JPH07119600A - Starter with planetary gear speed reducer - Google Patents

Abstract

PURPOSE:To realize absorption of shock with a simple structure so as to prevent operation error of a planetary gear speed reducer by allowing especially a projecting part and a recessed part disposed between an internal gear and a casing to be fitted each other. CONSTITUTION:An armature shaft 11 of a starter motor with a sun gear formed at its outer circumference is provided together with a drive shaft 4 having a large dia. part 11 pivotally mounting thereon a planetary gear 30 to be meshed with the sun gear 19 and being disposed coaxilly at one end of the shaft 11. An internal gear 44 is also provided which has an inner gear meshed with the gear 30 at its one end in the axial direction of the inner circumferential face while projected and recessed parts 7 fitted each other so as to turn freely with wear and disposed at the other end in the axial direction and the inner face of the casing facing a gear chamber. With such a constitution, shock transmitted to each part of planetry gear speed reduction mechanism through the inner gear face of the internal gear 44 form the fitting parts 7 is attenuated so as to prevent generation of various problems.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a starter with a planetary gear reduction mechanism for starting an internal combustion engine.

[0002]

2. Description of the Related Art In a starter equipped with a planetary gear speed reduction mechanism, the starter shock received as a reaction when the engine is driven increases as much as the torque is amplified. As a countermeasure against this, a shock absorbing structure is provided for a drive shaft for driving a pinion gear. And the armature shaft of the starter motor.

The internal gear of the planetary gear speed reduction mechanism is suitable for disposing this shock absorbing structure because it is normally fixed and used for the shock generated in the gear portion forming the speed reduction mechanism. Japanese Utility Model Unexamined Publication No. 62-158160 discloses that an outer peripheral surface of an internal gear and an inner peripheral surface of a casing adjacent to the inner gear are provided with concave and convex surfaces that are frictionally rotatably fitted to each other. This concavo-convex fitting type shock absorbing method has a simple structure, a small number of parts, and sufficient shock absorbing performance.

[0004]

However, in the above concave-convex fitting type, the concave-convex fitting portion is separated from the inner tooth surface of the internal gear meshing with the planetary gear by the thickness of the internal gear. It was found that the following problems are included because the uneven fitting portion is provided. First, the interface
This part of the null gear is heated by both the friction heat generated from the contact with the planetary gears and the friction heat generated from the concavo-convex fitting part, so the temperature becomes high and the strength of the internal gear, which is usually made of resin, deteriorates. Resulting in.

Further, radial thrust is frequently generated from the concavo-convex fitting portion, and the radial thrust causes uneven wear on the tooth surfaces and bearing surfaces of the planetary gear reduction mechanism, and abnormal noise.
This causes a problem such as a decrease in transmission efficiency. Also usually 1
Since the centering action of the three planetary gears arranged 20 degrees apart is disturbed, each of the above problems becomes more serious.

The present invention has been made in view of the above-mentioned problems, and a planetary gear speed reduction mechanism-type star capable of suppressing the above-described malfunction of the planetary gear speed reduction mechanism although shock absorption can be realized with a simple structure. -The purpose is to provide data.

[0007]

SUMMARY OF THE INVENTION A starter with a planetary gear speed reduction mechanism according to the present invention pivots an armature shaft of a starter motor having a sun gear formed on the outer periphery thereof and a planetary gear meshing with the sun gear. A drive shaft having a large diameter portion to be supported and coaxially arranged at one end of the armature shaft;
A cylindrical internal gear having inner teeth meshing with the planetary gear at one axial end of an inner peripheral surface; a casing having a gear chamber surrounding the sun gear, the planetary gear and the internal gear; It is characterized in that it is provided with an uneven fitting portion which is disposed on the other end portion in the axial direction of the null gear and on the inner surface of the casing facing the gear chamber and which is fitted to each other in a frictionally rotatable manner.

In a preferred embodiment, the internal gear is made of a resin body. In a preferred aspect, the concave-convex fitting portion includes a protrusion formed on the inner end surface of the casing and a concave-convex surface formed on the inner peripheral surface of the internal gear. In a preferred aspect, the concave-convex fitting portion is
It comprises a protrusion formed on the inner peripheral surface of the casing and an uneven surface formed on the outer peripheral surface of the internal gear.

