Actuator with modular fail-safe assembly

Abstract

A modular actuator is provided. The modular actuator includes a motor, a drive device, and a housing. The drive device is driven by the motor and coupled to a movable component for driving the movable component. The housing houses the motor and the drive device therein, and supports modular interfacing with a plurality of fail-safe assemblies, one at a time.

What is claimed is: 
     
         1 . A modular actuator, comprising:
 a motor;   a drive device driven by the motor and coupled to a movable component for driving the movable component; and   a housing configured to house the motor and the drive device therein, and support modular interfacing with a plurality of fail-safe assemblies.   
     
     
         2 . The modular actuator of  claim 1 , wherein in absence of a fail-safe assembly, the movable component retains a last position in response to power failure or control signal failure. 
     
     
         3 . The modular actuator of  claim 1 , wherein a fail-safe assembly coupled to the housing operates the motor to drive the movable component from a last position to a fail-safe position in response to power failure or control signal failure. 
     
     
         4 . The modular actuator of  claim 3 , wherein the fail-safe position comprises one of an open position and a closed position of the movable component. 
     
     
         5 . The modular actuator of  claim 1 , wherein the plurality of fail-safe assemblies comprise a spring return fail-safe assembly and a capacitor return fail-safe assembly. 
     
     
         6 . The modular actuator of  claim 1 , wherein the housing comprises a base portion and a top cover portion, wherein the motor and the drive device are housed within the base portion, and the top cover portion is removably coupled to conceal an opening of the base portion. 
     
     
         7 . The modular actuator of  claim 6 , wherein the base portion comprises a seal member for ingress protection. 
     
     
         8 . The modular actuator of  claim 6 , wherein the base portion comprises a modular interface that enables a fail-safe assembly among the plurality of fail-safe assemblies to be removably coupled to the opening of the base portion upon removal of the top cover portion. 
     
     
         9 . The modular actuator of  claim 6 , wherein the base portion further comprises one or more spring-loaded electrical connectors electrically coupled to the motor. 
     
     
         10 . The modular actuator of  claim 9 , wherein the one or more spring-loaded electrical connectors are held in a depressed state when the top cover portion is coupled to the base portion, and the one or more spring-loaded electrical connectors extend out of the base portion in response to removal of the top cover portion from the base portion. 
     
     
         11 . The modular actuator of  claim 10 , wherein the one or more spring-loaded electrical connectors are configured to make conductive contact with a capacitor return fail-safe assembly removably coupled to the base portion. 
     
     
         12 . The modular actuator of  claim 10 , wherein the one or more spring-loaded electrical connectors regain the depressed state without making conductive contact when a spring return fail-safe assembly is removably coupled to the base portion. 
     
     
         13 . The modular actuator of  claim 12 , wherein the spring return fail-safe assembly is configured to form a mechanical linkage with the drive device. 
     
     
         14 . The modular actuator of  claim 12 , wherein a return stroke of the modular actuator is controlled based on a spring action of the spring return fail-safe assembly. 
     
     
         15 . The modular actuator of  claim 10 , further comprising processing circuitry configured to determine a fail-safe assembly among the plurality of fail-safe assemblies coupled to the base portion. 
     
     
         16 . The modular actuator of  claim 15 , wherein the processing circuitry determines the fail-safe assembly among the plurality of fail-safe assemblies coupled to the base portion based on whether the one or more spring-loaded electrical connectors have made a conductive contact with the fail-safe assembly. 
     
     
         17 . A modular fail-safe assembly for actuators, comprising:
 a return mechanism; and   a housing configured to house the return mechanism and support modular interfacing with a non-fail-safe actuator, wherein the return mechanism is configured to implement a fail-safe operation in the non-fail-safe actuator in response to power failure or control signal failure, wherein the return mechanism is configured to be removably coupled to the modular fail-safe assembly.   
     
     
         18 . The modular fail-safe assembly of  claim 17 , wherein the return mechanism comprises a capacitor. 
     
     
         19 . The modular fail-safe assembly of  claim 17 , wherein the return mechanism comprises a spring. 
     
     
         20 . An actuator system for use in a heating, ventilating, or air conditioning (HVAC) system to drive a movable HVAC component, the actuator system comprising:
 one or more fail-safe assemblies provided as modular attachments; and   a modular actuator configured to support modular interfacing with the one or more fail-safe assemblies, the one or more fail safe assemblies being removably coupled to the modular actuator, wherein in response to power failure or control signal failure, a fail-safe assembly, of the one or more fail-safe assemblies, is configured to implement a fail-safe operation that drives the movable HVAC component to a fail-safe position.