JP2012007528A - Engine starter mechanism using ratchet type one-way clutch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten the axial length of an engine starter mechanism to save a space and reduce the cost by using a ratchet type one-way clutch.SOLUTION: The engine starter mechanism using the ratchet type one-way clutch includes: a starter motor; a ring gear for receiving driving force from the starter motor; and the ratchet type one-way clutch having an outer ring, an inner ring spaced in an inner diameter direction from the outer ring and arranged concentrically to be relatively rotatable, and latching pieces engaging with recesses provided in the outer periphery of the inner ring for transmitting torque between the outer ring and the inner ring. The ring gear is unified with the inner ring of the ratchet type one-way clutch.

Description

  The present invention relates to an engine starter mechanism using a ratchet type one-way clutch used in a vehicle or the like.

  Generally, in an engine starter mechanism using a one-way clutch, the starter motor and the ring gear are always meshed with each other, and the torque of the starter motor is connected to the outer ring of the one-way clutch through the one-way clutch to the engine crankshaft. It is transmitted to (connected to the inner ring of the one-way clutch) and the engine is started. After the engine is started, the crankshaft is overrun, so that the ring gear is stopped in synchronization with the engine rotation.

  The one-way clutch has a function of preventing the starter motor from being driven at an excessively high speed after the engine is started. An example of such an engine starter mechanism is described in Patent Document 1.

Prior art document information related to the invention of this application includes the following.
JP 2000-274337 A

  In an engine starter mechanism using a conventional one-way clutch, a sprag type or a roller type (Patent Document 1) is often used as the one-way clutch.

  However, in order to secure a high torque capacity with a sprag type one-way clutch or a roller type one-way clutch, the one-way clutch tends to be enlarged, and it is difficult to reduce the size of the one-way clutch. In addition, it is necessary to provide a cage for holding the sprags and rollers, and it is difficult to shorten the axial length. As a result, space saving of the engine starter mechanism has been difficult.

  Furthermore, since the one-way clutch cannot be reduced in size, the diameter of the oil seal cannot be reduced, and the sliding resistance due to the oil seal cannot be reduced.

  Accordingly, an object of the present invention is to provide an engine starter mechanism that can save space and cost by reducing the axial length of the engine starter mechanism by using a ratchet type one-way clutch. is there.

In order to achieve the above object, the engine starter mechanism using the one-way clutch of the present invention is:
An engine starter mechanism using a ratchet type one-way clutch,
A starter motor,
A ring gear for receiving a driving force from the starter motor;
Torque between the outer ring and the inner ring is engaged with an outer ring, an inner ring spaced from the outer ring in the inner diameter direction and concentrically disposed so as to be relatively rotatable, and a recess provided on the outer periphery of the inner ring. A ratchet type one-way clutch having a locking piece for transmitting
The ring gear is integrated with the inner ring of the ratchet type one-way clutch.

According to the present invention, the following effects can be obtained.
By using a ratchet type one-way clutch having a higher torque capacity than other one-way clutches of the same size, the one-way clutch can be reduced in size. With the downsizing of the one-way clutch, the oil seal diameter can be reduced, so that the sliding resistance can be reduced. In addition, since the cage is unnecessary, the shaft length of the one-way clutch can be shortened. Thereby, the axial direction length of the whole engine starter mechanism can be shortened, and space saving can be achieved.

  Since the inner ring and ring gear of the one-way clutch are integrated, the number of parts can be reduced. Further, after the engine is started, when the outer ring rotates at a predetermined rotational speed (about 500 to about 1200 rpm) or more, the latching piece of the ratchet type one-way clutch is lifted by the centrifugal force and is in a non-contact state with the inner ring. Thereby, sliding wear of the one-way clutch can be reduced.

1 is an axial partial sectional view of an engine starter mechanism using a ratchet type one-way clutch showing a first embodiment of the present invention. FIG. 6 is an axial partial cross-sectional view of an engine starter mechanism using a ratchet type one-way clutch showing a second embodiment of the present invention. 1 is a schematic front view of a ratchet type one-way clutch used in each embodiment of the present invention.

  Hereinafter, the present invention will be described in detail with reference to the drawings. In addition, it is needless to say that the embodiments described below are intended to illustrate the present invention and not to limit the present invention.

