Viscous fluid coupling and improved valve assembly therefor

• US 6,056,098 A
• Filed: 02/04/1998
• Issued: 05/02/2000
• Est. Priority Date: 02/04/1998
• Status: Expired due to Term

• Current Assignee: Borg-Warner Automotive Incorporated (BorgWarner Incorporated)
• Original Assignee: Borg-Warner Automotive Incorporated (BorgWarner Incorporated)
• Inventors: Koch, William E., Brown, Richard J.
• Primary Examiner(s): Marmor, Charles A
• Assistant Examiner(s): Pang, Roger
• Application Number:
  US09/018,188
• Time in Patent Office: 818 Days
• Field of Search: 192/58.61, 192/58.8, 192/58.66, 192/58 B, 192/82 T
• US Class Current: 192/58.61
• CPC Class Codes: F16D 35/024 the valve being actuated electrically, e.g. by an electromagnet F16D35/026 takes precedence

Abstract

A fluid coupling device is disclosed of the type having an output coupling assembly (13) and an input coupling member (11). Control of the flow of viscous fluid between a reservoir chamber (35) and an operating chamber (33) is by rotation of a valve arm (43), to cover or uncover a fill opening (45). Rotation of the valve arm is affected by an actuator assembly (61). A raised portion (79) on a plate (73) attached to an armature (67) biases the valve arm (43) into sealing engagement with a surface (31) which defines a fill port (45,89), thus reducing fluid leakage from the reservoir (35) back into the operating chamber (33). A portion (85) which covers the fill port includes a dimple (91) which is disposed within the fill opening when the valve arm is in its closed position (FIG. 5). As the valve arm begins to move toward its open position (FIG. 6), the dimple (91) causes a camming and axial separation of the valve arm from the adjacent surface, to reduce the undesirable results of viscous drag on the valve arm.

Claims

1. A fluid coupling device of the type including a first rotatable coupling assembly defining an axis of rotation, said first coupling assembly including a first coupling member and a cover member cooperating to define a fluid chamber therebetween;

valve means associated with said first coupling assembly and disposed to separate said fluid chamber into a fluid operating chamber and a fluid reservoir chamber;

a second rotatable coupling member disposed in said fluid operating chamber, and being rotatable relative to said first coupling member, and cooperating therewith to define a viscous shear space therebetween, said valve means being operable to control the flow of fluid between said reservoir chamber and said operating chamber, said valve means including a plate-like portion disposed generally perpendicular to said axis of rotation, and defining a fluid inlet port, and a valve member comprising a thin, generally flat member disposed to move in a plane parallel to said plate-like portion, and closely spaced thereto, said valve member being movable between an open position permitting fluid flow through said inlet port, and a closed position substantially blocking fluid flow;

an actuator assembly operably associated with said first coupling assembly and with said valve member and operable to move said valve member between said open and closed positions, said actuator assembly including a rotatable armature member and means operable to rotate said armature member in response to variations in an input signal;

characterized by;

(a) said valve member being fixed to said armature member at an attachment location transversely offset from said axis of rotation;

(b) said valve member including a port covering portion adapted to cover said inlet port when said valve member is in said closed position, said port covering portion being disposed diametrically opposite said attachment location, about said axis of rotation; and

(c) one of said armature member and a separate plate member fixed relative to said armature member including a biasing portion comprising a raised portion disposed axially between said armature member and said valve member, and radially between said axis of rotation and said attachment location, and operable to bias said port covering portion into sealing engagement with said plate-like portion.

2. A fluid coupling device as claimed in claim 1, characterized by said port covering portion of said valve member including a cam portion extending from a rearward surface of said port covering portion into said fluid inlet port, when said valve member is in said closed position, whereby rotation of said valve member from said closed position to said open position causes said cam portion to engage said plate-like portion, thereby lifting said port covering portion out of sealing engagement with the adjacent surface of said plate-like portion.

3. A fluid coupling device as claimed in claim 1, characterized by said valve member being fixed relative to said armature by means of a plurality of rivets.

4. A fluid coupling device as claimed in claim 2, characterized by said valve member comprising a stamped, spring steel member, and said cam portion comprises a small protuberance formed during the process of stamping said valve member.

5. A fluid coupling device of the type including a first rotatable coupling assembly defining an axis of rotation, said first coupling assembly including a first coupling member and a cover member cooperating to define a fluid chamber therebetween;

valve means associated with said first coupling assembly and disposed to separate said fluid chamber into a fluid operating chamber and a fluid reservoir chamber;

a second rotatable coupling member disposed in said fluid operating chamber, and being rotatable relative to said first coupling member, and cooperating therewith to define a viscous shear space therebetween, said valve means being operable to control the flow of fluid between said reservoir chamber and said operating chamber, said valve means including a plate-like portion disposed generally perpendicular to said axis of rotation, and defining a fluid inlet port, and a valve member comprising a thin, generally flat member disposed to move in a plane parallel to said plate-like portion, and closely spaced thereto, said valve member being movable between an open position permitting fluid flow through said inlet port, and a closed position substantially blocking fluid flow;

means operable to move said valve member between said open and closed positions;

characterized by;

(a) said valve arm including a port covering portion covering said inlet port when said valve arm is in said closed position;

(b) one of said port covering portion of said valve member and said plate-like portion including a cam portion extending axially toward the other of said plate-like portion and said port covering portion, whereby, during at least a major portion of the rotation of said valve member between said closed position and said open position, said cam portion maintains said port covering portion axially out of sealing engagement with the adjacent surface of said plate-like portion, to reduce the viscous drag therebetween.

6. A fluid coupling device as claimed in claim 5, characterized by said valve member defining said cam portion extending axially toward said plate-like portion.

7. A fluid coupling device as claimed in claim 5, characterized by said cam portion being disposed within said fluid inlet port, when said valve member is in said closed position, whereby rotation of said valve member from said closed position to said open position causes said cam portion to engage said plate-like portion, thereby lifting said port covering portion out of sealing engagement with the adjacent surface of said plate-like portion.