In a preferred aspect, the concave-convex fitting portion is
It comprises a protrusion formed on the inner end surface of the casing and an uneven surface formed on the outer end surface of the internal gear.

[0010]

When a starter shock is generated due to a poor meshing between the ring gear and the pinion of the internal combustion engine, a large reaction torque is applied to the drive shaft due to the reaction, and the planetary gear pivotally supported on the drive shaft has the above reaction. The torque is transmitted to the starter motor through the sun gear.
It is transmitted to the mating shaft and to the concave-convex fitting portion through an internal gear.

The concavo-convex fitting portion arranged between the internal gear and the casing has a concavo-convex surface which meshes with each other.
In particular, when both convex portions get over each other, the impact energy is converted into friction energy and the shock is alleviated. Furthermore, the present invention is characterized in that the concave-convex fitting portion is arranged at a position axially separated from the inner tooth surface of the internal gear that meshes with the planetary gear.

According to this structure, first, the heat generated in the concave-convex fitting portion hardly acts on the area of the inner tooth surface of the internal gear, and the temperature of this portion of the internal gear is reduced, It is possible to prevent deterioration of the strength of the null gear and deterioration of the lubricating oil. Moreover, radial thrust (exciting force) and circumferential twisting force are inevitably generated at the concave-convex fitting part, but these impact forces cause the internal gear cylindrical part to bend or generate heat. Are absorbed, dissipated or neutralized, and as a result, the impact force transmitted from the concavo-convex fitting part to each part of the planetary gear reduction mechanism through the internal tooth surface of the internal gear is attenuated, and uneven wear of the tooth surface and bearing surface is caused. It is possible to prevent the occurrence of troubles such as generation of abnormal noise and deterioration of transmission efficiency.

As a result, it is possible to provide a starter with a planetary gear speed reduction mechanism that can realize a smooth operation of the planetary gear speed reduction mechanism even though shock absorption can be realized with a simple structure.

[0014]

【Example】

(Embodiment 1) FIG. 1 shows an embodiment of a starter with a planetary gear speed reduction mechanism according to the present invention. A starter motor 2 is fastened to the right end of the housing 1, and in the figure of the starter motor 2,
The magnet switch 3 is fastened to the housing 1 adjacent to the upper side.

The armature shaft 1 of the starter motor 2
1 has a right end portion axially supported by an end bracket (not shown) of the starter motor 2, and a small diameter portion 11 at a left end of an armature shaft (rotating shaft of the starter motor 1) 11.
A is supported by a bearing 4a in the right end recess of the drive shaft 4. Reference numeral 12 is a yoke of the starter motor 2. The left end portion of the armature shaft 11 has a large-diameter portion 11b having a sun gear 19 formed on the outer periphery and a large-diameter portion 11b.
The small diameter portion 11a further protruding from the above.

The drive shaft 4 extends leftward in the figure along the same axis as the armature shaft 11, and the left end portion thereof is connected to the housing 1 via a bearing 4b.
The right end is supported by a center case (casing in the present invention) 5 via a bearing 4c. A spline tube 60 is connected to the outer periphery of the central portion of the drive shaft 4 by a helical spline coupling.
Clutch outer 6 constituting one-way clutch 6 from 0
2, the roller 63, and the clutch inner 64, and is connected to the pinion 65. On the other hand, a shift lever 66 is pivotally supported on a swing support portion 15 provided in the housing 1, one end of the shift lever 66 engages with the outer circumference of the spline tube 6, and the other end of the shift lever 66 not shown. Is connected to a plunger (not shown) of the magnet switch 3.

Next, the planetary gear speed reduction mechanism will be described with reference to FIGS. 1 and 2. A flange-shaped large-diameter portion 43 is provided at the right end of the drive shaft 4, and the projecting portions of the plurality of pins 31 press-fitted into the through-holes of the large-diameter portion allow the planetary gears 30 to rotate via bearings. keeping. These planetary gears 30 mesh with the sun gear 19 on the smaller diameter side and the inner teeth 45 of the internal gear 44 on the larger diameter side.
Meshes with.

