Title of Invention

A STARTER

Abstract

A starter includes a sun gear formed on an armature shaft, a plurality of planetary gears each disposed around the outer circumference of the sun gear so as to be meshed therewith and turning on its own axis while revolving around the sun gear, a planetary gear carrier interposed between the center shafts of the planetary gears and an output shaft while being fastened to the output shaft for transmitting the rotation of each planetary gear on its own axis to the output shaft, an internal gear member including an internal gear portion fastened on a bracket so as to be meshed with the planetary gears and a flange portion extending from the internal gear portion in a center direction, and a ball bearing interposed between the internal gear member and the planetary gear carrier.

Full Text

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a starter used for starting a vehicle and the like, and more particularly, to a starter having an internal speed reduction mechanism. 2. Description of the Related Art Fig. 3 is a side elevational view partly in cross section, showing a conventional starter shown in, for example, Japanese Unexamined Utility Model Application Publication No. 2526025 and the like. In Fig. 3, a starter 100 includes an armature 1. A sun gear 3 is formed on the armature shaft 2 of the armature 1. A plurality of planetary gears 4 are disposed around the outer circumference of the sun gear 3 so as to be meshed with the sun gear 3. Each of the planetary gears 4 has a planetary gear center shaft 5 at the center thereof. A needle bearing 6 is interposed between each planetary gear 4 and the planetary gear center shaft 5 thereof. Then, each planetary gear center shaft 5 pivotally supports each planetary gear 4. The respective planetary gear center shaft 5 are fastened to a planetary gear carrier 7. Then, the plurality of planetary gears 4 are supported by the planetary gear carrier 7 through the planetary gear center shafts 5. The planetary gear carrier 7 is fastened to an output shaft 8. On the other hand, an internal gear member 10 fixed on the inside of a front bracket 80 The internal gear member 10 includes an internal gear portion 10a to be meshed with the planetary gears 4 and a flange portion 10b extending from the internal gear portion 10a in a center direction. A needle bearing 12 is interposed between the flange portion 10b of the internal gear member 10 and the planetary gear carrier 7. When the armature 1 rotates, the sun gear 3 formed on the armature shaft 2 is rotated. The sun gear 3 rotates the planetary gears 4. Each planetary gear 4 turns on its own axis while revolving around the sun gear 3. The revolving motion of each planetary gear 4 around the sun gear 3 is transmitted to the output shaft 8 through the planetary gear center shaft 5 thereof. The sun gear 3, the planetary gears 4 and the planetary gear carrier 7 constitute an internal speed reduction mechanism. With this construction, the revolution of the armature 1 is transmitted to the output shaft 8 after it is greatly reduced. The output shaft 8 includes an over-running clutch 20 coupled therewith through helical spleens 8a and 21a. The output shaft 8 has a large diameter portion 8b at the rear end thereof as the armature 1 side. The over- running clutch 20 is composed of a clutch outer 21, which is coupled with the output shaft 8 through the helical splines 8a and 21a, and an clutch inner 22, which are coupled with the clutch outer 21 through a roller 23 and transmits rotation in one direction to a pinion 26 on and front end side. A helical spline is composed of the output shaft helical spline 8a, which is a convex portion extending spirally in an axis direction and formed on the output shaft 8, and the clutch outer helical spline 21a, which is a concave portion formed to the clutch outer 21 and engaged with the output shaft helical spline 8a. The over-running clutch 20 is advanced and retracted on the output shaft 8 by a shift lever 25. Then, the over-running clutch 20 advances and retracts and returns the pinion 26 disposed at the front end. Next, operation of the starter 100 will be described. Turning on a start switch of an engine of a vehicle and the like energizes the not shown exciting coil of an electromagnetic switch 110 and a not shown plunger is drawn and retracted inwardly so that the shift lever 25 is rotated counterclockwise in Fig. 3. Then, the over-running clutch 20 is moved forward. With this operation, the pinion 26 is meshed with the ring gear of the engine. Thereafter, the armature 1 rotates and the rotational force thereof is transmitted