Patent Description:
The present disclosure relates generally to actuators in a heating, ventilating, or air conditioning (HVAC) system and more particularly to HVAC actuators that use brushless direct current (BLDC) motors.

HVAC actuators are used to operate a wide variety of HVAC components such as air dampers, fluid valves, air handling units, and other components that are typically used in HVAC systems. For example, an actuator may be attached to a damper in a HVAC system and may be used to drive the damper between an open position and a closed position. An HVAC actuator typically includes a motor and a drive device (e.g., a hub, a drive train, etc.) that is driven by the motor and attached to the HVAC component. Documents <CIT> and <CIT> disclose actuators for HVAC of the prior art.

One implementation of the present disclosure is an actuator in a HVAC system. The actuator includes a drive device and a motor coupled to the drive device. The drive device is configured to attach to a movable HVAC component and to drive the movable HVAC component between multiple positions. The motor includes a shell defining an outer perimeter of the motor, a rotor shaft contained within the shell and configured to rotate when an electric current is applied to the motor, a drive shaft extending through the shell and coupled to the drive device, and a one-way clutch contained within the shell and rotatably coupling the rotor shaft to the drive shaft.

According to the invention, the one-way clutch is configured to engage both the rotor shaft and the drive shaft when the rotor shaft rotates in a first direction such that the drive shaft is driven by the rotor shaft in the first direction. The one-way clutch is configured to slip relative to at least one of the rotor shaft and the drive shaft when the rotor shaft rotates in a second direction opposite the first direction to allow rotation of the rotor shaft relative to the drive shaft in the second direction.

According to the invention, the motor is configured to provide torque to the drive device in the first direction. The actuator includes a return spring coupled to the drive device and configured to provide torque to the drive device in the second direction. The actuator includes an end stop defining an end of a mechanical range of motion for at least one of the drive device and the movable HVAC component. The torque provided by the return spring causes the drive device to move toward the end stop and to drive the motor in the second direction.

In some embodiments, the motor gains rotational inertia as the motor is driven in the second direction. The drive device can be configured to stop upon reaching the end stop. The one-way clutch can be configured to allow continued rotation of the motor in the second direction after the drive device stops to gradually dissipate the rotational inertia of the motor.

In some embodiments, the actuator includes a pinion gear rotatably fixed to an end of the drive shaft outside the shell and configured to drive the drive device. The pinion gear can be injection molded from a polymer material and press fit onto the end of the drive shaft.

In some embodiments, the one-way clutch includes a wrap spring wrapped around an end of the rotor shaft and an end of the drive shaft. The wrap spring can be fixed to one of the rotor shaft and the drive shaft. The wrap spring can be configured to slip relative to the other of the rotor shaft and the drive shaft when the rotor shaft rotates in the second direction. In some embodiments, the shell includes an outer rotor configured to rotate when the electric current is applied to the motor. The rotor shaft can be rotatably fixed to the outer rotor.

In some embodiments, the actuator includes stator windings contained within the shell and a flange coupled to the stator windings. The flange may define a surface of the shell. In some embodiments, the stator windings includes a central axial channel. The rotor shaft, the drive shaft, and the one-way clutch can be at least partially contained within the central axial channel. In some embodiments, the actuator includes a first bearing and a second bearing located within the central axial channel. The first bearing can be configured to facilitate rotation of the rotor shaft relative to the stator windings. T second bearing can be configured to facilitate rotation of the stator shaft relative to the stator windings.

Another implementation of the present disclosure is an actuator in a HVAC system. The actuator includes a drive device and a motor. The drive device is configured to attach to a movable HVAC component and to drive the movable HVAC component between multiple positions. The motor includes a one-way clutch contained within an outer perimeter of the motor. The one-way clutch is configured to rotatably couple the motor to the drive device when the motor rotates in a first direction and to allow the motor to rotate relative to the drive device when the motor rotates in a second direction opposite the first direction.

In some embodiments, the one-way clutch includes a rotor shaft rotatably coupled to the motor and configured to rotate when an electric current is applied to the motor, a drive shaft rotatably coupled to the drive device and configured to drive the drive device, and a wrap spring wrapped around an end of the rotor shaft and an end of the drive shaft.

In some embodiments, the wrap spring is configured to engage both the rotor shaft and the drive shaft when the rotor shaft rotates in the first direction such that the drive shaft is driven by the rotor shaft in the first direction. The wrap spring can be configured to slip relative to at least one of the rotor shaft and the drive shaft when the rotor shaft rotates in the second direction to allow rotation of the rotor shaft relative to the drive shaft in the second direction.

In some embodiments, the motor includes an outer rotor configured to rotate when the electric current is applied to the motor. The one-way clutch can be contained within a perimeter of the outer rotor. In some embodiments, the actuator includes a pinion gear rotatably fixed to an end of a drive shaft outside the perimeter of the motor and configured to drive the drive device.

Those skilled in the art will appreciate that the summary is illustrative only and is not intended to be in any way limiting. Other aspects, inventive features, and advantages of the devices and/or processes described herein, as defined solely by the claims, will become apparent in the detailed description set forth herein and taken in conjunction with the accompanying drawings.

Referring generally to the FIGURES, an HVAC actuator with a one-way clutch motor is shown, according to some embodiments. The actuator can be a damper actuator, a valve actuator, a fan actuator, a pump actuator, or any other type of actuator that can be used in a HVAC system. The actuator includes a motor and a drive device driven by the motor. In some embodiments, the motor is a brushless direct current (BLDC) motor. The drive device is attached to a movable HVAC component and configured to drive the movable HVAC component between multiple positions.

The actuator includes a one-way clutch mechanism contained within a perimeter of the motor. The one-way clutch mechanism can rotationally couple a rotor shaft of the motor to a drive shaft of the motor. In some embodiments, the rotor shaft is rotationally fixed to a rotary component of the motor (e.g., a rotor) and configured to rotate when an electric current is applied to the motor. The drive shaft can extend through the perimeter of the motor. In some embodiments, a pinion gear is fixed (e.g., press-fit) to an end of the drive shaft.

The one-way clutch mechanism allows the motor to continue rotating in a reverse direction after the drive device stops rotating. For example, a return spring may cause the actuator to return to an end position by applying a torque which drives the actuator in the reverse direction. The one-way clutch mechanism may cause the motor to be driven in the reverse direction by the drive device as the actuator rotates in the reverse direction. The drive device may stop rotating once the drive device reaches the end of a mechanical range of travel for the actuator. This may occur when the drive device or HVAC component operated by the actuator encounters a physical end stop. In some instances, the drive device and the drive shaft suddenly stop rotating once the end stop is reached (e.g., upon impacting the end stop).

The rotational momentum of the motor may cause the motor to continue rotating relative to the drive shaft and the drive device. The one-way clutch mechanism permits such rotation by allowing the rotor shaft to slip relative to the drive shaft when the rotor shaft rotates in the reverse direction. Such slippage allows the rotational momentum of the motor to gradually decrease rather than forcing the motor to stop suddenly. This feature reduces the impact force experienced when the end stop is reached and reduces the stress on the rotating components of the actuator. Additional features and advantages of the actuator are described in greater detail below.

Referring now to <FIG>, an exemplary building management system (BMS) and HVAC system in which the systems and methods of the present disclosure may be implemented are shown, according to some embodiments. Referring particularly to <FIG>, a perspective view of a building <NUM> is shown. Building <NUM> is served by a BMS. A BMS is, in general, a system of devices configured to control, monitor, and manage equipment in or around a building or building area. A BMS can include, for example, a HVAC system, a security system, a lighting system, a fire alerting system, any other system that is capable of managing building functions or devices, or any combination thereof.

The BMS that serves building <NUM> includes an HVAC system <NUM>. HVAC system <NUM> may include a plurality of HVAC devices (e.g., heaters, chillers, air handling units, pumps, fans, thermal energy storage, etc.) configured to provide heating, cooling, ventilation, or other services for building <NUM>. For example, HVAC system <NUM> is shown to include a waterside system <NUM> and an airside system <NUM>. Waterside system <NUM> may provide a heated or chilled fluid to an air handling unit of airside system <NUM>. Airside system <NUM> may use the heated or chilled fluid to heat or cool an airflow provided to building <NUM>. An exemplary waterside system and airside system which may be used in HVAC system <NUM> are described in greater detail with reference to <FIG>.

HVAC system <NUM> is shown to include a chiller <NUM>, a boiler <NUM>, and a rooftop air handling unit (AHU) <NUM>. Waterside system <NUM> may use boiler <NUM> and chiller <NUM> to heat or cool a working fluid (e.g., water, glycol, etc.) and may circulate the working fluid to AHU <NUM>. In various embodiments, the HVAC devices of waterside system <NUM> may be located in or around building <NUM> (as shown in <FIG>) or at an offsite location such as a central plant (e.g., a chiller plant, a steam plant, a heat plant, etc.). The working fluid may be heated in boiler <NUM> or cooled in chiller <NUM>, depending on whether heating or cooling is required in building <NUM>. Boiler <NUM> may add heat to the circulated fluid, for example, by burning a combustible material (e.g., natural gas) or using an electric heating element. Chiller <NUM> may place the circulated fluid in a heat exchange relationship with another fluid (e.g., a refrigerant) in a heat exchanger (e.g., an evaporator) to absorb heat from the circulated fluid. The working fluid from chiller <NUM> and/or boiler <NUM> may be transported to AHU <NUM> via piping <NUM>.

AHU <NUM> may place the working fluid in a heat exchange relationship with an airflow passing through AHU <NUM> (e.g., via one or more stages of cooling coils and/or heating coils). The airflow may be, for example, outside air, return air from within building <NUM>, or a combination of both. AHU <NUM> may transfer heat between the airflow and the working fluid to provide heating or cooling for the airflow. For example, AHU <NUM> may include one or more fans or blowers configured to pass the airflow over or through a heat exchanger containing the working fluid. The working fluid may then return to chiller <NUM> or boiler <NUM> via piping <NUM>.

Airside system <NUM> may deliver the airflow supplied by AHU <NUM> (i.e., the supply airflow) to building <NUM> via air supply ducts <NUM> and may provide return air from building <NUM> to AHU <NUM> via air return ducts <NUM>. In some embodiments, airside system <NUM> includes multiple variable air volume (VAV) units <NUM>. For example, airside system <NUM> is shown to include a separate VAV unit <NUM> on each floor or zone of building <NUM>. VAV units <NUM> may include dampers or other flow control elements that can be operated to control an amount of the supply airflow provided to individual zones of building <NUM>. In other embodiments, airside system <NUM> delivers the supply airflow into one or more zones of building <NUM> (e.g., via supply ducts <NUM>) without using intermediate VAV units <NUM> or other flow control elements. AHU <NUM> may include various sensors (e.g., temperature sensors, pressure sensors, etc.) configured to measure attributes of the supply airflow. AHU <NUM> may receive input from sensors located within AHU <NUM> and/or within the building zone and may adjust the flow rate, temperature, or other attributes of the supply airflow through AHU <NUM> to achieve setpoint conditions for the building zone.

