JP2007146759A - Starter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a starter capable of maintaining clutch performance for a long period of time by preventing other grease from being mixed with grease used in the clutch 4. <P>SOLUTION: An inner space A formed inside of an inner tube 2 and an air hole 40 communicating with an outside of an outer wall part 42 are formed on an outer wall part 42 of an clutch outer 20. Also, a ring shape collar 41 cutting off connection between the inner space A and a cam chamber of the clutch 4 is provided between the inner tube 2 and the outer wall part 42 facing in an axial direction, Consequently, air compressed in the inner space A can be released to the outside of the outer wall part 42 from the air hole 40 when a pinion shaft 5 returns. As a result, since grease or the like used in a spline part can be prevented from entering the cam chamber of the clutch 4, drop of friction coefficient of the grease used in the clutch 4 can be inhibited and slip of the clutch 4 can be prevented. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

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

In recent years, the starter's thermal environment has become severe due to high engine output and engine room overcrowding. In addition, a starter may be disposed in the vicinity of the exhaust pipe due to restrictions on the installation space. For this reason, the starter may be exposed to an environment of 150 degrees or more, and the lubricant (grease, lubricating coating, etc.) used for the sliding portion of the starter is softened and easily flows out.
Furthermore, the starter itself is also required to be smaller and lighter, and the gap between the parts that make up the starter is also reduced, which increases the possibility of mixing the lubricant used in each sliding part. Yes. In particular, the clutch that interrupts the transmission of torque uses silicon grease with a high friction coefficient in order to achieve both a constant frictional force and lubrication of the sliding part, but this silicone grease performance can be maintained. It is becoming a difficult situation.

  For example, as shown in FIG. 5, in the vicinity of the clutch 100, a means for moving the pinion shaft 110 in the axial direction, that is, a helical spline portion 120 that converts the driving torque of the motor into axial thrust force is provided. However, the helical spline portion 120 is coated with mineral or synthetic oil grease so as not to increase the sliding resistance at low temperatures. If the grease used for the helical spline portion 120 enters the clutch 100 (cam chamber in which the roller 130 is disposed) and mixes with the silicon grease due to heat generation and centrifugal force when the starter is used, the friction of the silicon grease The coefficient (force) decreases, and the friction coefficient further decreases when the temperature becomes low in that state. As a result, slip occurs in the clutch 100 during torque transmission, and torque transmission cannot be performed, resulting in a problem that the engine cannot be started.

On the other hand, in Patent Document 1, a rubber lip seal is disposed between an outer and an inner constituting the clutch to prevent the grease used for the clutch from flowing out, and other grease and water. A technique for preventing foreign matter such as the like from entering the clutch is disclosed.
Japanese Patent No. 3104810

However, in a starter used for a large displacement engine, the transmission torque is large and the clutch is enlarged, so that heat generation due to overrun is high, and in the worst case, it is 300 degrees or more. For this reason, the known technique described in Patent Document 1 has a problem that it cannot be applied to a starter used in a large displacement engine because the heat resistance of the lip seal (made of rubber) is low.
The present invention has been made on the basis of the above circumstances, and its object is to prevent clutch performance by preventing other grease from being mixed into the grease used for the clutch regardless of the engine displacement. Is to provide a starter that can be maintained over a long period of time.

(Invention of Claim 1)
The present invention includes a motor that generates a rotational force, a clutch outer that is rotated by transmission of a driving torque of the motor, and a cylindrical inner tube that is disposed so as to be relatively rotatable on the inner periphery of the clutch outer. A one-way clutch that transmits torque from the clutch outer to the inner tube via a roller, a pinion shaft whose one end in the axial direction is splined to the inner periphery of the inner tube, and an end of the pinion shaft that protrudes in the counter-motor direction from the inner tube A pinion gear supported by the portion, and the pinion gear moves in the counter-motor direction integrally with the pinion shaft and meshes with the ring gear of the engine, and the clutch outer has an end surface on the axial motor side of the inner tube. The outer wall portion is in contact with the outer wall portion, and the pinion shaft extends in the direction opposite to the motor. Wherein the vent hole communicating with the outside of the inner space and the outer wall portion which is formed inside the inner tube when the dynamic is formed.

