JPH0347431B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a starter that rotates a ring gear of an engine to perform cranking when starting the engine, and more particularly relates to a starter that rotates a ring gear of an engine to perform cranking when starting the engine. This relates to the combination of the running clutch and pinion.

As a combination of a starter overrunning clutch and a pinion, the outer or inner cylindrical part of the clutch and the pinion are integrated (that is, gear teeth are cut on the outer periphery of the outer end of the cylindrical part). The outer or inner cylindrical part of the clutch and the pinion are processed separately and both are serrated (or splined).
There is a known type that is slidably connected in the axial direction. The present invention belongs to the latter type.

In the type to which the present invention pertains, the pinion has an axially outer portion formed with gear teeth and a serration that is always in mesh with a serration provided on the inner surface of the inner or outer cylindrical portion of the clutch. The cylindrical portion has an axially inner portion provided with interlocking serrations, and an intermediate portion located between the inner portion and the outer portion and having a smaller diameter than the inner portion. A circumferential groove is formed on the inner circumferential surface, and a circlip having elasticity that tends to expand radially outward is forcibly installed (pushed) into this groove and engages with the inner portion of the pinion. It is designed to prevent the pinion from slipping out.

In this type of combination, in order to make it possible to attach the circlip, the overall length of the pinion becomes longer and the outer or inner cylindrical shape of the clutch increases, for reasons that will be explained later with reference to the attached drawings. The outer diameter of the starter has become larger, which is the key to making the starter smaller and lighter.

In the latter type of combination, the present invention provides that a second circumferential groove is formed between the inner portion and the intermediate portion of the pinion, and that the bottom surface of the second groove and the cylinder The dimension between the inner circumferential surface of the cylindrical portion and the radial thickness of the circlip is greater than the radial thickness of the circlip, and the dimension between the inner circumferential surface of the cylindrical portion and the outer circumferential surface of the intermediate portion of the pinion is greater than the radial thickness of the circlip. By making the thickness smaller than the thickness, it is intended to contribute to making the starter smaller and lighter.

Next, an embodiment of the present invention will be described with reference to FIGS. 1 and 2.

Reference numeral 1 designates an overrunning clutch for an engine starter, which includes an outer 2 having a cylindrical portion 2a spline-coupled to an armature shaft (not shown), and an inner 3 rotatably and axially slidably mounted on the armature shaft. and a roller 4 disposed between the outer 2 and the inner 3. 5 is a housing.

The inner 3 has a cylindrical part 6 that protrudes axially opposite to the outer 2, and a serration 7 is formed on the inner circumferential surface of the cylindrical part, and an axially outer end of the inner circumferential surface. a first circumferential groove 8 at a position close to
(See Figure 2) is formed.

A pinion 10 is rotatably and axially slidably mounted on an armature shaft (not shown), and includes an axially outer portion 11 formed with gear teeth capable of meshing with a ring gear of an engine (not shown), and a cylindrical pinion. an axially inner part 12 provided with serrations that are constantly engaged with the serrations 7 of the section 6; It has an intermediate portion 13. A second circumferential groove 14 is formed between the inner part 12 and the intermediate part 13, and this groove 1
4 and said inner portion 12 an axially outwardly directed shoulder is formed. A circlip 15 having elasticity that tends to expand outward in the radial direction (spring back) is forcibly attached to the first circumferential groove 8 provided on the inner circumferential surface of the cylindrical portion 6. When the pinion 10 is pushed axially outward from the cylindrical part 6 by the pinion spring 16, it engages with the shoulder and prevents the pinion 10 from coming off from the cylindrical part 6.

In the above configuration, when the not-shown magnetic switch is activated, the overrunning clutch 1 is pushed to the left together with the pinion 10 by the not-shown drive spring, and the pinion 10 hits the ring gear. . When the pinion and the ring gear are in tooth-to-tooth contact, the drive spring and the pinion spring 16
The pinion 10 bends, the contact of the magnetic switch closes, the armature rotates, and the teeth of the pinion 10 come between the teeth of the ring gear.The pinion 10 moves forward quickly under the action of the pinion spring 16, and the pinion and ring gear meshing occurs, the ring gear rotates, and engine cranking begins.

The present invention allows the circlip 15 to be inserted into the first circumferential groove 8 without using a jig. The dimension between the bottom surface and the inner circumferential surface of the cylindrical portion 6, that is, the inner circumferential surface of the serration 7, is larger than the thickness of the circlip 15 in the radial direction.
The dimensional relationship of the related parts is determined so that the dimension between the outer circumferential surface of the intermediate portion 13 and the outer peripheral surface of the circlip 13 is smaller than the thickness of the circlip 15 in the radial direction.