Referring now to <FIG>, a block diagram of a waterside system <NUM> is shown, according to some embodiments. In various embodiments, waterside system <NUM> may supplement or replace waterside system <NUM> in HVAC system <NUM> or may be implemented separate from HVAC system <NUM>. When implemented in HVAC system <NUM>, waterside system <NUM> may include a subset of the HVAC devices in HVAC system <NUM> (e.g., boiler <NUM>, chiller <NUM>, pumps, valves, etc.) and may operate to supply a heated or chilled fluid to AHU <NUM>. The HVAC devices of waterside system <NUM> may be located within building <NUM> (e.g., as components of waterside system <NUM>) or at an offsite location such as a central plant.

In <FIG>, waterside system <NUM> is shown as a central plant having a plurality of subplants <NUM>-<NUM>. Subplants <NUM>-<NUM> are shown to include a heater subplant <NUM>, a heat recovery chiller subplant <NUM>, a chiller subplant <NUM>, a cooling tower subplant <NUM>, a hot thermal energy storage (TES) subplant <NUM>, and a cold thermal energy storage (TES) subplant <NUM>. Subplants <NUM>-<NUM> consume resources (e.g., water, natural gas, electricity, etc.) from utilities to serve the thermal energy loads (e.g., hot water, cold water, heating, cooling, etc.) of a building or campus. For example, heater subplant <NUM> may be configured to heat water in a hot water loop <NUM> that circulates the hot water between heater subplant <NUM> and building <NUM>. Chiller subplant <NUM> may be configured to chill water in a cold water loop <NUM> that circulates the cold water between chiller subplant <NUM> building <NUM>. Heat recovery chiller subplant <NUM> may be configured to transfer heat from cold water loop <NUM> to hot water loop <NUM> to provide additional heating for the hot water and additional cooling for the cold water. Condenser water loop <NUM> may absorb heat from the cold water in chiller subplant <NUM> and reject the absorbed heat in cooling tower subplant <NUM> or transfer the absorbed heat to hot water loop <NUM>. Hot TES subplant <NUM> and cold TES subplant <NUM> may store hot and cold thermal energy, respectively, for subsequent use.

Hot water loop <NUM> and cold water loop <NUM> may deliver the heated and/or chilled water to air handlers located on the rooftop of building <NUM> (e.g., AHU <NUM>) or to individual floors or zones of building <NUM> (e.g., VAV units <NUM>). The air handlers push air past heat exchangers (e.g., heating coils or cooling coils) through which the water flows to provide heating or cooling for the air. The heated or cooled air may be delivered to individual zones of building <NUM> to serve the thermal energy loads of building <NUM>. The water then returns to subplants <NUM>-<NUM> to receive further heating or cooling.

Although subplants <NUM>-<NUM> are shown and described as heating and cooling water for circulation to a building, it is understood that any other type of working fluid (e.g., glycol, CO2, etc.) may be used in place of or in addition to water to serve the thermal energy loads. In other embodiments, subplants <NUM>-<NUM> may provide heating and/or cooling directly to the building or campus without requiring an intermediate heat transfer fluid. These and other variations to waterside system <NUM> are within the teachings of the present disclosure.

Each of subplants <NUM>-<NUM> may include a variety of equipment configured to facilitate the functions of the subplant. For example, heater subplant <NUM> is shown to include a plurality of heating elements <NUM> (e.g., boilers, electric heaters, etc.) configured to add heat to the hot water in hot water loop <NUM>. Heater subplant <NUM> is also shown to include several pumps <NUM> and <NUM> configured to circulate the hot water in hot water loop <NUM> and to control the flow rate of the hot water through individual heating elements <NUM>. Chiller subplant <NUM> is shown to include a plurality of chillers <NUM> configured to remove heat from the cold water in cold water loop <NUM>. Chiller subplant <NUM> is also shown to include several pumps <NUM> and <NUM> configured to circulate the cold water in cold water loop <NUM> and to control the flow rate of the cold water through individual chillers <NUM>.

Heat recovery chiller subplant <NUM> is shown to include a plurality of heat recovery heat exchangers <NUM> (e.g., refrigeration circuits) configured to transfer heat from cold water loop <NUM> to hot water loop <NUM>. Heat recovery chiller subplant <NUM> is also shown to include several pumps <NUM> and <NUM> configured to circulate the hot water and/or cold water through heat recovery heat exchangers <NUM> and to control the flow rate of the water through individual heat recovery heat exchangers <NUM>. Cooling tower subplant <NUM> is shown to include a plurality of cooling towers <NUM> configured to remove heat from the condenser water in condenser water loop <NUM>. Cooling tower subplant <NUM> is also shown to include several pumps <NUM> configured to circulate the condenser water in condenser water loop <NUM> and to control the flow rate of the condenser water through individual cooling towers <NUM>.

Hot TES subplant <NUM> is shown to include a hot TES tank <NUM> configured to store the hot water for later use. Hot TES subplant <NUM> may also include one or more pumps or valves configured to control the flow rate of the hot water into or out of hot TES tank <NUM>. Cold TES subplant <NUM> is shown to include cold TES tanks <NUM> configured to store the cold water for later use. Cold TES subplant <NUM> may also include one or more pumps or valves configured to control the flow rate of the cold water into or out of cold TES tanks <NUM>.

In some embodiments, one or more of the pumps in waterside system <NUM> (e.g., pumps <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, and/or <NUM>) or pipelines in waterside system <NUM> include an isolation valve associated therewith. Isolation valves may be integrated with the pumps or positioned upstream or downstream of the pumps to control the fluid flows in waterside system <NUM>. In various embodiments, waterside system <NUM> may include more, fewer, or different types of devices and/or subplants based on the particular configuration of waterside system <NUM> and the types of loads served by waterside system <NUM>.

Referring now to <FIG>, a block diagram of an airside system <NUM> is shown, according to some embodiments. In various embodiments, airside system <NUM> may supplement or replace airside system <NUM> in HVAC system <NUM> or may be implemented separate from HVAC system <NUM>. When implemented in HVAC system <NUM>, airside system <NUM> may include a subset of the HVAC devices in HVAC system <NUM> (e.g., AHU <NUM>, VAV units <NUM>, ducts <NUM>-<NUM>, fans, dampers, etc.) and may be located in or around building <NUM>. Airside system <NUM> may operate to heat or cool an airflow provided to building <NUM> using a heated or chilled fluid provided by waterside system <NUM>.

In <FIG>, airside system <NUM> is shown to include an economizer-type air handling unit (AHU) <NUM>. Economizer-type AHUs vary the amount of outside air and return air used by the air handling unit for heating or cooling. For example, AHU <NUM> may receive return air <NUM> from building zone <NUM> via return air duct <NUM> and may deliver supply air <NUM> to building zone <NUM> via supply air duct <NUM>. In some embodiments, AHU <NUM> is a rooftop unit located on the roof of building <NUM> (e.g., AHU <NUM> as shown in <FIG>) or otherwise positioned to receive both return air <NUM> and outside air <NUM>. AHU <NUM> may be configured to operate exhaust air damper <NUM>, mixing damper <NUM>, and outside air damper <NUM> to control an amount of outside air <NUM> and return air <NUM> that combine to form supply air <NUM>. Any return air <NUM> that does not pass through mixing damper <NUM> may be exhausted from AHU <NUM> through exhaust damper <NUM> as exhaust air <NUM>.

Each of dampers <NUM>-<NUM> may be operated by an actuator. For example, exhaust air damper <NUM> may be operated by actuator <NUM>, mixing damper <NUM> may be operated by actuator <NUM>, and outside air damper <NUM> may be operated by actuator <NUM>. Actuators <NUM>-<NUM> may communicate with an AHU controller <NUM> via a communications link <NUM>. Actuators <NUM>-<NUM> may receive control signals from AHU controller <NUM> and may provide feedback signals to AHU controller <NUM>. Feedback signals may include, for example, an indication of a current actuator or damper position, an amount of torque or force exerted by the actuator, diagnostic information (e.g., results of diagnostic tests performed by actuators <NUM>-<NUM>), status information, commissioning information, configuration settings, calibration data, and/or other types of information or data that may be collected, stored, or used by actuators <NUM>-<NUM>. AHU controller <NUM> may be an economizer controller configured to use one or more control algorithms (e.g., state-based algorithms, extremum seeking control (ESC) algorithms, proportional-integral (PI) control algorithms, proportional-integral-derivative (PID) control algorithms, model predictive control (MPC) algorithms, feedback control algorithms, etc.) to control actuators <NUM>-<NUM>.

Still referring to <FIG>, AHU <NUM> is shown to include a cooling coil <NUM>, a heating coil <NUM>, and a fan <NUM> positioned within supply air duct <NUM>. Fan <NUM> may be configured to force supply air <NUM> through cooling coil <NUM> and/or heating coil <NUM> and provide supply air <NUM> to building zone <NUM>. AHU controller <NUM> may communicate with fan <NUM> via communications link <NUM> to control a flow rate of supply air <NUM>. In some embodiments, AHU controller <NUM> controls an amount of heating or cooling applied to supply air <NUM> by modulating a speed of fan <NUM>.

Cooling coil <NUM> may receive a chilled fluid from waterside system <NUM> (e.g., from cold water loop <NUM>) via piping <NUM> and may return the chilled fluid to waterside system <NUM> via piping <NUM>. Valve <NUM> may be positioned along piping <NUM> or piping <NUM> to control a flow rate of the chilled fluid through cooling coil <NUM>. In some embodiments, cooling coil <NUM> includes multiple stages of cooling coils that can be independently activated and deactivated (e.g., by AHU controller <NUM>, by BMS controller <NUM>, etc.) to modulate an amount of cooling applied to supply air <NUM>.

Heating coil <NUM> may receive a heated fluid from waterside system <NUM>(e.g., from hot water loop <NUM>) via piping <NUM> and may return the heated fluid to waterside system <NUM> via piping <NUM>. Valve <NUM> may be positioned along piping <NUM> or piping <NUM> to control a flow rate of the heated fluid through heating coil <NUM>. In some embodiments, heating coil <NUM> includes multiple stages of heating coils that can be independently activated and deactivated (e.g., by AHU controller <NUM>, by BMS controller <NUM>, etc.) to modulate an amount of heating applied to supply air <NUM>.

