JPH09280143A - Starter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the diameter of a one-way clutch and production costs and provide a structure for reliably keeping grease in a cam room. SOLUTION: The outer 23 of a one-way clutch 5 comprises an outer cylindrical member 23A and an inner cylindrical member 23B which are divided into two in the radial direction and both cylindrical member 23A, 23B are fixed to each other by fitting. A plurality of semicircular grooves 29a, 29b which is made by dividing a press fitting-in hole fitted with a pin 24 into two are formed on the fitting-in surface of the outer cylindrical member 23A and an inner cylindrical member 23B. A wedge-like cam room for housing a roller 27 in formed on the inner peripheral side of the inner cylindrical member 23B. The outer cylindrical member 23A has one wall 23a for closing the one side of a cam room in the axial direction and the inner cylindrical member 23B has the other wall 23b for closing the other side of the cam room and the roller 27 is restrained from moving in the axial direction by the wall 23a and the other wall 23b.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a starter for starting an engine.

[0002]

2. Description of the Related Art A starter equipped with a planetary gear speed reducer and a one-way clutch has been heretofore known.
5522). Since this starter requires a clutch cover, the number of parts increases, and the number of assembling steps increases accordingly. Further, since the outer is centered only on one side of the roller in the axial direction, the outer is likely to lose balance during high-speed rotation. Furthermore,
There is a problem that the total length in the axial direction becomes long due to the necessity of setting a long press-fitting length of the pin press-fitted into the outer.

Therefore, the present applicant applied for a starter (Japanese Patent Application No. 7-238127) for solving the above problems. In this starter, a pin that supports the planetary gear is press-fitted into the outer through the side of the roller. As a result, the outer and the planet carrier can be made the same part, so that the length in the axial direction can be shortened as compared with a conventional starter (a starter having a structure in which the outer and the planet carrier are displaced in the axial direction). Further, a regulation plate for regulating the axial movement of the roller is arranged on the end surface of the outer, and the regulation plate is press-fitted and fixed to the pin. For this reason, a clutch cover for fixing the regulation plate is not required, so that the number of parts and the number of assembling steps can be reduced. Further, the outer part is integrally provided with a restriction plate for restricting the movement of the roller together with the restriction plate. The outer core can be surely centered by abutting against.

[0004]

However, the starter of the prior application has the following problems. When the pin is press-fitted into the outer, a tensile stress is generated on the cam surface of the outer, and the stress remains in the outer, so that the fatigue resistance of the outer is lowered. Therefore, by design,
There was a constraint that the thickness of the outer pin hole and the cam surface had to be large. Since it is necessary to form the press-fitting hole for press-fitting the pin into the outer by deep hole processing, the number of processing steps becomes large and the cost increases. Since a plurality of pins are press-fitted into the regulation plate, it is necessary to process each hole formed in the regulation plate with high accuracy. If the regulation plate is not completely attached to the outer end surface,
The grease in the cam chamber may come off and cause wear of the rollers. The present invention has been made based on the above circumstances, and an object thereof is to provide a starter that solves the above problems.

[0005]

According to a first aspect of the invention, an outer member is constituted by an outer cylindrical member and an inner cylindrical member that divide a press-fitting hole into two parts in a radial direction, and the outer cylindrical member and the inner cylindrical member are press-fitted to each other. It is fixed to each other. Therefore,
It is possible to form a press-fitting hole by forming a groove having a semicircular cross section in each cylindrical member and aligning the grooves. In this case, it is not necessary to form deep holes as in the past to form the press-fitting holes, and grooves can be easily formed by pressing or cold forging when processing each cylindrical member, reducing the number of processing steps and reducing costs. Can be down.

According to the second aspect of the invention, at least a part of the support shaft is press-fitted into the press-fitting hole so as to overlap in the radial direction of the roller. In this case, since the cam surface (the inner wall surface of the cam chamber) is formed on the inner circumference of the inner cylindrical member that overlaps in the radial direction of the roller, the inner cylindrical member has a tensile force generated when the support shaft is press-fitted into the press-fitting hole. A stress and a tensile stress generated by being pressed so as to be expanded from the roller at the time of torque transmission are applied. In response to this tensile stress, compressive stress is applied to the inner cylindrical member by press fitting with the outer cylindrical member, and the compressive stress acts to improve the fatigue resistance strength of the inner cylindrical member. As a result, the thickness of the outer (inner cylindrical member) can be made thinner than before, so that the size and weight can be reduced.