  According to the above configuration, when the pinion shaft moved in the direction opposite to the motor returns, the air compressed in the internal space formed inside the inner tube can be released from the vent hole to the outside of the outer wall portion. Thereby, it can suppress that the grease used for a spline part enters the inside of a clutch with an air pressure, and can suppress that other grease mixes in the grease used for a clutch. As a result, a reduction in the friction coefficient of grease used for the clutch can be suppressed, and slipping of the clutch can be prevented.

(Invention of Claim 2)
2. A starter according to claim 1, wherein a ring-shaped collar for blocking between a cam chamber and an inner space formed on the inner periphery of the clutch outer is provided between the inner tube and the outer wall portion facing each other in the axial direction. It is arranged.
As a result, the grease used for the spline portion can be prevented from entering the cam chamber of the clutch by centrifugal force, and mixing of the grease used for the clutch and the grease used for the spline portion can be reduced.

(Invention of Claim 3)
3. The starter according to claim 2, wherein one end side of the collar is press-fitted and fixed to the outer wall portion, and the other end side is provided to protrude from the end surface of the outer wall portion toward the inner tube side. An annular recess is formed in the recess to fit the recess.
According to the above configuration, when the pinion shaft moved in the direction opposite to the motor returns, when the grease of the spline is pushed into the outer wall portion side and enters the contact portion between the inner tube and the outer wall portion, The collar protruding from the end face of the outer wall portion toward the inner tube can prevent the grease from entering the clutch cam chamber.

(Invention of Claim 4)
The starter according to claim 3, wherein the opening portion of the air hole that opens in the axially opposite motor side end surface (end surface on the inner space side) of the outer wall portion is formed on the inner diameter side of the collar press-fitted into the outer wall portion. It is characterized by.
In this case, when the pinion shaft moved in the direction opposite to the motor returns, the air pressure generated in the inner space formed inside the inner tube tries to feed the grease in the spline part into the cam chamber of the clutch. The air pressure can be released to the outside of the outer wall portion through the vent hole opened to the side. Moreover, it is possible to guide the grease of the spline part to the vent hole together with the air pressure by the collar.

(Invention of Claim 5)
The starter according to any one of claims 1 to 4, wherein the vent hole formed in the outer wall portion is provided through the outer wall portion in the axial direction, and is provided at a plurality of locations in the circumferential direction of the outer wall portion. It is characterized by.
In this case, by providing a plurality of vent holes in the outer wall portion, the compressed air generated when the pinion shaft returns can be released to the outside of the outer wall portion more quickly. In addition, in the case where there is one vent hole, if the vent hole is closed with grease or the like, the compressed air generated when the pinion shaft returns cannot be released to the outside of the outer wall portion. By providing a plurality of vent holes in the wall portion, even if some of the vent holes are blocked with grease or the like, the compressed air can be released to the outside of the outer wall portion from the other vent holes.

(Invention of Claim 6)
The present invention includes a motor that generates a rotational force, a pinion shaft that rotates by transmission of a driving torque of the motor, a clutch outer that is splined to the outer periphery of the pinion shaft, and a pinion shaft that is fitted via a bearing. A one-way clutch that transmits torque from the clutch outer to the inner tube via a roller, and is arranged on the pinion shaft integrally with the clutch, and the rotation of the pinion shaft is achieved via the clutch. A starter that is engaged with the ring gear of the engine and that is engaged with the ring gear of the engine. The clutch outer is an outer contact with the end surface of the inner tube on the axial motor side. The outer wall has a wall and a space formed inside the inner tube and the outer wall. Wherein the vent hole communicating with the outside of are formed.

  According to the above configuration, when the clutch reciprocates on the pinion shaft integrally with the pinion gear, the air compressed in the space formed inside the inner tube can be released from the vent hole to the outside of the outer wall portion. it can. Thereby, it can suppress that the grease used for a spline part enters the inside of a clutch with an air pressure, and can suppress that other grease mixes in the grease used for a clutch. As a result, a reduction in the friction coefficient of grease used for the clutch can be suppressed, and slipping of the clutch can be prevented.