Each of valves <NUM> and <NUM> may be controlled by an actuator. For example, valve <NUM> may be controlled by actuator <NUM> and valve <NUM> may be controlled by actuator <NUM>. Actuators <NUM>-<NUM> may communicate with AHU controller <NUM> via communications links <NUM>-<NUM>. Actuators <NUM>-<NUM> may receive control signals from AHU controller <NUM> and may provide feedback signals to controller <NUM>. In some embodiments, AHU controller <NUM> receives a measurement of the supply air temperature from a temperature sensor <NUM> positioned in supply air duct <NUM> (e.g., downstream of cooling coil <NUM> and/or heating coil <NUM>). AHU controller <NUM> may also receive a measurement of the temperature of building zone <NUM> from a temperature sensor <NUM> located in building zone <NUM>.

In some embodiments, AHU controller <NUM> operates valves <NUM> and <NUM> via actuators <NUM>-<NUM> to modulate an amount of heating or cooling provided to supply air <NUM> (e.g., to achieve a setpoint temperature for supply air <NUM> or to maintain the temperature of supply air <NUM> within a setpoint temperature range). The positions of valves <NUM> and <NUM> affect the amount of heating or cooling provided to supply air <NUM> by cooling coil <NUM> or heating coil <NUM> and may correlate with the amount of energy consumed to achieve a desired supply air temperature. AHU controller <NUM> may control the temperature of supply air <NUM> and/or building zone <NUM> by activating or deactivating coils <NUM>-<NUM>, adjusting a speed of fan <NUM>, or a combination of both.

Still referring to <FIG>, airside system <NUM> is shown to include a building management system (BMS) controller <NUM> and a client device <NUM>. BMS controller <NUM> may include one or more computer systems (e.g., servers, supervisory controllers, subsystem controllers, etc.) that serve as system level controllers, application or data servers, head nodes, or master controllers for airside system <NUM>, waterside system <NUM>, HVAC system <NUM>, and/or other controllable systems that serve building <NUM>. BMS controller <NUM> may communicate with multiple downstream building systems or subsystems (e.g., HVAC system <NUM>, a security system, a lighting system, waterside system <NUM>, etc.) via a communications link <NUM> according to like or disparate protocols (e.g., LON, BACnet, etc.). In various embodiments, AHU controller <NUM> and BMS controller <NUM> may be separate (as shown in <FIG>) or integrated. In an integrated implementation, AHU controller <NUM> may be a software module configured for execution by a processor of BMS controller <NUM>.

In some embodiments, AHU controller <NUM> receives information from BMS controller <NUM> (e.g., commands, setpoints, operating boundaries, etc.) and provides information to BMS controller <NUM> (e.g., temperature measurements, valve or actuator positions, operating statuses, diagnostics, etc.). For example, AHU controller <NUM> may provide BMS controller <NUM> with temperature measurements from temperature sensors <NUM>-<NUM>, equipment on/off states, equipment operating capacities, and/or any other information that can be used by BMS controller <NUM> to monitor or control a variable state or condition within building zone <NUM>.

Client device <NUM> may include one or more human-machine interfaces or client interfaces (e.g., graphical user interfaces, reporting interfaces, text-based computer interfaces, client-facing web services, web servers that provide pages to web clients, etc.) for controlling, viewing, or otherwise interacting with HVAC system <NUM>, its subsystems, and/or devices. Client device <NUM> may be a computer workstation, a client terminal, a remote or local interface, or any other type of user interface device. Client device <NUM> may be a stationary terminal or a mobile device. For example, client device <NUM> may be a desktop computer, a computer server with a user interface, a laptop computer, a tablet, a smartphone, a PDA, or any other type of mobile or non-mobile device. Client device <NUM> may communicate with BMS controller <NUM> and/or AHU controller <NUM> via communications link <NUM>.

Referring now to <FIG>, a block diagram of a building management system (BMS) <NUM> is shown, according to some embodiments. BMS <NUM> may be implemented in building <NUM> to automatically monitor and control various building functions. BMS <NUM> is shown to include BMS controller <NUM> and a plurality of building subsystems <NUM>. Building subsystems <NUM> are shown to include a building electrical subsystem <NUM>, an information communication technology (ICT) subsystem <NUM>, a security subsystem <NUM>, a HVAC subsystem <NUM>, a lighting subsystem <NUM>, a lift/escalators subsystem <NUM>, and a fire safety subsystem <NUM>. In various embodiments, building subsystems <NUM> can include fewer, additional, or alternative subsystems. For example, building subsystems <NUM> may also or alternatively include a refrigeration subsystem, an advertising or signage subsystem, a cooking subsystem, a vending subsystem, a printer or copy service subsystem, or any other type of building subsystem that uses controllable equipment and/or sensors to monitor or control building <NUM>. In some embodiments, building subsystems <NUM> include waterside system <NUM> and/or airside system <NUM>, as described with reference to <FIG>.

Each of building subsystems <NUM> may include any number of devices, controllers, and connections for completing its individual functions and control activities. HVAC subsystem <NUM> may include many of the same components as HVAC system <NUM>, as described with reference to <FIG>. For example, HVAC subsystem <NUM> may include and number of chillers, heaters, handling units, economizers, field controllers, supervisory controllers, actuators, temperature sensors, and/or other devices for controlling the temperature, humidity, airflow, or other variable conditions within building <NUM>. Lighting subsystem <NUM> may include any number of light fixtures, ballasts, lighting sensors, dimmers, or other devices configured to controllably adjust the amount of light provided to a building space. Security subsystem <NUM> may include occupancy sensors, video surveillance cameras, digital video recorders, video processing servers, intrusion detection devices, access control devices and servers, or other security-related devices.

Still referring to <FIG>, BMS controller <NUM> is shown to include a communications interface <NUM> and a BMS interface <NUM>. Interface <NUM> may facilitate communications between BMS controller <NUM> and external applications (e.g., monitoring and reporting applications <NUM>, enterprise control applications <NUM>, remote systems and applications <NUM>, applications residing on client devices <NUM>, etc.) for allowing user control, monitoring, and adjustment to BMS controller <NUM> and/or subsystems <NUM>. Interface <NUM> may also facilitate communications between BMS controller <NUM> and client devices <NUM>. BMS interface <NUM> may facilitate communications between BMS controller <NUM> and building subsystems <NUM> (e.g., HVAC, lighting security, lifts, power distribution, business, etc.).

Interfaces <NUM>, <NUM> can be or include wired or wireless communications interfaces (e.g., jacks, antennas, transmitters, receivers, transceivers, wire terminals, etc.) for conducting data communications with building subsystems <NUM> or other external systems or devices. In various embodiments, communications via interfaces <NUM>, <NUM> may be direct (e.g., local wired or wireless communications) or via a communications network <NUM> (e.g., a WAN, the Internet, a cellular network, etc.). For example, interfaces <NUM>, <NUM> can include an Ethernet card and port for sending and receiving data via an Ethernet-based communications link or network. In another example, interfaces <NUM>, <NUM> can include a WiFi transceiver for communicating via a wireless communications network. In another example, one or both of interfaces <NUM>, <NUM> may include cellular or mobile phone communications transceivers. In some embodiments, communications interface <NUM> is a power line communications interface and BMS interface <NUM> is an Ethernet interface. In other embodiments, both communications interface <NUM> and BMS interface <NUM> are Ethernet interfaces or are the same Ethernet interface.

Still referring to <FIG>, BMS controller <NUM> is shown to include a processing circuit <NUM> including a processor <NUM> and memory <NUM>. Processing circuit <NUM> may be communicably connected to BMS interface <NUM> and/or communications interface <NUM> such that processing circuit <NUM> and the various components thereof can send and receive data via interfaces <NUM>, <NUM>. Processor <NUM> can be implemented as a general purpose processor, an application specific integrated circuit (ASIC), one or more field programmable gate arrays (FPGAs), a group of processing components, or other suitable electronic processing components.

Memory <NUM> (e.g., memory, memory unit, storage device, etc.) may include one or more devices (e.g., RAM, ROM, Flash memory, hard disk storage, etc.) for storing data and/or computer code for completing or facilitating the various processes, layers and modules described in the present application. Memory <NUM> may be or include volatile memory or non-volatile memory. Memory <NUM> may include database components, object code components, script components, or any other type of information structure for supporting the various activities and information structures described in the present application. According to some embodiments, memory <NUM> is communicably connected to processor <NUM> via processing circuit <NUM> and includes computer code for executing (e.g., by processing circuit <NUM> and/or processor <NUM>) one or more processes described herein.

In some embodiments, BMS controller <NUM> is implemented within a single computer (e.g., one server, one housing, etc.). In various other embodiments BMS controller <NUM> may be distributed across multiple servers or computers (e.g., that can exist in distributed locations). Further, while <FIG> shows applications <NUM> and <NUM> as existing outside of BMS controller <NUM>, in some embodiments, applications <NUM> and <NUM> may be hosted within BMS controller <NUM> (e.g., within memory <NUM>).

Still referring to <FIG>, memory <NUM> is shown to include an enterprise integration layer <NUM>, an automated measurement and validation (AM&V) layer <NUM>, a demand response (DR) layer <NUM>, a fault detection and diagnostics (FDD) layer <NUM>, an integrated control layer <NUM>, and a building subsystem integration later <NUM>. Layers <NUM>-<NUM> may be configured to receive inputs from building subsystems <NUM> and other data sources, determine optimal control actions for building subsystems <NUM> based on the inputs, generate control signals based on the optimal control actions, and provide the generated control signals to building subsystems <NUM>. The following paragraphs describe some of the general functions performed by each of layers <NUM>-<NUM> in BMS <NUM>.

Enterprise integration layer <NUM> may be configured to serve clients or local applications with information and services to support a variety of enterprise-level applications. For example, enterprise control applications <NUM> may be configured to provide subsystem-spanning control to a graphical user interface (GUI) or to any number of enterprise-level business applications (e.g., accounting systems, user identification systems, etc.). Enterprise control applications <NUM> may also or alternatively be configured to provide configuration GUIs for configuring BMS controller <NUM>. In yet other embodiments, enterprise control applications <NUM> can work with layers <NUM>-<NUM> to optimize building performance (e.g., efficiency, energy use, comfort, or safety) based on inputs received at interface <NUM> and/or BMS interface <NUM>.

Building subsystem integration layer <NUM> may be configured to manage communications between BMS controller <NUM> and building subsystems <NUM>. For example, building subsystem integration layer <NUM> may receive sensor data and input signals from building subsystems <NUM> and provide output data and control signals to building subsystems <NUM>. Building subsystem integration layer <NUM> may also be configured to manage communications between building subsystems <NUM>. Building subsystem integration layer <NUM> translate communications (e.g., sensor data, input signals, output signals, etc.) across a plurality of multi-vendor/multi-protocol systems.

