JP2789915B2 - Planetary gear reducer and coaxial starter using the reducer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a planetary gear reducer and a coaxial starter using the planetary gear reducer, and particularly to a planetary gear reducer suitable for starting an internal combustion engine and the planetary gear reducer. It relates to a coaxial starter.

[0002]

The internal gear of a conventional planetary gear reduction device, for example, JP 61-101668, mechanical gears inside the metallic material of the cylindrical shape, as is in the 60-149559 Patent Gazette Sho What has been processed into is generally known. Alternatively, there is also known a product in which a substantially cup-shaped internal gear is integrally formed by casting of resin or aluminum.

[0003]

The above prior art does not consider the possibility of reducing the thickness of the gear rim of the gear portion of the internal gear and the ease of assembling the planetary gear reduction device. When the gear rim thickness of the internal gear is reduced in order to make the reduction gear light and compact, the rigidity of the gear rim of the internal gear is reduced. The sun gear, the planetary gear, and the internal gear are meshed with each other. However, there is a problem that the insertability of the planetary gear into the rotating shaft is poor.

[0004] It is an object of the present invention to provide a planetary gear reduction device capable of extracting the function of the internal gear even if the gear rim thickness of the internal gear constituting the planetary gear reduction device is reduced.

Another object of the present invention is to provide a starter using a lightweight and highly rigid planetary gear reduction device.

[0006]

SUMMARY OF THE INVENTION The object of the present invention is to form a cup-shaped internal gear constituting a speed reducer from a metal member, and to project an annular thick portion from an outer peripheral edge on the side opposite to the opening in the axial direction. <br/> achieved by forming.

Another object of the present invention is to form a mounting flange at the opening end of an internal gear made of a metal member that can be cold-formed, and to form an annular thick portion on the outer peripheral edge opposite to the opening in the axial direction. Protruded into
This can be achieved by forming.

[0008]

The ring-shaped thick portion at the opposite end of the substantially cup-shaped internal gear having an opening on one side receives the bending load even if a tooth base bending load is applied to the gear portion of the internal gear. Therefore, the rigidity of the rim portion increases even if the gear rim thickness is small. Also,
Even when the planetary gear tries to push the internal gear in the outer peripheral direction, the planetary gear receives a bending load in cooperation with the flange of the opening and suppresses deformation during rolling.

The R-shape of the end of the gear portion of the internal gear is such that when the sun gear, the planetary gear, and the internal gear are meshed with each other and the planetary gear is inserted into the rotation shaft from the axial direction, the R portion is formed. It is easily inserted as a planetary gear insertion guide.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.
This will be described with reference to FIG.

The planetary gear reduction device 1 includes a sun gear 2a at the tip of an input shaft 2, an internal gear 4 which is a fixed gear concentric with the sun gear 2a, and meshes with the sun gear 2a and the internal gear 4. A plurality of planetary gears 3 that are rotatably supported on the rotating shaft 5 via a planet bearing 3a, a planetary arm 6 to which the rotating shaft 5 is fixed, and an output shaft 6a integrated with the planetary arm 6
A bracket 4b for rotatably supporting the output shaft 6a via an output-side bearing 4a; and a shaft 4b for restricting axial movement of the planetary gear 3 and rotatably supporting the input shaft 2 via an input-side bearing 7a. A center cover 7 is provided. The internal gear 4 and the bracket 4b are formed in a substantially cup shape with one opening integrally formed. The flange 8 provided at the opening end of the substantially cup shape is held between the front case 11 and the motor 12 to reduce the planetary gear. The device 1 is fixed inside the starter. At the end of the gear portion 4c on the inner periphery of the internal gear 4, an R shape 9 serving as a guide when the planetary gear 3 is inserted into the rotation shaft 5 while being engaged with the gear portion 4c is provided. Here, the above-mentioned internal gear 4 is made of a sheet metal material that can be cold forged as a material. By pressing this, the cylindrical body with the bottom and the flange is rotated together with the mandrel type, and is perpendicular to the rotation axis from the external direction. A roller is pressed against the outer periphery of the side of the cylindrical body, and the cylindrical body is plastically deformed along the mandrel-type tooth form. At this time, a part of the raw material flows to the outer peripheral edge due to the plastic deformation pressure, and an annular projection is formed.