The internal gear 44 has internal teeth 4 on its inner peripheral surface.
It has a cylindrical shape with openings 5 at both ends and is arranged concentrically with the armature shaft 11. The above-mentioned center case (casing in the present invention) 5 has a substantially bottomed cylindrical shape whose outer periphery is fixed to the housing 1, and forms a gear chamber that accommodates the planetary gear reduction mechanism described above. As shown in FIG. 2, the center case 5 has a large diameter cylindrical portion 51.
And an end wall portion 52 extending radially inward from the left end of the large diameter cylindrical portion 51, and a small diameter cylindrical portion 53 extending axially from the inner end of the end wall portion 52. A shaft supporting bearing 4c is fitted, and the left end of the small diameter cylindrical portion 53 is locked by a ser clip 19 via a stress washer 18.

Next, the concave-convex fitting portion 7 which is a feature of the present invention will be described with reference to FIG. Internal gear 44
The left end portion of the is slightly protruded in the radial direction, and as shown in FIG. 3, the inner peripheral surface of the small diameter left end portion has irregularities of about 1 mm formed at an angular pitch of about 36 degrees. 70 is formed. The average radius of the uneven surface 70 is about 25.
mm, and the axial width is about 10 mm.

On the other hand, a projection 71 is axially projected from the end wall portion 52 of the center case 5 at a position where it is fitted to the uneven surface 70. The protrusions 71 have a short-axis columnar shape, and six protrusions 71 are arranged at equal intervals. The protrusion 71 has a radius of about 6 mm and an axial length of about 8 mm. The uneven surface 70 and the projection 71 described above form the uneven fitting portion 7 in the present embodiment.

Next, the operation of the above device will be described. When the magnet switch 3 is activated, the plunger 30 is attracted and the lever 66 swings clockwise, and the tip of the lever 66 advances the pinion 65 via the spline tube 60 and the one-way clutch 6. . Immediately before the pinion 65 collides with a ring gear (not shown), the contact of the magnet switch 3 is closed, a current flows through the starter motor 2, and the starter motor 2 is activated.

The rotation torque of the armature shaft 11 is
It is decelerated and transmitted to the internal combustion engine through the planetary gear 30, the drive shaft 4, the spline tube 60, the one-way clutch 6, the pinion 65, and the ring gear via the sun gear 19. At this time, the protrusion 71 is fitted in the concave portion of the uneven surface 70, so that the rotation of the internal gear 44 is blocked by the housing 1 through the center case 5.

Now, a starter shock is generated due to a poor meshing between a ring gear (not shown) and the pinion 65 (for example, overload such as re-dive into the ring gear while the pinion 65 is rotating). Then, the reaction torque reaches the drive shaft 4 and is transmitted from the planetary gear 30 pivotally supported by the drive shaft 4 to the sun gear 19 and the internal gear 44. Internal gear 4
If the reaction torque transmitted to No. 4 is large enough for the projection 71 of the concave-convex fitting portion 7 to get over the convex portion of the concave-convex surface 70, the internal gear 44 rotates, and the rotation of the internal gear 44 causes the rotation of the internal gear 44. , The shock is alleviated. Further, frictional heat is generated in the uneven fitting portion 7, and impact energy is converted into heat.

Here, the uneven surface 70 is formed by the internal gear 4
Since the inner teeth 45 are arranged at the right end of the left end of 4, the impact force (generated in the radial direction and the circumferential direction) when the projection 71 gets over the projection of the uneven surface 70 is made of this resin. Twisting, distortion of the cylindrical portion 44a of the internal gear 44,
The flexure absorbs well, and the impact force reaching the inner teeth 45 is mitigated.

Therefore, the internal teeth 4 of the internal gear 44 are
The above-mentioned shock transmitted from 5 to each part of the planetary gear 30 and the planetary gear reduction mechanism is reduced, and the defects (uneven wear of the tooth surface and the bearing surface, the generation of abnormal noise, the deterioration of the transmission efficiency, etc.) due to it are greatly reduced. It Further, the heat generated in the concave-convex fitting portion 7 does not act on the inner teeth 45 of the internal gear 44, and the temperature at the inner tooth surface of the internal gear 44 is lowered, so that the strength of the inner teeth 45 is deteriorated and the lubricating oil is deteriorated. Can be avoided.

