JPH02125965A - Coaxial form starter device - Google Patents

Abstract

PURPOSE:To prevent effectively the breakage of an output rotary shaft, by forming the shaft portion of the output rotary shaft of the above device which covers a shaft portion from a helical spline portion to a portion supported with a bearing put into an armature rotary shaft, by making it thick. CONSTITUTION:A DC motor 11 has a york 11d whose combined use is the frame of a device, and a tubular armature rotary shaft 11a arranged on its center axis, and an armature core 11d is fixed at the outer perimeter of the rotary shaft 11a under pressure insertion. And an output rotary shaft 12 is arranged on the same axis with the rotary shaft 11a on one end side of the axis direction of the motor 11, and the one end side of this output rotary shaft 12 is inserted into the inner passage 11c of the armature rotary shaft 11a, and supported slidably in a shaft direction through a bearing 13. In this instance, the shaft portion 12b of the output rotary shaft 12 between the position of the bearing 13 and a helical spline portion 12a meshing with the clutch inner 15b of a one way clutch device 15, is formed so thickly as to come into contact with the inner perimeter surface of the armature rotary shaft 11a.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a coaxial starter device, and more particularly to a coaxial starter device used for starting a vehicle.

[Conventional technology]

Conventionally, this type of coaxial starter device was developed in U.S. Pat.
It is well known as disclosed in Japanese Utility Model No. 474 (Utility Application No. 166198/1988). As shown in FIG. 2, this conventional coaxial starter device 1 has a hollow armature rotating shaft 3 of a DC motor 2, and an electromagnetic switch device (not shown) disposed at the rear end of the DC motor 2. The plunger rod is passed through the internal passage 3a of the armature rotating shaft 3 and inserted into the internal passage 3a of the armature rotating shaft 3 in the output rotating shaft 4 coaxially disposed at the front end of the armature rotating shaft 3. It is configured to be able to push the output rotation shaft 4 forward by coming into contact with the end surface of the rear end portion.

To further explain the specific configuration of such a coaxial starter device, the front end side of the output rotating shaft 4 (towards the right in Fig. 2)
is equipped with a pinion 5 that meshes with the ring gear of the engine, and its rear end is inserted into the internal passage 3a of the armature rotating shaft 3, and the insertion shaft part 4a is a sleeve that is fitted and fixed to the inner circumference of the internal passage 3a. It is supported by a hair ring 6 and allows the output rotating shaft 4 to slide in the axial direction. As a means for transmitting the driving force from the armature rotating shaft 3 of the DC motor 2 to the output rotating shaft 4 that can slide in the axial direction, a driving force transmitting device 8 including an overrunning flanch device (one-way clutch device) 7 is used. It is configured.

That is, this driving force transmission device 8 includes a sun gear 9a and a planetary gear 9 formed around the front end of the armature rotating shaft 3.
b, a clutch outer 7a to which a center support shaft 9C of the planetary gear 9b is fixed, and a helical spline portion 4C created on the outer periphery of the enlarged diameter portion 4b formed on the output rotation shaft 4. The one-way latch device W7 is provided with the clutch inner 7b having a helical spline groove formed on the inner circumferential surface to engage with the one-way latch W7.

[Problem to be solved by the invention]

In the conventional coaxial starter device I configured as described above, when the output rotating shaft 4 slides and the pinion 5 meshes with the ring gear of the engine, the stress at the time of meshing is absorbed by the helical spline portion 4C and the sleeve. It will be received by bearing 6. However, the maximum bending moment position of the output rotating shaft 4 is at the rear step P of the enlarged diameter portion 4b forming the helical spline portion 4C, and therefore the stress applied to this step P becomes significantly large. There was a possibility of breakage occurring.

The purpose of the present invention was to solve the problems encountered in the conventional coaxial type starter device. The purpose is to prevent breakage near the maximum bending moment position.

[Failure to solve the problem]

The coaxial Stark device of the present invention includes an electric motor having a tubular armature rotation shaft, a pinion disposed on the front end side of the electric motor, which engages and disengages from a ring gear of an engine at one end, and whose other end is connected to the armature rotation shaft. an output rotation shaft slidable in the axial direction inserted into an internal passage; a one-way clutch device configured to transmit rotation of the armature rotation shaft to the output rotation shaft; A helical spline portion that engages with a helical spline groove provided on the inner periphery of the clutch inner of the one-way clutch device, and a helical spline portion that engages with the inner periphery of the armature rotation shaft located inside the yoke of the electric motor and the output rotation shaft. between a bearing supporting the armature rotating shaft and an inner circumferential surface of the armature rotating shaft that is a shaft portion of the output rotating shaft inserted into the internal passage of the armature rotating shaft from the helical spline portion to the position of the bearing. The shaft is thick enough to leave a small clearance between the shaft and the shaft.

