Engine starting system for a motorcycle

Field of the invention

The present invention relates to "Engine starting system for a motorcycle" and more particularly a means to eliminate the noise and vibration associated with the said system.

Description of the prior art

An engine starter for a vehicle is equipped with a starter motor; a gear group
structured from a plurality of gears, which transmits the rotation of the starter
motor to a crankshaft and clutch means provided between the starter motor
and the crankshaft, which permits the transmission of rotation from the starter
motor to the crankshaft but prevents the transmission of rotation from the
crankshaft to the starter motor.

The engine starter includes an electric motor, an output shaft, a pinion gear mounted on the output shaft, and an idler gear that is constantly meshed with a pinion gear, further, a starter gear having gear teeth engaged with those of said idler gear and a one way clutch mounted in continuous engagement with the starter gear to engage and disengage the transmission with the crank shaft.

The starter gear is mounted on crankshaft, away from the crankshaft main bearing that is being fitted on the crankcase provided with a boss to house the bearing. An axial clearance for starter gear is maintained between magneto rotor and the boss of the main bearing housing of the crankcase. A plurality of pillars is provided on crankcase projecting beyond the bearing housing boss to arrest the movement of starter gear and control the float. Occasional rubbing of starter gear due to float, the pillars on crankcase wear out over a period. This wear out of the pillars on crankcase creates a space causing excessive float of starter gear in axial direction. Further, this movement of starter gear in axial direction results in increased vibration and noise associated with starting mechanism of engine.

An object of the present invention is to prevent the movement of starter gear and to reduce the noise associated with starting of an internal combustion engine.

Brief description of the invention

An object of this invention is therefore to provide a starter for an internal combustion engine including a rotation transmitting mechanism for transmitting the rotation of an input portion to a crank shaft where the said rotation transmitting mechanism comprises a supporting shaft, a gear set, composed of an input gear and an output gear, said input gear and said output gear being integrally-fitted to each other and being mounted on said supporting shaft, a starter gear that permits the transmission of rotation form the output gear to the crankshaft through an one-way clutch. The said supporting shaft is characterized by a stopper, which is provided on said supporting shaft and sandwiched between output gear and boss of the crankcase to make the starter gear immovable in the axial direction. The said stopper is a thin spring steel plate located on the said supporting shaft. The tip of the stopper plate rests on the tip of the starter gear arresting its movement and controlling the float even in the case of wear out of crank case pillars.

The said stopper plate is rhombus in shape, and further, edges are bent on one side to make the stopper plate immovable on the supporting shaft and provide better grip over the supporting shaft.

The said stopper plate is bent on another edge slightly, and this bent rests on the tip of the starter gear to make starter gear immovable in the axial direction even in the case of wear out of crank case pillars.

Brief description of the drawings

The present invention will become more fully understood from the detailed
description given herein below and the accompanying drawings which are
given by way of illustration only, and thus are not limitative of the present
invention, and wherein:

FIG. 1 illustrates the cross sectional view of engine showing crankshaft assembly, electric starter system, gear shifting system & kick starting system excluding cylinder block & cylinder head;

FIG. 2 illustrates an enlarged cross sectional view showing electric starting
system;

FIG. 3 illustrates the perspective view of stopper starter gear;

FIG. 4 illustrates the perspective view of stopper starter gear;

FIG. 5 illustrates the perspective view of stopper starter gear;

FIG. 6 illustrates the front view of stopper starter gear;

FIG. 7 illustrates the side view of stopper starter gear;

The foregoing objects and other objects and advantages of the present invention will become apparent from the following description.

Detailed description of the invention

A selected illustrative embodiment of the present invention will be now described with respect to the accompanying figures.

Figure 1 and Figure 2 illustrates a single-cylinder four-stroke internal combustion engine that is started by a starter motor, with its crankshaft extending in the lateral axis motorcycle. The engine is divided into right and left parts with respect to the longitudinal centre plane of the vehicle, and a multi-stage gear transmission and a multi-disk friction clutch that are integrally assembled in the crank case.