Demand response layer <NUM> may be configured to optimize resource usage (e.g., electricity use, natural gas use, water use, etc.) and/or the monetary cost of such resource usage in response to satisfy the demand of building <NUM>. The optimization may be based on time-of-use prices, curtailment signals, energy availability, or other data received from utility providers, distributed energy generation systems <NUM>, from energy storage <NUM> (e.g., hot TES <NUM>, cold TES <NUM>, etc.), or from other sources. Demand response layer <NUM> may receive inputs from other layers of BMS controller <NUM> (e.g., building subsystem integration layer <NUM>, integrated control layer <NUM>, etc.). The inputs received from other layers may include environmental or sensor inputs such as temperature, carbon dioxide levels, relative humidity levels, air quality sensor outputs, occupancy sensor outputs, room schedules, and the like. The inputs may also include inputs such as electrical use (e.g., expressed in kWh), thermal load measurements, pricing information, projected pricing, smoothed pricing, curtailment signals from utilities, and the like.

According to some embodiments, demand response layer <NUM> includes control logic for responding to the data and signals it receives. These responses can include communicating with the control algorithms in integrated control layer <NUM>, changing control strategies, changing setpoints, or activating/deactivating building equipment or subsystems in a controlled manner. Demand response layer <NUM> may also include control logic configured to determine when to utilize stored energy. For example, demand response layer <NUM> may determine to begin using energy from energy storage <NUM> just prior to the beginning of a peak use hour.

In some embodiments, demand response layer <NUM> includes a control module configured to actively initiate control actions (e.g., automatically changing setpoints) which minimize energy costs based on one or more inputs representative of or based on demand (e.g., price, a curtailment signal, a demand level, etc.). In some embodiments, demand response layer <NUM> uses equipment models to determine an optimal set of control actions. The equipment models may include, for example, thermodynamic models describing the inputs, outputs, and/or functions performed by various sets of building equipment. Equipment models may represent collections of building equipment (e.g., subplants, chiller arrays, etc.) or individual devices (e.g., individual chillers, heaters, pumps, etc.).

Demand response layer <NUM> may further include or draw upon one or more demand response policy definitions (e.g., databases, XML files, etc.). The policy definitions may be edited or adjusted by a user (e.g., via a graphical user interface) so that the control actions initiated in response to demand inputs may be tailored for the user's application, desired comfort level, particular building equipment, or based on other concerns. For example, the demand response policy definitions can specify which equipment may be turned on or off in response to particular demand inputs, how long a system or piece of equipment should be turned off, what setpoints can be changed, what the allowable set point adjustment range is, how long to hold a high demand setpoint before returning to a normally scheduled setpoint, how close to approach capacity limits, which equipment modes to utilize, the energy transfer rates (e.g., the maximum rate, an alarm rate, other rate boundary information, etc.) into and out of energy storage devices (e.g., thermal storage tanks, battery banks, etc.), and when to dispatch on-site generation of energy (e.g., via fuel cells, a motor generator set, etc.).

Integrated control layer <NUM> may be configured to use the data input or output of building subsystem integration layer <NUM> and/or demand response later <NUM> to make control decisions. Due to the subsystem integration provided by building subsystem integration layer <NUM>, integrated control layer <NUM> can integrate control activities of the subsystems <NUM> such that the subsystems <NUM> behave as a single integrated supersystem. In some embodiments, integrated control layer <NUM> includes control logic that uses inputs and outputs from a plurality of building subsystems to provide greater comfort and energy savings relative to the comfort and energy savings that separate subsystems could provide alone. For example, integrated control layer <NUM> may be configured to use an input from a first subsystem to make an energy-saving control decision for a second subsystem. Results of these decisions can be communicated back to building subsystem integration layer <NUM>.

Integrated control layer <NUM> is shown to be logically below demand response layer <NUM>. Integrated control layer <NUM> may be configured to enhance the effectiveness of demand response layer <NUM> by enabling building subsystems <NUM> and their respective control loops to be controlled in coordination with demand response layer <NUM>. This configuration may advantageously reduce disruptive demand response behavior relative to conventional systems. For example, integrated control layer <NUM> may be configured to assure that a demand response-driven upward adjustment to the setpoint for chilled water temperature (or another component that directly or indirectly affects temperature) does not result in an increase in fan energy (or other energy used to cool a space) that would result in greater total building energy use than was saved at the chiller.

Integrated control layer <NUM> may be configured to provide feedback to demand response layer <NUM> so that demand response layer <NUM> checks that constraints (e.g., temperature, lighting levels, etc.) are properly maintained even while demanded load shedding is in progress. The constraints may also include setpoint or sensed boundaries relating to safety, equipment operating limits and performance, comfort, fire codes, electrical codes, energy codes, and the like. Integrated control layer <NUM> is also logically below fault detection and diagnostics layer <NUM> and automated measurement and validation layer <NUM>. Integrated control layer <NUM> may be configured to provide calculated inputs (e.g., aggregations) to these higher levels based on outputs from more than one building subsystem.

Automated measurement and validation (AM&V) layer <NUM> may be configured to verify that control strategies commanded by integrated control layer <NUM> or demand response layer <NUM> are working properly (e.g., using data aggregated by AM&V layer <NUM>, integrated control layer <NUM>, building subsystem integration layer <NUM>, FDD layer <NUM>, or otherwise). The calculations made by AM&V layer <NUM> may be based on building system energy models and/or equipment models for individual BMS devices or subsystems. For example, AM&V layer <NUM> may compare a model-predicted output with an actual output from building subsystems <NUM> to determine an accuracy of the model.

Fault detection and diagnostics (FDD) layer <NUM> may be configured to provide ongoing fault detection for building subsystems <NUM>, building subsystem devices (i.e., building equipment), and control algorithms used by demand response layer <NUM> and integrated control layer <NUM>. FDD layer <NUM> may receive data inputs from integrated control layer <NUM>, directly from one or more building subsystems or devices, or from another data source. FDD layer <NUM> may automatically diagnose and respond to detected faults. The responses to detected or diagnosed faults may include providing an alert message to a user, a maintenance scheduling system, or a control algorithm configured to attempt to repair the fault or to work-around the fault.

FDD layer <NUM> may be configured to output a specific identification of the faulty component or cause of the fault (e.g., loose damper linkage) using detailed subsystem inputs available at building subsystem integration layer <NUM>. In other exemplary embodiments, FDD layer <NUM> is configured to provide "fault" events to integrated control layer <NUM> which executes control strategies and policies in response to the received fault events. According to some embodiments, FDD layer <NUM> (or a policy executed by an integrated control engine or business rules engine) may shut-down systems or direct control activities around faulty devices or systems to reduce energy waste, extend equipment life, or assure proper control response.

FDD layer <NUM> may be configured to store or access a variety of different system data stores (or data points for live data). FDD layer <NUM> may use some content of the data stores to identify faults at the equipment level (e.g., specific chiller, specific AHU, specific terminal unit, etc.) and other content to identify faults at component or subsystem levels. For example, building subsystems <NUM> may generate temporal (i.e., time-series) data indicating the performance of BMS <NUM> and the various components thereof. The data generated by building subsystems <NUM> may include measured or calculated values that exhibit statistical characteristics and provide information about how the corresponding system or process (e.g., a temperature control process, a flow control process, etc.) is performing in terms of error from its setpoint. These processes can be examined by FDD layer <NUM> to expose when the system begins to degrade in performance and alert a user to repair the fault before it becomes more severe.

Referring now to <FIG>, an actuator <NUM> for use in a HVAC system is shown, according to some embodiments. In some implementations, actuator <NUM> may be used in HVAC system <NUM>, waterside system <NUM>, airside system <NUM>, or BMS <NUM>, as described with reference to <FIG>. For example, actuator <NUM> may be a damper actuator, a valve actuator, a fan actuator, a pump actuator, or any other type of actuator that can be used in a HVAC system or BMS. In various embodiments, actuator <NUM> may be a linear actuator (e.g., a linear proportional actuator), a non-linear actuator, a spring return actuator, or a non-spring return actuator.

Actuator <NUM> is shown to include a housing <NUM> having a front side <NUM> (i.e., side A), a rear side <NUM> (i.e., side B) opposite front side <NUM>, and a bottom <NUM>. Housing <NUM> may contain the mechanical and processing components of actuator <NUM>. In some embodiments, housing <NUM> contains a brushless direct current (BLDC) motor and a processing circuit configured to provide a pulse width modulated (PWM) DC output to control the speed of the BLDC motor. The processing circuit may be configured to compare a representation of the electric current output to the BLDC motor to a threshold and may hold the PWM DC output in an off state when the current exceeds the threshold. The processing circuit may also be configured to set the PWM DC output to zero and then ramp up the PWM DC output when actuator <NUM> approaches an end stop. The internal components of actuator <NUM> are described in greater detail with reference to <FIG>.

Actuator <NUM> is shown to include a drive device <NUM>. Drive device <NUM> may be a drive mechanism, a hub, or other device configured to drive or effectuate movement of a HVAC system component. For example, drive device <NUM> may be configured to receive a shaft of a damper, a valve, or any other movable HVAC system component in order to drive (e.g., rotate) the shaft. In some embodiments, actuator <NUM> includes a coupling device <NUM> configured to aid in coupling drive device <NUM> to the movable HVAC system component. For example, coupling device <NUM> may facilitate attaching drive device <NUM> to a valve or damper shaft.

Actuator <NUM> is shown to include an input connection <NUM> and an output connection <NUM>. In some embodiments, input connection <NUM> and output connection <NUM> are located along bottom <NUM>. In other embodiments, input connection <NUM> and output connection <NUM> may be located along one or more other surfaces of housing <NUM>. Input connection <NUM> may be configured to receive a control signal (e.g., a voltage input signal) from an external system or device. Actuator <NUM> may use the control signal to determine an appropriate PWM DC output for the BLDC motor. In some embodiments, the control signal is received from a controller such as an AHU controller (e.g., AHU controller <NUM>), an economizer controller, a supervisory controller (e.g., BMS controller <NUM>), a zone controller, a field controller, an enterprise level controller, a motor controller, an equipment-level controller (e.g., an actuator controller) or any other type of controller that can be used in a HVAC system or BMS.

In some embodiments, the control signal is a DC voltage signal. Actuator <NUM> may be a linear proportional actuator configured to control the position of drive device <NUM> according to the value of the DC voltage received at input connection <NUM>. For example, a minimum input voltage (e.g., <NUM> VDC) may correspond to a minimum rotational position of drive device <NUM> (e.g., <NUM> degrees, -<NUM> degrees, etc.), whereas a maximum input voltage (e.g., <NUM> VDC) may correspond to a maximum rotational position of drive device <NUM> (e.g., <NUM> degrees, <NUM> degrees, etc.). Input voltages between the minimum and maximum input voltages may cause actuator <NUM> to move drive device <NUM> into an intermediate position between the minimum rotational position and the maximum rotational position. In other embodiments, actuator <NUM> may be a non-linear actuator or may use different input voltage ranges or a different type of input signal (e.g., AC voltage or current) to control the position and/or rotational speed of drive device <NUM>.

