| 摘要 |
<p>The present invention relates to a piston of a hydraulic motor or pump. According to an embodiment of the present invention, the piston of a hydraulic motor has a tapered shape on both ends of a piston body to reduce friction loss while driving at high pressures and high speeds, and a spiral screw groove on an outer circumference of the piston body to improve a lubricating action while driving at high pressures and low speeds. In other word, in accordance to an embodiment of the present invention, the piston of a hydraulic motor stably drives at low speeds as well as at high speeds, and prevents abnormal life-shortening of the piston and a rotary cylinder unit.</p> |
