JP2009036072A - Engine starter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a sun gear from being interfered with a separator by stabilizing the thrust restraining position of the sun gear in an engine starter in which the sun gear is formed separately from a motor rotating shaft. <P>SOLUTION: This engine starter 1 comprises a pinion 6 rotatingly driven by an electric motor 3 and meshed with the ring gear of an engine, and a reduction gear 2 using a planetary gear mechanism interposed between the electric motor 3 and the pinion 6. The reduction gear 2 has the sun gear 13 formed separately from the rotating shaft 10 of the electric motor 3 and attached to the outer periphery of the rotating shaft 10. A flat part 72 is formed adjacently to the gear attaching part 50 of the rotating shaft 10, and a thrust restraining ring 71 is attached thereto. The flat part 72 is formed while cutting a shear drop R section 55 produced when a serration 51 is cold-pressed. The sun gear 13 is attached to the rotating shaft 10 in the state of being in contact with the thrust restraining ring 71. In this case, a gap G is secured between the sun gear and the separator 38. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a starter attached to an engine such as an automobile, and more particularly to an engine starter provided with a speed reduction mechanism using a planetary gear.

  In an engine used for an automobile, a motorcycle, a large generator, or the like, a starting operation is generally performed by an engine starting device (starter motor) using an electric motor. As such a starting device, for example, as disclosed in Patent Documents 1 and 2, a pinion that is rotationally driven by an electric motor is arranged so as to be movable in the axial direction. FIG. 6 is a cross-sectional view showing the configuration of the engine starting device 101 of Patent Document 1. As shown in FIG. As shown in FIG. 6, the pinion 102 of the engine starting device 101 is disposed so as to be able to mesh with and disengage from the engine ring gear 103, and both gears mesh when the engine is started, and the meshing is released after the engine is started. It has become so. For the movement of the pinion 102 in the axial direction, an electromagnetic device 104 arranged coaxially with the pinion 102 is used, and this electromagnetic device 104 surrounds the output shaft 105 that supports the pinion 102 so as to be movable in the axial direction. Are arranged to be.

  The pinion 102 is also connected to a rotating shaft 109 of a motor 108 via an overrunning clutch 106 and a speed reducer 107 using a planetary gear. The reduction gear 107 includes a gear support plate 113 to which a sun gear 111 formed on the motor rotation shaft 109 and a planetary gear 112 that meshes with the sun gear 111 are attached. Planetary gear 112 meshes with internal ring gear 116 of top plate 115 fixed in case 114 of engine starting device 101. On the other hand, the gear support plate 113 is fixed to the output shaft 105 described above, whereby the rotation of the motor 108 is decelerated and transmitted to the output shaft 105 and transmitted to the pinion 102 via the overrunning clutch 106. .

Further, in the engine starting device 101 as shown in FIG. 6, a separator 117 is provided between the reduction gear 107 and the motor 108 so that the lubricating grease on the reduction gear 107 side does not enter the motor 108 side. ing. Separator 117 is formed of a disk-shaped steel plate, and is disposed in engine starter 101 in a form interposed between yoke 118 of motor 108 and case 114.
Japanese Patent Laid-Open No. 10-318105 Japanese Unexamined Patent Publication No. 2005-2860

  On the other hand, when the transmission gear ratio of the reduction gear 107 is changed to increase the rotation of the pinion 102, the outer diameter of the sun gear 111 is increased accordingly, and the rotation shaft 109 is also increased in diameter. When the rotating shaft 109 is increased, the outer diameter of the motor 108 itself is increased accordingly, which causes a problem that the engine starting device 101 is increased in size. For this reason, the present inventors have formed a sun gear separately from the motor rotation shaft, and by mounting it on the outer periphery of the rotation shaft, it is possible to cope with higher rotation without changing the diameter of the rotation shaft. It came to invent. FIG. 7 is an explanatory diagram showing a configuration in the vicinity of the sun gear when the sun gear 111 is formed separately from the motor rotation shaft 109. As shown in FIG. 7, the sun gear 111 is separate from the rotating shaft 109, and serrations 119, 121 are formed on both sides by forging. The sun gear 111 is fixed to the rotating shaft 109 by engaging the serrations 119 and 121 with each other.