In some embodiments, the control signal is an AC voltage signal. Input connection <NUM> may be configured to receive an AC voltage signal having a standard power line voltage (e.g., <NUM> VAC or <NUM> VAC at <NUM>/<NUM>). The frequency of the voltage signal may be modulated (e.g., by a controller for actuator <NUM>) to adjust the rotational position and/or speed of drive device <NUM>. In some embodiments, actuator <NUM> uses the voltage signal to power various components of actuator <NUM>. Actuator <NUM> may use the AC voltage signal received via input connection <NUM> as a control signal, a source of electric power, or both. In some embodiments, the voltage signal is received at input connection <NUM> from a power supply line that provides actuator <NUM> with an AC voltage having a constant or substantially constant frequency (e.g., <NUM> VAC or <NUM> VAC at <NUM> or <NUM>). Input connection <NUM> may include one or more data connections (separate from the power supply line) through which actuator <NUM> receives control signals from a controller or another actuator (e.g., <NUM>-<NUM> VDC control signals).

In some embodiments, the control signal is received at input connection <NUM> from another actuator. For example, if multiple actuators are interconnected in a tandem arrangement, input connection <NUM> may be connected (e.g., via a communications bus) to the output data connection of another actuator. One of the actuators may be arranged as a master actuator with its input connection <NUM> connected to a controller, whereas the other actuators may be arranged as slave actuators with their respective input connections connected to the output connection <NUM> of the master actuator.

Output connection <NUM> may be configured to provide a feedback signal to a controller of the HVAC system or BMS in which actuator <NUM> is implemented (e.g., an AHU controller, an economizer controller, a supervisory controller, a zone controller, a field controller, an enterprise level controller, etc.). The feedback signal may indicate the rotational position and/or speed of actuator <NUM>. In some embodiments, output connection <NUM> may be configured to provide a control signal to another actuator (e.g., a slave actuator) arranged in tandem with actuator <NUM>. Input connection <NUM> and output connection <NUM> may be connected to the controller or the other actuator via a communications bus. The communications bus may be a wired or wireless communications link and may use any of a variety of disparate communications protocols (e.g., BACnet, LON, WiFi, Bluetooth, NFC, TCP/IP, etc.).

Still referring to <FIG>, actuator <NUM> is shown to include a first user-operable switch <NUM> located along front side <NUM> (shown in <FIG>) and a second user-operable switch <NUM> located along rear side <NUM> (shown in <FIG>). Switches <NUM>-<NUM> may be potentiometers or any other type of switch (e.g., push button switches such as switch <NUM>, dials, flippable switches, etc.). Switches <NUM>-<NUM> may be used to set actuator <NUM> to a particular operating mode or to configure actuator <NUM> to accept a particular type of input. However, it should be understood that switches <NUM>-<NUM> are optional components and are not required for actuator <NUM> to perform the processes described herein. As such, one or more of switches <NUM>-<NUM> may be omitted without departing from the teachings of the present disclosure.

Referring particularly to <FIG>, switch <NUM> may be a mode selection switch having a distinct number of modes or positions. Switch <NUM> may be provided for embodiments in which actuator <NUM> is a linear proportional actuator that controls the position of drive device <NUM> as a function of a DC input voltage received at input connection <NUM>. In some embodiments, the function of mode selection switch <NUM> is the same or similar to the function of the mode selection switch described in <CIT>, the entire disclosure of which is incorporated by reference herein. For example, the position of mode selection switch <NUM> may be adjusted to set actuator <NUM> to operate in a direct acting mode, a reverse acting mode, or a calibration mode. In some embodiments, switch <NUM> is an optional component and can be omitted.

Mode selection switch <NUM> is shown to include a <NUM>-<NUM> direct acting (DA) mode, a <NUM>-<NUM> DA mode, a calibration (CAL) mode, a <NUM>-<NUM> reverse acting (RA) mode, and a <NUM>-<NUM> RA mode. According to other exemplary embodiments, mode selection switch <NUM> may have a greater or smaller number of modes and/or may have modes other than listed as above. The position of mode selection switch <NUM> may define the range of DC input voltages that correspond to the rotational range of drive device <NUM>. For example, when mode selection switch <NUM> is set to <NUM>-<NUM> DA, an input voltage of <NUM> VDC may correspond to <NUM> degrees of rotation position for drive device <NUM>. For this same mode, an input voltage of <NUM> VDC may correspond to <NUM> degrees of rotation position, <NUM> VDC may correspond to <NUM> degrees of rotation position, <NUM> VDC may correspond to <NUM> degrees of rotation position, <NUM> VDC may correspond to <NUM> degrees of rotation position, <NUM> VDC may correspond to <NUM> degrees of rotation position, and <NUM> VDC may correspond to <NUM> degrees of rotation position. It should be understood that these voltages and corresponding rotational positions are merely exemplary and may be different in various implementations.

Referring particularly to <FIG>, switch <NUM> may be a mode selection switch having a distinct number or modes or positions. Switch <NUM> may be provided for embodiments in which actuator <NUM> is configured to accept an AC voltage at input connection <NUM>. In some embodiments, the function of mode selection switch <NUM> is the same or similar to the function of the mode selection switch described in <CIT>, the entire disclosure of which is incorporated by reference herein. For example, the position of switch <NUM> may be adjusted to set actuator <NUM> to accept various different AC voltages at input connection <NUM>. In some embodiments, switch <NUM> is an optional component and can be omitted.

Mode selection switch <NUM> is shown to include a "<NUM> VAC" position, a "<NUM> VAC" position, a "<NUM> VAC" position, an "Auto" position. Each position of switch <NUM> may correspond to a different operating mode. According to other exemplary embodiments, switch <NUM> may have a greater or lesser number of positions and/or may have modes other than the modes explicitly listed. The different operating modes indicated by switch <NUM> may correspond to different voltage reduction factors applied to the input voltage received at input connection <NUM>. For example, with switch <NUM> in the <NUM> VAC position, actuator <NUM> may be configured to accept an input voltage of approximately <NUM> VAC (e.g., <NUM>-<NUM> VAC) at input connection <NUM> and may apply a reduction factor of approximately <NUM> to the input voltage. With switch <NUM> in the <NUM> VAC position, actuator <NUM> may be configured to accept an input voltage of approximately <NUM> VAC (e.g., <NUM>-<NUM> VAC, <NUM>-<NUM> VAC, etc.) at input connection <NUM> and may apply a reduction factor of approximately <NUM> (e.g., <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, etc.) to the input voltage. With switch <NUM> in the <NUM> VAC position, actuator <NUM> may be configured to accept an input voltage of approximately <NUM> VAC (e.g., <NUM>-<NUM> VAC, <NUM>-<NUM> VAC, etc.) at input connection <NUM> and may apply a reduction factor of approximately <NUM> (e.g., <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, etc.) to the input voltage. With switch <NUM> in the "Auto" position, actuator <NUM> may be configured automatically determine the input voltage received at input connection <NUM> and may adjust the voltage reduction factor accordingly.

Referring now to <FIG>, a block diagram illustrating actuator <NUM> in greater detail is shown, according to some embodiments. Actuator <NUM> is shown to include input connection <NUM>, output connection <NUM>, and drive device <NUM> contained within housing <NUM>. Actuator <NUM> is shown to further include a brushless DC (BLDC) motor <NUM> connected to drive device <NUM>, a motor drive inverter <NUM> (e.g., an H-bridge) configured to provide a three-phase pulse width modulated (PWM) voltage output to BLDC motor <NUM>, a motor current sensor <NUM> (e.g., a current sense resistor) configured to sense the electric current provided to BLDC motor <NUM>, and position sensors <NUM> configured to measure the rotational position of BLDC motor <NUM> and/or drive device <NUM>.

BLDC motor <NUM> may be connected to drive device <NUM> and may be configured to rotate drive device <NUM> through a range of rotational positions. For example, a shaft of BLDC motor <NUM> may be coupled to drive device <NUM> (e.g., via a drive train or gearing arrangement) such that rotation of the motor shaft causes a corresponding rotation of drive device <NUM>. In some embodiments, the drive train functions as a transmission. The drive train may translate a relatively high speed, low torque output from BLDC motor <NUM> into a relatively low speed, high torque output suitable for driving a HVAC component connected to drive device <NUM> (e.g., a damper, a fluid valve, etc.). For example, the drive train may provide a speed reduction of approximately <NUM>:<NUM>, <NUM>:<NUM>, <NUM>:<NUM>, or any other speed reduction as may be suitable for various implementations.

BLDC motor <NUM> may be configured to receive a three-phase PWM voltage output (e.g., phase A, phase B, phase C) from motor drive inverter <NUM>. The duty cycle of the PWM voltage output may define the rotational speed of BLDC motor <NUM> and may be determined by processing circuit <NUM> (e.g., a microcontroller). Processing circuit <NUM> may increase the duty cycle of the PWM voltage output to increase the speed of BLDC motor <NUM> and may decrease the duty cycle of the PWM voltage output to decrease the speed of BLDC motor <NUM>. Processing circuit <NUM> is shown providing a PWM voltage output <NUM> and phase switch outputs <NUM> to motor drive inverter <NUM>. Motor drive inverter <NUM> may use phase switch outputs <NUM> to apply PWM output <NUM> to a particular winding of BLDC motor <NUM>. The operation of motor drive inverter <NUM> is described in greater detail with reference to <FIG>.

Position sensors <NUM> may include Hall effect sensors, potentiometers, optical sensors, or other types of sensors configured to measure the rotational position of BLDC motor <NUM> and/or drive device <NUM>. Position sensors <NUM> may provide position signals <NUM> to processing circuit <NUM>. Processing circuit <NUM> uses position signals <NUM> to determine whether to operate BLDC motor <NUM>. For example, processing circuit <NUM> may compare the current position of drive device <NUM> with a position setpoint received via input connection <NUM> and may operate BLDC motor <NUM> to achieve the position setpoint.

Motor current sensor <NUM> may be configured to measure the electric current provided to BLDC motor <NUM>. Motor current sensor <NUM> may generate a feedback signal indicating the motor current <NUM> and may provide feedback signal to processing circuit <NUM>. Processing circuit <NUM> may be configured to compare the motor current <NUM> to a threshold <NUM> (e.g., using comparator <NUM>) and may hold PWM output <NUM> in an off state when motor current <NUM> exceeds threshold <NUM>. Processing circuit <NUM> may also be configured to set PWM output <NUM> to zero and then ramp up PWM output <NUM> when the position of drive device <NUM> approaches an end stop. These and other features of actuator <NUM> are described in greater detail below.

Still referring to <FIG>, processing circuit <NUM> is shown to include a processor <NUM> and memory <NUM>. Processor <NUM> may be a general purpose or specific purpose processor, an application specific integrated circuit (ASIC), one or more field programmable gate arrays (FPGAs), a group of processing components, or other suitable processing components. Processor <NUM> may be configured to execute computer code or instructions stored in memory <NUM> or received from other computer readable media (e.g., CDROM, network storage, a remote server, etc.).

