JP2009236072A - Motor driven drive mechanism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the wear of a pinion while facilitating work for mounting the pinion on an output shaft by increasing the axial tooth size of the pinion to be mounted on an output shaft of a motor. <P>SOLUTION: The pinion 34 is externally fitted and mounted onto the output shaft 28 of the motor 16 via splines 37, 42. A fitting groove 38 is formed in the outer peripheral face of a base portion 28b of the output shaft 28 while extending in the peripheral direction. An elastic body 39 in an O-ring shape is provided which is fitted into the fitting groove 38 and whose outer peripheral portion is protruded from the outer peripheral face of the base porion 28b outward in the radial direction. An engaging groove 43 which can elastically engage with the outer peripheral portion of the elastic body 39 is formed in the inner peripheral face of the pinion 34. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an electric drive device having a small motor, such as for starting an internal combustion engine, and more specifically, an O-ring shaped elastic body is attached to the output shaft of the motor, and the elastic body provides the output described above. The present invention relates to an electric drive device in which a pinion is attached to a shaft.

  Conventionally, the above-described electric drive device is disclosed in Patent Document 1 below. According to this publication, the electric drive device includes a small motor for starting an internal combustion engine, and a pinion is externally fitted to the output shaft of the motor by a spline (serration). Further, a circlip is externally fitted and attached to the projecting end portion of the output shaft. The circlip prevents the pinion from falling off the output shaft and is attached to the output shaft.

When the motor is driven, the driving force is transmitted from the output shaft to the crankshaft of the internal combustion engine via the pinion, and cranking is performed.
JP 2007-16720 A

  By the way, in general, an internal combustion engine is required to be smaller, and each component including the driving device is required to be arranged extremely compactly. In addition to this, there is a limit to lengthening the output shaft of the motor of the drive device from the viewpoint of strength.

  On the other hand, the pinion of the driving device is rotated at a high speed by a motor to perform cranking. For this reason, it is required to increase the tooth size in the axial direction of the pinion to prevent its wear. .

  However, in the conventional technique, a circlip is attached to the protruding end portion of the output shaft, and the pinion and the circlip are juxtaposed in the axial direction. For this reason, when the circlip is provided in the situation where the length of the output shaft is limited as described above, it is difficult to increase the size of the teeth of the pinion.

  Therefore, it can be considered that the pinion is attached to the output shaft by press-fitting so that the circlip is not provided. However, in this press-fitting work, there is another problem that the work of attaching the pinion to the output shaft becomes complicated, for example, a press machine is required for press-fitting.

  The present invention has been made paying attention to the above situation, and the object of the present invention is to increase the tooth size in the axial direction of the pinion attached to the output shaft of the motor. It is intended to prevent wear and to make it easy to attach the pinion to the output shaft.

The invention of claim 1 is an electric drive device in which a pinion 34 is externally fitted to the output shaft 28 of the motor 16 by splines 37, 42.
A fitting groove 38 extending in the circumferential direction is formed on the outer peripheral surface of the base portion 28b of the output shaft 28, and is fitted into the fitting groove 38, and the outer peripheral portion projects radially outward from the outer peripheral surface of the base portion 28b. An electric drive characterized in that an O-ring-shaped elastic body 39 is provided, and an engagement groove 43 that can be elastically engaged with the outer peripheral portion of the elastic body 39 is formed on the inner peripheral surface of the pinion 34. Device.

  A second aspect of the present invention is the electric drive device according to the first aspect, wherein the pinion 34 is a bevel gear.

  The invention of claim 3 is formed such that the bottom surface 38a of the fitting groove 38 gradually becomes deeper in the axial direction of the output shaft 28 and in the direction from the protruding end portion 28a side to the base portion 28b side of the output shaft 28. The electric drive device according to claim 1, wherein the electric drive device is provided.

  In addition, in this section, the reference numerals and drawing numbers appended to the above terms are not intended to limit the technical scope of the present invention to the “Example” section and the contents of the drawings described later.

  The effects of the present invention are as follows.

The invention of claim 1 is an electric drive device in which a pinion is externally fitted to an output shaft of a motor by a spline.
A fitting groove extending in the circumferential direction is formed on the outer peripheral surface of the base portion of the output shaft, the O-ring-shaped elasticity is inserted into the fitting groove, and the outer peripheral portion projects radially outward from the outer peripheral surface of the base portion. A body is provided, and an engagement groove that can be elastically engaged with the outer peripheral portion of the elastic body is formed on the inner peripheral surface of the pinion.