  However, when such a sun gear configuration is employed, the thrust restricting position X of the sun gear 111 on the motor rotating shaft 109 becomes the innermost portion of the serration 121, that is, the sagging R portion during forging. Such a sag R portion is easily affected by wear of the mold, and dimensional variation as a thrust restricting position is likely to occur. For this reason, there is a problem that the thrust restricting position of the sun gear 111 is not stable and the variation in the axial position of the sun gear 111 becomes large. As shown in FIG. 7, a separator 117 is disposed in the vicinity of the sun gear 111. If the thrust restricting position X is not stable, the sun gear 111 interferes with the separator 117 as shown by a broken line in the figure. There was a problem that it might cause a device failure.

  An object of the present invention is to stabilize a thrust restricting position of a sun gear and prevent interference between the sun gear and a separator in an engine starter having a configuration in which a sun gear is formed separately from a motor rotation shaft.

  An engine starter according to the present invention is rotationally driven by an electric motor and is interposed between a pinion that meshes with an engine ring gear by moving in an axial direction, and the electric motor includes a planetary gear mechanism. An engine starter comprising a speed reducer that decelerates and transmits the rotation of the planetary gear to the pinion, wherein the planetary gear mechanism is formed separately from the rotating shaft of the electric motor, and is disposed on the outer periphery of the rotating shaft. A sun gear to be mounted; and the rotating shaft is provided adjacent to the gear mounting portion, and a gear mounting portion having a serration that engages with a serration formed in a shaft hole of the sun gear to which the sun gear is mounted. A thrust restricting member mounting portion including a portion obtained by cutting and removing a forging sag portion generated when the serration of the gear mounting portion is forged. The thrust control member mounting portion, the thrust regulating member for regulating the movement in the axial direction of said sun gear in contact with said sun gear, characterized in that mounted.

  In the present invention, the thrust regulating member mounting portion is formed adjacent to the gear mounting portion while removing the forged sag portion generated when the sun gear mounting portion is serrated, and the sun gear is moved in the axial direction there. A thrust regulating member to be regulated is attached. As a result, the forging sag portion that is easily affected by the wear of the mold and is likely to cause variations in dimensions as a thrust restricting position is mechanically removed, and the thrust restricting member attached to the site where the forging sag portion has been removed is Thrust position is regulated. Therefore, the thrust restricting position of the sun gear is stabilized, and it is possible to prevent the sun gear from interfering with other parts (for example, a separator) in the apparatus.

  In the engine starter, the thrust restricting member may be attached to the rotating shaft so as to cover an end portion of the serration formed on the rotating shaft. Thus, the thrust restricting member and the sun gear can be reliably brought into contact without being affected by the incomplete serration portion, and the thrust restricting position of the sun gear can be set more accurately.

  According to the engine starter of the present invention, the engine starter includes a pinion that is rotationally driven by an electric motor and meshes with a ring gear of the engine, and a speed reducer using a planetary gear mechanism interposed between the pinion and the electric motor. The planetary gear mechanism uses a sun gear formed separately from the rotating shaft of the motor, and the thrust regulating member mounting portion provided adjacent to the gear mounting portion of the rotating shaft is cut and removed from the forging sag portion. Since the thrust restricting member is attached to restrict the movement of the sun gear in the axial direction, the thrust restricting position of the sun gear can be set to a stable position. For this reason, interference between the sun gear and the separator can be prevented, and the reliability of the engine starting device can be improved.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a cross-sectional view showing a configuration of an engine starter according to an embodiment of the present invention, in which the upper side from the center line indicates a stationary state, and the lower side indicates an energized state. An engine starter 1 shown in FIG. 1 is used for starting an automobile engine, and gives a rotation necessary for fuel intake, atomization, compression, and ignition to a stopped engine.

  The engine starter 1 includes a reduction gear 2, an electric motor 3, an output shaft 4 connected to the electric motor 3 via the reduction gear 2, an overrunning clutch 5 slidably provided on the output shaft 4, and a pinion 6 and an electromagnetic device 7 for moving the pinion 6 in the axial direction. A separator 38 is interposed between the reduction gear 2 and the electric motor 3 to isolate the two.