Memory <NUM> may include one or more devices (e.g., memory units, memory devices, storage devices, etc.) for storing data and/or computer code for completing and/or facilitating the various processes described in the present disclosure. Memory <NUM> may include random access memory (RAM), read-only memory (ROM), hard drive storage, temporary storage, non-volatile memory, flash memory, optical memory, or any other suitable memory for storing software objects and/or computer instructions. Memory <NUM> may include database components, object code components, script components, or any other type of information structure for supporting the various activities and information structures described in the present disclosure. Memory <NUM> may be communicably connected to processor <NUM> via processing circuit <NUM> and may include computer code for executing (e.g., by processor <NUM>) one or more processes described herein. When processor <NUM> executes instructions stored in memory <NUM>, processor <NUM> generally configures actuator <NUM> (and more particularly processing circuit <NUM>) to complete such activities.

Processing circuit <NUM> is shown to include a main actuator controller <NUM>. Main actuator controller <NUM> may be configured to receive control signals <NUM> from input connection <NUM> (e.g., position setpoints, speed setpoints, etc.) and position signals <NUM> from position sensors <NUM>. Main actuator controller <NUM> may be configured to determine the position of BLDC motor <NUM> and/or drive device <NUM> based on position signals <NUM>. In some embodiments, main actuator controller <NUM> calculates the speed of BLDC motor <NUM> and/or drive device <NUM> using a difference in the measured positions over time. For example, the speed of BLDC motor <NUM> may be determined by main actuator controller <NUM> using a measured time between Hall sensor interrupt signals provided by Hall sensors integral to BLDC motor <NUM>.

Main actuator controller <NUM> may determine an appropriate speed setpoint <NUM> for BLDC motor <NUM> (e.g., in percentage terms, in terms of absolute position or speed, etc.). In some embodiments, main actuator controller <NUM> provides speed setpoint <NUM> to PWM speed controller <NUM>. In other embodiments, main actuator controller <NUM> calculates an appropriate PWM duty cycle to achieve a desired speed and provides the PWM duty cycle to PWM speed controller <NUM>. In some embodiments, main actuator controller <NUM> calculates speed setpoint <NUM> based on the position of drive device <NUM>. For example, main actuator controller <NUM> may be configured to set speed setpoint <NUM> to zero when the position of drive device is within a predetermined distance from an end stop. Main actuator controller <NUM> may then cause speed setpoint <NUM> to ramp up until the end stop is reached. These and other features of main actuator controller <NUM> are described in greater detail with reference to <FIG>.

Still referring to <FIG>, processing circuit <NUM> is shown to include a PWM speed controller <NUM>. PWM speed controller <NUM> may receive a speed setpoint <NUM> and/or a PWM duty cycle from main actuator controller <NUM>. PWM speed controller <NUM> may generate PWM output <NUM> (e.g., a PWM DC voltage output) and provide PWM output <NUM> to motor drive inverter <NUM>. The duty cycle of PWM output <NUM> may determine the speed of rotation for BLDC motor <NUM>. The width of the output PWM pulses can be adjusted by PWM speed controller <NUM> to achieve varying commanded motor speeds and/or to obtain varying motor or actuator positions.

In some embodiments, PWM speed controller <NUM> provides phase switch outputs <NUM> to motor drive inverter <NUM>. Phase switch outputs <NUM> may be used by motor drive inverter <NUM> to control the polarity of the PWM output <NUM> provided to the windings of BLDC motor <NUM>. In some embodiments, motor drive inverter <NUM> is an H-bridge. Some embodiments of such an H-bridge is shown in <FIG>. While an H-bridge is shown in drawings, other switching circuits or controls may be used to controllably vary the phase switching in synchronization with the desired speed or rotation of BLDC motor <NUM>.

Still referring to <FIG>, motor current sensor <NUM> may be coupled to motor drive inverter <NUM> in a manner that allows current sensor <NUM> to provide an output (e.g., a voltage output) that indicates the amount of the electric current <NUM> provided to BLDC motor <NUM> on any phase line. A reading representative of sensed current <NUM> may be provided from motor current sensor <NUM> to comparator <NUM>. Comparator <NUM> may be a discrete electronics part or implemented as part of main actuator controller <NUM> or another controller that forms a part of processing circuit <NUM>. Comparator <NUM> may be configured to compare motor current <NUM> to an electric current threshold <NUM>.

If the motor current <NUM> from current sensor <NUM> exceeds the threshold <NUM>, comparator <NUM> may output a reset signal <NUM> to PWM speed controller <NUM>. The application of reset signal <NUM> may cause PWM speed controller <NUM> to turn off PWM output <NUM> (e.g., by changing PWM output <NUM> to a duty cycle of <NUM>%, setting PWM output <NUM> to zero, etc.) for a period of time or until comparator <NUM> indicates that motor current <NUM> no longer exceeds threshold <NUM>. In other words, if the current threshold <NUM> for BLDC motor <NUM> is exceeded, comparator <NUM> may begin to interfere with PWM output <NUM> (e.g., by holding PWM output <NUM> in an off state), thereby causing BLDC motor <NUM> to slow down. Since the torque provided by BLDC motor <NUM> is proportional to motor current <NUM>, both the electric current and torque of BLDC motor <NUM> can be limited by the application of reset signal <NUM>.

The current threshold <NUM> may be controlled by main actuator controller <NUM>. For example, threshold <NUM> may start as a digital value stored within main actuator controller <NUM> (e.g., a maximum torque threshold <NUM> or a maximum current threshold <NUM>). Main actuator controller <NUM> may control threshold <NUM> by adjusting the thresholds <NUM> and/or <NUM> provided to PWM torque controller <NUM>. Main actuator controller <NUM> may increase threshold <NUM> by increasing the maximum torque threshold <NUM> and/or the maximum current threshold <NUM>. Main actuator controller <NUM> may decrease threshold <NUM> by decreasing the maximum torque threshold <NUM> and/or the maximum current threshold <NUM>.

PWM torque controller <NUM> may be configured to generate a PWM output <NUM> based on the maximum torque <NUM> and/or maximum current <NUM> provided by main actuator controller <NUM>. PWM torque controller <NUM> may convert the thresholds <NUM> and/or <NUM> to a PWM output <NUM> and provide the PWM output <NUM> to filter <NUM>. Filter <NUM> may be configured to convert the PWM output <NUM> from PWM torque controller <NUM> into a current threshold <NUM> (e.g., a DC voltage representative of an electric current) for comparison to the output of current sensor <NUM> using a filter <NUM>. In some embodiments, filter <NUM> is a first order low pass filter having a resistor in series with the load and a capacitor in parallel with the load. In other embodiments, filter <NUM> may be a low pass filter of a different order or a different type of filter.

In some embodiments, the threshold <NUM> provided to comparator <NUM> is based on a temperature sensor input. As the temperature sensor input varies (e.g., based on the changing ambient temperature, based on a temperature of a motor element, etc.), main actuator controller <NUM> may cause the threshold <NUM> to be adjusted. For example, as the temperature sensor input changes, main actuator controller <NUM> may adjust the thresholds <NUM> and/or <NUM> provided to PWM torque controller <NUM>. Adjusting the thresholds <NUM> and/or <NUM> provided to PWM torque controller <NUM> may cause the duty cycle of PWM output <NUM> to change, which causes a corresponding change in the current threshold <NUM> output by filter <NUM>.

In various embodiments, threshold <NUM> may be adjusted automatically by main actuator controller <NUM>, adjusted by a user, or may be a static value. In some embodiments, threshold <NUM> is a static or dynamic value based on one or more variables other than ambient temperature. For example, threshold <NUM> may be set to a value that corresponds to the maximum current that can safely be provided to BLDC motor <NUM> or a maximum torque that can safely be provided by BLDC motor <NUM> to drive device <NUM>.

Referring now to <FIG>, motor drive inverter <NUM>, BLDC motor <NUM>, and current sensor <NUM> are shown in greater detail, according to some embodiments. Motor drive inverter <NUM> is shown to receiving PWM output <NUM> and phase switch outputs <NUM> for each of three phase lines of BLDC motor <NUM>. Phase switch outputs <NUM> are shown to include a "Phase A High" output 556A, a "Phase A Low" output 556B, a "Phase B High" output 556C, a "Phase B Low" output 556D, a "Phase C High" output 556E, and a "Phase C Low" output 556F. Phase switch outputs <NUM> may be provided to switching elements <NUM>. Switching elements <NUM> may be transistors configured to allow or deny current to flow through switching elements <NUM> from PWM output <NUM>. Current sensor <NUM> is shown as a current sense resistor and may be configured to sense the motor current <NUM> provided to BLDC motor <NUM> regardless of the active winding.

Referring now to <FIG>, an exploded view of a previous one-way clutch motor assembly <NUM> for an actuator is shown, according to some embodiments. Motor assembly <NUM> can be used in actuator <NUM> and may be an embodiment of BLDC motor <NUM>. Motor assembly <NUM> is shown to have a bell assembly <NUM>. Bell assembly <NUM> can provide a shell or housing for components of motor assembly <NUM>. For example, bell assembly <NUM> can house shaft <NUM>, motor core <NUM>, etc. Bell assembly <NUM> can be a single piece, or bell assembly <NUM> can be separate pieces coupled to each other. Bell assembly <NUM> is shown to include bell <NUM> and shaft <NUM>. In some embodiments, bell assembly <NUM> can be a single component, with bell <NUM> and shaft <NUM> manufactured as a single piece. In other embodiments, bell assembly <NUM> can be an assembly in which shaft <NUM> is pressed into bell <NUM>. Bell assembly <NUM> can be arranged, constructed, and/or assembled in any way, and is not limited to ways specifically enumerated.

Bell <NUM> can be manufactured as a single piece, and can house components of motor assembly <NUM>. Shaft <NUM> can be a drive shaft. Shaft <NUM> can transfer the rotational energy from a motor core (e.g., motor core <NUM>) to another component. In some embodiments, shaft <NUM> is manufactured using a metal, metal alloy, etc. In other embodiments, shaft <NUM> is manufactured using a material such as plastic (e.g., Teflon, PVC, etc.). Shaft <NUM> can be manufactured using any material.

Referring still to <FIG>, motor assembly <NUM> is shown to include motor core <NUM>. Motor core <NUM> can be an electronically commutated motor and can be a synchronous motor that is powered by a DC electric source. In some embodiments, motor core <NUM> is powered by an integrated inverter or switching power supply, which produces an AC electric signal to drive the motor. Motor core <NUM> can be a permanent magnet synchronous motor. In some embodiments, motor core <NUM> interfaces with bell assembly <NUM> through roller bearing <NUM>. For example, roller bearing <NUM> can allow rotation of motor core <NUM> relative to shaft <NUM>. In some embodiments, motor core <NUM> includes a mounting flange <NUM>. Mounting flange <NUM> can be manufactured from any material, and can couple motor assembly <NUM> to a desired mounting location.

