JPH0381565A - Starter with planetary gear reducer mechanism - Google Patents

Abstract

PURPOSE:To obtain an inexpensive starter with planetary gear reducer mechanism with the number of parts reduced and assembly procedure saved by forming elastically deformable protrusions on an end face of an internal gear made of resin. CONSTITUTION:A flange-type protrusion 13 is formed on one end of a drive shaft 12 while a planetary gear is held freely rotatable via a bearing 18 to a pin 17 which protrudes from the protrusion 13. An internal gear 19 placed on the outer periphery of the flange-type protrusion 13 is formed in a cylinder while a tooth part 19a to be engaged with a gear 16 is formed on an approximately half on the side of an inner peripheral armature 5. Three protrusions 29 with equal intervals are integrally formed circumferentially on an end face of the internal gear 19. The protrusions 29 which receive thrust load are elastically deformable wherein the thrust load is absorbed by this elastic deformation, and cluttering of the internal gear along the axis can be prevented as well as it can be in contact with a center bracket 20 with appropriate friction.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a starter with a planetary gear reduction mechanism for starting an internal combustion engine.

(Prior Art) As a starter for starting an internal combustion engine, one equipped with a planetary gear reduction mechanism is known, for example, the one disclosed in Japanese Patent Application Laid-Open No. 6-3
It is shown in the publication No.-277859.

This device transmits the rotation of the armature shaft of the starter motor to the drive shaft through a planetary gear mechanism, and the rotation of this drive shaft is transmitted to the ring gear on the internal combustion engine side by means of a pinion.

This device is equipped with a brake device on the center bracket, and when a strong impact exceeding a predetermined torque occurs when the pinion and ring gear engage, the internal gear provided in the planetary gear mechanism is rotated to reduce the impact. has been adopted.

(Problem to be Solved by the Invention) The internal gear is installed between the center bracket and the yoke, and a wave washer is placed between the internal gear and the center bracket to receive thrust load.

However, when a wave washer is used, the number of parts increases, assembly time is required, and costs increase.

Therefore, it is an object of the present invention to provide a starter with a planetary gear reduction mechanism that has a reduced number of parts, requires less assembly effort, and is inexpensive.

(Means for Solving the Problems) The present invention is characterized in that an elastically deformable protrusion is formed on the end face of a resin internal gear.

(Function) According to the present invention, the protrusion formed on the end face of the resin internal gear receives the thrust load instead of the conventional wave washer, so the number of parts is reduced, the assembly effort is reduced, and the cost is reduced. .

(Example) The present invention will be described below based on an example shown in the drawings.

In FIG. 4, l indicates a starter motor, and 2 indicates a magnetic switch.

The starter motor 1 includes a cylindrical yoke 3, and a pole core 4 around which an excitation coil 4a is wound around the inner circumference of the yoke 3.
is installed. An armature 5 is arranged on the inner peripheral side of the pole core 4, and an armature shaft 6 is provided at the center of the armature 5.

One end of the armature shaft 6 is rotatably supported by an end frame 7. Further, a commutator 8 is fixed to one end of the armature shaft 6, and a brush 9 is slidably installed on the outer periphery of the commutator 8.

The other end of the armature shaft 6 has a sun gear 1 on its outer periphery.
°0 is formed. Further, at the other end of the armature shaft 6, the armature shaft 1 side is rotatably supported by a bearing 11 provided between the other end of the armature shaft 6, and the other end of the drive shaft 12. The side is connected to the housing 15 via another bearing 14.
It is pivoted on.

As shown in detail in Figure 1, on one end side of the drive shaft 12, a flange-shaped protrusion 13 is formed that protrudes in the outer radial direction. Pins 17 are provided in a protruding manner, and planetary gears 16 are rotatably held on these pins 17 via bearings 18.

These planetary gears 16 mesh with the outer periphery of the sun gear 10.

An internal gear 19 is arranged on the outer periphery of the flange-shaped protrusion 13 . This internal gear 19 is formed of synthetic resin into a cylindrical shape, and has a tooth portion 19 that meshes with the planetary gear 16 on about half of the inner circumference on the armature 5 side.
a is formed.

Therefore, the sun gear 10, the planetary gear 16, and the tooth portion 19a of one internal gear constitute a planetary gear reduction mechanism.

Furthermore, on the inner periphery of the internal gear 19, eight sparks 19b, for example, are formed at equal intervals in the circumferential direction, located on the other end side.

There is a disc 2 between the above internal gear and the yoke 3.
1 is inserted. This disk 21 is the planetary gear 1
6 prevents the pin 17 from being pulled out in the axial direction.

Reference numeral 20 designates a center bracket, which has a first cylindrical portion 20a on the center side, and a second cylindrical portion 2 formed on the outer peripheral side to protrude in the same direction as the first cylindrical portion 20a.
0c, and a disk portion 20b provided between the first cylindrical portion 20a and the second cylindrical portion 2Oc.

The first cylindrical portion 20a is rotatably attached to the other end of the protruding portion 13 of the drive shaft 12 via a bearing 22. A thread groove 2Of is formed on the outer peripheral surface of the first cylindrical portion 20a.

The second cylindrical portion 20c located on the outside is fitted onto the end face of the yoke 3, and one of the internal gears is accommodated on the inner peripheral side of the second cylindrical portion 20c.

For example, three positioning projecting portions 20d are formed on the disk portion 20b at equal intervals in the circumferential direction.

Reference numeral 23 denotes a disk-shaped rotating disk, which is made of a soft metal such as brass or phosphor bronze.

This rotating disk 23 has eight protruding parts 23c cut and raised at an angle at equal intervals around the circumference, and these protruding parts 23C are pushed into the eight slits 19b of the internal gear 19. ing.

Therefore, the rotating disk 23 cannot rotate with respect to one internal gear, that is, it rotates integrally with the internal gear 19.

24 is a disk-shaped fixed disk, and this fixed disk 24 includes a disk portion 20b of the center bracket 20.
A locking hole 24a is formed opposite to the three positioning protrusions 20d formed in the
and the locking hole 24a are fitted together.

This fixed disk 24 is pushed toward the disk portion 2Ob side of the center bracket 20 by a disc spring 25, and this disc spring 25 is pushed toward the first cylindrical portion 20a.
il: [tX is included. A nut 26 is screwed into this first cylindrical portion 20a.
6 is pushing the disc spring 25, and since the disc spring 25 is pushing the fixed disc 24, the rotary disc 23 is pinched between the fixed disc 24 and the disk portion 20b of the center bracket 20.

In this case, the friction torque between the fixed disk 24, the disk portion 20b of the center bracket 20, and the rotating disk 23 is adjusted by adjusting the force of the nut 26 pushing the disc spring 25.

The drive shaft 12 is covered by a housing 15, and the housing 15 and the end frame 7 are connected by through bolts 31. When fixing the housing 15 and the end frame 7 with the through bolts 31, the yoke 3 and the second cylindrical part 20c of the center bracket are sandwiched and fixed between the housing 15 and the end frame 7.

In this case, the internal gear 19 is arranged between the disk 21 and the disk portion 20b of the center bracket 20.

As shown in FIGS. 2 and 3, three protrusions 29 are formed on the end surface of the internal gear 19 at equal intervals in the circumferential direction. These protrusions 29 are integrally formed with the internal gear 19, and since one internal gear is made of resin, these protrusions 29 can be elastically deformed and receive thrust loads. Note that the height of the protrusion 29 is the same as that of the internal gear 19 including two protrusions.
The axial dimension L2 of the disc 21 and the center bracket 2 is
Space dimension L+ (first
(shown in the figure).

A helical spline 12a is formed on the drive shaft 12, and a spline tube 32 is engaged with the helical spline 12a.

The spline tube 32 is connected to a pinion 34 via a one-way clutch 33.

When the spline tube 32, one-way clutch 33, and pinion 34 are moved in the axial direction, the pinion 34 meshes with the ring gear 35 to start the internal combustion engine.

One end of a lever 36 is engaged with the spline tube 32, and the other end of this lever 36 is engaged with a joint portion 37a of a plunger 37 of the magnetic switch 2.

The operation of the tip embodiment having such a configuration will be explained.

When the magnetic switch 2 is activated, the plunger 37
is attracted and the lever 3 is engaged with the joint portion 37a.
6 is pulled toward the magnetic switch 2 side. Therefore, the lever 36 rotates clockwise in the drawing, and the spline tube 32 engaged with one end of the lever 36 is moved forward together with the one-way clutch 33 and pinion 34.

When the pinion 34 comes into contact with the ring gear 35, the contacts of the magnetic switch 2 close, and current flows through the excitation coil 4a of the starter motor 1.

The armature 5 is rotated by the excitation magnetic flux of the excitation coil 4a, and the armature shaft 6 is rotated. The rotation of the armature shaft 6 is caused by the planetary gear 1 via the sun gear 10.
6 can be conveyed.

In this case, the internal gear 19 has a rotating disc 23 which is rotationally engaged with the internal gear 19 and a disc spring 25.
Fixed disk 24 and center bracket 2 subjected to the force of
Since it is clamped between the disk portion 20b and the disk portion 20b, rotation is prevented below a predetermined rotational torque.

Therefore, the rotation of the armature shaft 6 is controlled by the sun gear 1.
0 to rotate the planetary gear 16 at a reduced speed, thus causing the protrusion 13 of the drive shaft 12 to rotate at a reduced speed.

This decelerated rotational motion is transmitted to the pinion 34 via the spline tube 32 on the drive shaft 12 side and the one-way clutch 33.

The rotation of the pinion 34 is transmitted to the internal combustion engine by the pinion 341 meshing with the ring gear 35 to start the internal combustion engine.

Therefore, when a force exceeding a predetermined torque is applied when the pinion 34 meshes with the ring gear 35, the rotating disk 23, which is clamped between the fixed disk 24 and the disk portion 20b of the center bracket 20, It becomes rotatable by sliding on these fixed disks 24 and center bracket I.20. As a result, the internal gear 19, which had been prevented from rotating by the rotating disk 23, rotates.
This prevents the planetary gear 16 from turning and allows the planetary gear 16 to rotate. For this reason, from the armature 5 to the pinion 34
Since the protrusions 29 are formed on the end face of the null gear 19 so that the torque is greater than a predetermined torque in the torque transmission system, these protrusions 29 receive the thrust load in place of the conventional wave washer.

Since the two protrusions are integrally molded into one resin internal gear, they can be elastically deformed, and this elastic deformation absorbs the thrust load. Therefore, it is possible to prevent the internal gear from shaking in the axial direction and to contact the center bracket 20 with appropriate friction.

With such a configuration, the conventional web washer is not required, so the number of parts is reduced, the assembly effort is reduced, and costs are reduced.

Although it is possible to form a protrusion in place of the protrusion 29 on the disc 21 or the disc portion 20b of the center bracket 20, forming it on the end face of the center bracket 20 is the cheapest.

(Effects of the Invention) As explained above, according to the present invention, since projections are formed on the end face of the resin internal gear, these projections are elastically deformed and can absorb thrust loads in place of conventional wave washers. I can do it. Therefore, conventional wave washers are no longer required, reducing the number of parts.
Assembly time is reduced and costs are reduced.

3

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, and FIG. 1 is an enlarged sectional view of the main part, FIG. 2 is a sectional view of the internal gear, and FIG. 3 is a sectional view of the internal gear.
The figure is an end view thereof, and FIG. 4 is a partially sectional side view showing the overall structure of the stator. DESCRIPTION OF SYMBOLS 1... Starter motor, 2... Magnet switch, 3... Yoke, 5... Armature, 6... Armature shaft, 10... Sun gear, 12... Drive shaft, 15... Housing, 16... Planetary gear, one internal gear, 20... Center bracket, 21... Disc, 23... Rotating disk,
24... Fixed disk, 25... Belleville spring, 29...
・Protrusion, 12a...Helical spline, 32...
Spline tube, 33... One-way clutch, 34
...Pinion, 35...Ring gear, 36...Lever

Claims (1)

[Claims] The rotation of the starter motor shaft is transmitted to a planetary gear, which decelerates and transmits it to the drive shaft.The rotation of this drive shaft is transmitted to the ring gear of the internal combustion engine by a pinion, and the planetary gear is connected to a resin internal gear. In a starter with a planetary gear reduction mechanism, the internal gear is restrained by a brake device so that it cannot rotate below a predetermined torque.
A starter with a planetary gear reduction mechanism, characterized in that an elastically deformable protrusion that receives a thrust load is integrally formed on the end face of the resin internal gear.