Actuator
An actuator includes a housing, a first nut in the housing, a second nut in the housing, and a threaded spindle screwed into the first nut and the second nut. The first nut exerts a first force in a first direction on the threaded spindle, and the second nut exerts a second force in a second direction on the threaded spindle, the first direction being different than the second direction.
1. An actuator comprising:
a housing;
a first nut in the housing;
a second nut in the housing;
a threaded spindle screwed into the first nut and the second nut, wherein the first nut exerts a first force in a first direction on the threaded spindle, and the second nut exerts a second force in a second direction on the threaded spindle, the first direction being different than the second direction; and
at least one first rolling-element bearing having an inner ring and an outer ring, wherein the inner ring exerts the first force on the first nut.
2. The actuator according to claim 1 , wherein there is an angle of at least 30° between the first direction and the second direction.
3. The actuator according to claim 1 , further including at least one second rolling-element bearing having an inner ring and an outer ring, wherein the inner ring of the at least one second rolling-element bearing exerts the second force on the second nut.
4. The actuator according to claim 3 , wherein the first nut is coupled to the second nut by a torque-transmitting claw coupling.
5. The actuator according to claim 1 , including a cavity between the first and second nuts, said cavity configured to receive a third nut arranged to receive a load if the first nut or the second nut breaks.
6. The actuator according to claim 1 , wherein the threaded spindle is free of clearance with respect to at least one of the first and second nuts.
7. An operating table or a treatment chair including an actuator according to claim 1 .
8. The actuator according to claim 1 ,
wherein the first nut has a first shoulder and the second nut has a second shoulder,
wherein the housing includes a first annular surface and a second annular surface, the actuator including:
a first rolling-element bearing having an inner ring and an outer ring, the outer ring of the first rolling-element bearing contacting the first annular surface and the inner ring of the first rolling-element bearing contacting the first shoulder, and
a second rolling-element bearing having an inner ring and an outer ring, the outer ring of the second rolling-element bearing contacting the second annular surface and the inner ring of the second rolling-element bearing contacting the second shoulder.
9. The actuator according to claim 8 , wherein the first rolling-element bearing and the second rolling-element bearing have a negative clearance.