(Invention of Claim 7)
The starter according to claim 6, wherein a space between a cam chamber formed on an inner periphery of the clutch outer and a space formed on an inner side of the inner tube is provided between the inner tube and the outer wall portion facing each other in the axial direction. It is characterized by arranging a ring-shaped collar for blocking.
As a result, the grease used for the spline portion can be prevented from entering the cam chamber of the clutch by centrifugal force, and mixing of the grease used for the clutch and the grease used for the spline portion can be reduced.

(Invention of Claim 8)
The starter according to claim 7, wherein one end of the collar is press-fitted and fixed to the outer wall portion, and the other end is provided so as to protrude from the end surface of the outer wall portion toward the inner tube side. An annular recess is formed in the recess to fit the recess.
According to the above configuration, when the clutch reciprocates on the pinion shaft integrally with the pinion gear, even if the grease in the spline enters the contact portion between the inner tube and the outer wall portion, the end surface of the outer wall portion The collar protruding from the inner tube to the inner tube side prevents grease from entering the clutch cam chamber.

(Invention of Claim 9)
The starter according to any one of claims 6 to 8, wherein a plurality of vent holes formed in the outer wall portion are provided in a circumferential direction of the outer wall portion.
In this case, by providing a plurality of vent holes in the outer wall portion, the air pressure generated when the clutch reciprocates on the pinion shaft integrally with the pinion gear can be released to the outside of the outer wall portion more quickly. In addition, when there is one vent hole, if the vent hole is blocked with grease, the air pressure cannot be released to the outside of the outer wall portion. However, according to the present invention, some of the vent holes are blocked with grease. However, the air pressure can be released to the outside of the outer wall portion from other vent holes.

  The best mode for carrying out the present invention will be described in detail with reference to the following examples.

FIG. 1 is a cross-sectional view of a starter 1 according to the first embodiment.
The starter 1 of this embodiment includes a motor 2 that generates a rotational force, a speed reducer 3 that decelerates the rotation of the motor 2, a pinion shaft 5 that is connected to the speed reducer 3 via a clutch 4, and the pinion The pinion gear 6 supported by the shaft 5 and a main contact (described later) provided in the energization circuit (referred to as a motor circuit) of the motor 2 are opened and closed, and the pinion shaft 5 is moved in the axial direction via the shift lever 7. It is composed of an electromagnetic switch 8 having a function. In FIG. 1, the upper side of the center line of the pinion shaft 5 and the electromagnetic switch 8 indicates the stopped state of the starter 1, and the lower side of the center line indicates the operating state of the starter 1.

The motor 2 is configured by winding an armature coil 13 around an armature core 12 fixed to the armature shaft 11 and a field magnet configured by arranging a plurality of field coils 10 on the inner periphery of the yoke 9. This is a well-known DC series motor in which the field coil 10 and the armature coil 13 are connected in series via a brush 15.
The speed reducer 3 is a planetary gear speed reducer that can decelerate coaxially with the armature shaft 11. As shown in FIG. 2, this planetary gear speed reducer includes a sun gear 16 provided on the armature shaft 11, and a ring-shaped internal tooth disposed concentrically with the sun gear 16 and restricted in rotation by the center case 17. A gear 18 (see FIG. 1) and a plurality of planetary gears 19 meshing with the two gears 16 and 18, and the revolving motion of the planetary gear 19 is transmitted to the pinion shaft 5 via the clutch 4.

  As shown in FIG. 2, the clutch 4 has a cylindrical outer shape that is rotatably supported by the center case 17 via a clutch outer 20 that transmits the driving torque of the motor 2 via the speed reducer 3 and a ball bearing 21. The inner tube 22 and a roller 23 disposed in a wedge-shaped cam chamber formed on the inner periphery of the clutch outer 20 are configured, and torque transmission from the clutch outer 20 to the inner tube 22 is permitted via the roller 23. And it is comprised as a one-way clutch which interrupts | blocks the torque transmission from the inner tube 22 to the clutch outer 20. FIG. The clutch 4 uses silicon grease having a high friction coefficient as a lubricant.

