초록 ▼

A control valve (80) of a hydraulic coupling (32) controls pumping from a casing inlet port (58) by a hydraulic pump (48) through a casing outlet port (78) to control coupling between two rotary members such as by operation of a clutch (68). The casing (34) is connected to one of the rotary members

A control valve (80) of a hydraulic coupling (32) controls pumping from a casing inlet port (58) by a hydraulic pump (48) through a casing outlet port (78) to control coupling between two rotary members such as by operation of a clutch (68). The casing (34) is connected to one of the rotary members while a pumping component embodied by an impeller (50) is connected to the other rotary member and meshed with an internal ring gear (54) having one more tooth than the number of impeller teeth to provide sufficient pumping capacity so that the pump can act as a brake while still having relatively constant pumping pressure. The control valve (80) includes an elongated valve element (82) mounted within a recess (98) to provide accurate control of its closure when the pumped hydraulic fluid reaches a predetermined pressure corresponding to a predetermined extent of relative rotation between the two drivetrain members. This elongated valve element (82) is made from a bimetallic strip so as to be temperature compensated and the outlet port (78) is provided with a main passage (94) as well as a bleed passage (96,96′) that is cleaned when the valve element is opened. One construction has a valve body defining both the main passages (94) and the bleed passage (96) of the port, while another construction has the valve body defining the main passage (94) and the valve element (82) defining the bleed passage (96′). Another construction has the recess (98) provided with an inclination extending from the port (78) and has a flat elongated valve element (82) that may be either straight or curved.

대표청구항 ▼

In a vehicle drivetrain including a pair of rotary members, a control valve for use in controlling rotative coupling of the pair of rotary members, comprising: a valve element; a port through which pressurized hydraulic fluid selectively flows to control the coupling of the pair of rotary members; t

In a vehicle drivetrain including a pair of rotary members, a control valve for use in controlling rotative coupling of the pair of rotary members, comprising: a valve element; a port through which pressurized hydraulic fluid selectively flows to control the coupling of the pair of rotary members; the port including a main passage and a bleed passage that is communicated with the main passage; and the valve element being mounted for movement between an open position spaced from the main passage of the port and a closed position where the valve element closes the main passage of the port but permits pressurized hydraulic fluid to bleed through the bleed passage; and the bleed passage upon subsequent movement of the valve element to the open position being cleaned by fluid flow through both passages of the port.