# US 12,181,027 B2 · Electromechanical linear actuator

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- Number: US 12,181,027 B2
- Document ID: US12181027B2
- Status: Granted
- Kind: B2
- Application number: 18/462,095
- Filed: 2023-09-06
- Published: 2024-04-11
- Granted: 2024-12-31
- Earliest claimed: 2022-10-06
- Assignees: Robert Bosch GmbH
- Applicants: Robert Bosch GmbH
- Inventors: Reiner Knoell; Marco Knoell; Michael Goldbach
- Web page: https://patentgrep.com/patent/US12181027B2

## CPC

- F16H 25/2454: {Brakes; Rotational locks}
- H02K 7/06: Means for converting reciprocating motion into rotary motion or vice versa
- F16H 25/20: Screw mechanisms (with automatic reversal F16H25/12)
- F16H 25/2252: {Planetary rollers between nut and screw}
- H02K 7/003: {Couplings; Details of shafts (means for mounting rotors on shafts H02K1/28)}
- H02K 7/083: {radially supporting the rotary shaft at both ends of the rotor (H02K7/086, H02K7/09 take precedence)}
- F16H 2025/2031: {Actuator casings}
- F16H 2025/2075: {Coaxial drive motors}
- F16H 2025/2078: {the rotor being integrated with the nut or screw body}
- F16H: GEARING
- H02K: DYNAMO-ELECTRIC MACHINES (dynamo-electric relays H01H53/00; conversion of DC or AC input power into surge output power {H03K3/53})

## Abstract

An electromechanical linear actuator having a threaded drive, which comprises a threaded nut connected to a cantilever tube and a lead screw connected to a hollow shaft of an electric motor via a rotationally fixed connection in such a way that, by a rotation of the hollow shaft and the lead screw, the threaded nut and the cantilever tube are linearly movable. An axial design length of the electromechanical linear actuator in the maximally retracted state is minimized in that a holding brake for the lead screw and a first rotary bearing for bearing the lead screw on a housing of the linear actuator are arranged within the hollow shaft.

## Claims

### Claim 1

An electromechanical linear actuator, comprising:
a threaded drive which comprises a threaded nut connected to a cantilever tube and a lead screw connected to a hollow shaft of an electric motor via a rotationally fixed connection, such that the threaded nut and the cantilever tube are linearly movable by a rotation of the hollow shaft and the lead screw, wherein
a holding brake for the lead screw and a first rotary bearing for bearing the lead screw on a housing of the linear actuator are arranged within the hollow shaft.

### Claim 2 (depends on 1)

The electromechanical linear actuator according to claim 1, wherein the housing comprises a first hollow beam which projects into the hollow shaft of the electric motor and whose inner circumference serves to receive the first rotary bearing arranged on an outer circumference of the lead screw.

### Claim 3 (depends on 1)

The electromechanical linear actuator according claim 1, wherein a screw support configured as a piston is arranged on the lead screw in an end region of the lead screw facing away from the rotationally fixed connection via which the lead screw is rotatably borne in the cantilever tube and via which the cantilever tube is also guided linearly along the end region of the lead screw.

### Claim 4 (depends on 1)

The electromechanical linear actuator according to claim 1, wherein the first rotary bearing comprises two tapered roller bearings or spherical roller bearings in an O-arrangement.

### Claim 5 (depends on 1)

The electromechanical linear actuator according to claim 1, wherein a rotary encoder arranged on a front face of the lead screw facing away from the cantilever tube is arranged within the hollow shaft.

### Claim 6 (depends on 1)

The electromechanical linear actuator according to claim 1, wherein the holding brake is configured as a mechanical brake.

### Claim 7 (depends on 1)

The electromechanical linear actuator according to claim 1, wherein a second rotary bearing is arranged between an outer circumference of a second hollow beam of the housing projecting into the hollow shaft of the electric motor and the inner circumference of the hollow shaft in an end region of the electric motor facing away from the cantilever tube.

### Claim 8 (depends on 7)

The electromechanical linear actuator according claim 7, wherein the second rotary bearing comprises a radial groove ball bearing.

### Claim 9 (depends on 7)

The electromechanical linear actuator according to claim 7, wherein the second rotary bearing is configured as a floating bearing, such that a heat-induced relative movement between the hollow shaft and the second hollow beam in the longitudinal direction of the hollow shaft is enabled.