(First embodiment)
FIG. 1 is an axial partial cross-sectional view of an engine starter mechanism using a ratchet type one-way clutch showing a first embodiment of the present invention. For convenience of explanation, in the following explanation, the “ratchet type one-way clutch” is simply referred to as “one-way clutch”.

  As shown in FIG. 1, an engine starter mechanism 50 using a one-way clutch 20 is for receiving a driving force from a starter motor 1 that is an electric motor driven by power supply from a power source (not shown) and the starter motor 1. A ring gear 6 and a one-way clutch 20 are provided.

  The ring gear 6 includes a gear portion 4 that always meshes with a pinion gear 3 fixed to the output shaft 2 of the starter motor 1 and a plate portion 5 to which the gear portion 4 is fixed. A one-way clutch 20 is disposed between the ring gear 6 and a crankshaft 13 of an engine (not shown).

  As shown in FIG. 3, the one-way clutch 20 includes an outer ring 21, an inner ring 22 that is spaced from the outer ring 21 in the inner diameter direction and is concentrically disposed so as to be relatively rotatable, and a recess 26 provided on the outer periphery of the inner ring 22. And a ratchet (claw) -like locking piece 23 that transmits torque between the outer ring 21 and the inner ring 22.

  The locking pieces 23 are provided at three positions equally in the circumferential direction, but a number of locking pieces 23 other than three may be provided. The outer ring 21 is provided with a concave portion 41 and a concave portion 42 larger than the concave portion 41, the spring 40 is accommodated in the concave portion 41, and the locking piece 23 is accommodated in the concave portion 42. The spring 40 constantly urges the distal end side of the locking piece 23 so that the locking piece 23 fits into the recess 26 of the inner ring 22.

  One end portion of the outer ring 21 of the one-way clutch 20 in the axial direction is provided with an annular retainer 24 for preventing the locking piece 23 from coming off in the axial direction. At the other end of the outer ring 21 that faces the retainer 24 in the axial direction, a protruding portion 25 that protrudes in the axial direction toward the locking piece 23 is provided to support the locking piece 23. Since the locking piece 23 is supported on the side surface by the protruding portion 25, the posture at the time of swinging is stabilized. Further, since the one-way clutch 20 is not provided with a retainer that accommodates and holds the locking piece 23, the axial length of the one-way clutch 20 can be shortened.

  As shown in FIG. 1, the ring gear 6 is integrated with the inner ring 22 of the one-way clutch 20 via the plate 5. The outer ring 21 arranged to face the inner ring 22 in the radial direction includes an inner diameter portion 28. The inner diameter portion 28 is fixed to the crankshaft 13 of the engine by a bolt 36. A bearing 33 is provided between the inner ring 22 and the inner diameter portion 28 of the outer ring 21. A flywheel 32 is fixed to the crankshaft 13.

  An annular oil seal 12 is provided on the inner diameter side of the retainer 24 and seals between the retainer 24 and the outer peripheral surface of the inner ring 22. Therefore, the one-way clutch 20 is surrounded by the outer ring 21, the retainer 24, the oil seal 12, and the inner ring 22, and a substantially sealed space is formed. The one-way clutch 20 is filled with grease as a lubricant. As a result, the one-way clutch 20 is sealed together with the grease in this space, and the supply of lubricating oil from the outside becomes unnecessary.

  By doing in this way, since the conventional lubrication path | route becomes unnecessary, the freedom of a layout and space saving are attained. Further, conventionally, since the lubricating oil from the engine is sealed, the oil seal provided at the outer diameter portion of the outer ring 21 of the one-way clutch 20 becomes unnecessary, and the oil seal 30 at the outer diameter portion of the crankshaft 13 is replaced. Therefore, the diameter of the oil seal 30 can be reduced and the sliding resistance can be reduced.

  By operating the one-way clutch 20 without externally supplying lubricating oil, that is, without lubrication, the one-way clutch 20 is not damaged by foreign matters or components carried by the lubricating oil, and the life of the one-way clutch 20 is increased. Extend.

  A member 29 fixed to the member 31 is provided on the opposite side of the oil seal 12 of the one-way clutch 20 in the axial direction, and an oil seal 30 is disposed between the member 29 and the outer diameter portion of the crankshaft 13, and the engine The lubricating oil from is sealed.

