Rotary coupling for torque transmission

A rotary coupling for torque transmission between first and second shafts comprising:

• a housing coaxially arranged between said first and second shafts and connected to said first shaft;
• clutch means received in said housing for transmitting rotational torque between said housing and said second shaft;
• a piston axially slidably received in said housing for thrusting said clutch means, said piston and said housing defining a cylindrical space;
• a rotor received in said cylindrical space and coupled to said second shaft for rotational movement therewith;
• a high viscous fluid filled in said cylindrical space to be displaced by said rotor to generate a pressure for pushing said piston toward said clutch means;
• and
• a plurality of circumferentially separated depressions formed in at least one side surface of said rotor facing said housing or said piston, each of said depressions having an inclined surface inclining so as to increase the depth of the depressions in the rotational direction of said rotor;
• wherein all of said inclined surfaces face a forward rotational direction of said rotor.

A rotary coupling for torque transmission between first and second shafts comprising:

• a housing coaxially arranged between said first and second shafts and connected to said first shaft;
• clutch means received in said housing for transmitting rotational torque between said housing and said second shaft;
• a piston axially slidably received in said housing for thrusting said clutch means, said piston and said housing defining a cylindrical space;
• a rotor received in said cylindrical space and coupled to said second shaft for rotational movement therewith;
• a high viscous fluid filled in said cylindrical space to be displaced by said rotor to generate a pressure for pushing said piston toward said clutch means;
• and
• a plurality of circumferentially separated depressions formed in at least one side surface facing said housing or said piston, each of said depressions having an inclined surface inclining so as to increase the depth of the depressions in the rotational direction of said rotor;
• wherein one of every adjacent two of said inclined surfaces has a length and a gradient angle different from those of the other of said adjacent two inclined surfaces.

A rotary coupling for torque transmission between first and second shafts comprising:

• a housing coaxially arranged between said first and second shafts and connected to said first shaft;
• clutch means received in said housing for transmitting rotational torque between said housing and said second shaft;
• a piston axially slidably received in said housing for thrusting said clutch means, said piston and said housing defining a cylindrical space;
• a rotor received in said cylindrical space and coupled to said second shaft for rotational movement therewith;
• a high viscous fluid filled in said cylindrical space to be displayed by said rotor to generate a pressure for pushing said piston toward said clutch means;
• and
• a plurality of circumferentially separated depressions which are formed in at least one side surface of the rotor facing said housing or said piston;
• wherein each of said depression is formed with a pair of inclined surfaces, one of said inclined surfaces facing a forward rotational direction of said rotor and having a predetermined length in the circumferential direction and a predetermined gradient angle, and the other thereof facing a reverse rotational direction of said rotor and having a length and a gradient angle different from those of the one of said inclined surfaces.