JPH0662779U - Capacitor operation type motor - Google Patents

Abstract

(57) [Abstract] [Purpose] When the power is cut off while the motor is being rotated by an external force, the power generation is stopped and the application of voltage to other equipment connected to the motor is stopped to ensure safety. It is the one that enhances sex. [Configuration] The main coil 1 and the auxiliary coil 2 are connected in parallel,
In a capacitor operation type motor in which a circuit in which a starting capacitor CS connected in series with a low rotation switch SW1 is connected in parallel with an operating capacitor CR is connected in series with the auxiliary coil 2, the motor is rotated by an external force. A protective switch SW2 that cuts off in a state is provided in series with the operating capacitor CR to stop the application of voltage to other equipment connected to the motor when the motor is rotated by external force. .

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an improvement in a capacitor-operated motor that prevents power generation in the event of an abnormality such as a power failure while the motor is rotated by an external force.

[0002]

[Prior art]

 As shown in Fig. 5, the circuit configuration of the conventional capacitor-operated motor is such that the main coil 1 and the auxiliary coil 2 are connected in parallel, and the starting capacitor CS connected in series with the low-speed switch SW1 is the operating capacitor CR. A circuit connected in parallel with is connected in series with the auxiliary coil 2.

In this capacitor operation type motor, the low speed switch SW1 formed by a centrifugal force switch or the like is turned on at the time of starting the motor, that is, between about 0% and 80% of the synchronous speed. The starting capacitor CS and the operating capacitor CR connected in series are connected in series to the auxiliary coil 2 to rotate the motor. When the rotation speed of the motor rises and reaches a range of about 80% of the synchronous speed, the low speed switch SW1 turns off, and at higher speeds, only the operating capacitor CR is connected in series with the auxiliary coil 2. It operates at a speed of about 95% of the synchronous speed under normal operating conditions.

Since this capacitor operation type motor has a small loss and a high efficiency, a small size and a large torque can be obtained, and it is used as an elevator motor or a pump motor. When this capacitor-operated motor rotates when a voltage is applied to the motor, the speed-torque curve for a motor with a synchronous speed of 1500 RPM is as shown in Fig. 7, for example. With the low speed switch SW1 turned on in the range up to about 1200 RPM, the torque increases as the speed increases, the low speed switch SW1 turns off at about 1200 RPM, peaks at about 1300 RPM, and then gradually falls. The torque becomes zero at a speed slightly lower than 1500 RPM. The speed at this time is called the no-load speed. When this motor is rotated from the outside at a speed faster than the no-load speed, braking torque is generated, and the braking torque also increases as the number of rotations increases.

Further, in the case of a capacitor operation type motor in which a brake 3 used as a drive source of a lifting device as shown in FIG. 6 is connected in parallel with a power source 4, a power switch SW and a motor are used when raising or lowering a conveyed object. The switch SW2 is turned on to rotate the motor. During the ascent and descent, the rotation direction changeover switch SW3 is switched to reverse the polarity of the auxiliary coil 2 with respect to the main coil 1 of the motor, thereby reversing the rotation direction. The torque generated by the motor is used to raise the conveyed object when it rises, and the conveyed object is lowered when it descends, but after the start, the motor is rotated by the weight of the conveyed object, causing It will be driving. In the operation in the regenerative region, the motor generates a braking torque as shown in Fig. 9, which balances with the load torque in the descending direction due to the weight of the conveyed object, and descends at a speed higher than the synchronous speed, for example, about 1600 RPM. In this case, when the motor switch SW2 interlocking with the power supply 4 is cut off, the brake 3 automatically operates.

However, during operation in the regenerative region, if the power switch is shut off while the motor switch SW2 interlocking with the power source 4 remains on due to, for example, a power failure, the charge stored in the operating capacitor causes excitation again. It is operated continuously in the regeneration area. In this case, the load of the motor, which is the generator, is applied not only to the excitation but also to the operation circuit, so the number of rotations is increased more than usual, and the speed-generated voltage curve becomes as shown in FIG. When the motor is rotated at a speed faster than the synchronous speed, the voltage rapidly increases from a certain speed and the motor is in a power generating state, and the braking torque also rapidly increases accordingly.