  For this reason, the pinion is attached to the output shaft in addition to the engagement of the pinion splines to the output shaft, and the engagement between the elastic body set on the output shaft and the engagement groove formed on the pinion. This is achieved by the combination.

  In this case, the engagement groove that is engaged with the elastic body is formed on the inner peripheral surface of the pinion, and the length of the output shaft is limited as in the conventional circlip. Under the circumstances, the pinion and the axial direction are not arranged side by side. Therefore, it is possible to secure a larger tooth dimension in the axial direction of the pinion and to prevent the pinion from being worn.

  The pinion is attached to the output shaft by simply elastically deforming the elastic body set on the output shaft as described above, and engaging the elastic body on the inner peripheral surface of the pinion. This is accomplished by engaging the groove. For this reason, for example, the attachment operation can be performed extremely easily as compared with the case where the pinion is press-fitted into the elastic body as the attachment operation.

  According to a second aspect of the present invention, the pinion is a bevel gear.

  For this reason, the pinion is applied with an external force from the side of the input gear meshing with the pinion, and is urged in the direction in which the fitting with the output shaft proceeds. Therefore, the attachment of the pinion to the output shaft is due to the elasticity of the elastic body, and it is considered that the attachment strength is not sufficiently increased. Abrupt drop-out from the output shaft is prevented, and the attachment state of the pinion to the output shaft is maintained well.

  According to a third aspect of the present invention, the bottom surface of the fitting groove is formed so as to be gradually deeper in the axial direction of the output shaft and in the direction from the protruding end portion side to the base portion side of the output shaft.

  Here, in the mounting operation, when the fitting of the pinion is advanced from the protruding end portion side of the output shaft toward the base portion side, and the elastic body is pushed by the opening edge portion of the inner hole of the pinion, This elastic body tends to be pushed into the base portion side portion in the axial direction of the fitting groove.

  By the way, as described above, the bottom surface of the fitting groove is formed so that the base side is deeper. Further, since the elastic body tends to be pushed into the deeper fitting groove portion as described above, the elastic deformation amount of the elastic body is suppressed to be small in this case.

  For this reason, the progress of the fitting of the pinion with respect to the output shaft is smoothly achieved without receiving a large reaction force from the elastic body. Therefore, the engagement of the engagement groove of the pinion with the outer peripheral portion of the elastic body can be smoothly performed, that is, the attachment work can be facilitated.

  On the other hand, when the pinion is about to be detached from the output shaft, the elastic body is pushed by the inner surface of the engagement groove of the pinion, and the elastic body protrudes in the upper axial direction of the fitting groove. It tends to be pushed into the end side portion.

  By the way, as described above, the bottom surface of the fitting groove is formed so that the base side is deeper. In other words, the bottom surface of the fitting groove is formed so that the protruding end side is shallower. . In addition, since the elastic body tends to be pushed into the shallower fitting groove portion as described above, the elastic deformation amount of the elastic body is increased in this case.

  For this reason, detachment of the pinion from the output shaft is prevented by a large reaction force from the elastic body. Therefore, the pinion can be prevented from being unintentionally detached from the output shaft more reliably, and the pinion is more firmly attached to the output shaft.

  The present invention relates to an electric drive device according to the present invention, in which a pinion attached to an output shaft of a motor has a larger tooth dimension in the axial direction to prevent wear of the pinion, and the pinion to the output shaft The best mode for carrying out the present invention is as follows in order to realize the object of facilitating the mounting operation.

  That is, in the electric drive device in which the pinion is externally fitted to the output shaft of the motor by the spline, a fitting groove extending in the circumferential direction is formed on the outer peripheral surface of the base portion of the output shaft. An O-ring-shaped elastic body is provided which is inserted into the fitting groove and whose outer peripheral portion protrudes radially outward from the outer peripheral surface of the base portion. An engagement groove that can be elastically engaged with the outer peripheral portion of the elastic body is formed on the inner peripheral surface of the pinion.

  In order to describe the present invention in more detail, Example 1 will be described with reference to FIGS.

  1-3 (1) (2), the code | symbol 1 is an internal combustion engine mounted in vehicles, such as a motorcycle. The internal combustion engine 1 includes an engine case 2 that constitutes an outer shell thereof and is supported by the vehicle body, and is supported by the engine case 2 so as to be rotatable about a horizontal axis 3 included in the engine case 2. For starting the internal combustion engine 1, a crankshaft 4 to be cranked is provided for starting the internal combustion engine 1.