  The electric motor 3 is a known commutator type DC motor, and the rotation shaft 10 is rotatably supported at the center of the bottom plate 11 at the right end in the drawing. On the other hand, the left end portion of the rotating shaft 10 in the figure is rotatably supported at the center of the right end of the output shaft 4 arranged coaxially with the rotating shaft 10. A top plate 12 is attached to the left end of the electric motor 3, and the top plate 12 is joined to a gear cover 17 that also serves as a fixed bracket for the engine. A free end of the output shaft 4 is rotatably supported at the center of the inner surface of the left wall of the gear cover 17.

  As shown in FIG. 1, a speed reducer 2 using a planetary gear mechanism is accommodated inside the top plate 12. FIG. 2 is an exploded perspective view showing the configuration of the reduction gear 2, and FIG. 3 is an explanatory view showing the gear arrangement. As shown in FIG. 2, the reduction gear 2 has a configuration in which a sun gear 13 is provided at the center, three planetary gears 14 are provided around the sun gear 13, and an internal ring gear 15 is provided outside the planetary gear 14. The sun gear 13 is formed separately from the rotary shaft 10 and attached to the rotary shaft 10 at a position adjacent to the output shaft support portion 10a at the left end of the rotary shaft.

  In this case, the rotating shaft 10 having the same diameter as that of the engine starting device 101 of FIG. 6 is used, and a small-diameter gear mounting portion 50 is provided in a portion where the sun gear 111 has been formed. A serration 51 is formed on the left side of the gear mounting portion 50 in the figure in place of the conventional gear. On the other hand, a shaft hole 52 into which the rotary shaft 10 is inserted is formed in the sun gear 13, and a serration 53 that meshes with the serration 51 is formed on the inner periphery of the shaft hole 52. The sun gear 13 is lightly press-fitted into the rotary shaft 10 so that the serrations 51 and 53 are engaged with each other. As a result, the sun gear 13 is mounted on the outer periphery of the rotary shaft 10 while being prevented from rotating. Thus, in the engine starting device 1, the sun gear 13 can be made larger in diameter than before (for example, 9 teeth → 13 teeth in the same module) without changing the diameter of the rotating shaft 10. The pinion 6 can be rotated at a high speed without increasing the physique.

  In the engine starting device 1, a thrust regulating ring 71 is disposed at the back of the serration 51 (right end in FIG. 1) to regulate the thrust position of the sun gear 13. FIG. 4 is an explanatory diagram showing a configuration in the vicinity of the sun gear 13. As shown in FIG. 4, the sag R portion 55 (see FIG. 5A) is removed by cutting between the shaft main body portion 56 (the portion on the electric motor 3 side) of the rotary shaft 10 and the gear mounting portion 50. In the form, a flat portion (thrust restricting member attaching portion) 72 is provided, and a thrust restricting ring (thrust restricting member) 71 is attached thereto. As described above, the sagging R portion 55 of the rotating shaft 10 is likely to be affected by mold wear and the like, and if this is used as the thrust restricting position of the sun gear 13, the thrust position of the sun gear 13 is not stable. Therefore, in the engine starter 1 according to the present invention, the flat portion 72 is formed on the rotary shaft 10 by cutting and removing the sag R portion 55, and the thrust restricting ring 71 is attached thereto to stabilize the thrust position of the sun gear 13. We are trying to make it.

  5A shows a method of forming the flat portion 72, and FIG. 5B shows a state where the sun gear 13 and the thrust regulating ring 71 are attached to the gear mounting portion 50 and the flat portion 72, respectively. As shown in FIG. 5A, when the serration 51 of the gear mounting portion 50 is forged, a sag R portion (forging sag portion) 55 as shown by a broken line is formed at the back of the serration. In the engine starting device 1, the sag R portion 55 is removed by cutting after the forging process, and a flat portion 72 is formed in a form including a portion where the sag R portion 55 is removed. The flat portion 72 is formed between the shaft main body portion 56 of the rotating shaft 10 and the gear mounting portion 50, and has an outer diameter smaller than that of the shaft main body portion 56. A boundary portion between the flat portion 72 and the shaft main body portion 56 is stepped, and a ring contact surface 73 is formed on the end surface of the shaft main body portion 56 so as to face the flat portion 72. Further, the outer diameter of the flat portion 72 is slightly larger than the outer diameter of the serration 51 so that the thrust restricting ring 71 can be press-fitted and attached from the serration 51 side.