[For production]

In the coaxial starter device of the present invention, the shaft is thickened from the helical spline part of the output rotating shaft to the bearing arrangement part of the shaft inserted into the armature rotating shaft to the extent that it touches the inner peripheral surface of the tubular armature rotating shaft. Because of this, it can sufficiently resist the stress exerted on the output rotating shaft when the pinion and ring gear mesh, and therefore, the output rotating shaft is less likely to break near the maximum bending moment position.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the coaxial starter device of the present invention will be described in more detail with reference to embodiments shown in the accompanying drawings.

FIG. 1 shows a coaxial starter device 10 according to an embodiment of the present invention. The coaxial starter device 10 of this embodiment includes a DC electric motor I'll having a yoke lid which also serves as a machine frame of the device, and a tubular armature rotating shaft Za disposed on the central axis of the yoke lid. Tubular armature rotating shaft 11
An armature core llb is press-fitted and fixed to the outer periphery of a.

At one end of the DC motor 11 in the axial direction (on the right side in FIG. 1), there is an output rotating shaft 12 on the same axis as the armature rotating shaft 11a.
is located. This output rotating shaft 12 has one end side (rear side) inserted into the internal passage 11C of the armature rotating wheel 11a, and the armature rotating shaft 11a located inside the yoke lid.
It is supported so as to be slidable in the axial direction via a sleeve bearing 13 fitted to the inner peripheral portion of the shaft.

The rotational force of the armature rotating wheel 11a is transmitted to the output rotating shaft 12 through a planetary gear reduction device 14 and a one-way clutch device 15.
This is done via a driving force transmission device 16 consisting of. Zunawaji, the planetary gear reduction device 14 is provided between a sun gear 14a integrally formed on the outer periphery of one end of the armature rotating shaft 11a, and a front bracket 17, which is the machine frame of the starter device 10, and a yoke lid. The internal gear 14b, the sun gear 14a, and the internal gear 1 formed on the sandwiched bracket 18
4b and is fixed to a carrier 14C that is integral with the collage outer 15a of the one-way clutch device 15.
It is composed of a plurality of planetary gears 14e rotatably supported by.

In addition, the clutch inner 15b of the one-way clutch device 15
The helical spline groove 15c formed on the inner peripheral surface of the output rotating shaft 12 meshes with the helical spline portion 12a formed on the outer peripheral surface of the enlarged diameter portion of the output rotating shaft 12.
can slide in the axial direction while receiving rotational force from the clutch inner 15b.

A pinion 19 that meshes with the ring gear of the engine is attached to the end of the output rotating shaft 12 that projects from the front plugget 17.

Further, the carrier 14C in the planetary gear reduction gear 14 has a bearing 20 fitted on its inner circumference, and the bearing 20 is attached to the armature rotation shaft 11a at the front end adjacent to the sun gear 14a formed on the armature rotation shaft 11a. It is supported by 'ζ by being attached to a small diameter stepped portion lie formed on the outer periphery of 11a. Thereby, the radial movement of the carrier 14c is completely restricted by the bearing 20, so there is no room for eccentricity. In addition, one-way clutch device 1
A bearing 22 is fitted onto the outer periphery of an integral cylindrical portion 21 extending from the clutch inner 15b of No. 5 toward the pinion side (in the axial direction), and the bearing 22 is held by the placket 18. A bearing 23 is fitted onto the inner peripheral surface of the cylindrical portion 21, and supports the output rotation shaft 12 by the bearing 23.

By the way, the bearing 1 supporting the output rotating shaft 12 at the rear
3 is fitted on the inner circumference of the armature rotating shaft 11a located inside the yoke lid of the DC motor 11 as described above, but the more accurate position is between the armature core Ilb and the sun gear 14a. It is. The reason why the bearing 13 is removed from the position of the armature core llb and placed in front (to the right in FIG. 1) is that in this position, the armature core 1
1b can be attached without being affected by internal deformation that may occur when press-fitting the armature rotating shaft 11a. The position of the bearing 13 and the helical spline portion 12a are heated to such an extent that the shaft portion 12b of the output rotating shaft 12 comes into contact with the inner peripheral surface of the armature rotating ring 11a. Therefore, the portion of the output rotating shaft 12 from the rear end of the helical spline portion 12a to the portion passing through the position of the sun gear 14a formed at the end of the armature rotating shaft 11a becomes a taillight. A slight clearance 24 is formed between the outer circumferential surface of the shaft portion 12b of the armature and the inner circumferential surface of the armature rotating shaft 11a.