One end side of the pinion shaft 5 is rotatably and slidably supported by the front housing 25 via a bearing 24, and the other end side is inserted into the inner periphery of the inner tube 22 and is helically splined. That is, in the pinion shaft 5, the male helical spline 5a formed on the outer periphery of the other end of the pinion shaft 5 is meshed with the female helical spline 22a formed on the inner periphery of the inner tube 22 (see FIG. 2). Mineral oil or synthetic oil grease is applied to the surface of the spline portion where the male helical spline 5a and the female helical spline 22a mesh with each other in order not to increase sliding resistance at low temperatures. Further, a lubricating film may be used in combination with grease.
The pinion gear 6 is splined to the front end portion of the pinion shaft 5 protruding forward (leftward in the drawing) from the bearing 24 and is urged by a pinion spring 26 disposed on the inner periphery of the pinion gear 6. It is positioned in contact with a stopper 27 attached to the end.

  The electromagnetic switch 8 includes a solenoid that forms an electromagnet by energizing the electromagnetic coil 28 and drives (sucks) the plunger 29 with the attraction force of the electromagnet, and a resin contact cover 30 that is caulked and fixed to the solenoid. The main contact is arranged inside the contact cover 30. The solenoid includes a return spring 31 for pushing back the plunger 29 when the attraction force of the electromagnet disappears, a drive spring 33 for storing a reaction force for meshing the pinion gear 6 with the ring gear 32 of the engine, and the drive spring 33. A shift rod 34 for transmitting the movement of the plunger 29 to the shift lever 7 is provided.

The main contact includes a set of fixed contacts 37 connected to the motor circuit via two external terminals 35 and 36, and a movable contact 38 that moves integrally with the plunger 29 and intermittently connects between the set of fixed contacts 37. The main contact is closed when the set of fixed contacts 37 is conducted through the movable contact 38, and the main contact is opened when the set of fixed contacts 37 is cut off. It becomes a state.
The two external terminals 35 and 36 are a B terminal 35 connected to the in-vehicle battery via a battery cable (not shown) and an M terminal 36 to which a terminal 39 taken out from the motor 2 is connected. The contact cover 30 is insert-molded and has a fixed contact 37 inside the contact cover 30.

  The shift lever 7 has a lever fulcrum portion 7a that is supported in a swingable manner. A lever end portion 7b on one end side of the lever fulcrum portion 7a is connected to the shift rod 34, and other than the lever fulcrum portion 7a. The end portion 7c on the end side engages with the pinion shaft 5 to transmit the movement of the plunger 29 to the pinion shaft 5. That is, when the plunger 29 is attracted by the electromagnet and moves rightward in FIG. 1, the lever end 7b connected to the shift rod 34 is pulled and moved by the plunger 29, so that the lever end 7c becomes the lever fulcrum. The pinion shaft 5 swings around the portion 7a and pushes the pinion shaft 5 in the counter-motor direction (left direction in the figure).

Next, the air hole 40 and the collar 41 according to the present invention will be described with reference to FIG.
The above-described clutch outer 20 has an outer wall portion 42 with which the end surface of the inner tube 22 on the axial motor side (right side in the drawing) abuts, and the inner periphery of the center hole that penetrates the radially central portion of the outer wall portion 42. A bearing 43 is press-fitted to the armature shaft 11 and is rotatably supported by the end of the armature shaft 11 via the bearing 43, and a gear shaft 44 that supports the planetary gear 19 is press-fitted and fixed to the outer wall portion 42.
A vent hole 40 is formed in the outer wall portion 42 to communicate the internal space A formed inside the inner tube 22 and the outside of the outer wall portion 42 when the pinion shaft 5 moves in the counter-motor direction. .

  The vent hole 40 is provided so as to penetrate the outer wall portion 42 in the axial direction, and one end side opening portion that opens to the non-motor side end surface (the left end surface in the drawing) of the outer wall portion 42 is located inside the inner diameter of the inner tube 22. It leads to the internal space A on the circumferential side. On the other hand, the opening on the other end side of the vent hole 40 communicates with an annular groove 45 formed on the motor side end surface of the outer wall portion 42. The annular groove 45 is concentrically located with the central hole of the outer wall portion 42 and is formed in a circular shape having an inner diameter slightly larger than the outer diameter (tooth diameter) of the sun gear 16 used in the speed reducer 3. It communicates with the gear chamber of the machine 3 (the space in which the planetary gear 19 is disposed).

