This Non-provisional Application claims priority under U.S.C. ยง 119(a) on Patent Application No(s). 094128354, filed in Taiwan, Republic of China on Aug. 19, 2005, the entire contents of which are hereby incorporated by reference.
The invention relates to a method for producing a dynamic bearing, and in particular to a method for forming grooves on a plate, and following the plate being rolled into a cylindrical bearing.
In general, a dynamic bearing for supporting a shaft of a motor provides several miniature grooves formed on an inner wall thereof for receiving oil. When the shaft is rotated, oil received in the grooves spreads over the surface of the shaft by attraction force to form a dynamic pressure to support the shaft at the center of the dynamic bearing. Thus, friction between the shaft and the inner wall of the bearing and noise can be reduced and reliability of the motor can be increased.
However, forming grooves with desired width and depth on the inner wall of the bearing is not easily controlled. Some methods, such as tooling, rolling, plastic injection molding, erosion, assembling and coating with post-manufacturing, require high skill and precision and cost more than traditional methods, particularly when trade secrets are involved.
The invention provides a method for producing a dynamic bearing without using above described particular tools and machines so as to reduce manufacturing costs.
The invention provides a dynamic bearing manufacturing method including steps as follow. A plate is provided and a plurality of grooves is formed on a surface of the plate. The plate formed with grooves is rolled into a hollow cylinder. The grooves are located on the inner surface of the hollow cylinder, and thus the cost of the manufacturing process can be reduced.
The plate prepared for the bearing is characterized by a predetermined size, circumferential length and axial hole. The plate is preferably made of flexible materials such as copper, metal or plastic. If the plate is made of metal, the grooves can be formed by a tool slitting the surface thereof, or the grooves can be pressed by a punch machine. If the plate is made of plastic, the grooves of the plate can be formed by injection molding.
The dynamic bearing is usually disposed within an axial hole of a sleeve. On the other hand, a sleeve can be formed by a plurality of separable parts, and thus the dynamic bearing can be enclosed by the assembled parts.
The invention can be more fully understood by reading the subsequent detailed description and examples with references made to the accompanying drawings, wherein:
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The feature of the invention is that the grooves are pre-formed on the surface of the plate, and then the plate formed with the grooves is rolled into a hollow cylinder, i.e., a dynamic bearing. As the result, no particular tools machines are required, and cost can be reduced. Additionally, it is to be understood that the shape of the plate 1 is not limited to the above-disclosed embodiments. In a preferred embodiment, the plate can be formed into the shape shown in
While this invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.
Number | Date | Country | Kind |
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94128354 | Aug 2005 | TW | national |