Adjustable hysteresis driver

An adjustable hysteresis driver comprising:

• a stator component (7′);
• an armature component (8) on an output side being fixed with a shaft (4);
• a hysteresis component (9) connected to the armature component (8);
• the stator component (7′) comprises an electromagnet (7a) which induces magnetic flux in the stator component (7′) such that the stator component (7′) electromagnetically couples the armature component (8) to transmit torque therebetween, the torque transmitted between the stator component (7′) and the armature component (8) being electromagnetically adjustable by means of the electromagnet (7a);
• a hysteresis brake and a mechanical coupling for implementing “fail-safe” operation, if an electrical current supply to the electromagnet (7a) fails, the mechanical coupling ensuring that torque is transferred between the stator component (7′) of the hysteresis brake and the armature component (8);
• the mechanical coupling comprising at least one first mechanical clutch element (12) in rotationally fixed connection with the stator component (7″) and axially movable, such that during the “fail-safe” operation when supply of electric current to the electromagnet (7a) fails, the first mechanical clutch element (12) engages a second mechanical clutch element (13) which is fixed with the armature component (8),
• the first mechanical clutch element (12) is moved toward the second mechanical clutch element (13) by a spring force during the “fail-safe” operation and is fixed by magnetic force on the stator component (7′) of the hysteresis brake by the electromagnet (7a) during normal operation;
• and
• the spring force providing overload protection which at least reduces engagement between the first and the second mechanical clutch elements (12,13).

An adjustable hysteresis driver comprising:

• a stator (7′) being fixed to a housing (6) and comprising an electromagnet (7a);
• a rotor (5) being rotatably supported by an output shaft (4) and comprising an annular air gap (11), the rotor (5) and the output shaft (4) being rotatable with respect to each other and the stator (7′) and housing (6);
• an armature (8) being fixed to the output shaft (4) and comprising a hysteresis component (9) that is fixed to the armature (8) and extends within the annular air gap (11) of the rotor (5), the armature (8) being rotatable with respect to the rotor (5) and the stator (7′);
• the electromagnet (7a) produces a magnetic field when electrical current is applied to the electromagnet (7a) and is arranged such that the magnetic field induces a magnetic flux in the rotor (5), the magnetic flux influences the hysteresis component (9) such that the hysteresis component (9) is rotationally driven by rotation of the rotor (5), torque being transmitted between the rotor (5) and the armature (8) being adjustable by means of the electromagnet (7a);
• a hysteresis clutch for implementing “fail-safe” operation, if electrical current to the electromagnet (7a) fails, to ensure that torque is transferred between the rotor (5) and the armature (8);
• the hysteresis clutch comprising a first mechanical clutch element (12) that is rotationally fixed to the rotor (5) and axially movable, such that during “fail safe” operation when supply of the electrical current to the electromagnet (7a) fails, the first mechanical clutch element (12) engages a second mechanical clutch element (13) which is fixed to the armature component (8);
• a spring (17b) engages and applies a spring force on the first mechanical clutch element (12) to bias the first mechanical clutch element (12) into engagement with the second mechanical clutch element (13) during “fail safe” operation, the first mechanical clutch element (12) being axially biased away from the second mechanical clutch element (13), against the spring force, and fixed by magnetic force on the rotor component (5) of the hysteresis clutch by the electromagnet (7a) when current is applied to the electromagnet (7a);
• and
• the spring force providing overload protection which at least reduces engagement between the first and the second mechanical clutch elements (12,13).