  The thrust restricting ring 71 attached to the flat portion 72 is an annular member having a shaft hole 74 at the center, and is formed of a metal such as stainless steel. The shaft hole 74 is formed to be slightly smaller in diameter than the outer diameter of the flat portion 72, and the thrust restricting ring 71 is attached to the outer periphery of the flat portion 72 in a press-fit state. The thrust restricting ring 71 is press-fitted into the flat portion 72 until the right end surface 71a thereof abuts against the ring abutting surface 73, and is fixed to the rotating shaft 10 in that state. At this time, the left end surface (gear contact surface) 71b of the thrust restricting ring 71 extends to the right end portion 75 of the serration 51 formed on the rotating shaft 10, particularly to a position beyond the portion where the serration formation is incomplete. ing.

  In the engine starting device 1, after the thrust restricting ring 71 is attached to the flat portion 72, the sun gear 13 is attached to the gear attaching portion 50. The sun gear 13 is pushed in until the right end of the sun gear 13 abuts on the left end surface 71 b of the thrust restricting ring 71 while meshing the serrations 51 and 53. Thereby, the movement of the sun gear 13 in the axial direction is restricted by the thrust restricting ring 71, and the sun gear 13 is fixed to the rotating shaft 10 in a state of being positioned in the thrust direction. In the engine starting device 1, since the right end portion 75 of the serration 51 is covered with the thrust regulating ring 71, the engine starting device 1 contacts the thrust regulating ring 71 without being affected by the incomplete serration portion 76. The sun gear 13 can be pushed in to the full position.

  On the other hand, as shown in FIG. 4, when the sun gear 13 is brought into contact with the thrust restricting ring 71, a gap (gap G) is formed between the gear portion end surface 62 of the sun gear 13 and the separator 38. That is, in the engine starting device 1, the axial length of the thrust restricting ring 71 is such that when the thrust restricting ring 71 and the sun gear 13 are attached to the rotary shaft 10, a gap G is generated between the sun gear 13 and the separator 38. Is set to Therefore, a gap is always ensured between the sun gear 13 and the separator 38 in a state where the parts of the engine starter are assembled.

  As described above, in the engine starting device 1 of the present invention, the sagging R portion 55 of the rotating shaft 10 is removed to provide the flat portion 72, and the thrust position of the sun gear 13 is regulated by the thrust regulating ring 71 attached thereto. That is, the sun gear 13 is attached to the rotary shaft 10 with the thrust position regulated by a thrust regulating ring 71 fixed at a predetermined position of the rotary shaft 10. Therefore, the thrust position of the sun gear 13 is regulated at an accurate position based on machining, and the thrust regulation position of the sun gear 13 is more accurate and stable than in the case of position regulation by the sag R portion 55. The position can be set.

  Further, by setting the dimension of the thrust regulating ring 71 so that a gap G is generated between the gear portion end surface 62 of the sun gear 13 and the separator 38 in a state where the thrust regulating ring 71 and the sun gear 13 are attached to the rotary shaft 10. Interference between the sun gear 13 and the separator 38 can be avoided. That is, since the thrust position of the sun gear 13 is stable, if the gap G is secured between the sun gear 13 and the separator 38 with the closest approach, they will not interfere with each other in terms of dimensions. . For this reason, it is possible to prevent a failure such as the sun gear 13 and the separator 38 interfering with each other and the sun gear 13 being caught in the separator 38, and the reliability of the apparatus can be improved.

  On the other hand, the output shaft 4 is rotatably supported at the center of the top plate 12. A gear support plate 16 to which a planetary gear 14 is rotatably attached is fixed to the right end portion of the output shaft 4. The internal ring gear 15 is formed on the inner peripheral surface of the top plate 12, and the planetary gear 14 is engaged therewith. Thereby, the planetary gear 14 revolves around the sun gear 13 while rotating, and the rotation of the rotary shaft 10 is decelerated by the reduction gear 2 and transmitted to the output shaft 4.