According to the third aspect, the axial movement of the roller can be restricted by the one wall portion of the outer cylindrical member and the other wall portion of the inner cylindrical member. Therefore, in addition to the outer cylindrical member and the inner cylindrical member, a regulation plate for regulating the movement of the roller is not required, so that highly precise machining of the regulation plate (machining of holes for press-fitting a plurality of support shafts) )
Is unnecessary, and the cost can be reduced. Further, since the outer cylindrical member and the inner cylindrical member overlap each other in the radial direction at the portion where the press-fitting hole is formed, the outer cylindrical member and the inner cylindrical member are provided over the entire radial direction from the inner peripheral surface to the outer peripheral surface of the outer. There are no axial contact points. That is,
There is no gap extending radially from the cam chamber to the outer peripheral surface of the outer, and a reliable oil retaining structure for the grease in the cam chamber can be provided.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Next, an embodiment of the starter of the present invention will be described. (First Embodiment) As shown in FIG. 3, a starter 1 includes a starter motor 2 that generates a rotational force when energized, an output shaft 3 that rotates by transmitting the rotational force of the starter motor 2, and an output shaft 3, a pinion gear 4 fitted to the outer periphery of the planetary gear 3, a planetary gear speed reducer for reducing the rotational speed of the starting motor 2 (described later), and a one-way clutch 5 for transmitting the rotation reduced by the speed reducer to the output shaft 3 (see FIG. 1). And FIG. 2), it is constituted by a magnet switch 6 and the like for controlling energization to the starting motor 2 and for generating a force for moving the pinion gear 4 on the output shaft 3.

The starting motor 2 has an armature 9 in which both ends of a shaft 7 are rotatably supported via bearings 8, a fixed magnetic pole 10 arranged on the outer circumference of the armature 9, and a fixed magnetic pole 10 held on the inner circumference. It is a well-known DC electric motor including a cylindrical yoke 11 and a brush (not shown) slidably contacting a commutator (not shown) provided at the other end (right side in FIG. 3) of the shaft 7. When a starter switch (not shown) is turned on and a motor contact (not shown) built in the magnet switch 6 is closed, power is supplied from a battery (not shown) installed in the vehicle through a brush.

The output shaft 3 has one end rotatably supported by the end of the housing 13 via the bearing 12 and the other end rotatably supported by the center case 15 via the bearing 14. ing. A hollow cylindrical recess 3a is formed in the other end of the output shaft 3 along the axial direction. The bearing 8 is arranged in the recess 3a to rotate one end of the shaft 7. Supports freely. A helical spline 3b is formed on the outer circumference of the output shaft 3, and a spline tube 16 provided integrally with the pinion gear 4 is fitted to the helical spline 3b. Center case 15
Is sandwiched between the housing 13 and the yoke 11 while covering the outer periphery of the speed reducer and the one-way clutch 5.

The pinion gear 4 meshes with the ring gear 17 of the engine to apply the rotational force of the starting motor 2 to the ring gear 1.
7, and is provided integrally with the spline tube 16 on the output shaft 3 so as to be movable back and forth along the helical spline 3b. However, the forward movement of the pinion gear 4 (movement to the left in FIG. 3) is restricted by contacting the stop collar 18 attached to the outer periphery of the output shaft 3. The stop collar 18 is restricted from moving in the axial direction via a snap ring 19 fitted into a circumferential groove 3c formed on the outer circumference of the output shaft 3.

The speed reducer is composed of a sun gear 20 formed on the outer periphery of the shaft 7, a plurality of planet gears 21 meshing with the sun gear 20, and an internal gear 22 meshing with each planet gear 21. The sun gear 20 transmits the rotation of the shaft 7 to each planet gear 21 by rotating integrally with the shaft 7. The planetary gear 21 is rotatably supported on the outer periphery of a pin 24 (support shaft of the present invention) press-fitted into the outer 23 of the one-way clutch 5 via a bearing 25, meshes with the sun gear 20 and the internal gear 22, and rotates. While revolving around the outer periphery of the sun gear 20. The internal gear 22 is formed on the center case 15.

As shown in FIG. 2, the one-way clutch 5 includes an outer 23, an inner 26, a roller 27, and a spring 2.
It is composed of 8 etc. The outer 23 is shown in FIGS.
As shown in, the outer cylindrical member 23A is divided into two in the radial direction.
And the inner cylindrical member 23B, and the outer cylindrical member 23
A and the inner cylindrical member 23B are fixed to each other by press fitting. Grooves 29 recessed in a semicircular cross section are formed on the press-fitting surfaces of the outer cylindrical member 23A and the inner cylindrical member 23B.
a and 29b are formed in a plurality of positions in the circumferential direction, and when the cylindrical members 23A and 23B are fixed by press fitting, the grooves 29a and 29b formed in the cylindrical members 23A and 23B.
A press-fitting hole 29 for press-fitting the pin 24 is formed by the two. The grooves 29a and 29b formed on the outer cylindrical member 23A and the inner cylindrical member 23B can be easily formed by a process such as pressing or cold forging.