Further, a ring-shaped collar 41 is provided between the inner tube 22 and the outer wall portion 42 facing each other in the axial direction to block between the cam chamber formed on the inner periphery of the clutch outer 20 and the inner space A. It has been. One end side of the collar 41 is press-fitted and fixed to the outer wall portion 42, and the other end side is provided so as to protrude from the end surface of the outer wall portion 42 to the inner tube 22 side. On the other hand, an annular recess 22 b is formed at the end of the inner tube 22 so as to be engaged with the other end of the collar 41.
The outer diameter of the collar 41 is set to be 0.2 to 0.4 mm smaller than the inner diameter of the recess 22b formed in the inner tube 22, and the inner diameter of the collar 41 is smaller than the outer diameter of the male helical spline 5a of the pinion shaft 5. It is set to be larger by 0.1 to 0.2 mm.

Next, the operation of the starter 1 will be described.
When the electromagnetic coil 28 of the electromagnetic switch 8 is energized and the plunger 29 is attracted by closing the start switch (not shown), the movement of the plunger 29 is transmitted to the pinion shaft 5 via the shift lever 7. . As a result, the pinion shaft 5 moves in the counter-motor direction while rotating with respect to the inner tube 22 by the action of the helical spline, and after the end surface of the pinion gear 6 comes into contact with the end surface of the ring gear 32, the pinion spring 26 is compressed. Stop in the state.

  After that, when the plunger 29 further moves and closes the main contact while accumulating the reaction force in the drive spring 33, the motor 2 is supplied with electric power from the battery and a rotational force is generated in the armature 14, and the armature 14 rotates. After being decelerated by the speed reducer 3, it is transmitted to the pinion shaft 5 via the clutch 4. As a result, the pinion shaft 5 is forcibly rotated, so that when the pinion gear 6 rotates to a position where it can mesh with the ring gear 32, the pinion shaft 5 moves forward due to the reaction force stored in the drive spring 33. Thus, the pinion gear 6 is engaged with the ring gear 32. As a result, the driving torque of the motor 2 amplified by the speed reducer 3 is transmitted from the pinion gear 6 to the ring gear 32 to crank the engine.

After starting the engine, when the energization of the electromagnetic coil 28 is stopped by opening the start switch and the attraction force of the electromagnet disappears, the plunger 29 is pushed back by the reaction force of the return spring 31. When the power supply to the motor 2 is stopped, the rotation of the armature 14 is gradually decelerated and stopped.
On the other hand, when the plunger 29 is pushed back, the shift lever 7 swings in the direction opposite to that at the start of the engine, so that the pinion shaft 5 is retracted and the pinion gear 6 is disengaged from the ring gear 32 and the rear end surface of the pinion shaft 5 is outer. It stops in contact with the end face of the wall 42.

(Effect of Example 1)
According to the starter 1 described above, when the pinion shaft 5 that has moved in the counter-motor direction returns to the motor direction, air compressed in the internal space A formed inside the inner tube 22 is passed from the vent hole 40 to the outer wall portion 42. To the outside (the gear chamber of the speed reducer 3). In other words, when the pinion shaft 5 returns, the air in the inner space A formed inside the inner tube 22 is temporarily compressed, but the outer wall portion 42 includes the inner space A and the outer wall portion 42 outside. Are formed, the air compressed in the internal space A can be released from the vent hole 40 to the outside of the outer wall portion 42.

  Further, on the outer side (outer diameter side) of the vent hole 40, one end side of the collar 41 is press-fitted and fixed to the outer wall portion 42, and the other end side of the collar 41 protrudes from the end surface of the outer wall portion 42 toward the inner tube 22 side. The recess 22b formed in the inner tube 22 is concavo-convexly fitted. As a result, at the contact portion between the inner tube 22 and the outer wall portion 42 facing each other in the axial direction, the space between the cam chamber of the clutch 4 and the internal space A is blocked by the collar 41, so that it is compressed in the internal space A. Air can be prevented from entering the cam chamber. That is, even if the air compressed in the internal space A tries to enter the cam chamber through the gap between the contact portions between the inner tube 22 and the outer wall portion 42 facing each other in the axial direction, the cam chamber and the internal space A It is possible to prevent the compressed air from entering the cam chamber by the collar 41 that blocks the gap.