  An overrunning clutch 5 using a one-way roller clutch is attached to an intermediate portion of the output shaft 4. A clutch outer 18 of the overrunning clutch 5 is provided with a coupling portion 18 a with the output shaft 4, and an inner peripheral portion of the coupling portion 18 a and an outer peripheral surface of the output shaft 4 are coupled via a helical spline 19. . In addition, a return spring 21 is disposed between the coupling portion 18 a and the plate 20 that is supported by the left end of the output shaft 4. The return spring 21 is wound around a gap defined between the inner peripheral surface of the coupling portion 18 a and the outer peripheral surface of the output shaft 4. The clutch outer 18 is always elastically biased toward the right in the figure by the return spring 21.

  A clutch inner 22 of the overrunning clutch 5 is engaged with the clutch outer 18 so as not to be displaced in the relative axial direction and to be relatively rotatable. A pinion 6 is integrally formed on the outer peripheral portion of the left end of the clutch inner 22. As described above, the pinion 6 meshes with the engine ring gear 23 to drive the engine. The clutch inner 22 is fitted on the outer periphery of the left end portion of the output shaft 4 so as to be rotatable and axially displaceable.

  An excitation coil 24 that constitutes an electromagnetic device and is electrically connected to an ignition switch (not shown) is provided at an intermediate portion of the gear cover 17. The exciting coil 24 is disposed so as to surround the output shaft 4 formed of a nonmagnetic material, and is fixed to the inner peripheral surface of the gear cover 17. The exciting coil 24 is also surrounded by a yoke composed of a holder 25 having a flange 25a and a ring-shaped disk 26. An armature outer 27 and an armature inner 28 (hereinafter abbreviated as armatures 27 and 28) are mounted in the gap between the inner peripheral surface of the exciting coil 24 and the outer peripheral surface of the output shaft 4. The armatures 27 and 28 are both made of a magnetic material, and are provided so as to be slidable relative to each other inside and outside. The left end surfaces of the armatures 27 and 28 are opposed to the inner surface of the center portion of the flange 25a of the holder 25, and the center portion of the flange 25a is a pole for the armatures 27 and 28.

  An annular stopper 30 is interposed between the holder 25 and the pinion 6. The stopper 30 is made of synthetic resin so that the overrunning clutch 5 and the pinion 6 do not collide with the left end surface of the holder 25 when the overrunning clutch 5 and the pinion 6 move along the axial direction during the engine starting operation. .

  The right end of the armature outer 27 is connected to a switch unit (not shown) disposed adjacent to the commutator portion 31 of the electric motor 3. The armature outer 27 is always elastically biased toward the right in the drawing by a return spring 35 disposed between the armature outer 27 and the flange 25a. At that time, the armature outer 27 is normally stationary with the contact points of the switch unit being opened.

  The armature inner 28 is constantly urged by a coil spring 36 from the top plate 12 toward the left in the figure. The spring force of the coil spring 36 is weaker than the spring force of the return spring 21 provided in the clutch outer 18. Further, a shifter member 37 made of a nonmagnetic material is coupled to the armature inner 28. The left end of the shifter member 37 is in contact with the right end of the clutch inner 22.

  A metal separator 38 is interposed between the top plate 12 and the commutator portion 31. The separator 38 is formed in a ring shape and isolates the speed reduction device 2 from the electric motor 3. A cylindrical portion 38 a is formed at the center of the separator 38 so as to protrude toward the commutator portion 31. The inner peripheral surface of the cylindrical portion 38a is opposed to the outer peripheral surface of the rotating shaft 10 with a minute gap. The free end (right end portion in the drawing) of the cylindrical portion 38a enters the recess 31a formed on the left end surface of the commutator portion 31 in the drawing, whereby the grease of the reduction gear 2 leaks to the commutator portion 31 side. Is prevented.