On the other hand, an electromagnetic switch device (not shown) is provided at the other end of the DC motor 11 (on the left side in FIG. 1). The function of this electromagnetic switch device is activated when the key switch of the vehicle is turned on, and the rod 25 is moved by the movement of the plunger due to the electromagnetic force.
5 pushes out the output rotating shaft 12, causing the pinion 19 to mesh with the engine ring gear, and at the same time turning on the power to the DC electric motor @11.

Next, regarding the operation of the starter device according to the above embodiment,
Explain briefly.

When the starter switch of the vehicle is closed, the excitation coil of the electromagnetic switch device is energized, and the electromagnetic force generated by this excitation causes the rod 25 to move in the axial direction as seen in FIG. As a result, the output rotating shaft 12 is pushed out, and the pinion 19 provided at the end thereof meshes with the ring gear of the engine. At the same time, as the plunger moves, the movable contact and the fixed contact (both not shown) come into contact to turn on the power to the DC motor 11 and operate the DC motor 4111. As a result, the armature rotating wheel 11a
The rotational force is reduced by the planetary gear reduction device 14 and transmitted to the clutch outer 15a of the one-way clutch device 15, and the rotation of the clutch outer 15a is transmitted to the clutch inner 15b via the cylindrical roller. The rotation of this clutch inner 15b is controlled by helical splines 12a and 15c.
is transmitted to the output rotating shaft 12, thereby rotating the pinion 19 and starting the engine. After the start of release, the one-way clutch device 15 prevents reverse drive.

In the operation of such a coaxial starter device IO, the shaft portion from the rear end of the helical spline portion 12a of the output rotating shaft 12 to the portion supported by the bearing 13 fitted to the inner peripheral surface of the armature rotating ring 11a. Since the pinion 12b is closed, even if the stress applied to the output rotating shaft 12 when the pinion 19 and the ring gear mesh is applied near the maximum bending moment position, it can be sufficiently resisted.

〔Effect of the invention〕

As explained above, according to the coaxial starter device of the present invention, the shaft portion of the output rotating shaft from the helical spline portion to the portion supported by the bearing fitted in the armature rotating shaft is heated. By doing so, even if the stress applied to the output rotating shaft when the binion and ring gear mesh is applied near the maximum bending moment position, it can be sufficiently counteracted, and breakage at that part can be prevented. . In addition, since the shaft portion of the output rotating shaft located near the end of the armature rotating shaft is exposed and there is only a small clearance around it, grease does not flow out or the armature It is also possible to prevent dust, wear particles, etc. from entering the rotating shaft.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing the main parts of a coaxial starter device according to an embodiment of the present invention, and FIG. 2 is a sectional view showing the main parts of a conventional coaxial starter device. IO... Coaxial starter device, 11... DC motor, 11a... Armature rotating shaft, IIC... Internal passage,
12... Output rotating shaft, 12a... Helical spline part, 12b... Shaft part of the sleeve, 13... Bearing, 1
5... One-way clutch device, 19... Pinion, 2
4...Minor clearance. Note that the same reference numerals in each figure indicate the same or equivalent parts.

Claims (1)

[Claims] An electric motor having a tubular armature rotating shaft, and a pinion disposed at the front end side of the electric motor and engaging and disengaging with a ring gear of an engine at one end, and the other end is inserted into an internal passage of the armature rotating shaft in an axial direction. a slidable output rotating wheel; a one-way clutch device that transmits the rotation of the armature rotating shaft to the output rotating shaft; and an inner periphery of a clutch inner of the one-way clutch device formed on the outer periphery of the output rotating shaft. a helical spline portion that meshes with a helical spline groove provided in the armature; a bearing that is fitted into an inner peripheral portion of the armature rotating shaft located inside the yoke of the electric motor and supports the output rotating shaft; A shaft portion of the output rotating shaft that is inserted into the internal passage of the rotating shaft, and is thick enough to leave a minute clearance between the helical spline portion and the inner circumferential surface of the armature rotating shaft from the helical spline portion to the position of the bearing. A coaxial starter device comprising a thick shaft portion.