  As a result, it is possible to prevent grease or a lubricant film used for the spline portion from entering the cam chamber of the clutch 4 due to air pressure. In particular, the one end side opening of the vent hole 40 that opens to the end surface of the outer wall 42 opposite to the motor is formed on the inner diameter side of the collar 41 press-fitted into the outer wall 42, so that it is compressed in the inner space A. It is possible to guide the grease in the spline portion together with the air to the vent hole 40 by the collar 41. For this reason, it is possible to prevent grease or a lubricant film used for the spline portion from being mixed into the grease used for the clutch 4, and to suppress a decrease in the friction coefficient of the grease used for the clutch 4. As a result, the clutch 4 can be prevented from slipping and the clutch performance can be maintained over a long period of time.

  Further, the outer diameter of the ring-shaped collar 41 is set to be 0.2 to 0.4 mm smaller than the inner diameter of the recess 22 b formed in the inner tube 22, and the inner diameter of the collar 41 is that of the male helical spline 5 a of the pinion shaft 5. It is set larger by 0.1 to 0.2 mm than the outer diameter. In this case, for example, when the inner tube 22 rotates at a high speed and is eccentric from the axis of the clutch outer 20, it is possible to prevent the collar 41 from increasing the eccentricity and to prevent the pinion shaft 5 from tilting.

FIG. 3 is a sectional view of the starter 1 according to the second embodiment, and FIG. 4 is a sectional view of the clutch 4 and its surroundings.
The starter 1 described in the first embodiment has a configuration in which the pinion shaft 5 moves on the inner periphery of the inner tube 22, but the starter 1 according to the second embodiment is arranged on the pinion shaft 5 as shown in FIG. 3. The pinion gear 6 and the clutch 4 move together.
One end side of the pinion shaft 5 is supported by the front housing 25 via the bearing 24, and the other end side is connected to the armature shaft 11 via the speed reducer 3, and the rotation of the armature 14 is transmitted via the speed reducer 3. Is done.
As shown in FIG. 4, the clutch 4 has a female helical spline 42 a formed on the inner periphery of the outer wall portion 42, and the female helical spline 42 a meshes with a male helical spline 5 a formed on the outer periphery of the pinion shaft 5. Yes.
The pinion gear 6 is disposed on the pinion shaft 5 on the side opposite to the motor (the left side in the drawing) of the clutch 4 and is provided integrally with the inner tube 22 of the clutch 4.

  Also in this starter 1, a vent hole 40 is formed in the outer wall portion 42 of the clutch 4, and a collar 41 is provided to block between the cam chamber of the clutch 4 and the space formed inside the inner tube 22. In addition, it is possible to suppress the grease or the lubricating coating applied to the surface of the spline portion from entering the cam chamber of the clutch 4. As a result, similar to the first embodiment, the grease used for the clutch 4 can be prevented from being mixed with other greases, and the reduction in the friction coefficient of the grease used for the clutch 4 can be suppressed. 4 can be prevented and the clutch performance can be maintained for a long time.

(Modification)
A plurality of ventilation holes 40 formed in the outer wall portion 42 can be provided in the circumferential direction of the outer wall portion 42. In this case, by providing a plurality of vent holes 40 in the outer wall portion 42, the compressed air generated when the pinion shaft 5 returns can be released to the outside of the outer wall portion 42 more quickly. In the case where there is one vent hole 40, if the vent hole 40 is closed with grease or the like, the compressed air generated when the pinion shaft 5 returns cannot be released to the outside of the outer wall portion 42. If there is a plurality, the compressed air can be released to the outside of the outer wall portion 42 from the other vent holes 40 even if some of the vent holes 40 are blocked with grease or the like.

  In the first and second embodiments, the example in which both the vent hole 40 and the collar 41 are provided is described. However, the collar 41 may be omitted and only the vent hole 40 may be provided. In this case, since the compressed air can be released from the vent hole 40 to the outside of the outer wall portion 42, it is possible to obtain an effect capable of suppressing the grease or the like used for the spline portion from entering the cam chamber of the clutch 4.

