Hydrostatic continuously variable transmission for motorcycle has communication groove formed between valve spool and spool hole for moving valve spool between two positions and connected to outside of spool hole via main discharge oil path

摘要

A communication groove between the outer periphery of a valve spool and a spool hole enables the valve spool to move between a clutch release position, wherein the clutch ports are connected, and a clutch engagement position wherein the valve spool covers the high-pressure clutch port. The communication groove is connected to the outside of the spool through a main discharge oil path in the valve spool. The hydrostatic continuously variable transmission (CVT) includes the valve spool in the spool hole formed in a support shaft (6) that rotatably holds a hydraulic pump (P) and a hydraulic motor (M). The support shaft includes a high-pressure clutch oil path and a low-pressure clutch oil path respectively connected to the high-pressure oil path and low-pressure oil path of a hydraulic closed circuit. Both clutch oil paths are provided with the corresponding clutch ports opened to the spool hole. An independent claim is also included for an internally dampened hydrostatic continuously variable transmission clutch valve.