Linear Actuator

• US 20090151489A1
• Filed: 09/28/2005
• Published: 06/18/2009
• Est. Priority Date: 09/30/2004
• Status: Active Grant

• Current Assignee: Linak A/S (Linak Holding A/S)
• Original Assignee: Linak A/S (Linak Holding A/S)
• Inventors: Jensen, Svend Erik Knudsen
• Granted Patent: US 8,725,438 B2
• Time in Patent Office: Days
• US Class Current: 74/89.330
• CPC Class Codes: F16H 2025/2031 Actuator casings
• CPC Class Codes: F16H 2025/2084 Perpendicular arrangement of drive motor to screw axis
• CPC Class Codes: F16H 2057/012 of gearings
• CPC Class Codes: F16H 25/20 Screw mechanisms with automatic reversal F16H25/12
• CPC Class Codes: F16H 25/2472 Safety nuts
• CPC Class Codes: Y10T 74/18056 Rotary to or from reciprocating or oscillating
• CPC Class Codes: Y10T 74/18656 Carriage surrounded, guided, and primarily supported by member other than screw [e.g., linear guide, etc.]
• CPC Class Codes: Y10T 74/18672 Plural screws in series [e.g., telescoping, etc.]
• CPC Class Codes: Y10T 74/18696 including means to selectively transmit power [e.g., clutch, etc.]
• CPC Class Codes: Y10T 74/18752 Manually driven
• CPC Class Codes: Y10T 74/19828 Worm

Abstract

A linear actuator comprises a reversible electric motor (2) which, via a transmission, is capable of driving a spindle (4) having a spindle nut (5) secured against rotation and comprises a power supply and a controller. The actuator moreover comprises a memory unit for collecting at least one set of data from the operation, indicating how long and how hard the actuator has worked. It is hereby possible to obtain an overview of the mechanical state of the actuator and thereby prevent unfortunate occurrences and accidents as a consequence of wear-out of the actuator.

Claims

1. A linear actuator comprising a reversible electric motor (2) which, via a transmission, is capable of driving a spindle (4) having a spindle nut (5) secured against rotation and comprises a power supply and a controller, and a memory unit for collecting at least one set of data from the operation, indicating how long and how hard the actuator has worked.

2. An actuator according to claim 1, including a microprocessor for collecting the data.

3. An actuator according to claim 2, wherein the microprocessor is arranged externally relative to the actuator and collects and saves these data in the memory unit of the actuator via a form of bus.

4. An actuator according to claim 1, the power is used for evaluating the state of the actuator by measuring it across a serial resistor in the power path to the motor.

5. An actuator according to claim 2, wherein the period of time during which the power has been switched on, is obtained directly from the microprocessor.

6. An actuator according to claim 1, including a temperature sensor in the actuator for measuring and collecting data on the temperature.

7. An actuator according to claim 1, including strain gauges for measuring and collecting data on the load.

8. An actuator according to claim 7, wherein the strain gauges are arranged in connection with the spindle bearing.

9. An actuator according to claim 1, wherein the revolutions of the spindle are measured and summed up by means of a mechanical counter or optical or magnetic encoders or scanning of the commutator pulses of the motor.

10. An actuator according to claim 1, wherein the actuator is provided with a linear slide potentiometer disposed in parallel with the spindle, and that the signal from this is used as a parameter for the evaluation of the state of the actuator.

11. An actuator according to claim 1, wherein the actuator and/or the control box is equipped with light emitting diodes to signal wear-out of the actuator.

12. An actuator according to claim 11, wherein a colour code signals wear-out or optionally the degree of wear-out.

13. An actuator according to claim 11, wherein the signal generator is arranged in the hand control, where it is directly visible.

14. An actuator according to claim 1, incorporated in a mounting bracket of the actuator, preferably a rear attachment.