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US-20260126101-A1 - ELECTROMECHANICAL ACTUATOR

US20260126101A1US 20260126101 A1US20260126101 A1US 20260126101A1US-20260126101-A1

Abstract

An electromechanical actuator including an electric motor housed in a housing, the electric motor acting on a torque output element capable of being coupled to an element of a transmission gearbox of a motor vehicle. The torque output element is connected to the electric motor by drive means, and the torque output element is a main shaft configured to rotate about its axis of rotation with a first end and a second end. The actuator further includes a circuit board located in the housing, the circuit board comprises a sensor which faces a magnet mounted on a support coupled to the second end of the main shaft by means of a first swivel-linear mechanism.

Inventors

  • Sylvain Gautier
  • SACHIDHANANDAM BASKARAN
  • Sylvain Favelier

Assignees

  • VALEO ELECTRIFICATION

Dates

Publication Date
20260507
Application Date
20231116
Priority Date
20221207

Claims (20)

  1. 1 . An electromechanical actuator comprising an electric motor housed in a housing, the electric motor acting on a torque output element able to be coupled to an element of a transmission gearbox of a motor vehicle, the torque output element being connected to the electric motor by drive means, the torque output element being a main shaft configured to rotate about its axis of rotation with a first end and a second end, the actuator further comprising an electronic board situated inside the housing, the electronic board comprising a sensor that faces a magnet mounted on a support coupled to the second end of the main shaft by means of a first rotary-linear mechanism.
  2. 2 . The electromechanical actuator as claimed in claim 1 , wherein the main shaft is connected to the electric motor by means of a pinion-wheel system so as to rotate the main shaft.
  3. 3 . The electromechanical actuator as claimed in claim 1 , wherein the first rotary-linear mechanism is coupled to a surface of the housing in order to perform an anti-rotation function.
  4. 4 . The electromechanical actuator as claimed in claim 1 , wherein the first rotary-linear mechanism is associated with the magnet support by a cam-slot system.
  5. 5 . The electromechanical actuator as claimed in claim 1 , wherein a second rotary-linear mechanism is coupled to the first end of the main shaft.
  6. 6 . The electromechanical actuator as claimed in claim 5 , wherein the travel of the first rotary-linear mechanism is different than the travel of the second rotary-linear mechanism.
  7. 7 . The electromechanical actuator as claimed in claim 5 , wherein the travel of the first rotary-linear mechanism is shorter than the travel of the second rotary-linear mechanism, or the travel of the first rotary-linear mechanism is longer than the travel of the second rotary-linear mechanism.
  8. 8 . The electromechanical actuator as claimed in claim 1 , wherein the main shaft is guided in rotation by a rolling bearing, the inner ring of the rolling bearing being in contact with the main shaft and the outer ring of the rolling bearing being in contact with the housing and a flange fixed to the housing.
  9. 9 . The electromechanical actuator as claimed in claim 8 , wherein the rolling bearing is a double-row ball bearing.
  10. 10 . The electromechanical actuator as claimed in claim 1 , wherein the electric motor comprises a front face facing toward the drive means and a rear face, the housing comprising a removable blanking plug at the rear face of the electric motor.
  11. 11 . The electromechanical actuator as claimed in claim 2 , wherein the first rotary-linear mechanism is coupled to a surface of the housing in order to perform an anti-rotation function.
  12. 12 . The electromechanical actuator as claimed in claim 2 , wherein the first rotary-linear mechanism is associated with the magnet support by a cam-slot system.
  13. 13 . The electromechanical actuator as claimed in claim 2 , wherein a second rotary-linear mechanism is coupled to the first end of the main shaft.
  14. 14 . The electromechanical actuator as claimed in claim 6 , wherein the travel of the first rotary-linear mechanism is shorter than the travel of the second rotary-linear mechanism, or the travel of the first rotary-linear mechanism is longer than the travel of the second rotary-linear mechanism.
  15. 15 . The electromechanical actuator as claimed in claim 2 , wherein the main shaft is guided in rotation by a rolling bearing, the inner ring of the rolling bearing being in contact with the main shaft and the outer ring of the rolling bearing being in contact with the housing and a flange fixed to the housing.
  16. 16 . The electromechanical actuator as claimed in claim 2 , wherein the electric motor comprises a front face facing toward the drive means and a rear face, the housing comprising a removable blanking plug at the rear face of the electric motor.
  17. 17 . The electromechanical actuator as claimed in claim 3 , wherein the first rotary-linear mechanism is associated with the magnet support by a cam-slot system.
  18. 18 . The electromechanical actuator as claimed in claim 3 , wherein a second rotary-linear mechanism is coupled to the first end of the main shaft.
  19. 19 . The electromechanical actuator as claimed in claim 3 , wherein the main shaft is guided in rotation by a rolling bearing, the inner ring of the rolling bearing being in contact with the main shaft and the outer ring of the rolling bearing being in contact with the housing and a flange fixed to the housing.
  20. 20 . The electromechanical actuator as claimed in claim 3 , wherein the electric motor comprises a front face facing toward the drive means and a rear face, the housing comprising a removable blanking plug at the rear face of the electric motor.