When power is input from the input shaft 2 which is the tip of the output shaft of the motor, the planetary gear 3 revolves around the orbital circle 10 concentric with the sun gear 2 while rotating around the rotation shaft 5. Thus, the power is reduced and output from the planetary arm 6 to the output shaft 6a.

FIG. 3 is a diagram in which the planetary gear reduction device 1 is used as a coaxial starter for starting an internal combustion engine.

The substantially cup-shaped end opposite to the opening is described in detail.
As shown in FIG. 6, the outer peripheral edge is annular and protrudes in the axial direction.
The thick portion 4d is used to reinforce the gear portion 4c as described later. A ring-shaped cushioning member 13 made of a rubber member or the like is arranged and fixed between the flange 8 and the thick portion 4d to absorb and attenuate noise or vibration generated by the planetary gear 3. The planetary arm 6 is stolen except for a necessary portion for fixing the rotation shaft 5.

The center cover 7 is fixed to the inner periphery of the motor 12, and the cover of the motor 12 and the motor 1 are fixed.
It is also used for fixing the second field pole 12a. Further, the center cover 7 is provided with a groove 7b for retaining grease sealed in the planetary gear reduction device 1 to improve the sliding lubrication of the planetary gear 3. Of course, if the center cover 7 is formed of resin, the groove 7b can be easily manufactured.

According to the present embodiment, since the annular thick portion 4d which protrudes in the axial direction is provided at the outer peripheral edge of the substantially cup-shaped side opposite to the opening having one opening, the teeth loaded on the gear portion 4c are provided. The same reinforcing effect as increasing the gear rim thickness with respect to the original bending load is obtained, and the gear rim thickness can be reduced by 30 to 50%. The thick portion 4d also has a reinforcing effect against the load of the planetary gear 3 pushing the internal gear 4 in the outer peripheral direction.

FIG. 4 is a finite element method analysis model diagram in which the internal gear 4 of this embodiment is divided into two parts in the axial direction and three parts in the circumferential direction. However, the thick part 4d protrudes in the radial direction for convenience.
It has been analyzed by replacing it with the one provided.

FIG. 5 shows an example of a result of strain analysis from the point A to the point E on the outer peripheral surface of the internal gear 4 by applying a tangential load F to the gear portion 4c in the analysis model of FIG.

The horizontal axis in FIG. 5 indicates the extraction points from the point A to the point E on the outer peripheral surface of the internal gear 4, and the vertical axis indicates the distortion in the circumferential direction. A broken line a is an analysis result in the case where the thick portion 4d is not provided, and a solid line b is an analysis result in the case of the present embodiment in which the thick portion 4d is provided.

According to this result, the distortion at point C, which corresponds to the midpoint of the axial length of the internal gear 4 of this embodiment, can be reduced by 9% by providing the thick portion 4d, and the gear rim thickness can be reduced. Can be reduced. In addition, since the round shape 9 is provided at the end of the gear portion 4c, the gear of the planetary gear 3 and the gear portion 4c of the internal gear 4 can mesh with each other while being wrapped in the axial direction. There is an advantage that the planetary gear 3 can be easily inserted from the axial direction.

Further, the internal gear 4 and the bracket 4b are integrally formed in a substantially cup shape, and a flange 8 provided at an opening side end of the substantially cup shape is provided with a front case 11 and a motor 12
And the planetary gear reduction device 1 is fixed inside the starter, so that the cover on the output shaft 6a side and the fixing bracket of the planetary gear reduction device 1 are unnecessary, and the number of components can be reduced.

Further, since the ring-shaped buffer member 13 is provided between the flange 8 and the thick portion 4d, noise or vibration generated by the planetary gear 3 can be attenuated. Further, the cushioning member 13 does not fall off or shift.

Further, since the planetary arm 6 is stolen except for a necessary portion for fixing the rotation shaft 5, the weight of the apparatus can be reduced.

Further, since the center cover 7 is also used for fixing the cover of the motor 12 and the field poles 12a of the motor 12, the number of components can be reduced.

Further, since the center cover 7 is provided with the groove 7b for retaining grease, depletion and outflow of grease are suppressed, and sliding lubrication of the planetary gear 3 is improved.

FIG. 6 shows an example of the present embodiment in which the thick portion 4d at the end opposite to the opening on the opposite side of the substantially cup shape having one opening is projected in the axial direction.
It shows details .

