HVAC actuator with internal heating

• US 8,084,980 B2
• Filed: 03/04/2009
• Issued: 12/27/2011
• Est. Priority Date: 01/30/2009
• Status: Active Grant

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Carlson, Nathan, Mikulica, Miroslav
• Primary Examiner(s): Benson, Walter
• Assistant Examiner(s): GLASS, ERICK DAVID
• Application Number:
  US12/397,404
• Publication Number:
  US 20100194326A1
• Time in Patent Office: 1,028 Days
• Field of Search: 318/436, 318/40, 318/159, 318/471
• US Class Current: 318/471
• CPC Class Codes: F24F 2013/1433 with electric motors
• CPC Class Codes: G05B 19/19 characterised by positioning or contouring control systems, e.g. to control position from one programmed point to another or to control movement along a programmed continuous path
• CPC Class Codes: G05B 2219/2614 HVAC, heating, ventillation, climate control
• CPC Class Codes: H02P 29/62 for raising the temperature of the motor

Abstract

An HVAC actuator configured to function in cold environments by providing a supplemental current component to an HVAC actuator in order to generate supplemental heat to warm the HVAC actuator.

Claims

1. An HVAC actuator for driving an HVAC component, comprising:

a drive train configured to drive the HVAC component along a range of motion from a first HVAC component position to a second HVAC component position;

a motor coupled to the drive train for driving the drive train and thus the HVAC component; and

a controller for controlling the motor to move the HVAC component from the first HVAC component position to the second HVAC component position, the controller configured to detect a selected condition, and in response to detecting the selected condition, applying a supplemental current component to the motor, wherein the supplemental current component does not substantially move the HVAC component but warms the motor; and

wherein the supplemental current component causes the motor to move in a first direction and then in a second direction, without substantially moving the HVAC component.

2. The HVAC actuator of claim 1, wherein the selected condition corresponds to a cold temperature condition.

3. The HVAC actuator of claim 2, wherein the controller is coupled to a temperature sensor, and the controller detects the cold temperature condition by monitoring an output of the temperature sensor.

4. The HVAC actuator of claim 1, wherein the supplemental current component causes the HVAC component to move less than 10 percent of the range of motion.

5. The HVAC actuator of claim 1, wherein the supplemental current component causes the HVAC component to move less than 5 percent of the range of motion.

6. The HVAC actuator of claim 1, wherein the supplemental current component causes the HVAC component to move less than 3 percent of the range of motion.

7. The HVAC actuator of claim 1, wherein the HVAC component comprises an air damper or a ball valve.

8. The HVAC actuator of claim 1, wherein the controller warms the motor by operating the motor inefficiently while the motor is driving the drive train.

9. The HVAC actuator of claim 1, further comprising a resistive heating element controllable by the controller in order to warm the motor.

10. An HVAC actuator for driving an HVAC component, comprising:

a drive train configured to drive the HVAC component along a range of motion from a first HVAC component position to a second HVAC component position;

a motor coupled to the drive train for driving the drive train and thus the HVAC component; and

a controller for controlling the motor to move the HVAC component from the first HVAC component position to the second HVAC component position, the controller configured to detect a selected condition, and in response to detecting the selected condition, applying a supplemental current component to the motor, wherein the supplemental current component does not substantially move the HVAC component but warms the motor; and

wherein the supplemental current component causes the HVAC component to move back and forth about an HVAC component position, wherein the back and forth movement of the HVAC component is less than 5 percent of the range of motion of the HVAC component.

11. The HVAC actuator of claim 10, further comprising a bias mechanism for providing a bias force that urges the HVAC component from the second HVAC component position to the first HVAC component position, the controller configured to provide a first level of current to the motor, wherein the first level of current is required to hold the HVAC component at a selected position against bias force of the bias mechanism.

12. The HVAC actuator of claim 11, wherein the bias mechanism comprises a resilient material.

13. The HVAC actuator of claim 11, wherein the bias mechanism comprises a return spring.

14. An HVAC actuator for driving an HVAC component, comprising:

a drive train configured to drive the HVAC component along a range of motion from a first HVAC component position to a second HVAC component position;

a motor coupled to the drive train for driving the drive train and thus the HVAC component;

a controller for controlling the motor to move the HVAC component from the first HVAC component position to the second HVAC component position, the controller configured to detect a selected condition, and in response to detecting the selected condition, applying a supplemental current component to the motor, wherein the supplemental current component does not substantially move the HVAC component but warms the motor;

a bias mechanism for providing a bias force that urges the HVAC component from the second HVAC component position to the first HVAC component position, the controller configured to provide a first level of current to the motor, wherein the first level of current is required to hold the HVAC component at a selected position against bias force of the bias mechanism and

wherein the supplemental current component is above and beyond the first level of current.