Description

The invention relates to an electromechanical actuator. The invention applies more specifically to the field of actuators for a parking lock system for immobilizing a gearbox of a vehicle, notably a motor vehicle equipped with an automatic gearbox, for example a hybrid vehicle. The invention also applies to a parking lock system for immobilizing a reducer associated with an electric vehicle motor. The gearbox or the reducer will more generally be referred to as the transmission gearbox. This locking system is better known as a park-lock or parking lock. Such an actuator allows the transmission gearbox to be immobilized when parked, by means of a lever engaging with a toothset of the transmission gearbox. The invention also applies to the field of actuators for a system for connecting/disconnecting elements in the transmission of the above-mentioned vehicles. Actuators of this type are known, for example, from document ES1217209UA. This type of actuator has the disadvantage of proposing a complex mechanism for detecting the position of the main shaft using a worm and wheel system. It is therefore necessary to propose a system that is less expensive and simpler to implement, while yet remaining effective. The invention therefore proposes an electromechanical actuator comprising an electric motor housed in a housing, the electric motor acting on a torque output element able to be coupled to an element of a transmission of a motor vehicle, the torque output element being connected to the electric motor by drive means, the torque output element being a main shaft configured to rotate about its axis of rotation with a first end and a second end. The actuator further comprises an electronic board situated inside the housing, the electronic board comprising a sensor that faces a magnet mounted on a support coupled to the second end of the main shaft by means of a first rotary-linear mechanism. This design allows reliable measurement of the position of the main shaft using a design that is simple and inexpensive. According to one aspect of the invention, the sensor is preferably a Hall-effect sensor and the magnet is a permanent magnet and is polarized. Advantageously, the first rotary-linear mechanism is a screw-nut system. The screw part is on the main shaft, more specifically at the second end thereof. The nut part may be the magnet support directly or may be indirectly connected to the magnet support. Any other type of rotary-linear mechanism may be employed as an alternative, for example a ball-screw system. According to the invention, the main shaft is connected to the electric motor by means of a pinion-wheel system so as to rotate the main shaft. The pinion is on the shaft of the electric motor and the wheel is on the torque output element, namely the main shaft. As a preference, the pinion-wheel system has straight-cut teeth. According to the invention, the first rotary-linear mechanism is coupled to a surface of the housing in order to perform an anti-rotation function. More specifically, the nut part of the first rotary-linear mechanism is coupled to the surface of the housing. According to an alternative embodiment, the first rotary-linear mechanism is associated with the magnet support by a cam-slot system. That enables the linear movement of the first rotary-linear mechanism to be converted into a rotation of the magnet support. According to an additional feature of the invention, a second rotary-linear mechanism is coupled to the first end of the main shaft. The second rotary-linear mechanism enables the rotary movement of the main shaft to be converted into a linear movement. The second rotary-linear mechanism is a screw-nut system, the screw part being on the main shaft, more specifically at the first end thereof, and the nut part being a thrust member. Any other type of rotary-linear mechanism may be employed as an alternative, for example a ball-screw system. According to another feature of the invention, the travel of the first rotary-linear mechanism is different than the travel of the second rotary-linear mechanism. For example, the ratio between the travel of the first rotary-linear mechanism and the travel of the second rotary-linear mechanism is comprised between 0.1 and 3. In particular, the travel of the first rotary-linear mechanism may be shorter than the travel of the second rotary-linear mechanism. This feature makes it possible to reduce the travel of the first rotary-linear mechanism associated with the magnet support and to use a standard sensor. Alternatively, the travel of the first rotary-linear mechanism may be longer than the travel of the second rotary-linear mechanism. This feature makes it possible to increase the measurement precision. Advantageously, the main shaft is guided in rotation by a rolling bearing, the inner ring of the rolling bearing being in contact with the main shaft and the outer ring of the rolling bearing being in contact with the housing and a flange fix