FIG. 7 shows a second embodiment in which the thick portion 4d at the opposite end of the substantially cup-shaped opening with one opening protrudes in the inner circumferential direction, and has the same functions and functions as those of the first embodiment. Has an effect.

FIG. 8 shows a fourth embodiment in which the substantially cup-shaped bracket 4b is arranged on the input shaft 2 side and the center cover 7 is arranged on the output shaft 6a side, and has the same functions and functions as those of the first embodiment. Has an effect.

[0029]

According to the present invention, an axially protruding portion is formed on the outer peripheral edge of the opposite end of the substantially cup-shaped opening on one side.
By providing such a thick portion, it is possible to provide a planetary gear reduction device that can bring out the function of the internal gear even if the gear rim thickness of the internal gear constituting the planetary gear reduction device is reduced.

According to the present invention, the same reinforcing effect as increasing the thickness of the gear rim can be obtained with respect to the root bending load applied to the gear portion of the internal gear, and the thinner gear rim is lighter and more rigid. A coaxial starter using a planetary gear reduction device can be provided.

[Brief description of the drawings]

FIG. 1 is a sectional view of a planetary gear reduction device according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line II of FIG. 1;

FIG. 3 is a partial sectional view of a coaxial starter using the planetary gear reduction device of the present invention.

FIG. 4 is a finite element method analysis model diagram in which an internal gear of a coaxial starter using the planetary gear reduction device of the present invention is divided into two parts in an axial direction and three parts in a circumferential direction.

FIG. 5 is a graph showing a result of strain analysis by a finite element method of an internal gear of a coaxial starter using the planetary gear reduction device of the present invention.

FIG. 6 is a partial sectional view of an internal gear according to a second embodiment of the present invention.

FIG. 7 is a partial sectional view of an internal gear according to a third embodiment of the present invention.

FIG. 8 is a sectional view of a planetary gear reduction device according to a fourth embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Planetary gear reduction device, 2 ... Input shaft, 2a ... Sun gear,
3 planetary gears, 3a planetary bearings, 4 internal gears, 4a
Output side bearing, 4b: bracket, 4c: gear part 4d: thick part, 5: rotating shaft, 6: planetary arm, 6a: output shaft, 7: center cover, 7a: input side bearing, 8: flange, 9 ... R shape,
10: orbital circle, 11: front case, 12: motor, 12a: field pole, 13: buffer member, A to E: extraction point, F: tangential load, a to b: analysis result.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A 63-79473 (JP, U) JP-A 2-136562 (JP, U) JP-A 61-107976 (JP, U) JP-A 2-107 28577 (JP, U) Fully open sho 60-149559 (JP, U) Fully open sho 55-4305 (JP, U) Fully open sho 56-120359 (JP, U) Fully open sho 61-107977 (JP, U) Japanese Utility Model 1-152068 (JP, U) Japanese Utility Model 61-138867 (JP, U) Japanese Utility Model 60-118375 (JP, U) Japanese Utility Model 1-141371 (JP, U) Japanese Utility Model 4-69671 (JP, U) (58) Field surveyed (Int. Cl. ⁶ , DB name) F02N 15/02 F02N 11/00 F16H 1/28-1/48

Claims (2)

(57) [Claims] 1. A sun gear serving as an input shaft, a substantially cup-shaped internal gear having a gear portion concentric with the sun gear and having one end opened, and meshed between the sun gear and the internal gear. A plurality of planetary gears, and a planetary arm that holds a rotation shaft that rotatably supports the planetary gears and that rotates integrally with the output shaft, wherein the internal gear is made of a metal member. A planetary gear speed reducer, wherein an annular thick portion protrudes in the axial direction at an outer peripheral edge on the side opposite to the opening. 2. A sun gear driven by an electric motor and serving as an input shaft; a substantially cup-shaped internal gear having a gear portion concentric with the sun gear and having one end opened; an sun gear and the internal gear; A starter using a speed reducer including a plurality of planetary gears meshed therebetween, and a planetary arm that holds a rotation shaft that rotatably supports the planetary gears and that rotates integrally with an output shaft, The internal gear is formed of a metal member that can be cold-formed, forms a mounting flange at an opening end thereof, and forms an annular thick portion at an outer peripheral edge opposite to the opening so as to protrude in the axial direction. A coaxial starter using a planetary gear reduction device.