to the output shaft 8. The rotation of the armature 1 is further transmitted to the pinion 26 through the over-running clutch 20 so as to start the engine by rotating the ring gear thereof. When the engine starts, the engine rotating at high speed drives the pinion 26 in the same direction as the engine. However, the driving force is not transmitted to the armature by the existence of the over-running clutch 20. When the engine starts and the start switch is turned off, the plunger of the electromagnetic switch 110 is advanced and returned so as to rotate clockwise and return the shift lever 25. As a result, the over-running clutch 20 is retracted and returned. In the conventional starter constructed as described above, the needle bearing 12 is interposed between the internal gear member 10 and the planetary gear carrier 7 because it is less expensive. However, there is recently arisen a problem of durability of the needle bearing 12 because a large load is applied to the planetary gear carrier 7 due to the increase in size of the starter and a higher output therefrom. Further, while the characteristic of the needle bearing 12 is such that it is resistible to a radial load and irresistible to an axial load, a large axial load is applied to the output shaft 8 by the advancing motion and the retracting motion of the over running clutch 20 causing a problem of durability to the needle bearing 12 Furthermore, the needle bearing 12 is not hermetically sealed, whereby caused is a problem of leakage of grease sealed into the interior of the needle bearing 12 SUMMARY OF THE INVENTION An object of the present invention, which was made to solve the above problems, is to provide a starter having improved durability, a long life and high reliability A starter of the present invention includes a sun gear formed on an armature shaft, a plurality of planetary gears each disposed around the outer circumference of the sun gear so as to be meshed therewith and turning on its own axis while revolving around the sun gear, a planetary gear carrier interposed between the center shafts of the planetary gears and an output shaft while being fastened to the output shaft for transmitting the rotation of each planetary gear on its own axis to the output shaft, an internal gear member including an internal gear portion fastened on a bracket so as to be meshed with the planetary gears and a flange portion extending from the internal gear portion in a center direction and a ball bearing interposed between the internal gear member and the planetary gear carrier. Accordingly, the present invention provides a starter comprising: a sun gear formed on an armature shaft a plurality of planetary gears each disposed around the outer circumference of said sun gear so as to be meshed therewith and turning on its own axis while revolving around said sun gear; a planetary gear carrier interposed between the center shafts of said planetary gears and an output shaft while being fastened to said output shaft for transmitting the rotation of each planetary gear on its own axis to said output shaft; an internal gear member including an internal gear portion fastened on a bracket so as to be meshed with said planetary gears and a flange portion extending from said internal gear portion in a center direction; and a ball bearing interposed between said internal gear member and said planetary gear carrier. With reference to the accompanying drawings, in which Fig. 1 is a side elevational view, partly in cross section, showing a starter of the present invention; Fig. 2 is a sectional view showing an internal gear and a ball bearing; and Fig. 3 is a side elevational view, partly in cross section, showing a conventional starter. DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 Fig. 1 is a side elevational view, partly in cross section, showing a starter of the present invention. Fig. 2 is a sectional view showing an internal gear and a ball bearing. In Fig. 1, a starter 100 includes an armature 1. A sun gear 3 is formed on the armature shaft 2 of the armature 1. Four planetary gears 4 are disposed around the outer circumference of the sun gear 3 so as to be meshed with the sun gear 3. A reason why the four planetary gears 4 are disposed is to improve durability thereof. Each of the planetary gears 4 has a planetary gear center shaft 5 at the center thereof. A needle bearing 6 is interposed between each planetary gear 4 and the planetary gear center shaft 5 thereof. Then, each planetary gear center shaft 5 pivotally supports each planetary gear 4. The respective planetary gear center shafts 5 are fastened to a planetary gear carrier 