Motor assembly <NUM> is further shown to include wave washer <NUM>, roller bearing <NUM>, and retaining ring <NUM>. Wave washer <NUM> can provide axial force to motor core <NUM> and roller bearing <NUM>. In some embodiments, wave washer <NUM> can be any other type of washer, and is not limited to being a wave washer. Roller bearing <NUM> can provide an interface between motor core <NUM> and bell assembly <NUM>. For example, roller bearing <NUM> can allow rotation of motor core <NUM> relative to shaft <NUM>, similarly to roller bearing <NUM>. In some embodiments, roller bearing <NUM> can be the same type of bearing as roller bearing <NUM>. In other embodiments, roller bearing <NUM> can be a type of bearing different from roller bearing <NUM>. Retaining ring <NUM> can hold an assembly including bell assembly <NUM>, motor core <NUM>, roller bearing <NUM>, wave washer <NUM>, and roller bearing <NUM> together. In some embodiments, each of the previously enumerated components is assembled to form one assembly. In other embodiments, some of the components are assembled. In some embodiments, retaining ring <NUM> can be a snap ring. In other embodiments, retaining ring can be any type of retaining ring.

Referring still to <FIG>, motor assembly <NUM> is further shown to a one-way clutch mechanism including sleeve <NUM>, spring <NUM>, pinion <NUM>, and retaining ring <NUM>. Sleeve <NUM> can be a bushing. Sleeve <NUM> can be pressed onto shaft <NUM> and may be rotationally fixed to shaft <NUM> such that shaft <NUM> and sleeve <NUM> rotate in unison. Sleeve <NUM> can interface with spring <NUM>. In some embodiments, sleeve <NUM> can provide a surface for spring <NUM> to grip. Spring <NUM> can interface with sleeve <NUM> and pinion <NUM>. In some embodiments, spring <NUM> is coupled to sleeve <NUM> to fix its rotation relative to sleeve <NUM>. In other embodiments, spring <NUM> is coupled to pinion <NUM> to fix its rotation to pinion <NUM>.

In some embodiments, spring <NUM> acts as a one-way clutch, driven by sleeve <NUM>. For example, the inner diameter of spring <NUM> can decrease as motor core <NUM> rotates in one direction, gripping pinion <NUM> more tightly, until the rotation of pinion <NUM> is completely restricted. The inner diameter of spring <NUM> can increase as motor core <NUM> rotates in a second direction opposite to the first direction, loosening its grip on pinion <NUM> until the rotation of pinion <NUM> is no longer restricted. The directional gripping of pinion <NUM> causes pinion <NUM> to rotate in unison with sleeve <NUM> and shaft <NUM> in the first direction, but allows pinion <NUM> to rotate freely relative to sleeve <NUM> and shaft <NUM> in the second direction.

The grip of spring <NUM> on pinion <NUM> can necessitate manufacturing pinion <NUM> from a material of equal or greater hardness to prevent damage and wear to pinion <NUM>. For example, if spring <NUM> is manufactured from steel, pinion <NUM> can be made from steel. The material choice for pinion <NUM> can increase weight and cost of production. Pinion <NUM> can engage an external gearbox. In some embodiments, pinion <NUM> is a slip fit to shaft <NUM> and is driven by spring <NUM>.

Referring still to <FIG>, retaining ring <NUM> can hold the clutch assembly (e.g., sleeve <NUM>, spring <NUM>, and pinion <NUM>) to shaft <NUM>. In some embodiments, retaining ring <NUM> is a c-clip that is assembled from the side. In other embodiments, retaining ring <NUM> can be any other type of retaining ring. In some embodiments, components <NUM>-<NUM> of motor assembly <NUM> are designed by the manufacturer. The manufacturer may be responsible for assembly, manufacturing labor, and quality control of many small components which may be difficult to install. Due to the small size of retaining ring <NUM>, installation and quality control can be difficult. In some cases, if retaining ring <NUM> is not installed properly, pinion <NUM> can slip off shaft <NUM>, which can result in unintended actuator operation.

Referring now to <FIG>, a cross-sectional view of one-way clutch motor assembly <NUM> is shown according to some embodiments. <FIG> shows motor assembly <NUM> in an assembled state and provides a view of interfaces between components of motor assembly <NUM>. It is shown that bell assembly <NUM> (bell <NUM> and shaft <NUM>) are manufactured as one piece. Bell <NUM> is shown housing a portion of shaft <NUM>, motor core <NUM>, and roller bearing <NUM>. Clutch assembly <NUM> (including sleeve <NUM>, spring <NUM>, pinion <NUM>, and retaining ring <NUM>) is shown external to bell assembly <NUM>. Retaining ring <NUM> is shown holding pinion <NUM> onto shaft <NUM>.

Referring now to <FIG>, an exploded view of a new one-way clutch motor assembly <NUM> for an actuator is shown according to some embodiments. Motor assembly <NUM> can be used in actuator <NUM> and may be an embodiment of BLDC motor <NUM>. Motor assembly <NUM> is shown to include a bell assembly <NUM>. Bell assembly <NUM> can provide a shell or housing for components of motor assembly <NUM>. In some embodiments, bell assembly <NUM> forms a shell which defines an outer perimeter of motor assembly <NUM>. Bell assembly <NUM> can be a single piece, or bell assembly <NUM> can be separate pieces coupled to each other. For example, bell assembly <NUM> is shown to include bell <NUM> and upper shaft <NUM>. In some embodiments, bell assembly <NUM> is manufactured as one piece. In other embodiments, bell assembly <NUM> can be an assembly which includes bell <NUM> and upper shaft <NUM>. Upper shaft <NUM> may be a rotor shaft configured to rotate when an electric current is applied to the motor. Upper shaft <NUM> can be pressed into bell <NUM> and may be contained entirely within bell <NUM> (e.g., entirely within the shell defined by bell <NUM>). Bell assembly <NUM> can be arranged, constructed, and/or assembled in any way, and is not limited to ways specifically enumerated.

Referring still to <FIG>, motor assembly <NUM> is shown to include motor core <NUM> and roller bearing <NUM>. Motor core <NUM> can be an electronically commutated motor and can be a synchronous motor that is powered by a DC electric source. In some embodiments, motor core <NUM> is powered by an integrated inverter or switching power supply, which produces an AC electric signal to drive the motor. Motor core <NUM> can be a permanent magnet synchronous motor. In some embodiments, motor core <NUM> interfaces with bell assembly <NUM> and/or upper shaft <NUM> through roller bearing <NUM>. For example, roller bearing <NUM> can allow rotation of motor core <NUM> relative to upper shaft <NUM>. In some embodiments, motor core <NUM> includes a mounting flange <NUM>. Mounting flange <NUM> can be manufactured from any material, and can couple motor assembly <NUM> to a desired mounting location.

Referring still to <FIG>, motor assembly <NUM> is shown to include spring <NUM>. Spring <NUM> can interface with bell assembly <NUM> and/or upper shaft <NUM> and lower shaft <NUM>. In some embodiments, spring <NUM> acts as a one-way clutch, driven by upper shaft <NUM>. For example, the inner diameter of spring <NUM> can decrease as motor core <NUM> rotates in one direction, gripping lower shaft <NUM> more tightly, until the rotation of lower shaft <NUM> is completely restricted. The inner diameter of spring <NUM> can increase as motor core <NUM> rotates in a second direction opposite to the first direction, loosening its grip on lower shaft <NUM> until the rotation of lower shaft <NUM> is no longer restricted. In some embodiments, spring <NUM> is coupled to upper shaft <NUM> to fix its rotation to upper shaft <NUM>. In other embodiments, spring <NUM> is coupled to lower shaft <NUM> to fix its rotation to lower shaft <NUM>.

Referring still to <FIG>, motor assembly <NUM> is shown to include lower shaft <NUM>. Lower shaft <NUM> can be a drive shaft. Lower shaft <NUM> can be located partially within the shell defined by bell <NUM> and partially outside the shell defined by bell <NUM>. In other words, lower shaft <NUM> may extend through the shell. Lower shaft <NUM> may be coupled to drive device <NUM> via pinion <NUM>. In some embodiments, lower shaft <NUM> is assembled with a free fit on upper shaft <NUM>. Lower shaft <NUM> can transfer the rotational energy from a motor core (e.g., motor core <NUM>) to another component. In some embodiments, lower shaft <NUM> is manufactured using a metal, metal alloy, etc. In other embodiments, lower shaft <NUM> is manufactured using a material such as plastic (e.g., Teflon, PVC, etc.). Lower shaft <NUM> can be manufactured using any material. In some embodiments, lower shaft <NUM> is driven by spring <NUM> or slips through spring <NUM>.

The interaction between spring <NUM> and lower shaft <NUM> provides a one-way clutch mechanism. Unlike the previous embodiment shown in <FIG>, the one-way clutch mechanism is located within bell assembly <NUM> instead of external to bell assembly <NUM>. For example, spring <NUM> may be contained within the shell defined by bell <NUM> and may be configured to rotatably couple lower shaft <NUM> to upper shaft <NUM> within the shell. Since spring <NUM> does not grip pinion <NUM>, it is not necessary to manufacture pinion <NUM> from a material of equal or greater hardness compared to the material of spring <NUM>.

Referring still to <FIG>, motor assembly <NUM> is further shown to include roller bearing <NUM>, retaining ring <NUM>, and retaining ring <NUM>. Roller bearing <NUM> can provide an interface between lower shaft <NUM> and motor core <NUM>. For example, roller bearing <NUM> can allow rotation of motor core <NUM> relative to lower shaft <NUM>, providing a similar interface as the interface provided by roller bearing <NUM> between upper shaft <NUM> and motor core <NUM>. In some embodiments, roller bearing <NUM> can be the same type of bearing as roller bearing <NUM>. In other embodiments, roller bearing <NUM> can be a type of bearing different from roller bearing <NUM>. Retaining ring <NUM> can hold roller bearing <NUM> within motor core <NUM>. Retaining ring <NUM> can hold lower shaft <NUM> to roller bearing <NUM>. In some embodiments, retaining rings <NUM> and <NUM> can be snap rings. In other embodiments, retaining rings <NUM> and <NUM> can be any type of retaining rings. The outer diameter of retaining ring <NUM> can be smaller than the inner diameter of retaining ring <NUM> such that retaining ring <NUM> is inside of retaining ring <NUM> when assembled.

