US 12,259,029 B2
Linear actuator
Reiner Knoell, Burgsinn (DE); Marco Knoell, Burgsinn (DE); and Michael Goldbach, Lohr A. Main (DE)
Assigned to Robert Bosch GmbH, Stuttgart (DE)
Filed by Robert Bosch GmbH, Stuttgart (DE)
Filed on Sep. 7, 2023, as Appl. No. 18/462,555.
Claims priority of application No. 10 2022 210 561.3 (DE), filed on Oct. 6, 2022.
Prior Publication US 2024/0117866 A1, Apr. 11, 2024
Int. Cl. F16H 25/24 (2006.01); F16H 25/20 (2006.01)
CPC F16H 25/2454 (2013.01) [F16H 25/2021 (2013.01); F16H 2025/2075 (2013.01)] 10 Claims
OG exemplary drawing
 
1. A linear actuator, comprising:
a screw drive which comprises (i) a threaded nut connected to an extension arm tube and (ii) a threaded spindle that is couplable to a motor for torque transmission such that the threaded nut and the extension arm tube are moved in a linear manner by a rotation of the threaded spindle and, regardless of the position the extension arm tube, a first end of the threaded spindle projects into the extension arm tube and is connected to a piston which partitions an interior space formed by the extension arm tube into a first region on a side of the piston opposite to the threaded nut and a second region on a side of the piston facing the threaded nut such that the first and the second region are separated from one another in a fluid-tight manner,
wherein:
the threaded nut is embodied as or comprises a fluid-tight annular piston that delimits an annular fluid space which is configured between a housing of the linear actuator and the extension arm tube in a fluid-tight manner, and a hydraulically effective surface of the fluid-tight annular piston is the same size as a hydraulically effective surface of the first region, and
the first region and the annular fluid space are configured to be fluidically connected to one another by a switching valve having an open position and a closed position.