| 摘要 |
<p>An infinitely variable transmission in which the pitches of a driving pulley (7) and a driven pulley (8) are variable by means of hydraulic fluid pressure to va ry the velocity ratio between the two pulleys. A lower pressure fluid and a higher pressure fluid are created from a hydraulic fluid from a hydraulic fluid supply source (68), with a constant pressure difference therebetween. The lower pressure fluid has its pressure value varied in response to the velocity ratio. The lower pressure fluid and the higher pressure fluid are selectively supplied to the movable pulley elements (23,32) of the driving pulley and driven pulley. A hv draulic clutch (4) and a pressure regulating valve (166) are connected together by a hydraulic fluid supply passageway (124) which is selectively closed and opened by a suppl y control valve (167). A drain passage (183) is connected t o the hydraulic fluid supply passageway to a(low hydraulic fluid to escape from the hydraulic clutch, when the passageway is closed by the supply control valve. In, at least one maovable pulley element, an orifice (333, 358) is formed through a sealing element (327, 352) which, seats between an inmer peripheral surface (22c', 32c1 of a cylindrical portion (2.2c, 32c) and a radially extending annular flange (23b, 33b) of a stationary piston element (23, 33) to communicate between first and second hydraulic pressure chambers (24,35,25,36) defined within an annular space (s, s') in a pulley main body (22b,32b) at opposite sides of the annular flange of the stationary piston element.</p> |