Referring still to <FIG>, motor assembly <NUM> is further shown to include pinion <NUM>. As pinion <NUM> no longer interfaces with a spring (e.g., spring <NUM>), pinion <NUM> can be made of any material. In some embodiments, pinion <NUM> is made of plastic - a low cost, light material. Pinion <NUM> can be molded instead of machined, extruded, etc. In some embodiments, pinion <NUM> is press fit to lower shaft <NUM>, which results in pinion <NUM> being rotationally fixed to lower shaft <NUM>. Press fitting pinion <NUM> to lower shaft <NUM> eliminates the need for using a small retaining ring which may be difficult to install. Such a configuration was not possible in motor assembly <NUM> while maintaining the operation of a one-way clutch since the entire shaft <NUM> was fixed to bell assembly <NUM>. However, since the shaft in motor assembly <NUM> both an upper shaft <NUM> and a lower shaft <NUM>, pinion <NUM> can be rotationally fixed to lower shaft <NUM> while preserving the one-way clutch action relative to upper shaft <NUM>.

In some embodiments, pinion <NUM> and the assembly of pinion <NUM> to the rest of motor assembly <NUM> can be the only components a manufacturer would need to provide. The other components can be purchased as an assembly, reducing stress on the manufacturer regarding quality control and manufacturing labor. Press fitting pinion <NUM> onto lower shaft <NUM> results in a simpler manufacturing process and eliminates the need to add a small retaining ring to hold pinion <NUM> onto lower shaft <NUM> (as was required in motor assembly <NUM>).

Referring now to <FIG>, a cross-sectional view of one-way clutch motor assembly <NUM> is shown according to some embodiments. <FIG> shows assembly <NUM> in an assembled state and provides a view of interfaces between components of motor assembly <NUM>. In some embodiments, bell assembly <NUM> (bell <NUM> and upper shaft <NUM>) are separate pieces press-fit together. In other embodiments, bell assembly <NUM> is manufactured as on piece. Bell <NUM> and motor core <NUM> are shown housing all components of motor assembly <NUM> except a portion of lower shaft <NUM> and pinion <NUM>. Clutch assembly <NUM> (including upper shaft <NUM>, spring <NUM>, and lower shaft <NUM>) is shown internal to bell assembly <NUM> and/or motor core <NUM>. The reduced complexity of motor assembly <NUM> and relocation of clutch assembly <NUM> inside bell assembly <NUM> provides a safer assembly with fewer parts for the manufacturer to assemble and reduces the likelihood of motor failure.

Referring now to <FIG>, bell assembly <NUM> is shown in greater detail, according to some embodiments. Bell assembly <NUM> is shown to include bell <NUM> and upper shaft <NUM>. Bell assembly <NUM> can provide a shell or housing for components of a motor assembly. Bell assembly <NUM> can be a single piece, or bell assembly <NUM> can be separate pieces coupled to each other. In some embodiments, bell assembly <NUM> is manufactured as a single component, such that bell <NUM> and upper shaft <NUM> are manufactured as one piece. In other embodiments, bell assembly <NUM> can be an assembly which includes bell <NUM> and upper shaft <NUM>. Upper shaft <NUM> can be press-fit to bell <NUM>. In some embodiments, upper shaft <NUM> can be coupled to bell <NUM> using a positive retention means, such as a bolt and a nut, etc. Bell assembly <NUM> can be assembled or manufactured in any way.

Referring now to <FIG>, lower shaft <NUM> is shown in greater detail, according to some embodiments. In some embodiments, lower shaft <NUM> is coupled to another shaft (e.g., upper shaft <NUM> of <FIG>). In some embodiments, lower shaft <NUM> is a slip-fit, free-fit, etc. to upper shaft <NUM>. Lower shaft <NUM> may be held to upper shaft <NUM> by a spring (e.g., spring <NUM>), a bearing (e.g., roller bearing <NUM>), and/or retaining rings (e.g., retaining rings <NUM> and <NUM>). In some embodiments, lower shaft <NUM> is manufactured from metal. In other embodiments, lower shaft <NUM> is manufactured from any material. Lower shaft <NUM> is shown to have external splines <NUM>. In some embodiments, lower shaft <NUM> is coupled to pinion <NUM>. Pinion <NUM> can have corresponding internal splines which mesh with external splines <NUM>. In other embodiments, pinion <NUM> is broached such that external splines <NUM> create internal splines in pinion <NUM>.

Referring now to <FIG>, pinion <NUM> is shown in greater detail, according to some embodiments. In some embodiments, pinion <NUM> is coupled to a shaft (e.g., lower shaft <NUM> of <FIG>). Pinion <NUM> can be press-fit to lower shaft <NUM> by inserting lower shaft <NUM> into a bore <NUM> located at one end of pinion <NUM>. In some embodiments, pinion <NUM> has internal splines which correspond to external splines of lower shaft <NUM>. Pinion <NUM> can be manufacture from any material. In some embodiments, pinion <NUM> is manufactured from a plastic material (e.g., Teflon, PVC ,etc.). Since pinion <NUM> does not experience wear or stress from interacting with a spring (e.g., spring <NUM>), pinion <NUM> does not need to be metal and can be made of a less rigid material such as a polymer. Pinion <NUM> is shown to include gear teeth <NUM> which can mesh with corresponding gear teeth of a gear box within actuator <NUM> to rotationally couple pinion <NUM> to drive device <NUM>.

The one-way clutch mechanism provided by clutch assembly <NUM> rotationally couples pinion <NUM> to bell assembly <NUM> in a first rotational direction, but allows relative rotation between pinion <NUM> and bell assembly <NUM> in a second rotational direction. For example, when motor core <NUM> is powered, bell assembly <NUM> and upper shaft may be driven in the first direction (e.g., clockwise) relative to motor core <NUM>. As bell assembly <NUM> rotates in the first direction, spring <NUM> may grip both upper shaft <NUM> and lower shaft <NUM>, causing lower shaft <NUM> to rotate in the first direction in unison with upper shaft <NUM>. In other words, the one-way clutch mechanism engages both upper shaft <NUM> (i.e., the rotor shaft) and lower shaft <NUM> (i.e., the drive shaft) when upper shaft <NUM> rotates in the first direction such that lower shaft <NUM> is driven by upper shaft <NUM> in the first direction.

Pinion <NUM> can be rotationally fixed to lower shaft <NUM> (e.g., via a press-fitting) which causes pinion <NUM> to rotate in the first direction in unison with lower shaft <NUM>. Pinion <NUM> can be coupled to drive device <NUM> which causes actuator <NUM> to drive in the first direction as pinion <NUM> is rotated. The one-way clutch action provided by clutch assembly <NUM> may allow pinion <NUM> to continue rotating in the first direction after bell assembly <NUM> stops rotating. However, continued rotation of pinion <NUM> in the first direction may be opposed by a return spring.

According to the invention, actuator <NUM> is a spring return actuator. Actuator <NUM> includes a return spring configured to wind (e.g., store energy) as actuator <NUM> drives in the first direction. The return spring applies a torque to drive device <NUM> in a second rotational direction (e.g., counterclockwise). When motor core <NUM> is not powered, the torque provided by the return spring causes drive device <NUM> to rotate in the second direction toward a counterclockwise end position (e.g., a zero position). Rotation of drive device <NUM> in the second direction drives pinion <NUM> in the second direction, which causes lower shaft <NUM> to rotate in the second direction. As lower shaft <NUM> rotates in the second direction, spring <NUM> may grip both upper shaft <NUM> and lower shaft <NUM>, causing upper shaft <NUM> and bell assembly <NUM> to rotate in the second direction in unison with lower shaft <NUM>.

The one-way clutch action provided by clutch assembly <NUM> allows upper shaft <NUM> and bell assembly <NUM> to continue rotating in the second direction after lower shaft <NUM> stops rotating. Lower shaft <NUM> stops rotating once drive device <NUM> reaches the counterclockwise end position and encounters a physical end stop. In some instances, drive device <NUM> and lower shaft <NUM> suddenly stop rotating once the end stop is reached (e.g., upon impacting the end stop). The rotational momentum of bell assembly <NUM> may cause bell assembly <NUM> and upper shaft <NUM> to continue rotating in the second direction relative to lower shaft <NUM>. One-way clutch assembly <NUM> permits such rotation by allowing upper shaft <NUM> to slip relative to lower shaft <NUM> when upper shaft <NUM> rotates in the second direction. Such slippage allows the rotational momentum of bell assembly <NUM> to gradually decrease rather than forcing bell assembly <NUM> to stop suddenly. This feature reduces the impact force experienced when the end stop is reached and reduces the stress on the rotating components of actuator <NUM> (e.g., gear box components, pinion <NUM>, etc.).

The construction and arrangement of the systems and methods as shown in the various exemplary embodiments are illustrative only. Although only a few embodiments have been described in detail in this disclosure, many modifications are possible (e.g., variations in sizes, dimensions, structures, shapes and proportions of the various elements, values of parameters, mounting arrangements, use of materials, colors, orientations, etc.). For example, the position of elements may be reversed or otherwise varied and the nature or number of discrete elements or positions may be altered or varied. Accordingly, all such modifications are intended to be included within the scope of the present disclosure. The order or sequence of any process or method steps may be varied or re-sequenced according to alternative embodiments. Other substitutions, modifications, changes, and omissions may be made in the design, operating conditions and arrangement of the exemplary embodiments without departing from the scope of the present disclosure.

The present disclosure contemplates methods, systems and program products on any machine-readable media for accomplishing various operations. The embodiments of the present disclosure may be implemented using existing computer processors, or by a special purpose computer processor for an appropriate system, incorporated for this or another purpose, or by a hardwired system. Embodiments within the scope of the present disclosure include program products comprising machine-readable media for carrying or having machine-executable instructions or data structures stored thereon. Such machine-readable media can be any available media that can be accessed by a general purpose or special purpose computer or other machine with a processor. By way of example, such machine-readable media can comprise RAM, ROM, EPROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to carry or store desired program code in the form of machine-executable instructions or data structures and which can be accessed by a general purpose or special purpose computer or other machine with a processor. Combinations of the above are also included within the scope of machine-readable media. Machine-executable instructions include, for example, instructions and data which cause a general purpose computer, special purpose computer, or special purpose processing machines to perform a certain function or group of functions.

Claim 1:
An actuator (<NUM>) for a HVAC system (<NUM>), the actuator (<NUM>) comprising:
- a drive device (<NUM>) configured to attach to a movable HVAC component and to drive the movable HVAC component between multiple positions; and
- a motor coupled to the drive device (<NUM>) and configured to provide torque to the drive device (<NUM>) in a first direction; and
- a return spring coupled to the drive device (<NUM>) and configured to provide torque to the drive device (<NUM>) in a second direction opposite to the first direction,
the motor comprising:
- a shell defining an outer perimeter of the motor;
- a rotor shaft contained within the shell and configured to rotate when an electric current is applied to the motor;
- a drive shaft extending through the shell and coupled to the drive device (<NUM>); and
- a one-way clutch contained within the shell and rotatably coupling the rotor shaft to the drive shaft,
wherein the one-way clutch is configured to permit the rotor shaft to slip relative to the drive shaft, when rotating in the second direction, to gradually dissipate a rotational inertia of the motor after the drive device (<NUM>) stops upon reaching an end stop.