As a result, although the shock absorption can be realized with a simple structure, the smooth operation of the planetary gear speed reduction mechanism can be realized. Hereinafter, a method of manufacturing the internal gear 44 and the center case 5, which are the main constituent elements of this embodiment, will be described. The internal gear 44 is formed by molding nylon, and the center case 5
Is formed by a deep drawing process and a multi-step pressing process of a carbon steel plate, and the protrusion 71 is formed at any of these processes.
Of course, the projection 71 may be replaced with an uneven surface that fits with the uneven surface 70.

(Embodiment 2) Another embodiment is shown in FIG. In this embodiment, a concavo-convex surface 70 is provided on the outer peripheral surface of the left end portion of the internal gear 44, and the protrusion 7 is formed on the inner peripheral surface of the center case 5.
1 is provided, and the same effect as that of the first embodiment can be obtained.

(Embodiment 3) Another embodiment is shown in FIG. In this embodiment, the uneven surface 7 is formed on the left end surface of the internal gear 44.
0 is provided and the projection 71 is provided on the inner end surface of the center case 5, and the same effect as that of the first embodiment can be obtained.

Further, in this embodiment, the projection 71 has the uneven surface 7.
The impact when riding over the convex portion of 0 results in thrust in the axial direction and torsional force in the circumferential direction, which is preferable because it does not promote eccentricity of each part of the planetary gear reduction mechanism. (Modification) In each of the above-described embodiments, the concave-convex fitting portion 7 is provided on the internal gear 44 and the center case 5, but it is composed of a member fixed to the internal gear 44 and a member fixed to the center case 5. It is also possible to configure the concave-convex fitting portion 7. (Modification) In each of the above-described embodiments, the uneven surface 70 is used as an interface.
Although the protrusion 71 is provided on the null gear 44 on the center case 5, the combination may be reversed.

[Brief description of drawings]

FIG. 1 is a partial sectional front view showing an embodiment of a starter with a planetary gear speed reduction mechanism according to the present invention.

FIG. 2 is an enlarged sectional view of a main part of FIG.

FIG. 3 is a cross-sectional view taken along the arrow X in FIG.

FIG. 4 is a partial cross-sectional view showing another embodiment.

FIG. 5 is a partial cross-sectional view showing another embodiment.

[Explanation of symbols]

2 is a starter motor, 4 is a drive shaft, 7 is a concave-convex fitting portion, 11 is an armature shaft, 19 is a sun gear,
4 is a drive shaft, 65 is a pinion, 30 is a planetary gear, 44 is an internal gear, 45 is an internal tooth of an internal gear, 5 is a center case (casing), 70 is an uneven surface of an uneven fitting portion, and 71 is uneven. Protrusion of fitting part.

Claims (5)

[Claims] 1. A starter motor having a sun gear formed on the outer periphery thereof.
Armature shaft, a drive shaft coaxially arranged at one end of the armature shaft, having a large diameter portion for pivotally supporting a planetary gear that meshes with the sun gear, and an inner shaft that meshes with the planetary gear. A cylindrical internal gear having teeth on one axial end of the inner peripheral surface, a casing having a gear chamber surrounding the sun gear, planetary gears and internal gear, and the other axial end of the internal gear. A planetary gear reduction mechanism-equipped star, which is provided on the inner surface of the casing facing the gear chamber, and which is fitted in a frictionally rotatable manner.
Ta. 2. A starter with a planetary gear speed reduction mechanism according to claim 1, wherein said internal gear is made of a resin body. 3. The planetary gear reduction mechanism according to claim 1, wherein the concave-convex fitting portion includes a protrusion formed on the inner end surface of the casing and a concave-convex surface formed on the inner peripheral surface of the internal gear. Starter with. 4. The planetary gear reduction mechanism according to claim 1, wherein the uneven fitting portion includes a protrusion formed on an inner peripheral surface of the casing and an uneven surface formed on an outer peripheral surface of the internal gear. Starter with. 5. The planetary gear reduction mechanism according to claim 1, wherein the concave-convex fitting portion comprises a protrusion formed on an inner end surface of the casing and a concave-convex surface formed on an outer end surface of the internal gear. Starter.