Direct-current brushless actuator

Abstract

The utility model discloses a direct-current brushless actuator which comprises a machine shell, and a motor, a speed reducer, a worm and worm wheel assembly and a controller are installed in the machine shell. The controller is provided with a change-over switch; the controller is provided with a rectifier module and a relay, the rectifier module is provided with a first input end, a second input end and a second input end, and the first input end is electrically connected with the first interface and the second interface through a voltage division circuit; the relay comprises a coil, a first normally-open switch and a second normally-open switch, the two ends of the coil are electrically connected with the first interface and the third interface respectively, the input end of the first normally-open switch is electrically connected with the third interface, and the output end of the first normally-open switch is electrically connected with the first input end; the output end of the rectification module is electrically connected with the two ends of the direct-current brushless motor, and the two ends of the second normally-open switch are electrically connected with the negative electrode end of the direct-current brushless motor and the reversing end of the direct-current brushless motor respectively. The direct-current brushless motor is used for replacing an alternating-current motor on the electric actuator, and great line transformation is not needed.

Description

Technical Field

[0001] The utility model relates to the technical field of valve electric actuators, in particular to a direct current brushless actuator. Background Art

[0002] The motors used by electric valve actuators include: AC motors and DC motors. Among them, part of the energy consumption of AC motors is converted into the heat of the motor itself, which has relatively obvious energy consumption and heat dissipation problems, and the control is relatively complex. The advantage of AC motors is that the manufacturing and maintenance costs are low; DC motors are divided into: brushed motors and brushless motors. Among them, brushed DC motors have the problem of troublesome replacement of carbon brushes, and their service life depends largely on the life of carbon brushes. The advantages of brushless DC motors include: energy saving, long life, low noise and easy control. Therefore, brushless DC motors are also a relatively good driving power source.

[0003] Most of the existing valve electric actuators use AC motors as the driving power source. When replacing the motors of existing valve electric actuators, the AC motors can be replaced with DC brushless motors. However, this requires not only replacing the motors and controllers, but also circuit modification. Therefore, how to replace the DC brushless motors of valve electric actuators in a low-cost and highly compatible way has become a problem to be solved. Utility Model Content

[0004] In order to solve one or more problems existing in the prior art, the utility model provides a brushless DC actuator. The utility model adopts the following technical solutions to solve the above problems: a brushless DC actuator, comprising: a housing, in which a motor, a reducer and a worm gear assembly are installed; the motor is a brushless DC motor, and a controller is also installed in the housing;

[0005] The AC interface terminal includes: a first interface, a second interface and a third interface, the controller is provided with a switch, the switch is electrically connected to the second interface and the third interface respectively, the switch is electrically connected to the first AC end, the switch is used to control the circuit on and off of the second interface and the third interface, and the first interface is electrically connected to the second AC end;

[0006] The controller is provided with a rectifier module, the rectifier module is provided with a first input end and a second input end, the second input end is electrically connected to the first interface through a voltage divider circuit, and the first input end is electrically connected to the second interface through the voltage divider circuit;

[0007] The controller is provided with a relay, and the relay includes: a coil, a first normally open switch and a second normally open switch. After the coil is powered on, the first normally open switch and the second normally open switch are closed, the two ends of the coil are electrically connected to the first interface and the third interface respectively, the input end of the first normally open switch is electrically connected to the third interface, and the output end of the first normally open switch is electrically connected to the first input end;

[0008] The positive output end of the rectifier module is electrically connected to the positive end of the DC brushless motor, the negative output end of the rectifier module is electrically connected to the negative end of the DC brushless motor, the input end of the second normally open switch is electrically connected to the negative end of the DC brushless motor and the negative output end of the rectifier module, and the output end of the second normally open switch is electrically connected to the commutation end of the DC brushless motor.

[0009] In some embodiments, a voltage stabilizing diode, a filter capacitor, and a resistor are respectively connected in parallel between the positive output terminal and the negative output terminal of the rectifier module.

[0010] In some embodiments, the voltage divider circuit includes: a first capacitor and a second capacitor;

[0011] A first end of the first capacitor is electrically connected to the first interface, and a second end of the first capacitor is electrically connected to the second input end;

[0012] The first end of the second capacitor is electrically connected to the second end of the first capacitor and the second input end, and the second end of the second capacitor is electrically connected to the second interface and the first input end.