On the inner peripheral side of the inner cylindrical member 23B, as shown in FIG. 2, a wedge-shaped cam chamber 30 for accommodating the roller 27 is formed.
And a spring chamber 31 accommodating the spring 28 are formed adjacent to each other. However, the cam chamber 30 and the spring chamber 31 are formed at a plurality of positions at equal intervals in the circumferential direction of the inner cylindrical member 23B. The outer cylindrical member 23A has one wall portion 23a that closes one side of the cam chamber 30 and the spring chamber 31 along the axial direction of the pin 24 (left and right direction in FIG. 1), and the inner cylindrical member 23B is , The cam chamber 30 and the spring chamber 3 along the axial direction of the pin 24
It has the other wall part 23b which closes the other side of 1. Therefore, the cam chamber 30 and the spring chamber 31 include the inner peripheral surface of the inner cylindrical member 23B, the outer peripheral surface of the inner 26, one wall portion 23a of the outer cylindrical member 23A, and the other wall portion 23b of the inner cylindrical member 23B. And form a substantially sealed space. Further, as shown in FIG. 1, the inner peripheral surface of the one wall portion 23a is in sliding contact with the outer peripheral surface of the output shaft 3, and the inner peripheral surface of the other wall portion 23b is in sliding contact with the outer peripheral surface of the inner 26. Two
3 and the output shaft 3 are centered.

The inner 26 is integrally provided on the other end of the output shaft 3 on the inner circumference of the outer 23, and rotates integrally with the output shaft 3. The roller 27 is housed in the cam chamber 30, and its axial movement is restricted by one wall portion 23a of the outer cylindrical member 23A and the other wall portion 23b of the inner cylindrical member 23B. The spring 28 is in the spring chamber 3
1, the roller 27 is biased toward the narrow side of the cam chamber 30 (counterclockwise rotation direction in FIG. 2).

The magnet switch 6 is a coil (not shown) which is energized by turning on the starter switch.
It has a plunger (not shown) slidably arranged in the hollow inside of this coil, the above-mentioned motor contact, etc., and the motor contact is closed by attracting the plunger by the magnetic force of the coil, and it is connected to the plunger. The lever 33 is driven via the joint 32. The lever 33 has one end engaged with the joint 32 and the other end engaged with the outer circumference of the spline tube 16, and is swingably provided about a fulcrum 13 a provided on the housing 13.

Next, the operation of this embodiment will be described. When the starter switch is turned on, the magnet switch 6
When the inner motor contact is closed and the armature 9 is energized, a rotational force is generated in the armature 9. This allows
When the sun gear 20 rotates together with the shaft 7, each planetary gear 21 revolves around the pin 24 while rotating around the pin 24. The revolution force of this sun gear 20 is
The output shaft 3 is rotationally driven by being transmitted to the outer 23 via the pin 24 and further transmitted from the outer 23 to the inner 26 via the roller 27.

On the other hand, when the plunger attraction force of the magnet switch 6 is transmitted to the spline tube 16 via the lever 33, the spline tube 16 and the pinion gear 4 move on the output shaft 3 to the ring gear 17 side, and the pinion gear 4 moves. By engaging with 17, the starter motor 2
Is transmitted to the ring gear 17 to start the engine. After the engine starts, when the pinion gear 4 rotates at a high speed and the inner 26 rotates faster than the outer 23,
The roller 27 resists the urging force of the spring 28 and the cam chamber 3
Since the inner arm 26 and the outer arm 23 are disconnected from each other and the torque transmission from the inner arm 26 to the outer arm 23 is cut off, the armature 9 can be prevented from overrunning.

(Effect of this Embodiment) In this embodiment, the pin 2 is used.
An outer cylindrical member 23A and an inner cylindrical member 23B, which divide the press-fitting hole 29 for press-fitting 4 into two in the radial direction, are fixed to each other by press-fitting. As a result, compressive stress is applied to the inner cylindrical member 23B forming the cam surface by press fitting with the outer cylindrical member 23A. The compressive stress is applied to the inner cylindrical member 23B against the tensile stress generated when the pin 24 is press-fitted into the press-fitting hole 29 and the tensile stress generated when the pin 27 is expanded and pushed by the roller 27 during torque transmission. Works to improve fatigue strength. As a result, the wall thickness from the cam surface to the press-fitting hole 29 (that is, the wall thickness of the inner cylindrical member 23B) can be reduced, so that the one-way clutch 5 can be reduced in size and weight.

Further, when the outer cylindrical member 23A and the inner cylindrical member 23B are press-fitted, the press-fitting hole 29 is formed by aligning the grooves 29a and 29b formed in both the cylindrical members 23A and 23B in the circumferential direction. You can In this case, it is not necessary to form a deep hole as in the conventional case to form the press-fitting hole 29, and the grooves 29a and 29b can be easily formed by pressing or cold forging when processing the cylindrical members 23A and 23B. The number of processing steps can be reduced and the cost can be reduced.