An engine starter includes a starting motor 15, and a gear train that transmits torque from the motor 15 to a crankshaft assembly 8 of the engine mounted on left 10 and right main 6 bearings.

The starter motor includes an electric motor 15, an output shaft, a pinion gear 18 mounted on the output shaft, and an idler gear 16 that is constantly meshed with a pinion gear 18, further, a starter gear 14 having gear teeth engaged with those of said idler gear 16 and a one way clutch 38 mounted in continuous engagement with the starter gear 14 to engage and disengage the transmission of torque with the crank shaft 46.

The starter gear 14 is mounted on crankshaft, away from the crankshaft main bearing, which is fitted on the crankcase 44 provided with a boss to house the bearing. An axial clearance for starter gear 14 is maintained between magneto rotor 34 and the boss of the main bearing housing of the crankcase 44. A plurality of pillars is provided on crankcase 44 projecting beyond the bearing housing boss to arrest the movement of starter gear 14 and control the float. Occasional rubbing of starter gear due to float, the pillars 12 on crankcase 44 wear out over a period. This wear out of the pillars 12 on crankcase creates a space causing excessive float of starter gear 14 in axial direction. Further, this movement of starter gear 14 in axial direction results in increased vibration and noise associated with starting mechanism of engine. Accordingly, the present invention provides a starter for an internal combustion engine includes a rotation transmitting mechanism for transmitting the rotation of an input portion to a crank shaft 46, wherein said rotation transmitting mechanism comprises a supporting shaft 22, a gear set composed of an input gear and an output gear 16, said input gear and said output gear 16 being integrally-fitted to each other and being mounted on said supporting shaft 22, a starter gear 14 which permits the transmission of rotation form the output gear 16 to the crankshaft 46 through one-way clutch 38, and the said supporting shaft 22 is characterized by a stopper 24, which is provided on said supporting shaft 22 and sandwiched between output gear 16 and boss of the crankcase 44 to make the starter gear 14 immovable in the axial direction.

Figure 3, Figure 4 and Figure 5 illustrate different perspective views of stopper for starter gear.

The said stopper 24 is a thin spring steel plate located on the said supporting shaft 22. The tip of the stopper plate rests on the tip of the starter gear arresting its movement and controlling the float even in the case of wear out of crank case pillars.

The starter for an internal combustion engine, said stopper plate 24 having
rhombus shape is bent at one end having a split at middle portion not exceeding the bent area, to locate between the ribs provided above the boss locating the supporting shaft 22.
The said stopper plate 24 is bent at another end slightly, and this bent rests on the tip of the starter gear 14 to make starter gear immovable in the axial direction even in the case of wear out of crank case pillars 12.

It is obvious that the present invention is not limited within the preferred embodiment described above, but includes all the modifications within the scope and spirit of the invention.

Claims

We claim

1. A starter for an internal combustion engine includes a rotation transmitting
mechanism for transmitting the rotation of an input portion to a crank shaft,

wherein said rotation transmitting mechanism comprising:

a supporting shaft;

a gear set composed of an input gear and an output gear, said input gear and

said output gear being integrally-fitted to each other and being mounted on
said supporting shaft;

a starter gear that permits the transmission of rotation from the output gear to the crankshaft through one-way clutch, and the said supporting shaft is characterized by a stopper, which is provided on said supporting shaft and sandwiched between output gear and boss of the crankcase to make the starter gear immovable in the axial direction.

2. The starter for an internal combustion engine according to claim 1, wherein said stopper is a thin spring steel plate located on said supporting shaft.

3. The starter for an internal combustion engine according to claim 1, wherein said stopper plate is rhombus in shape.

4. The starter for an internal combustion engine according to claim 1, wherein said stopper plate having rhombus shape is bent at one end having a split at middle not exceeding the bent area, to locate between ribs provided above the boss locating the supporting shaft.

5. The starter for an internal combustion engine according to claim 1, wherein said stopper plate is slightly bent at another end and rests on the starter gear to make the starter gear immovable in axial direction even in the case of wear out of crank case pillars.