  The engine starter mechanism 50 configured as described above operates as follows. First, when the starter motor 1 is driven by an ignition operation, the rotational force is transmitted via the pinion gear 3 to the ring gear 6 that is always meshed with the pinion gear 3. Since the ring gear 6 is integral with the inner ring 22 of the one-way clutch 20, the inner ring 22 also rotates clockwise in FIG. The engaging piece 23 engages with the recess 26 of the inner ring 22 and abuts against the inner wall of the recess 42 of the outer ring 21, whereby the rotational force of the inner ring 22 is transmitted to the outer ring 21.

  The rotational force of the outer ring 21 is transmitted to the crankshaft 13 via an inner diameter portion 28 fixed to the crankshaft 13, and an engine (not shown) is started. After the engine is started, the crankshaft 13 overruns and synchronizes with the engine rotation, so that the ring gear 6 is stopped.

  When the outer ring 21 starts rotating at a predetermined rotation speed (about 500 to about 1200 rpm) after the engine is started, the locking piece 23 is lifted by centrifugal force against the urging force of the spring 40, and from the recess 26 of the inner ring 22. It comes off and is in a non-contact (non-engagement) state with the inner ring 22. That is, the outer ring 21 overruns the inner ring 22, and transmission of rotational torque from the outer ring 21 to the inner ring 22 is interrupted. This prevents the starter motor from being driven at an excessively high speed.

  In order to prevent wear due to the fitting into the recess 26 and the friction between the outer ring 21 and the inner ring 22, diamond-like carbon (DLC) or the like is formed on the whole or part of the surface of the engagement piece 23 of the one-way clutch 20. A hard film may be formed. For the same reason, a solid lubricant coating may be formed.

(Second embodiment)
FIG. 2 is a partial sectional view in the axial direction of an engine starter mechanism using a ratchet type one-way clutch showing a second embodiment of the present invention. Since the basic configuration and operation are the same as those of the first embodiment, different parts will be described below.

  In the second embodiment, the oil seal 12 provided in the first embodiment is not provided. Instead, the length of the retainer 24 in the radial direction is increased to approach the outer peripheral surface of the inner ring 22. A slight clearance is provided in the inner ring 22 so that the inner diameter portion of the retainer 24 does not come into contact with the inner ring 22 during operation.

  In the second embodiment, the one-way clutch 20 is not filled with grease. Accordingly, the one-way clutch 20 operates in a dry and non-lubricated state. Also in this embodiment, since it is not necessary to secure a lubricating oil path for lubricating the one-way clutch 20 and a space for the lubricating path, the layout can be liberated and the space can be saved.

  Also in the second embodiment, a hard film such as diamond-like carbon (DLC) can be formed on the whole or a part of the surface of the engagement piece 23 of the one-way clutch 20. For the same reason, a solid lubricant coating may be formed.

DESCRIPTION OF SYMBOLS 1 Starter motor 6 Ring gear 12 Oil seal 13 Crankshaft 20 Ratchet type one-way clutch 21 Outer ring 22 Inner ring 23 Locking piece 26 Inner ring recess 33 Bearing 50 Engine starter mechanism

Claims (7)

An engine starter mechanism using a ratchet type one-way clutch,
A starter motor,
A ring gear for receiving a driving force from the starter motor;
Torque between the outer ring and the inner ring is engaged with an outer ring, an inner ring spaced from the outer ring in the inner diameter direction and concentrically disposed so as to be relatively rotatable, and a recess provided on the outer periphery of the inner ring. A ratchet type one-way clutch having a locking piece for transmitting
An engine starter mechanism, wherein the ring gear is integrated with the inner ring of the ratchet type one-way clutch.   The engine starter mechanism according to claim 1, wherein the locking piece has a hard coating.   The engine starter mechanism according to claim 1, wherein the locking piece has a solid lubricant coating.   The engine starter mechanism according to any one of claims 1 to 3, wherein the ratchet type one-way clutch is sealed with an oil seal.   The engine starter mechanism according to claim 4, wherein the ratchet type one-way clutch is filled with grease.   The engine starter mechanism according to any one of claims 1 to 3, wherein the ratchet type one-way clutch is provided with a retainer at one end in an axial direction for sealing the one-way clutch.   The engine starter mechanism according to claim 6, wherein the ratchet type one-way clutch operates in a non-lubricated state.

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