, 27
Is a cylindrical portion, 28 is a protrusion, and 29 and 30 are holes.

The armature 2 of the motor 1 is rotatably supported by the shaft 3 and the bearings 15 and 16, and the torque thereof is transmitted to the armature pinion 4 formed integrally with the shaft 3.

The armature pinion 4 constitutes the central sun gear of the planetary gear set, while the inner ring gear 6 constitutes the outer sun gear. Then, a plurality of planet gears 7, for example, three planet gears 7 are arranged at equal intervals in an annular space 5 formed between the armature pinion 4 and the internal gear ring gear 6 so that they are in mesh with each other. It constitutes a planetary gear unit.

In order to make the three planetary gears 7 rotatable, they are held by support pins 8 via, for example, needle roller bearings, and all of these support pins 8 are press-fitted and fixed to planetary arms 9.

A planetary arm 9 to which three support pins 8 are press-fitted and fixed at equal intervals is integrally formed with a pinion shaft 10, and this shaft 10 has a bearing 1
The gear cover 17 and the pinion side center bracket 18 are rotatably supported by 9 and 20. As a result,
The planetary gear 7 can rotate around the support pinion 8 and can revolve around the pinion shaft 10.

Therefore, electric power is supplied to the starter motor 1 and the armature 2
When torque is generated and the armature shaft 3 rotates, it is applied to the pinion shaft 10 through a planetary gear device including an armature pinion 4, an internal ring gear 6, and a planetary gear 7 under a predetermined reduction ratio. As a result, the pinion shaft 10 is rotated with a large torque.

The rotation of the pinion shaft 10 is transmitted to the pinion 12 via the screuse spline and the roller clutch 11. At that time, the roller clutch 11 operates as a one-way clutch, and further, the pinion 12 and the ring gear of the anti-combustion engine are connected to each other. The meshing control is performed by an electromagnetic solenoid and functions as a starter. However, since the structure and operation of this part are the same as those of a known starter, description thereof will be omitted.

The fixing bolt 21 serves to assemble the motor 1 by attaching and fixing the rear cover 13 and the yoke 22 to the gear case 17.

FIG. 2 shows the internal gear ring gear 6 taken out and shown, in which the internal gear 23 is formed on the inner surface of an annular member 24 made of a suitable plastic material, and the recessed portion 2 is formed on one end surface thereof.
A predetermined number of 5 are formed. A V-shaped groove 26 for escaping the fixing bolt 21 is formed on the outer peripheral surface thereof.

On the other hand, FIG. 3 shows the center bracket 18 on the pinion side.
This bracket 18 has a cup shape having a tubular portion 27, and when the internal ring gear 6 is inserted into the tubular portion 27, the recessed portion 2 is formed on the inner surface of the bottom portion thereof.
5 (FIG. 2), a plurality of protrusions 28 are formed. In addition, the fixing bolt 21
There is a hole 29 for escaping.

Further, FIG. 4 shows the armature-side center bracket 14, which has a hole 3 through which the fixing bolt 21 escapes from the bearing 16.
It is clarified that 0 is set.

As is clear from FIG. 1, the internal gear ring gear 6 shown in FIG. 2 is inserted into the cylindrical portion 27 of the pinion side center bracket 18 shown in FIG. The projection 28 is brought into a fitted state. Then, the pinion side center bracket 18 is inserted into the mounting portion formed on the gear case 17 together with the armature side center bracket 14 and is fixed together with the rear cover 13 and the yoke 22 by the fixing bolt 21.
Fixed to.

As a result, in the assembled state, the internal ring gear 6 and the planetary gears 7 are placed in the annular space 5 (FIG. 1) formed by the center pinion side bracket 18 and the armature side center bracket 14. It will be held in a substantially sealed state.

Therefore, as shown in FIGS. 2 and 3, the outer diameter of the annular member 24 constituting the internal ring gear 6 is θ, the dimension in the thickness direction thereof is L, and the recess 25 is formed. The dimension between the outer peripheries is D, the width of each is W, and the length is B. On the other hand, the inner dimension of the cylindrical portion 27 of the pinion-side center bracket 18 in the depth direction is 1, and the inner diameter dimension is i,
The dimension between the outer circumferences of the protrusions 28 is d, the width of each is w, and the length is b, and the relationship between them is defined as follows.

θ <i L <l D> d W> w B> b For example, as an example, θ = 61 mm, i = 62 mm L = 16.2 mm l = 16.4 mm D = 56.05 mm d = 55.95 mm W = 8.1 mm w = 7.9 mm B = 4.2mm b = 3.8mm. That is, in the relationship of D> d, the difference between the two is made relatively small, and in the other relationships, the difference between the two is made considerably large.

As a result, when assembling in the state of FIG. 1, the outer peripheral portion of the recessed portion 25 of the internally toothed ring gear 6 and the outer peripheral portion of the projection 28 of the vinylon side center bracket 18 are fitted with normal fitting accuracy. However, in other parts, there is a considerable gap between the internally toothed ring gear 6 and the pinion side center bracket 18, and in particular, the outer periphery of these gears 6 and the bracket 18 are It will be assembled with a gap of 0.5 mm left between it and the circumference.