15. An HVAC actuator for driving an HVAC component, comprising:

a drive train configured to drive the HVAC component along a range of motion from a first HVAC component position to a second HVAC component position;

a motor coupled to the drive train for driving the drive train and thus the HVAC component;

a controller for controlling the motor to move the HVAC component from the first HVAC component position to the second HVAC component position, the controller configured to detect a selected condition, and in response to detecting the selected condition, applying a supplemental current component to the motor, wherein the supplemental current component does not substantially move the HVAC component but warms the motor;

a bias mechanism for providing a bias force that urges the HVAC component from the second HVAC component position to the first HVAC component position, the controller configured to provide a first level of current to the motor, wherein the first level of current is required to hold the HVAC component at a selected position against bias force of the bias mechanism and

wherein the supplemental current component includes a plurality of current pulses to the motor such that the motor will with each current pulse drive the HVAC component a short distance against the bias mechanism and then allow the HVAC component to move a short opposite distance driven by the bias mechanism.

16. An HVAC actuator for driving an HVAC component, comprising:

a drive train configured to drive the HVAC component along a range of motion from a first HVAC component position to a second HVAC component position;

a motor coupled to the drive train for driving the drive train and thus the HVAC component; and

a controller for controlling the motor to move the HVAC component from the first HVAC component position to the second HVAC component position, the controller configured to detect a selected condition, and in response to detecting the selected condition, applying a supplemental current component to the motor, wherein the supplemental current component does not substantially move the HVAC component but warms the motor; and

wherein the motor is a brushless DC motor with PWM control, and the controller warms the motor by locking onto a single phase.

17. A spring return HVAC actuator for driving an HVAC component, comprising:

a motor;

a drive train driven by the motor, the drive train configured to drive the HVAC component in a first direction toward a first HVAC component position along a range of motion;

a return spring configured to drive the HVAC component in a second, opposing direction;

a controller configured to operate the motor in order to drive the HVAC component in the first direction; and

a thermal monitor that detects an HVAC actuator temperature of the HVAC actuator and provides the controller with a signal representing the HVAC actuator temperature;

wherein the controller is also configured to apply a supplemental current component to the motor if the HVAC actuator temperature is too low in order to warm the spring return HVAC actuator, wherein the supplemental current component does not substantially move the HVAC component.

18. The spring return HVAC actuator of claim 17, wherein the controller is configured to apply the supplemental current component to the motor only when the controller is not driving the HVAC component in the first direction toward the first HVAC component position.

19. The spring return HVAC actuator of claim 17, wherein the controller will, if the HVAC actuator temperature is too low, provide a current pulse to the motor that is sufficient to slightly move the motor but not substantially move the HVAC component.

20. The spring return HVAC actuator of claim 17, wherein the supplemental current component does not move the HVAC component more than 5 percent of the range of motion of the HVAC component.

21. The spring return HVAC actuator of claim 17, wherein the controller will, if the HVAC actuator temperature is too low, provide a plurality of current pulses to the motor such that the motor will with each current pulse drive the drive train a short distance against the return spring and then allow the drive train to move a short opposite distance driven by the return spring.

22. An HVAC actuator for driving an HVAC component, comprising:

a motor;

a drive train driven by the motor, the drive train being configured to drive the HVAC component; and

a controller configured to operate the motor in order to drive the HVAC component in a first direction to open the HVAC component and a second direction to close the HVAC component along a range of motion; and

a thermal monitor that detects a temperature of the HVAC actuator and provides the controller with a signal representing the HVAC actuator temperature;

wherein the controller is also configured to actuate the motor without substantially moving the HVAC component if the HVAC actuator temperature is too low in order to warm the spring return HVAC actuator.

23. The HVAC actuator of claim 22, wherein the controller is configured to actuate the motor in order to increase the HVAC actuator temperature only when the motor is not driving the HVAC component open or closed.

24. The HVAC actuator of claim 22, wherein if the HVAC actuator temperature is too low, the controller actuate the motor without moving the HVAC component by more than 5 percent of the range of motion of the HVAC component.