[0013] The beneficial value achieved by the utility model is that the brushless DC motor of the utility model can be well compatible with and installed on the existing electric actuator through the above-mentioned controller, so that the brushless DC motor can be used to replace the AC motor on the electric actuator, and there is no need to carry out major circuit modification, thus achieving good circuit adaptability; with the cooperation of the above-mentioned controller, the electric actuator can obtain a faster valve opening and closing speed, achieve a 100% switching action rate, and avoid overheating protection of the motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the utility model;

[0015] Figure 2 It is a schematic diagram of the principle of the controller of the utility model.

[0016] [Reference Signs]

[0017] 1... housing 2... brushless DC motor 3... reducer 4... worm and worm gear assembly 5... controller. DETAILED DESCRIPTION

[0018] In order to make the above-mentioned purposes, features and advantages of the utility model more understandable, the specific implementation methods of the utility model are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the utility model. However, the utility model can be implemented in many other ways different from this description, and those skilled in the art can make similar improvements without violating the connotation of the utility model. Therefore, the utility model is not limited by the specific embodiments disclosed below.

[0019] The utility model discloses a DC brushless actuator, such as Figure 1 As shown, it comprises: a housing 1, a motor, a reducer 3 and a worm gear assembly 4 are installed in the housing 1, the motor is a brushless DC motor 2, a controller 5 is also installed in the housing 1, the motor rotates under the drive of the controller 5, the motor drives the worm gear assembly 4 to rotate through the reducer 3, and the worm gear assembly 4 drives the valve body to switch;

[0020] like Figure 2 As shown, the AC interface terminal includes: a first interface 1, a second interface 2 and a third interface 3, the controller is provided with a switch K, the switch K is electrically connected to the second interface 2 and the third interface 3 respectively, the switch K is electrically connected to the first AC terminal L, the switch K is used to control the circuit on and off of the second interface 2 and the third interface 3, the first interface 1 is electrically connected to the second AC terminal N, the first AC terminal L and the second AC terminal N are AC power terminals of the device;

[0021] The controller is provided with a rectifier module B, and the rectifier module B is provided with a first input terminal AC1 and a second input terminal AC2, the second input terminal AC2 is electrically connected to the first interface 1 through a voltage divider circuit, and the first input terminal AC1 is electrically connected to the second interface 2 through the voltage divider circuit;

[0022] The controller is provided with a relay, and the relay includes: a coil J, a first normally open switch J1, and a second normally open switch J2. After the coil J is powered on, the first normally open switch J1 and the second normally open switch J2 are closed, and the two ends of the coil J are electrically connected to the first interface 1 and the third interface 3 respectively, the input end of the first normally open switch J1 is electrically connected to the third interface 3, and the output end of the first normally open switch J1 is electrically connected to the first input end AC1;

[0023] The positive output end of the rectifier module B is electrically connected to the positive end of the DC brushless motor, the negative output end of the rectifier module is electrically connected to the negative end of the DC brushless motor, the input end of the second normally open switch J2 is electrically connected to the negative end of the DC brushless motor and the negative output end of the rectifier module, and the output end of the second normally open switch J2 is electrically connected to the commutation end of the DC brushless motor.

[0024] It should be noted that the controller may also be provided with a conventional overload protection module and an overcurrent protection module, which are generally provided at the output end of the rectifier module. The rectifier module may be an existing rectifier bridge module.

[0025] The controller can be used on the original AC line of the actuator without reducing the use effect. Furthermore, the DC brushless motor can achieve energy saving effect under the drive of the controller. At the same time, the actuator needs less current (under the same driving force, the DC brushless motor requires less driving current than the AC motor), which can reduce the cost of laying the actuator line, reduce the load of the upper control device, and improve the reliability of the system.

[0026] Specifically, combined Figure 2 As shown, a voltage stabilizing diode ZD is connected in parallel between the positive output terminal and the negative output terminal of the rectifier module B; a filter capacitor C3 is connected in parallel between the positive output terminal and the negative output terminal of the rectifier module B; and a resistor R is connected in parallel between the positive output terminal and the negative output terminal of the rectifier module B.