Next, the function and effect of this embodiment will be described.

As described above, the occurrence of one-sided contact of the gear in the gear reduction mechanism is often due to the accuracy error between the parts,
In a reduction mechanism using a planetary gear device using a plurality of planetary gears, for example, three planetary gears as in this embodiment, irregular mounting dimensions of the plurality of planetary gears also play a major role.

Therefore, it is now assumed that one of the planetary gears 7 has a large mounting dimension irregularity in the above embodiment.

However, in this embodiment, as described above,
The inner toothed ring gear 6, which serves as the outer sun gear, is retained in the annular space 5 formed by the armature-side center bracket 14 and the pinion-side setter bracket 18 with a dimensional allowance. , The space 5 is assembled so as to be freely displaceable over a certain range.

As a result, even if the mounting dimension of the planetary gear 7 is irregular, if it is in the range of (D−d) / 2 = (56.05−55.95) /2=0.05 mm, the planetary gear 7 revolves. In response to this, the internal toothed ring gear 6 changes relatively easily and acts so as to eliminate the one-sided contact, so that there is no difference in torque transmission between the three planetary gears 7.

Further, when the mounting irregularity of the planetary gears 7 exceeds the above-mentioned 0.05 mm, the internal ring gear 6 is kept within the above range of θ <i.
Elastically deforms to suppress the occurrence of one-sided gear contact and equalize torque transmission. Note that the elastic deformation of the gear 6 at this time does not occur as a partial deformation because the gear 6 is held so that it can be freely displaced without being constrained by its outer peripheral surface, and is almost entirely deformed. Since the internal stress of the internal gear ring 6 does not become too large, there is no fear of breakage due to this.

Therefore, according to this embodiment, even if a slight margin is given to the dimensional accuracy and mounting dimensional accuracy of each part, there is no risk of partial contact of the gear, and a reduction starter of sufficient performance can be obtained at low cost. be able to.

It should be noted that, in the above-described embodiment, the recessed portion 25 and the protrusion 28 are used in order to restrain the movement of the internal toothed ring gear 6 in the rotational direction, which facilitates the configuration and assembly and can be expected to further reduce the cost. However, instead of this, pins or bolts may be used.

Further, in the above embodiment, the armature side center bracket 1
4 and the pinion side center bracket 18 are used to form the annular space 5, and the planetary gear device is provided therein. Therefore, by filling a lubricating agent such as grease in this portion, the annular space 5 can be easily provided. The problem of lubrication can be solved and high performance can be achieved.

By the way, although omitted in the above description, in the above embodiment, if the clearance between the pinion shaft 10 and the bearing 20 is appropriately widened, the armature pinion can be prevented when the above-mentioned mounting dimension of the planetary gear 7 is irregular. It is possible to eliminate the occurrence of uneven contact with No. 4 and obtain more excellent characteristics.

〔The invention's effect〕

As described above, according to the present invention, without restricting the outer sun gear of the planetary gear device, it is possible to freely displace within a predetermined range by a simple configuration that the accuracy of each part of the gear is reduced by Since the occurrence of one-sided contact can be prevented, a high-performance reduction starter having the effects listed below can be provided at a low cost, except for the drawbacks of the prior art.

(1) Since there is no one-sided contact with the gear, torque transmission characteristics close to the design value can be stably obtained.

(2) Since the torque is uniformly transmitted by the plurality of planetary gears, the gear strength has a margin, and the outer sun gear can be easily plasticized.

(3) As a result of (2), the cost can be further reduced and the weight can be reduced.

(4) The structure is simpler than the method in which one contact is absorbed by an elastic body, and cost reduction can be achieved also in this respect.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part showing an embodiment of a reduction starter according to the present invention, and FIGS. 2, 3, and 4 show some of the components in the embodiment of FIG. FIG. 3 ... armature shaft, 4 ... armature pinion (central sun gear), 5 ... annular space, 6 ... internal ring gear (outer sun gear), 7 ... planet gear, 10 ... pinion shaft, 14
...... Armature side center bracket, 17 ...... Gear case, 18 ...... Pinion side center bracket, 25 ......
Recess, 28 ... Protrusion

Claims (1)

[Claims] Claim: What is claimed is: 1. A coaxial reduction starter equipped with a planetary gear device having a central sun gear shaft as an input shaft and an orbital shaft of a planetary gear as an output shaft as a speed reduction mechanism, wherein a sun outside the planetary gear mechanism is provided. A plurality of recesses formed on the side surface of the gear, and a pinion side center bracket having a plurality of projections that fit into the recess while maintaining a predetermined gap are provided, and the plurality of recesses formed on the side surface of the outer sun gear are The outer sun gear is held in a displaceable state over a predetermined range with respect to a direction perpendicular to the centerlines of the input shaft and the output shaft by fitting the protrusions formed on the pinion-side center bracket into a plurality of protrusions. A reduction starter characterized by being configured as described above.