GB1564739A

GB1564739A - Starter with a shock absorbing arrangement

Info

Publication number: GB1564739A
Application number: GB5029376A
Authority: GB
Original assignee: NipponDenso Co Ltd
Current assignee: Denso Corp
Priority date: 1975-12-03
Filing date: 1976-12-02
Publication date: 1980-04-10
Also published as: JPS5274931U; JPS5615404Y2; DE2654987A1; DE2654987C2; FR2333974B1; FR2333974A1

Description

(54) A STARTER WITH A SHOCK ABSORBING ARRANGEMENT (71) We, NIPPONDENSO CO., LIMITED, a corporation organised under the laws of Japan, of 1-1, Showa-cho, Kariya-shi, Aichi-ken, Japan, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- This invention relates to a shock absorbing arrangement of a starter for an internal combustion engine.

One of conventional starters for an internal combustion engine comprises a pinion shaft driven by an armature gear through reduction gears. In this type of starter, when the pinion engages with a flywheel gear of an engine while the starter motor is running at high speed, the reduction gears and the pinion shaft may be broken by the shock caused by the abrupt engagement or clash.

It is an object of the present invention to obviate such inconvenience as above mentioned.

It is a further object of the present invention to provide a simple shock absorbing arrangement between an armature shaft of a starter motor and a pinion shaft thereof. This simple shock absorbing arrangement is attained by providing a torque transmitting connection which may slip when a torque larger than a predetermined value is transmitted.

According to this invention there is provided a starter with a shock absorbing arrangement for an internal combustion engine comprising an electric motor having an armature shaft, a pinion and a torque transmitting mechanism interposed between the armature shaft and said pinion, wherein the shock absorbing arrangement comprises: an input member composed of a part of the torque transmitting mechanism to receive the driving torque of electric motor, and an output member composed of another part of the transmitting mechanism to transmit the driving torque to the pinion, the said parts being directly fitted to each other with a shrink fit, such that when a driving torque applied to the input member exceeds a predetermined value the input and output members slip relative to one another.

A drawing shows a partial cross sectional view of a starter according to the present invention.

In the attached drawing, an internal gear 1 has a pinion shaft 2 forced thereinto to transmit driving torque to an engine. The connection of the internal gear 1 and the pinion shaft 2 is made so that when the torque greater than a predetermined value arises the portion A between the internal gear 1 and the pinion shaft 2 may slip thereby to form a shock absorbing arrangement.

In this shock absorbing arrangement the internal gear corresponds to an input member and the pinion shaft corresponds to an output member.

The pinion shaft 2 drives the pinion 5 through a helical spline 5a and an over running clutch 5b to slide thereon. This pinion shaft 2 is carried by a center bearing member 7 and a starter housing 6.

An armature gear 3 transmits driving torque from a starter motor 8 to the internal gear 1, reducing the speed.

The armature 8a of the starter motor 8 is carried by a ball bearing 4 disposed in the center bearing member 7, which is disposed between the starter motor 8 and the housing 6. A lever 9 is connected between the pinion 5 and a solenoid switch 11 to make the - pinion 5 slide in response to the operation of the solenoid switch. Numeral 10 is a pinion stop collar disposed at an outer end of the pinion 5. A thrust washer 12 is provided to adjust axial clearance of the pinion shaft 2.

On the portion designated by A mentioned above solid lubricating material such as molybdenum sulphide may be coated, to facilitate long stability of shock absorbing function.

In operation, when the solenoid switch 11 is energized to pull in the lever 9 to make the pinion 5 slide on the pinion shaft 2 and, at the same time the starter motor 8 runs at a low speed, the pinion 5 engages with a flywheel or ring gear of an internal combustion engine which is not shown.

The main switch of the solenoid switch 11 is, then, closed so that the starter motor 8 runs at a high speed. The driving torque of the starter motor 8 is transmitted, through the armature gear 3, internal gear 1 and pinion shaft 2 to the pinion 5 thereby to crank up an internal combustion engine.

In the engaging operation of the pinion 5 with the fly wheel gear and in the engine starting with the high speed running of the starter motor, abnormally large shocks of driving torque often appear.

When those shocks appear the pinion shaft and the internal gear slip relatively to each other to absorb such shocks.

The degree of shock absorbing effect is changed by adjusting the clearance between the pinion shaft 2 and the internal gear by way of shrink fitting.

In the above embodiment, the shock absorbing arrangement is provided between the pinion shaft 2 and the internal gear, however, it may be disposed any portion between the armature shaft and the pinion shaft in the drive mechanism. Such places are shown, for example, as B, C, D or E in the drawing.

WHAT WE CLAIM IS: 1. A starter with a shock absorbing arrangement for an internal combustion engine including an electric motor having an armature shaft, a pinion and a torque transmitting mechanism interposed between the armature shaft and said pinion, wherein the shock absorbing arrangement comprises: an input member composed of a part of the torque transmitting mechanism to receive the driving torque of the electric motor, and an output member composed of another part of the transmitting mechanism to transmit the driving torque to the pinion, the parts being directly fitted to each other with a shrink fit such that when a driving torque applied to the input member exceeds a predetermined value, the input and output members slip relative to one another.

2. A starter according to Claim 1 wherein at least one member engages the other member at a surface treated with a friction reducing material.

3. A starter according to Claim 2 wherein the said friction reducing material is molybdenum sulphide.

4. A starter according to any preceding Claim when interengagement of the two members is accomplished at position B, C, D or E as shown in the accompanying drawing.

5. A starter constructed and arranged substantially as hereinbefore described with reference to and as shown in the accompanying drawing.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. is energized to pull in the lever 9 to make the pinion 5 slide on the pinion shaft 2 and, at the same time the starter motor 8 runs at a low speed, the pinion 5 engages with a flywheel or ring gear of an internal combustion engine which is not shown. The main switch of the solenoid switch 11 is, then, closed so that the starter motor 8 runs at a high speed. The driving torque of the starter motor 8 is transmitted, through the armature gear 3, internal gear 1 and pinion shaft 2 to the pinion 5 thereby to crank up an internal combustion engine. In the engaging operation of the pinion 5 with the fly wheel gear and in the engine starting with the high speed running of the starter motor, abnormally large shocks of driving torque often appear. When those shocks appear the pinion shaft and the internal gear slip relatively to each other to absorb such shocks. The degree of shock absorbing effect is changed by adjusting the clearance between the pinion shaft 2 and the internal gear by way of shrink fitting. In the above embodiment, the shock absorbing arrangement is provided between the pinion shaft 2 and the internal gear, however, it may be disposed any portion between the armature shaft and the pinion shaft in the drive mechanism. Such places are shown, for example, as B, C, D or E in the drawing. WHAT WE CLAIM IS:

1. A starter with a shock absorbing arrangement for an internal combustion engine including an electric motor having an armature shaft, a pinion and a torque transmitting mechanism interposed between the armature shaft and said pinion, wherein the shock absorbing arrangement comprises: an input member composed of a part of the torque transmitting mechanism to receive the driving torque of the electric motor, and an output member composed of another part of the transmitting mechanism to transmit the driving torque to the pinion, the parts being directly fitted to each other with a shrink fit such that when a driving torque applied to the input member exceeds a predetermined value, the input and output members slip relative to one another.