  The bottom plate 11 is attached to the gear cover 17 by a through bolt 40 together with the yoke 39 and the separator 38 of the electric motor 3. On the outer peripheral portion of the bottom plate 11, a step-shaped stamping fitting portion 11 a is formed, and the right end portion of the yoke 39 is fitted with the stamping stamp. On the other hand, the left end portion of the yoke 39 is also inlayed with an inlay fitting portion 38 b formed on the outer peripheral portion of the separator 38. In addition, the outer peripheral edge of the separator 38 is stamped and fitted into a stamped fitting part 17 a formed on the inner circumferential surface of the gear cover 17.

  Next, the operation procedure of the engine starting device 1 will be described. First, in a stationary state where no current is applied to the exciting coil 24, the armature outer 27 is urged by the return spring 35 and moves fully to the right. At the same time, the clutch outer 18 is urged by the return spring 21 and moves fully to the right along with the clutch inner 22, integral with the pinion 6, the shifter member 37, and the armature inner 28. At this time, the pinion 6 and the ring gear 23 are not meshed with each other, and the connection between them is broken.

  When the ignition switch is turned on, the electromagnetic device 7 is energized and the exciting coil 24 is excited. Then, a magnetic path passing through the armatures 27 and 28 is formed, and the armatures 27 and 28 are attracted and moved to the left. At this time, since the armature outer 27 is closer to the center portion (pole) of the flange 25a of the holder 25 among the armatures 27 and 28, the armature outer 27 moves ahead of the armature inner 28. In conjunction with this, a movable contact (not shown) connected to the armature outer 27 moves and contacts a fixed contact connected to the battery. The movable contact is electrically connected to the brush of the electric motor 3, whereby the electric power of the battery is supplied to the electric motor 3 and the rotating shaft 10 rotates.

  On the other hand, the armature outer 27 stops when the flange 27a integrally formed on the right end side thereof contacts the ring-shaped disk 26. At this time, a gap is formed between the left end surface of the armature outer 27 and the center portion of the flange 25a.

  When the rotary shaft 10 rotates, this rotational force is decelerated by the reduction gear 2 and transmitted to the output shaft 4. At this time, the clutch outer 18 attached to the output shaft 4 tends to be stationary due to inertial resistance. For this reason, the axial force by the action of the helical spline 19 is applied to the clutch outer 18, and the clutch outer 18 starts to move to the left. On the other hand, the armature inner 28 is subjected to a suction force to the left by the exciting coil 24 and a pressing force of the coil spring 36, and the armature inner 28 also starts to move to the left. Accordingly, the moving force of the armature inner 28 is also applied as an axial force to the clutch outer 18 via the shifter member 37.

  By these axial forces, the clutch outer 18 is pushed leftward against the urging force of the return spring 21. When the clutch outer 18 moves leftward, the clutch inner 22 is also pushed leftward, and the pinion 6 integrated with the clutch inner 22 also moves leftward. The clutch outer 18 moves to a position where it abuts on the plate 20, and the pinion 6 reaches a normal meshing position with the ring gear 23. As a result, the pinion 6 and the ring gear 23 mesh with each other, the rotational force of the output shaft 4 is transmitted to the ring gear 23, and the engine is started. When the engine is started and the rotational speed of the pinion 6 exceeds that of the rotary shaft 10, the pinion 6 idles due to the action of the overrunning clutch 5 and is not transmitted to the electric motor 3 side.

  On the other hand, when the clutch outer 18 moves to a position where it comes into contact with the plate 20, the left end surface of the armature inner 28 comes into contact with the center portion of the flange 25 a of the holder 25. The armature inner 28 moves integrally with the shifter member 37, and a minute gap is formed between the left end surface of the shifter member 37 and the clutch outer 18. Thus, when the armature inner 28 comes into contact with the center portion of the flange 25a, the attractive force of the exciting coil 24 acts on the armature inner 28 to the maximum. For this reason, even if a force acts in the direction in which the pinion 6 comes out of the ring gear 23, the rightward movement of the clutch outer 18 is blocked via the shifter member 37, and the pinion 6 is prevented from coming out of the ring gear 23. .

  When the engine is started and the ignition switch is turned off, the energization to the exciting coil 24 is stopped and the attractive force disappears. Then, the pinion 6 moves rightward and is detached from the ring gear 23 by the urging force of the return spring 21 against the clutch outer 18 and the urging force of the return spring 35 against the armature outer 27. Along with this, the movable contact connected to the armature outer 27 also moves and moves away from the fixed contact. Thereby, the power supply to the electric motor 3 is stopped, the rotary shaft 10 is stopped, and the engine starter 1 returns to a stationary state.

It goes without saying that the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the invention.
For example, in the above-described embodiment, the engine starting device is shown in which the pinion 6 attached to the output shaft 4 is engaged with the ring gear 23 to start the engine. However, an idle shaft is provided in parallel with the output shaft 4 and Furthermore, the present invention is also applicable to an engine starter with an idle gear in which an idle gear that is movable in the axial direction while meshing with the pinion 6 is provided, and this idle gear is meshed with the ring gear of the engine.

It is sectional drawing which shows the structure of the engine starting apparatus which is one Example of this invention, the upper side from the centerline has shown the stationary state, and the lower side has shown the energized state. It is a disassembled perspective view which shows the structure of the speed reducer in the engine starting apparatus of FIG. It is explanatory drawing which shows the gear arrangement | positioning of the reduction gear of the engine starting apparatus of FIG. It is explanatory drawing which shows the structure of a sun gear vicinity. (A) shows the formation method of a flat part, (b) has shown the state which attached the sun gear and the thrust control ring to the gear mounting part and the flat part, respectively. It is sectional drawing which shows the structure of the conventional engine starter. It is explanatory drawing which shows the structure of the sun gear vicinity at the time of forming a sun gear separately from a motor rotating shaft.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Engine starter 2 Reduction gear 3 Electric motor 4 Output shaft 5 Overrunning clutch 6 Pinion 7 Electromagnetic device 10 Rotating shaft 10a Output shaft support portion 11 Bottom plate 11a Sealing fitting portion 12 Top plate 13 Sun gear 14 Planetary gear 15 Internal gear 16 Gear support plate 17 Gear cover 17a Sealing fitting portion 18 Clutch outer 18a Coupling portion 19 Helical spline 20 Plate 21 Return spring 22 Clutch inner 23 Ring gear 24 Exciting coil 25 Holder 25a Flange 26 Ring disk 27 Armature outer 27a Flange 28 Armature inner 30 Stopper 31 Commutator portion 31a Recess 35 Return spring 36 Coil spring 37 Shifter member 38 Separator 38a Cylindrical portion 38b Sealing fitting portion 39 Yoke 0 through bolt 50 gear mounting portion 51 serration 52 shaft hole 53 serration 55 sagging R unit (heading sagging portion)
56 Shaft body 62 Gear end surface 71 Thrust restricting ring 71a Right end surface 71b Left end surface 72 Flat portion 73 Ring contact surface 74 Shaft hole 75 Right end portion 76 Incomplete serration portion
101 engine starter
102 Pinion
103 Ring gear
104 Electromagnetic devices
105 Output shaft
106 Overrunning clutch
107 Reduction gear
108 motor
109 Rotation axis
111 Sungear
112 Planetary gear
113 Gear support plate
114 cases
115 Top plate
116 Internal ring gear
117 Separator
118 York
119 Serration
121 Serration G Clearance X Thrust restriction position

Claims (2)

A pinion that is rotationally driven by an electric motor and meshes with an engine ring gear by moving in an axial direction;
An engine starter comprising a reduction gear interposed between the electric motor and the pinion and decelerating and transmitting the rotation of the electric motor to the pinion by a planetary gear mechanism;
The planetary gear mechanism is formed separately from the rotating shaft of the electric motor, and has a sun gear attached to the outer periphery of the rotating shaft,
The rotating shaft is provided adjacent to the gear mounting portion, the gear mounting portion having a serration to which the sun gear is mounted and meshing with a serration formed in a shaft hole of the sun gear, and the serration of the gear mounting portion. A thrust restricting member mounting portion including a portion obtained by cutting and removing the forging sag portion generated when forming the forging,
The engine starting device according to claim 1, wherein a thrust restricting member that contacts the sun gear and restricts movement of the sun gear in the axial direction is attached to the thrust restricting member mounting portion.   2. The engine starter according to claim 1, wherein the thrust restricting member is attached to the rotary shaft so as to cover an end portion of a serration formed on the rotary shaft.

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