In the present invention, the dimensional relationship of each part is determined as described above, so when assembling, the circlip 15 is first placed over the second circumferential groove 14 of the pinion 10. Since the inner diameter of the circlip in the free state is larger than the outer diameter of the inner portion 12 of the pinion 10, the inner diameter of the inner portion 12 of the pinion 10 is
All you have to do is insert the . Next, after inserting the pinion spring 16 into the cylindrical portion 6, the circlip is compressed radially inward to form the second circumferential groove 14.
2, push the pinion 10 in the direction shown by the arrow in FIG.
2 to overrunning clutch 1 inner 3
(In this case, insert so that the serrations of both sides are engaged with each other). When the inner part 12 of the pinion is inserted into the cylindrical part 6 in this way, the inner peripheral surface of the cylindrical part 6 and the pinion 1
Since the dimension between the bottom surface of the second circumferential groove 14 on the zero side and the radial thickness of the circlip 15 is larger than the radial thickness of the circlip 15, if the circlip is sufficiently compressed inward in the radial direction, the circlip will be The position of the circlip pushed rightward by the left side wall of the second circumferential groove 14 into the shaft hole of the cylindrical portion 6 (see FIG. 2), and thus pushed rightward. When the circlip coincides with the first circumferential groove 8 of the cylindrical portion 6, the circlip expands radially outward due to its own elasticity and fits into the first circumferential groove 8. At this time, the inner portion 12 of the pinion 10 and the second
The shoulder between the circumferential groove 14 and the circlip 1
5 to prevent the pinion 10 from coming out of the cylindrical portion 6.

3 and 4 are diagrams showing the structure of a conventional clutch. In the case of the conventional clutch shown in FIG. In order to be able to arrange tool A between the cylindrical portion 6a and the gear toothed outer portion 11a of the pinion 10a, the axial dimension of the intermediate portion 13a of the pinion 10a had to be large. . Further, as shown in FIG. 4, if the outer diameter of the gear-toothed outer portion 11b of the pinion 10b and the outer diameter of the intermediate portion 13b are made the same, the outer peripheral surface of the intermediate portion 13b and the overrunning clutch 1b Since it is necessary to leave enough space between the inner peripheral surface of the cylindrical part 6b and the circlip insertion jig A to insert the circlip insertion jig A, it is necessary to increase the outer diameter of the cylindrical part 6b of the clutch 1b. Ta. In this way, in the past, since it was necessary to use jig A for inserting the circlip,
It has been necessary to use a pinion 10a having a long intermediate portion 13a and an overrunning clutch 1b having a cylindrical portion 6b having a large outer diameter, which has been the key to reducing the size and weight of the starter. When fitting, the dimensional relationships of the related parts are set as described above, so when inserting the axially inner portion 12 of the pinion 10 into the overrunning clutch 1 and preventing it from coming off with the circlip 15, it is necessary to Since the use of a jig is not required at all, the axial dimension of the intermediate portion 13 of the pinion 10 does not become too long, and the outer diameter of the cylindrical portion 6 of the overrunning clutch 1 does not become too large. It is clear that this greatly contributes to making the starter smaller and lighter.

In the illustrated embodiment, the pinion 10 is connected to the cylindrical portion 6 of the overrunning clutch 1, but the pinion 10 is spline connected to an armature (not shown) of the cylindrical portion 6, and the pinion 10 is connected to the cylindrical portion 2a of the outer 2 by spline connection.
It is obvious to those skilled in the art that 0 may be combined.

[Brief explanation of drawings]

FIG. 1 is a partially side and partially axial sectional view of a combination of an overrunning clutch and pinion embodying the present invention. FIG. 2 is an enlarged sectional view of the main part of FIG. 1, showing the insertion of a circlip. FIGS. 3 and 4 are sectional views similar to FIG. 2, but show the conventional structure and circlip insertion jig. DESCRIPTION OF SYMBOLS 1... Overrunning clutch, 2... Same outer, 3... Same inner, 6... Cylindrical part, 7... Serration, 8... First circumferential groove, 10... Pinion, 11... Coaxial direction outer part, 12 ...coaxial inner portion, 13... coaxial middle portion, 14... second circumferential groove, 15... circlip.

Claims (1)

[Claims] 1 An overrunning clutch rotationally driven by an armature, and a pinion connected to an inner or outer cylindrical portion of the clutch so as to be slidable in the axial direction via a serration, the pinion having gear teeth formed therein. an axially outer part provided with a serration provided on the inner surface of the cylindrical part, an axially inner part provided with a serration that is always fitted with a serration provided on the inner surface of the cylindrical part, and between the outer part and the inner part. a first circumferential groove is formed in the inner circumferential surface of the cylindrical part, and a first circumferential groove is formed in the groove, and a first circumferential groove is formed in the inner circumferential surface of the cylindrical part. In a combination of an overrunning clutch for an engine starter and a pinion, a circlip having elasticity that tends to expand is forcibly attached to prevent the pinion from coming out of the cylindrical portion. A second circumferential groove is formed between the inner portion and the intermediate portion, and the dimension between the bottom surface of the second circumferential groove and the inner circumferential surface of the cylindrical portion is The thickness of the circlip in the radial direction is larger than that of the circlip, and the dimension between the inner circumferential surface of the cylindrical portion and the outer circumferential surface of the intermediate portion of the pinion is smaller than the radial thickness of the circlip. A combination of an overrunning clutch and pinion for engine starters featuring: