KR100662431B1 - Starter for single phase induction motor and single phase induction motor with the same - Google Patents

Abstract

A starter for a single phase induction motor and a single phase induction motor with the same are provided to reduce a generation of noise by decreasing mechanical components and save a manufacturing cost by simplifying an assembly process. In a starter for a single phase induction motor, a plurality of terminals, to which a first and second main coils are connected, is divided for applying a high start-up current when starting up the motor and applying a low drive current during a normal drive, wherein the first and second main coils are connected in series. The other terminal is in contact with a sub coil, which is connected with a main coil in parallel, wherein the main coil comprises the first and the second main coils from a power terminal and the sub coil is wound on a stator with the main coil for starting up a rotator. The power terminal supplies the power to the main coil and the sub coil. A first contact point connects the first main coil with the power terminal by turning on when starting up. A second contact point turns on or off with the first contact point selectively and connects the first and second main coils with the power terminal during a normal drive by turning on. A third contact point turns on/off with the first contact point synchronously and blocks the sub coil from the power terminal by turning off during the normal drive. An electronic three contact point relay turns on/off the first, the second, and the third contact points.

Description

Starter for single phase induction motor and single phase induction motor with the same

1 is a simplified circuit diagram of a conventional single phase induction motor.

Figure 2 is an exploded cross-sectional view of a conventional single phase induction motor.

3 is a plan view schematically showing a centrifugal force switch box of a conventional single phase induction motor.

Figure 4 is a state diagram briefly showing the main part during the normal operation of the starting device of the single-phase induction motor according to the present invention.

Fig. 5 is a state diagram briefly showing the main parts at the start of the starting device of the single-phase induction motor according to the present invention.

* Explanation of symbols for main parts of drawings *

10: centrifugal force switch box 11: lever

12: first push bar 13: second push bar

14: first plate 15: second plate

17: terminal 21: bracket

22: shaft 23: bearing

24: color 25: balance weight

26: rotor 27: stator

30: 3 contact relay 31: amateur

32: terminal 33: spring

34: solenoid

The present invention relates to a single-phase induction motor, and more particularly, to a single-phase induction motor and a single-phase induction motor having the same improved the start-up device of the single-phase induction motor to improve the ease of use and reliability.

In general, a single phase induction motor is wound around the stator where the main coil and the subcoil are spaced 90 ° apart from each other, and the power supply voltage is directly applied to the main coil and the subcoil through a capacitor. This is because the main coil alone does not start even when a voltage is applied. Therefore, the rotor can be started by generating a magnetic field in the stator through a starting device such as the subcoil.

Such starting devices are classified into a divided phase starting type, a shading coil type, a condenser starting type, or a rebound starting type according to the type thereof.

An example of a single phase induction motor having such a starting device is a shading coil type single phase induction motor, which generates an elliptical magnetic field in the stator to enable the rotor to be started. Here, a stator coil of one phase is wound around the stator, and a shading coil is wound around the stator coil at a predetermined angle and serves as the other phase.

When only the stator coil is wound around the stator, only an alternating magnetic field is generated in the stator, so that the rotor is not started. Thus, winding a shading coil to the stator generates an elliptical rotor field, and the rotor is started and rotated by the elliptical rotor field in a constant direction.

Of course, in the case of a three-phase induction motor, even if only the main coil is wound on the stator, the rotor field is generated, and thus the above-described shading coils or sub coils do not need to be wound on the stator.

On the other hand, in the case of the condenser starting type, the initial starting torque is generated because the phase of the current applied to the subcoil through the capacitor is different from the phase of the current applied to the main coil.

In the case of the split-phase starting type, it is similar to the condenser starting type except that the capacitor is not required by winding the subcoil at a position 90 ° different from the main coil in the spatial electric angle.

Since the divided phase induction motor is a subcoil, which is wound with a smaller number of turns than a main coil, and is wound with a high resistance and low reactance, there is little delay in voltage, resulting in an incomplete but elliptical rotating magnetic field. Thus, this results in an initial starting torque.

On the other hand, in the single-phase induction motor is essentially provided with a shading coil or sub-coil for the generation of the initial starting torque, but such a coil is not required in the normal operation state. In other words, in the normal operation state, the current flowing through the coil causes power waste, which causes the overall efficiency of the single-phase induction motor to be reduced.

Therefore, centrifugal force switches are generally used as a starter of a single phase induction motor to reduce such waste. That is, when the rotational speed of the rotor reaches 70-80% or more of the synchronous speed and approaches normal operation, the subcoil is cut off from the power supply stage using centrifugal force.

In addition, in recent years, the main coil is divided and the current flowing to the main coil is increased at the initial stage of start-up to generate a large starting torque, resulting in a faster time to reach the normal operation, while reducing the current flowing to the main coil during normal operation. Therefore, a single phase induction motor is provided which minimizes power loss.

Hereinafter, with reference to Figs. 1 to 3, a conventional divided phase starting type induction motor having a form in which a main coil is divided using a centrifugal force switch will be described.

First, as shown in FIG. 1, in the conventional motor, a main coil in which a first main coil M ₁ and a second main coil M ₂ are connected in series is selectively connected to a single phase power supply terminal via a B contact. Sub-coil S is selectively connected to the single-phase power supply terminal as a C contact in parallel with the main coil.

On the other hand, the split point of the first main coil (M ₁₎ and the second main coil (M ₂ ) and the single-phase power supply terminal is selectively connected to the A contact.

Here, the A contact and the B contact are selectively turned on (on) / off (off), the A contact and the C contact is on / off synchronously. In other words, if contact A is on, contact B is always off. If contact A is off, contact B is always on. And if contact A is on, contact C is always on. If contact A is off, contact C is always off.

Here, the portion 10 surrounded by the dotted line corresponds to the switch box.

When power is applied during initial startup, the A contact and the C contact are turned on so that current flows only in the first main coil and the subcoil, and the rotor is started by the initial large starting torque and gradually rotates at the synchronous speed.

Then, after rotating at a constant speed or more, the B contact is turned on, and the C contact is turned off so that the current flows only in the first main coil and the second main coil, so that the current flowing in the main coil decreases, thereby reducing power loss. have.

That is, when starting, the current flowing to the main coil is increased, and during the normal operation, the current flowing to the main coil is reduced, and at the same time, the current flowing to the subcoil is cut off to implement a high efficiency single phase induction motor.

Referring to Figures 2 and 3 will be described how to implement the on / off of the above-described contact.

The conventional single phase induction motor 20 includes a stator 27, a rotor 26, a rotating shaft 22, a bracket 21, a centrifugal force switch, a centrifugal force switch box 10, and the like. That is, as shown in the rotor (26) is provided inside the stator (27), the rotating shaft 22 is pressed into the center of the rotor is rotated integrally with the rotor.

In addition, the bracket 21 is fastened to the upper and lower sides of the stator, and the rotating shaft is rotatably supported by the bearing 23 on the bracket.

Here, the centrifugal force switch includes a balance weight 25, a collar 24, a lever 11, a first plate 14, and a second plate 15. 11), the first plate 14 and the second plate 15 are provided in the centrifugal switch box 10.

First, when the rotor 26 of the motor rotates at a predetermined speed or more, the rotation shaft 22 rotates integrally therewith. Therefore, the balance weight 25 mounted on the rotary shaft and rotated integrally with the rotary shaft causes the edge portion to rise as a whole while flying by the centrifugal force at an appropriate rotation speed or more.

Then, as the balance weight 25 rises, the collar 25 rises, thereby rotating the lever 11 provided in the centrifugal force switch.

As shown in FIG. 3, when the lever 11 rotates in a clockwise direction, the first push bar 12 and the second push bar 13 provided in the lever 11 are disposed on the first plate. 14 and the second plate 15 are pushed up, so that the A contact and the C contact are turned on, and the B contact is turned off.

On the other hand, when the lever 11 rotates in the counterclockwise direction, the contact point A and C are caused by the magnetic force of the first plate 14 and the second plate 15 or the elastic force or the second push bar 13 to restore itself. The contact is turned off and the B contact is turned on.

In other words, the state in which the lever 11 rotates in the clockwise direction corresponds to the start-up, and the state in which the lever 11 rotates in the counterclockwise direction corresponds to the normal operation. In addition, the direction in which the lever 11 rotates when the collar 24 is raised can be easily changed.

In FIG. 3, reference numeral 17 denotes various terminals. These terminals may include a power supply terminal to which a power source for supplying power to the main coil is connected, terminals to which the ends of the first main coil and the second main coil are respectively connected, and terminals to which the ends of the subcoil are connected. Of course, the terminal may also include a terminal to which the ground wire is connected.

In such a conventional motor, turning three contacts on and off through the rotation of one lever and two plates could cause deterioration of the reliability of the motor.

In addition, the structure, the shape, and the mechanical moldability act as important factors for accurate on / off, and there is a concern that reliability may be degraded due to contact wear, wear of a collar, lever, and the like.

In addition, since the collar 24 and the balance weight 25 are to be separately mounted on the rotating shaft 22, the assembly process in the field is complicated and the manufacturing cost increases.

The present invention is to solve the above problems, an object of the present invention is to improve the starting device of the single-phase induction motor to improve the ease of use and to increase the reliability of the single-phase induction motor starting device and a single-phase induction motor having the same To provide.

In order to achieve the above object, the present invention is divided in order to apply a high starting current during start-up and a low operating current during normal operation, the terminal is connected to the first main coil and the second main coil connected in series with each other With; A terminal connected in parallel with a main coil including the first main coil and the second main coil from a power supply terminal, and connected to the sub coil for winding the stator together with the main coil to start the rotor; A starter of a single-phase induction motor comprising a power supply terminal for supplying power to the main coil and the subcoil, comprising: a first contact point that is turned on during startup to connect only the first main coil to a power supply terminal; A second contact selectively turned on / off with the first contact, the contact being turned on during normal operation to connect the first main coil and the second main coil to a power supply terminal; A third contact that is turned on / off in synchronization with the first contact and that the contact is turned off during normal operation to cut off the sub-coil from the power supply terminal; And it provides a starting device for a single-phase induction motor comprising an electronic three-contact relay for turning on / off the first contact, the second contact and the third contact.

The electronic three-contact relay may include a solenoid coil wound around an armature to magnetize the armature; An elastic member provided at one side of the armature to apply an elastic force in a direction opposite to the movement of the armature; And a plurality of terminals selectively connected / blocked with the first contact, the second contact, and the third contact according to the movement of the armature.

Preferably, the plurality of terminals move integrally with the armature and are electrically disconnected from each other.

In addition, the solenoid coil is preferably connected in series with the first main coil in the front side based on the split point of the first main coil and the second main coil, the starting device of the single-phase induction motor is connected to a single switch box It is preferred to be provided.

On the other hand, in order to achieve the above object, the present invention is divided in order to apply a high starting current during startup and a low operating current during normal operation, comprising a first main coil and a second main coil connected in series with each other Main coil; A sub-coil connected to the main coil in parallel from a power supply terminal and wound on a stator together with the main coil to start a rotor; A first contact point which is turned on at startup so as to connect only the first main coil to a power supply terminal; A second contact selectively turned on / off with the first contact, the contact being turned on in normal operation to connect the first main coil and the second main coil to a power source; A third contact that is turned on / off in synchronization with the first contact, and the contact is turned off during normal operation to cut off the sub-coil from power; And it provides a single-phase induction motor comprising an electronic three-contact relay for turning on / off the first contact, the second contact and the third contact.

Hereinafter, exemplary embodiments of a single phase induction motor and a single phase induction motor having the same according to the present invention will be described in detail with reference to the accompanying drawings, and a detailed description thereof will be omitted.

First, the starting device of the single phase induction motor according to the present invention will be described with reference to FIGS. 3 to 4. 4 is a schematic state diagram at the time of normal operation of the starting device according to the present invention, and FIG. 5 is a schematic state diagram at the time of starting the starting device according to the present invention.

As shown in FIGS. 4 to 5, the starting device according to the present invention improves the structure of the D portion, which is a dotted line of the conventional centrifugal force switch box 10 shown in FIG.

That is, unlike the conventional one, the configuration of the collar or the balance weight for mechanically recognizing the rotational speed of the rotating shaft is omitted in the single-phase induction motor, while the configuration of the lever 11 and the plates 14 and 15 in the centrifugal force switch box 10 is omitted. D is to improve the three-point relay (30).

Accordingly, the starter of the single-phase induction motor according to the present invention turns on the terminals to which the first main coil and the second main coil are connected, the terminals to which the subcoil is connected, the power supply terminal, three contacts, and the three contacts. It comprises an electronic three-contact relay 30 to turn on / off. Here, three contacts are referred to as A contacts, B contacts, and C contacts, respectively, and the operation and action of these contacts are as described above.

First, the electronic three-contact relay 3 includes an armature 31, a solenoid 34 for magnetizing the armature 31 when current flows, and a plurality of terminals 32 connected to respective contacts. Is done.

Here, one side of the armature 31 is provided with an elastic member to apply an elastic force in a direction opposite to the movement of the armature 31, an example spring 33 is shown.

4 and 5 illustrate a form in which a plurality of terminals 32 are integrally connected with the armature 31 and selectively connected to the contacts, on the contrary, the contacts are integrally moved with the armature 31 to selectively It is also possible to be connected to the terminals (32).

Here, the solenoid coil is preferably connected so that the same current as the current flowing in the first main coil flows, and simply the first main coil on the front side based on the split point of the first main coil and the second main coil. This connection is possible by connecting in series with.

Therefore, according to the strength of the current flowing through the first main coil, the armature is magnetized to change the force to move by the magnetic force, this force may be formed to balance the appropriate force with the spring 33.

And, the starter of the single-phase induction motor is provided in a single switch box as shown in Figure 3 will be easy to manufacture can reduce the production cost.

Hereinafter, the operation of the starting device of the single-phase induction motor according to the present invention with reference to FIGS.

Fig. 4 shows the state of the initial starting device with no power applied. Once power is applied, the strength of the current is rapidly increased in the main coil. As a result, the armature is magnetized instantaneously, thereby increasing the elasticity of the spring as shown in FIG. 5 to connect the A contact and the C contact. Thus, as described above, the circuit configuration of the initial starting state is achieved, and the rotor is started and rotated, and FIG. 5 shows the state of the starting device at the start.

On the other hand, when the rotational speed of the rotor exceeds a certain speed, the current flowing through the main coil is reduced by the counter electromotive force, and thus the armature of the armature does not overcome the elasticity or the self-weight of the spring, thereby falling. Therefore, as shown in FIG. 4, only the B contact is turned on, thereby performing normal operation.

In this case, when the motor load increases during normal operation of the motor or an external force is applied to stop the rotation of the motor, it is necessary to apply starting torque again. That is, the circuit configuration must be switched back to the circuit at startup.

As described above, since the solenoid 34 is connected in the same way as the current flowing through the main coil, when the load of the motor increases, the back EMF decreases, and the current flowing through the main coil increases again. Switch to the circuit.

That is, the driving of the three-contact relay is controlled according to the strength of the current flowing through the solenoid 34.

On the other hand, it is possible to provide a single-phase induction motor having a starting device including the above-described three contacts and an electronic three-contact relay, including a first main coil, a second main coil and a sub coil.

The present invention is not limited to the above embodiment. That is, the single-phase induction motor has been described as an example, but other single-phase induction motors such as a capacitor-driven or shading coil-type single-phase induction motor will also belong to the present invention.

And those skilled in the art can be modified without departing from the spirit of the present invention and such modifications are within the scope of the present invention.

According to the present invention described above,

First, it is possible to provide a reliable single-phase induction motor through an electronic three-contact relay.

Second, it is possible to reduce the production of noise by reducing the mechanical components, and to simplify the assembly process.

Third, it is possible to provide an effect of reducing the power loss by reducing the components causing the power loss.

Fourth, it is possible to provide a compact single-phase induction motor as compared to using three relays or two relays using a single three-contact relay formed integrally.

Claims (10)

Terminals which are divided to apply a high starting current during start-up and a low operating current during normal operation, and to which the first main coil and the second main coil connected in series are connected; A terminal connected in parallel with a main coil including the first main coil and the second main coil from a power supply terminal, and connected to the sub coil for winding the stator together with the main coil to start the rotor; In the starting device of the single-phase induction motor comprising a power supply terminal for supplying power to the main coil and the sub-coil, A first contact point at which the contact point is turned on to connect only the first main coil to a power supply terminal; A second contact selectively turned on / off with the first contact, the contact being turned on during normal operation to connect the first main coil and the second main coil to a power supply terminal; A third contact that is turned on / off in synchronization with the first contact and that the contact is turned off during normal operation to cut off the sub-coil from the power supply terminal; And And an electronic three-contact relay for turning on / off the first contact, the second contact, and the third contact. The method of claim 1, The electronic three contact relay, A solenoid coil wound around the armature to magnetize the armature; An elastic member provided at one side of the armature to apply an elastic force in a direction opposite to the movement of the armature; And And a plurality of terminals selectively connected / blocked with the first contact, the second contact, and the third contact according to the movement of the armature. The method of claim 2, And said plurality of terminals move integrally with said armature and are electrically isolated from each other. The method of claim 3, wherein The solenoid coil is a starting device of a single-phase induction motor, characterized in that connected in series with the first main coil on the front side based on the split point of the first main coil and the second main coil. The method of claim 1, Starting device of the single-phase induction motor is provided in a single switch box. A main coil which is divided to apply a high starting current at start-up and a low operating current at normal operation and includes a first main coil and a second main coil connected in series with each other; A sub-coil connected to the main coil in parallel from a power supply terminal and wound on a stator together with the main coil to start a rotor; A first contact point which is turned on at startup so as to connect only the first main coil to a power supply terminal; A second contact selectively turned on / off with the first contact, the contact being turned on in normal operation to connect the first main coil and the second main coil to a power source; A third contact that is turned on / off in synchronization with the first contact, and the contact is turned off during normal operation to cut off the sub-coil from power; And Single-phase induction motor comprising an electronic three-contact relay for turning on / off the first contact, the second contact and the third contact. The method of claim 6, The electronic three contact relay, A solenoid coil wound around the armature to magnetize the armature; An elastic member provided at one side of the armature to apply an elastic force in a direction opposite to the movement of the armature; And And a plurality of terminals selectively connected / blocked with the first contact, the second contact, and the third contact according to the movement of the armature. The method of claim 7, wherein And said plurality of terminals move integrally with said armature and are electrically isolated from each other. The method of claim 8, The solenoid coil is a single-phase induction motor, characterized in that connected in series with the first main coil on the front side based on the split point of the first main coil and the second main coil. The method of claim 9, Single phase induction motor, characterized in that the contacts and the electronic three-contact relay is provided in a single switch box.

Images