  The starting device 5 is disposed on a cylindrical bracket 9 supported on the engine case 2 by a fastener 8 and an axis 10 of the bracket 9 so as to be rotatable around the axis 10. 9, a drive gear 12 supported by a bearing 11, a driven gear 13 that is attached to the crankshaft 4 and rotates with the crankshaft 4 and meshes with the drive gear 12, and a drive device that drives the drive gear 12. 14. The drive gear 12 and the driven gear 13 are a worm gear set. The drive gear 12 is a worm and the driven gear 13 is a worm wheel.

  The driving device 14 includes a small starter motor 16. The motor 16 constitutes an outer shell of the motor 16, and one end portion in the axial direction is removably fitted into the bracket 9 and attached to the bracket 9, and the other end portion is fastened to the engine case 2. A motor case 18 attached by a tool 17 and an armature 21 included in the motor case 18 and supported by a bearing 20 on the motor case 18 so as to be rotatable around an axis 19 of the motor case 18 are provided. ing.

  The armature 21 is positioned on the shaft center 19 and is supported by the motor case 18 so as to be rotatable around the shaft center 19, and the axial direction of the drive shaft 23. A coil 25 wound around a core 24 fixed to the part, a commutator 26 fixed to one end of the drive shaft 23, a brush 27 supported by the motor case 18 and slidably contacting the commutator 26. It has. One end portion of the drive shaft 23 protrudes outward from one end portion of the motor case 18, and this protrusion portion serves as an output shaft 28 that outputs the drive force of the drive device 14.

  A bolt 31 is formed on the shaft center 10 at one end of the drive gear 12, and an input gear 32 is fitted on the base of the bolt 31. The input gear 32 is fixed to the drive gear 12 by a nut 33 screwed to the bolt 31. On the other hand, a pinion 34 is attached to the output shaft 28.

  The shaft center 10 of the input gear 32 and the shaft center 19 of the pinion 34 are orthogonal to each other, and the input gear 32 and the pinion 34 are both bevel gears and mesh with each other. In this case, the input gear 32 has a bevel structure in which the diameter decreases in the axial direction of the drive gear 12 toward the shaft end side of one end of the drive gear 12. The pinion 34 has a bevel structure in which the diameter decreases in the axial direction of the output shaft 28 toward the projecting end side of the output shaft 28. Further, the nut 33 and the axial end face of the pinion 34 are close to each other, and these 33 and 34 are arranged compactly.

  The mounting structure of the pinion 34 to the output shaft 28 will be specifically described.

  A spline 37 is formed on the outer peripheral surface of the protruding end portion 28 a of the output shaft 28. The base portion 28b of the output shaft 28 is slightly larger in diameter than the protruding end portion 28a, and a fitting groove 38 is formed on the outer peripheral surface of the base portion 28b so as to extend in the entire circumference in the circumferential direction.

  An annular stopper surface 28c extending flat in the radial direction and in the circumferential direction is formed at the step portion between the protruding end portion 28a and the base portion 28b of the output shaft 28. In the axial direction of the output shaft 28 and in the direction from the protruding end portion 28a side of the output shaft 28 to the base portion 28b side, the bottom surface 38a of the fitting groove 38 is an inclined surface that becomes gradually deeper. A rubber elastic body 39 is provided in an O-ring shape that is fitted into the fitting groove 38 and whose outer peripheral portion protrudes radially outward from the outer peripheral surface of the base portion 28b.

  Of the inner holes of the pinion 34, a spline 42 that fits with the spline 37 of the output shaft 28 is formed on the inner peripheral surface of the one end hole 34a on the smaller diameter side of the pinion 34 in the axial direction. Further, the other end hole 34b of the inner hole of the pinion 34 is larger in diameter than the one end hole 34a and can be fitted into the base portion 28b of the output shaft 28. Engagement grooves 43 are formed on the circumferential surface extending along the entire circumference in the circumferential direction.

  An annular stopper surface 34c is formed at the step between the one end hole 34a and the other end hole 34b of the pinion 34 so as to extend flat in the radial direction and the circumferential direction. The bottom surface 43a of the 43 is an inclined surface that gradually becomes shallower in the axial direction of the pinion 34 and in the direction from the one end hole 34a of the pinion 34 toward the other end hole 34b.

  As shown in FIG. 3 (2), when the pinion 34 is attached to the output shaft 28 from the outside in the axial direction of the output shaft 28, the pinion 34 is externally fitted to the output shaft 28. The spline 37 of the shaft 28 and the spline 42 of the pinion 34 are fitted. Next, the other end hole 34 b of the pinion 34 is fitted into the base portion 28 b of the output shaft 28. Further, when these fittings are advanced, the opening edge of the other end hole 34b of the pinion 34 temporarily compresses the elastic body 39 (FIG. 3 (3)). Further, when the pinion 34 is fitted to the output shaft 28, the outer peripheral portion of the elastic body 39 is fitted into the engagement groove 43, and the shape is elastically restored. At this time, the elastic body 39 is in pressure contact with the inner surfaces of the fitting groove 38 and the engaging groove 43. Then, the pinion 34 is attached to the output shaft 28 by fitting both the splines 37 and 42 and engaging the elastic body 39 and the engaging groove 43.

  In the above case, the stopper surface 28c of the output shaft 28 and the stopper surface 34c of the pinion 34 are in contact with each other, and the pinion 34 is prevented from further fitting to the output shaft 28. Further, the elastic body 39 is pressed against the bottom surface 43a of the engaging groove 43 of the pinion 34, and the stopper surfaces 28c, 34c are pressed against each other. As a result, the pinion 34 is elastically prevented from falling off from the output shaft 28, and the attachment state of the pinion 34 to the output shaft 28 is maintained.

  When the motor 16 of the driving device 14 in the starting device 5 is driven, the driving force of the internal combustion engine 1 is sequentially driven from the output shaft 28 through the pinion 34, the input gear 32, the driving gear 12, and the driven gear 13. 4 is transmitted so that cranking is performed.

According to the above configuration, in the electric drive device in which the pinion 34 is externally fitted to the output shaft 28 of the motor 16 by the splines 37 and 42,
A fitting groove 38 extending in the circumferential direction is formed on the outer peripheral surface of the base portion 28b of the output shaft 28, and is fitted into the fitting groove 38, and the outer peripheral portion projects radially outward from the outer peripheral surface of the base portion 28b. An O-ring-shaped elastic body 39 is provided, and an engagement groove 43 that can be elastically engaged with the outer peripheral portion of the elastic body 39 is formed on the inner peripheral surface of the pinion 34.

  For this reason, the pinion 34 is attached to the output shaft 28 in addition to the fitting of the splines 37 and 42 of the pinion 34 to the output shaft 28, and the elastic body 39 set on the output shaft 28 and the pinion 34. This is achieved by engagement with the engagement groove 43 formed in the above.

  In this case, the engaging groove 43 to be engaged with the elastic body 39 is formed on the inner peripheral surface of the pinion 34, and the length of the output shaft 28 is the same as a conventional circlip. However, it is not the case that the pinion 34 and the pinion 34 are arranged in parallel in the axial direction. Therefore, it is possible to secure a larger tooth dimension in the axial direction of the pinion 34 and to prevent the pinion 34 from being worn.

  The pinion 34 is attached to the output shaft 28 by simply elastically deforming the elastic body 39 set on the output shaft 28 as described above, and with respect to the elastic body 39, the inner peripheral surface of the pinion 34. This is achieved by engaging the engaging grooves 43 formed in the. For this reason, for example, as compared with the case where the pinion 34 is press-fitted into the elastic body 39 as the attachment operation, the attachment operation can be performed very easily.

  Further, as described above, the pinion 34 is a bevel gear.

  For this reason, the pinion 34 is applied with an external force from the side of the input gear 32 that meshes with the pinion 34 and is urged in a direction in which the fitting with the output shaft 28 proceeds, and the output shaft 28 and the pinion 34 are Both stopper surfaces 28c, 34c are maintained in pressure contact with each other. Therefore, the attachment of the pinion 34 to the output shaft 28 is due to the elasticity of the elastic body 39, and it is considered difficult to increase the attachment strength sufficiently. However, by making the pinion 34 a bevel gear, The pinion 34 is prevented from being accidentally dropped from the output shaft 28, and the attachment state of the pinion 34 to the output shaft 28 is maintained well.

  Further, as described above, the bottom surface 38a of the fitting groove 38 is gradually deepened in the axial direction of the output shaft 28 and in the direction from the protruding end portion 28a side to the base portion 28b side of the output shaft 28. ing.

  Here, in the mounting operation, the fitting of the pinion 34 is caused to proceed from the protruding end portion 28a side of the output shaft 28 toward the base portion 28b side, and the elastic body 39 is moved by the opening edge portion of the inner hole of the pinion 34. When pushed (FIG. 3 (3)), the elastic body 39 tends to be pushed into a portion of the fitting groove 38 on the base 28 b side in the axial direction.

  By the way, as described above, the bottom surface 38a of the fitting groove 38 is formed so that the base portion 28b side is deeper. Further, since the elastic body 39 tends to be pushed into the deeper fitting groove 38 as described above, the elastic deformation amount of the elastic body 39 is suppressed to be small in this case. The

  For this reason, the progress of the fitting of the pinion 34 to the output shaft 28 is smoothly achieved without receiving a large reaction force from the elastic body 39. Therefore, the engagement groove 43 of the pinion 34 can be smoothly engaged with the outer peripheral portion of the elastic body 39, that is, the attachment work can be facilitated.

  On the other hand, when the pinion 34 is about to be detached from the output shaft 28, the elastic body 39 is pushed by the bottom surface 43a, in particular, of the inner surface of the engagement groove 43 of the pinion 34, and the elastic body 39 is thus fitted. Of the groove 38, the groove 38 tends to be pushed into a portion on the protruding end portion 28 a side in the axial direction.

  By the way, as described above, the bottom surface 38a of the fitting groove 38 is formed so that the base portion 28b side is deeper. In other words, the bottom surface 38a of the fitting groove 38 is shallower on the protruding end portion 28a side. It is formed to become. In addition, since the elastic body 39 tends to be pushed into the shallower fitting groove 38 as described above, the elastic deformation amount of the elastic body 39 is increased in this case.

  For this reason, the detachment of the pinion 34 from the output shaft 28 is prevented by a large reaction force from the elastic body 39. Therefore, the pinion 34 is prevented from being unexpectedly detached from the output shaft 28 more securely, and the pinion 34 is attached to the output shaft 28 more firmly.

  Although the above is based on the illustrated example, the protruding end portion 28a and the base portion 28b of the output shaft 28 may have the same diameter, and the spline 37 may be formed on the base portion 28b. Further, the elastic body 39 does not have to be strictly an O-ring shape, and may be a C shape in which a part thereof is cut. In this case, the elastic body 39 may be formed of a metal spring material.

  FIG. 4 below shows a second embodiment. The second embodiment is common in many respects to the configuration and operational effects of the first embodiment. Therefore, regarding these common items, common reference numerals are attached to the drawings, and redundant description thereof is omitted, and different points are mainly described. In addition, the configuration of each part in these embodiments may be variously combined in light of the object and operational effects of the present invention.

  In order to describe the present invention in more detail, Example 2 will be described with reference to FIG.

  In FIG. 4, the pinion 34 is a spur gear. The protruding end portion 28a and the base portion 28b of the output shaft 28 have the same diameter. Therefore, the stopper surfaces 28c and 34c are not formed on the output shaft 28 and the pinion 34.

1 is a front sectional view of a starting device according to a first embodiment. FIG. 1 is a side cross-sectional view of a starting device according to a first embodiment. FIG. (1) shows Example 1, partial expanded sectional view of FIG. 1, (2) shows Example 1, developed view of what is shown in (1), (3) shows Example 1, output shaft It is a figure explaining the attachment operation | work of the pinion to. FIG. 4 is a diagram illustrating Example 2 and corresponding to FIG. 3.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Internal combustion engine 2 Engine case 4 Crankshaft 5 Starter 10 Axle 12 Drive gear 13 Driven gear 14 Driver 16 Motor 18 Motor case 19 Axis 28 Output shaft 28a Projection end 28b Base 28c Stopper surface 31 Bolt 32 Input gear 33 Nut 34 Pinion 34a One end hole 34b Other end hole 34c Stopper surface 37 Spline 38 Fitting groove 38a Bottom surface 39 Elastic body 42 Spline 43 Engaging groove 43a Bottom surface

Claims (3)

In the electric drive device in which the pinion is externally fitted to the output shaft of the motor by a spline,
A fitting groove extending in the circumferential direction is formed on the outer peripheral surface of the base portion of the output shaft, the O-ring-shaped elasticity is inserted into the fitting groove, and the outer peripheral portion projects radially outward from the outer peripheral surface of the base portion. An electric drive device characterized in that a body is provided and an engagement groove that can be elastically engaged with the outer peripheral portion of the elastic body is formed on the inner peripheral surface of the pinion.   2. The electric drive device according to claim 1, wherein the pinion is a bevel gear.   The axial direction of the output shaft and the bottom surface of the fitting groove are formed so as to gradually become deeper in the direction from the protruding end portion side to the base portion side of the output shaft. The electric drive device described.

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