7. Then, the plurality of planetary gears 4 are supported by the planetary gear carrier 7 through the planetary gear center shafts 5 The planetary gear carrier 7 is fastened to an output shaft 8. On the other hand, an internal gear member 10 is fixed on the inside of a front bracket 80 The internal gear member 10 includes an internal gear portion 10a to be meshed with the planetary gears 4 and a flange portion 10b extending from the internal gear portion 10a in a center direction. A ball bearing 15 is interposed between the flange portion 10b of the internal gear member 10 and the planetary gear carrier 7. As shown in Fig. 2, the ball bearing 15 is sealed with seals 15a on both the sides thereof in an axial direction. When the armature 1 rotates, the sun gear 3 formed on the armature shaft 2 is rotated. The sun gear 3 rotates the planetary gears 4. Each planetary gear 4 turns on its own axis while it revolves around the sun gear 3. The revolving motion of each planetary gear 4 around the sun gear 3 is transmitted to the output shaft 8 through the planetary gear center shaft 5 thereof. The sun gear 3 the planetary gears 4 and the planetary gear carrier 7 constitute a speed reduction mechanism. With this construction, the revolution of the armature 1 is transmitted to the output shaft 8 after it is greatly reduced. The output shaft 8 includes an overrunning clutch 20 coupled therewith through helical splines 8a and 21a. The output shaft 8 has a large diameter portion 8b at the rear end thereof as the armature 1 side. The over¬running clutch 20 is composed of a clutch outer 21, which is coupled with the output shaft 8 by the helical splines 8a and 21a, and an clutch inner 22, which is coupled with the clutch outer 21 through a roller 23 and transmits rotation in one direction to a pinion 26 at a front end. A helical spline is composed of the output shaft helical spline 8a, which is a convex portion extending spirally in the axis direction and formed on the output shaft 8 and the clutch outer helical spline 21a, which is a concave portion formed to the clutch outer 21 and engaged with the output shaft helical spline 8a. The over-running clutch 20 is advanced and retracted on the output shaft 8 by a shift lever 25. Then, the over-running clutch 20 advances and retracts the pinion 26 disposed at the front end. In the starter constructed as described above, the ball bearing 15 is interposed between the internal gear member 10 and the planetary gear carrier 7. The ball bearings 15 has such a characteristic that it is resistible To both a radial load and an axial load As a result the starter is excellent in durability and no problem is caused even if a large axial load is applied to the output shaft 8 by the advancing motion and the retracting motion of the over-running clutch 20 Further in the starter constructed as described above the ball bearings 15 is sealed on both the sides thereof in the axial direction Accordingly a problem of leakage of grease sealed in the interior of the bearing 15 can be solved. WE CLAIM 1. A starter comprising a sun gear formed on an armature shaft; a plurality of planetary gears each disposed around the outer circumference of said sun gear so as to be meshed therewith and turning on its own axis while revolving around said sun gear; a planetary gear carrier interposed between the center shafts of said planetary gears and an output shaft while being fastened to said output shaft for transmitting the rotation of each planetary gear on its own axis to said output shaft; an internal gear member including an internal gear portion fastened on a bracket so as to be meshed with said planetary gears and a flange portion extending from said internal gear portion in a center direction; and a ball bearing interposed between said internal gear member and said planetary gear carrier. 2. The starter as claimed in claim 1, wherein said ball bearing is sealed on both the sides in the axial direction thereof 3. The starter as claimed in claim 1, wherein four sets of said planetary gears are disposed. 4. A starter substantially as herein described with reference to figures 1 and 2 of the accompanying drawings.

Documents:

38-mas-2001 abstract duplicate.pdf

38-mas-2001 abstract.pdf

38-mas-2001 claims duplicate.pdf

38-mas-2001 claims.pdf

38-mas-2001 correspondence others.pdf

38-mas-2001 correspondence po.pdf

38-mas-2001 description (complete) -dup.pdf

38-mas-2001 description (complete).pdf

38-mas-2001 drawings duplicate.pdf

38-mas-2001 drawings.pdf

38-mas-2001 form-1.pdf

38-mas-2001 form-19.pdf

38-mas-2001 form-26.pdf

38-mas-2001 form-3.pdf

38-mas-2001 petition.pdf