1 is a sectional view of a starter according to Embodiment 1. FIG. (Example 1) which is sectional drawing of a clutch and its periphery. It is sectional drawing of the starter which concerns on Example 2. FIG. (Example 2) which is sectional drawing of a clutch and its periphery. It is sectional drawing of a clutch and its periphery (prior art).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Starter 2 Motor 4 Clutch 5 Pinion shaft 5a Male helical spline formed on the outer periphery of the pinion shaft 6 Pinion gear 20 Clutch outer 22 Inner tube 22a Female helical spline formed on the inner periphery of the inner tube 22b Annular recess 23 Roller 32 Ring gear 40 Ventilation hole 41 Collar 42 Outer wall A A Internal space formed inside the inner tube

Claims (9)

A motor that generates rotational force;
A clutch outer that rotates by transmitting a driving torque of the motor, and a cylindrical inner tube that is rotatably arranged on the inner periphery of the clutch outer, and the inner tube that passes through the roller from the clutch outer A one-way clutch that transmits torque to
A pinion shaft whose one end in the axial direction is splined to the inner periphery of the inner tube;
A pinion gear supported at the end of the pinion shaft protruding in the counter-motor direction from the inner tube,
A starter in which the pinion gear moves in the counter-motor direction integrally with the pinion shaft and meshes with a ring gear of an engine;
The clutch outer has an outer wall portion with which an end surface of the inner tube on the axial direction motor side abuts, and the outer wall portion is formed inside the inner tube when the pinion shaft moves in the counter-motor direction. The starter is characterized in that a vent hole is formed to communicate the internal space to be communicated with the outside of the outer wall portion. The starter according to claim 1,
A ring-shaped collar is disposed between the inner tube and the outer wall facing each other in the axial direction to block between the cam chamber formed on the inner periphery of the clutch outer and the internal space. Starter. The starter according to claim 2,
The collar is press-fitted and fixed at one end side to the outer wall portion, and the other end side is provided to protrude from the end surface of the outer wall portion to the inner tube side,
The inner tube is formed with an annular recess to be engaged with the other end of the collar. The starter according to claim 3,
The opening portion of the vent hole that opens in the axially opposite motor side end surface (end surface on the inner space side) of the outer wall portion is formed on the inner diameter side of the collar press-fitted into the outer wall portion. A characteristic starter. In any starter as described in Claims 1-4,
The vent hole formed in the outer wall portion is provided through the outer wall portion in the axial direction, and is provided at a plurality of locations in the circumferential direction of the outer wall portion. A motor that generates rotational force;
A pinion shaft that rotates when the driving torque of the motor is transmitted;
A clutch outer that is spline-coupled to the outer periphery of the pinion shaft, and a cylindrical inner tube that is fitted onto the pinion shaft via a bearing, and transmits torque from the clutch outer to the inner tube via a roller. A one-way clutch,
A pinion gear disposed on the pinion shaft integrally with the clutch, to which rotation of the pinion shaft is transmitted via the clutch;
A starter in which the pinion gear moves in the direction opposite to the motor integrally with the clutch and meshes with an engine ring gear;
The clutch outer has an outer wall portion with which an end surface of the inner tube on the axial direction motor side abuts, and the outer wall portion includes a space formed inside the inner tube and an outside of the outer wall portion. A starter characterized in that a vent hole is formed to communicate with each other. The starter according to claim 6, wherein
Between the inner tube and the outer wall portion facing each other in the axial direction, a ring shape that blocks between a cam chamber formed on the inner periphery of the clutch outer and a space formed on the inner side of the inner tube Starter characterized by the arrangement of colors. The starter according to claim 7,
The collar is press-fitted and fixed at one end side to the outer wall portion, and the other end side is provided to protrude from the end surface of the outer wall portion to the inner tube side,
The inner tube is formed with an annular recess to be engaged with the other end of the collar. The starter according to any one of claims 6 to 8,
The starter characterized in that a plurality of vent holes formed in the outer wall portion are provided in the circumferential direction of the outer wall portion.