Patent Application
20080305904
The present invention generally relates to alternators of motor vehicles, and more particularly to a transmission wheel of the alternator capable of absorbing the jitter of engine ignition.
The electrical system of a motor vehicle is mainly powered by a battery and the battery is charged by the alternator of the motor vehicle. The rotor of the alternator is belt-driven via a transmission wheel as shown in
The foregoing design has a number of disadvantages. First, when the engine is ignited, some inevitable jitter is transmitted to the sleeve 80 via the transmission shaft 83. The jitter would cause the sleeve 80 and the belt 90 to turn in a reversed direction before the sleeve 80 spins in a forward direction steadily, and some negative charge is thereby produced. Even though it is a small twist, the operational life span of the belt and the alternator would be adversely affected by the jitter and the negative charge. In addition, as the vibration of the engine is directly transmitted to the transmission wheel 80 and the belt 90 during ignition and running, a louder noise is thereby produced.
The primary purpose of the present invention is to provide a novel transmission wheel which is capable of absorbing the jitter during engine ignition.
To absorb the jitter, the present invention provides a cushion ring between the transmission shaft and the sleeve. The cushion ring has a number of centripetal teeth, thereby forming a number of chambers around the cushion ring. Inside each chamber, there is a slope section slanting towards an adjacent first tooth, and there is a spring element pressing a ball (or cylinder) against the slope section and an adjacent tooth. The diameter of the ball or cylinder is such that it stands on the slope section to be slightly beyond the teeth and contacts an outside surface of the transmission shaft.
As such, when the engine is ignited and a jitter causes the transmission shaft to turn in a reversed direction, the balls and cylinders are rolled towards the spring elements. As the rotational force is absorbed by the spring elements, the cushion ring and the sleeve will not spin in the reversed direction.
The foregoing objectives and summary provide only a brief introduction to the present invention. To fully appreciate these and other objects of the present invention as well as the invention itself, all of which will become apparent to those skilled in the art, the following detailed description of the invention and the claims should be read in conjunction with the accompanying drawings. Throughout the specification and drawings identical reference numerals refer to identical or similar parts.
Many other advantages and features of the present invention will become manifest to those versed in the art upon making reference to the detailed description and the accompanying sheets of drawings in which a preferred structural embodiment incorporating the principles of the present invention is shown by way of illustrative example.
The following descriptions are exemplary embodiments only, and are not intended to limit the scope, applicability or configuration of the invention in any way. Rather, the following description provides a convenient illustration for implementing exemplary embodiments of the invention. Various changes to the described embodiments may be made in the function and arrangement of the elements described without departing from the scope of the invention as set forth in the appended claims.
As shown in
The cushion ring 30 has a number of centripetal teeth 31 extending into an inner space 300 of the cushion ring 30, thereby forming a number of chambers 32 around the cushion ring 30 and partitioning an inner surface of the cushion ring 30 into a number of segments 34. As more clearly shown in
Inside each chamber 32, there is a spring element 50 whose one end is attached to an adjacent second tooth 31 and whose other end presses a ball (or cylinder) 40 against the slope section 33 and the first tooth 31. Please note that the diameter of the ball or cylinder 40 is such that it stands on the slope section 33 to be slightly beyond the teeth 31 into the inner space 300.
The cushion ring 30 is sandwiched between two washers 21 and 21a. The cushion ring 30 and the washers 21, 21a are then further sandwiched between two bearings 20 and 20a. The washers 21, 21a and the bearings 20, 20a are also accommodated in the center opening 11 of the sleeve 10.
A transmission shaft 60 is threaded through the bearings 20, 20a, and the washers 21, 21a, and the cushion ring 30. The diameter of the transmission shaft 60 is such that its outside surface 61 a contacts the balls or cylinders 40.
Please note that all balls or cylinders 40 are positioned such that they are pressed by the spring elements 50 in the sleeve 80's normal spinning direction (i.e., the direction that the transmission shaft 60 is turned). Therefore, when the transmission shaft 60 turns, the balls or cylinders 40 are rolled towards the first teeth 31, and the cushion ring 30 and the sleeve 80 are turned in the same direction accordingly.
As shown in
An additional advantage of the present invention is that, as at least a portion of the vibration from the engine and the transmission shaft 60 is absorbed by the spring elements 50, a less amount of noise would be produced.
It will be understood that each of the elements described above, or two or more together may also find a useful application in other types of methods differing from the type described above.
While certain novel features of this invention have been shown and described and are pointed out in the annexed claim, it is not intended to be limited to the details above, since it will be understood that various omissions, modifications, substitutions and changes in the forms and details of the device illustrated and in its operation can be made by those skilled in the art without departing in any way from the spirit of the present invention.
| Number | Date | Country | Kind |
|---|---|---|---|
| 096209386 | Jun 2007 | TW | national |