Further, one wall portion 2 of the outer cylindrical member 23A.
The movement of the roller 27 in the axial direction can be regulated by 3a and the other wall portion 23b of the inner cylindrical member 23B.
Therefore, in addition to the outer cylindrical member 23A and the inner cylindrical member 23B, a regulating plate for regulating the movement of the roller 27 is not required, so that highly precise processing of the regulating plate (for inserting the plurality of pins 24 by press fitting). Since it is not necessary to process the holes), the cost can be reduced. Also, the press-fitting hole 2
Since the outer cylindrical member 23A and the inner cylindrical member 23B are radially overlapped with each other at a portion forming the outer circumferential surface 9, the outer cylindrical member 23A and the inner cylindrical member 23B are radially covered from the inner peripheral surface to the outer peripheral surface of the outer 23. There is no place where and come into axial contact. That is, from the cam chamber 30 directly to the outer 23
There is no gap extending radially to the outer peripheral surface of the (outer cylindrical member 23A), and a reliable oil retaining structure for the grease in the cam chamber 30 can be provided.

Further, the inner cylindrical member 23 forming the cam surface
In B, since the outer cylindrical member 23A is press-fitted to the outer periphery thereof and one wall portion 23a of the outer cylindrical member 23A is arranged on the side opposite to the other wall portion 23b with the roller 27 interposed therebetween,
Even if the cam surface is pressed by the roller 27 during torque transmission, it does not open. Thereby, the inner cylindrical member 23B
Since a uniform pressure can be applied between the cam surface of the roller and the roller 27, the inner 26 that receives pressure from the roller 27
Can be prevented from prematurely peeling, and the life of the one-way clutch 5 can be extended.

(Second Embodiment) FIG. 4 is a sectional view taken along the axial direction of the one-way clutch 5. In this embodiment, the planetary gear 2 is used.
The pin 24 that supports 1 is the roller 27 of the one-way clutch 5.
It shows an example in the case of not overlapping in the radial direction. In this case, since it is not necessary to form the cam surface on the inner cylindrical member 23B, the position of the press-fitting hole 29 in the radial direction can be moved to the inner peripheral side as compared with the case of the first embodiment. As a result, the outer cylindrical member 23A can be thinned to reduce the diameter of the one-way clutch 5. Further, according to the present embodiment, the first
As in the embodiment, it is not necessary to form the press-fitting holes 29 by deep hole processing, the number of processing steps can be reduced, and a regulation plate for regulating the movement of the rollers 27 is not required.
Since it is not necessary to process the regulation plate with high precision, it is possible to reduce costs. In addition, since there is no gap extending radially from the cam chamber 30 directly to the outer peripheral surface of the outer 23 (outer cylindrical member 23A), the cam chamber 30
Can provide a reliable oil retaining structure for the grease inside

(Modification) In the first embodiment, the planetary gear 21 is used.
Although the case where the pin 24 supporting the shaft is press-fitted into the press-fitting hole 29 to a position where it overlaps with the entire roller 27 is shown, as shown in FIG. good.

[Brief description of drawings]

FIG. 1 is a sectional view taken along the axial direction of a one-way clutch.

FIG. 2 is a sectional view taken along the radial direction of the one-way clutch.

FIG. 3 is an overall view of a starter.

FIG. 4 is a sectional view taken along the axial direction of the one-way clutch (second embodiment).

FIG. 5 is a sectional view taken along the axial direction of the one-way clutch (modification).

[Explanation of symbols]

 1 Starter 5 One-way Clutch 21 Planetary Gear 23 Outer 23A Outer Cylindrical Member 23B Inner Cylindrical Member 23a One Wall Part 23b Other Wall Part 24 Pin (Support Shaft) 27 Roller 29 Press-fit Hole 30 Cam Chamber

Claims (3)

[Claims] 1. A starter in which a support shaft for pivotally supporting a planetary gear of a planetary gear speed reducer is press-fitted into an outer of a one-way clutch, wherein the outer has a press-fitting hole into which the support shaft is press-fitted in a radial direction. 1. A starter comprising an outer cylindrical member and an inner cylindrical member that are divided into two parts, and the outer cylindrical member and the inner cylindrical member are fixed to each other by press fitting. 2. The support shaft is press-fitted into the press-fitting hole such that at least a part of the support shaft is overlapped in a radial direction of a roller housed in a cam chamber formed on an inner peripheral surface of the outer. The starter according to claim 1. 3. The outer cylindrical member has one wall portion that closes one side of the cam chamber along the axial direction of the support shaft, and the inner cylindrical member extends in the axial direction of the support shaft. It has the other wall part which closes the other side of the said cam chamber along, The said roller is characterized by the axial movement being controlled by the said one wall part and the said other wall part. The starter according to claim 1 or 2.