[0027] The voltage divider circuit includes: a first capacitor C1 and a second capacitor C2; the first end of the first capacitor C1 is electrically connected to the first interface 1, and the second end of the first capacitor C1 is electrically connected to the second input end AC2; the first end of the second capacitor C2 is electrically connected to the second end of the first capacitor C1 and the second input end AC2, and the second end of the second capacitor C2 is electrically connected to the second interface 2 and the first input end AC1. The voltage divider circuit can also be an existing voltage divider circuit or a step-down circuit.

[0028] When in use, the switching switch K is turned on, the second interface 2 is powered on, the first interface 1 and the second interface 2 form an AC power supply circuit, the AC power enters the rectifier module B after being stepped down by the voltage divider circuit, the rectifier module B outputs DC power to the rear end, the DC power enters the DC brushless motor after filtering and voltage stabilization, at this time the DC brushless motor rotates forward, and the actuator drives the valve body to open the valve;

[0029] If the switching switch K is closed, the third interface 3 is powered on and the second interface 2 is disconnected; at this time, the coil J of the relay is powered on, and the first normally open switch J1 and the second normally open switch J2 both perform a closing action, and the first interface 1 and the third interface 3 form an AC power supply circuit; since the second normally open switch J2 is closed, the commutation end of the DC brushless motor is powered on, and the DC brushless motor is reversed at this time, and the actuator drives the valve body to close the valve.

[0030] In summary, the brushless DC motor of the utility model can be well compatible with and installed on the existing electric actuator through the above-mentioned controller, so that the brushless DC motor can be used to replace the AC motor on the electric actuator, and there is no need for major circuit modification, thus achieving good circuit adaptability; with the cooperation of the above-mentioned controller, the electric actuator can obtain a faster valve opening and closing speed, achieve a 100% switching action rate, and avoid overheating protection of the motor.

[0031] The above-described embodiments only express one or more implementation methods of the utility model, and the description is relatively specific and detailed, but it cannot be understood as a limitation of the utility model patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the utility model, which all belong to the protection scope of the utility model. Therefore, the protection scope of the utility model shall be based on the attached claims.

Claims

1. A brushless DC actuator, comprising: A casing, wherein a motor, a reducer and a worm gear assembly are installed in the casing, wherein the motor is a brushless DC motor, and a controller is also installed in the casing; The AC interface terminal includes: a first interface, a second interface and a third interface, the controller is provided with a switch, the switch is electrically connected to the second interface and the third interface respectively, the switch is electrically connected to the first AC end, the switch is used to control the circuit on and off of the second interface and the third interface, the first interface is electrically connected to the second AC end, and the first AC end and the second AC end are AC power terminals of the device; The controller is provided with a rectifier module, the rectifier module is provided with a first input end and a second input end, the second input end is electrically connected to the first interface through a voltage divider circuit, and the first input end is electrically connected to the second interface through the voltage divider circuit; The controller is provided with a relay, and the relay includes: a coil, a first normally open switch and a second normally open switch. After the coil is powered on, the first normally open switch and the second normally open switch are closed, the two ends of the coil are electrically connected to the first interface and the third interface respectively, the input end of the first normally open switch is electrically connected to the third interface, and the output end of the first normally open switch is electrically connected to the first input end; The positive output end of the rectifier module is electrically connected to the positive end of the DC brushless motor, the negative output end of the rectifier module is electrically connected to the negative end of the DC brushless motor, the input end of the second normally open switch is electrically connected to the negative end of the DC brushless motor and the negative output end of the rectifier module, and the output end of the second normally open switch is electrically connected to the commutation end of the DC brushless motor.

2. The brushless DC actuator according to claim 1, characterized in that: A voltage stabilizing diode is connected in parallel between the positive output terminal and the negative output terminal of the rectifier module.

3. The brushless DC actuator according to claim 1, characterized in that: A filter capacitor is connected in parallel between the positive output terminal and the negative output terminal of the rectifier module.

4. The brushless DC actuator according to claim 1, characterized in that: A resistor is connected in parallel between the positive output terminal and the negative output terminal of the rectifier module.

5. The brushless DC actuator according to claim 1, characterized in that: The voltage divider circuit comprises: a first capacitor and a second capacitor; A first end of the first capacitor is electrically connected to the first interface, and a second end of the first capacitor is electrically connected to the second input end; The first end of the second capacitor is electrically connected to the second end of the first capacitor and the second input end, and the second end of the second capacitor is electrically connected to the second interface and the first input end.

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