Therefore, in the motor of the lifting device, when the power supply 4 is cut off during the descent, the descending speed of the conveyed object is increased and the motor is forcibly rotated. For example, as shown by a point A in FIGS. 8 and 9. A condition can occur where it can be rotated at 2500 RPM. In this way, when the motor is rotated by an external force at a speed faster than the synchronous speed and the power is cut off while the motor is a generator, a voltage equal to or higher than the rated voltage is generated as shown by the broken line. A voltage will be applied to the brake 3 connected to this. As shown in FIG. 6, the brake 3 is activated when the power source 4 is shut off by the motor switch SW2 which is interlocked with the power source switch SW to brake the motor, but it is forced to rotate from the outside. The generated voltage causes the brake 3 to continue to be supplied with power, braking is not performed, and there is a risk that the conveyed goods will descend without stopping and become dangerous.

[0008]

[Problems to be solved by the device]

 The present invention eliminates the above-mentioned drawbacks and stops the power generation when the power is cut off in the state where the motor is rotated by an external force, and stops the application of voltage to other devices connected to the motor for safety. The present invention provides a capacitor-operated motor with improved performance.

[0009]

[Means for Solving the Problems]

 The present invention is a capacitor operation type in which a main coil and an auxiliary coil are connected in parallel, and a circuit in which a starting capacitor connected in series with a low-speed switch is connected in parallel with an operating capacitor is connected in series with the auxiliary coil. In the motor, a protection switch is provided in series with the operating capacitor, the protection switch being turned off when the motor is rotated by an external force.

[0010]

[Action]

 In the capacitor operation type motor of the present invention, the low speed switch is turned on in the stopped state. When the power switch is turned on, power is supplied from the power supply to the main coil and auxiliary coil of the motor, and is supplied to the auxiliary coil through the starting capacitor and operating capacitor that are connected in parallel. When the motor speed rises to about 80% of the synchronous speed, the low speed switch turns off, and power is supplied to the auxiliary coil from the operating capacitor only, and normal rotation occurs.

Further, when the motor is rotated by an external force while the power is being supplied, when the protection switch is turned off, the circuit of the driving capacitor connected in series with this is opened, so that the speed is faster than the synchronous speed. Even if it is rotated by an external force, the voltage is hardly generated, and it is possible to prevent the voltage from being applied to the device connected to the motor.

[0012]

【Example】

 Hereinafter, the present invention will be described in detail with reference to FIGS. The main coil 1 and the auxiliary coil 2 are connected in parallel to the power supply 4 via a motor switch SW2 and a power switch SW interlocked with the motor switch SW2. Further, a circuit in which a starting capacitor CS connected in series with the low speed switch SW1 is connected in parallel with an operating capacitor CR is connected in series with the auxiliary coil 2. The auxiliary coil 2 is connected to the motor switch SW2 via the rotation direction changeover switch SW3, and the motor is rotated by an external force between the motor switch SW2 and the power switch SW in series with the driving capacitor CR. Protective switch SW4, which turns off in the state, is connected.

The protection switch SW4 is interlocked with the rotation direction changeover switch SW3, and is operated, for example, interlocked with a lowering switch of an elevator (not shown). A brake 3 is connected in parallel with the power source 4 between the power switch SW and the motor switch SW2. The brake 3 brakes the motor when the motor switch SW2 is turned off.

When the above-mentioned capacitor operation type motor is used as a motor for an elevator, the low speed switch SW1 is turned on in the stopped state as shown in FIG. First, when raising the elevator, turn on the power switch SW and turn on the motor switch SW2 that works with this. Next, when the lift switch of the elevator (not shown) is turned on, the rotation direction changeover switch SW3 is changed to the upside, and the contact of the protection switch SW4 linked with this is turned on.

In this state, power is supplied from the power supply 4 to the main coil 1 and the auxiliary coil 2 of the motor, and is supplied to the auxiliary coil 2 through the starting capacitor CS and the operating capacitor CR connected in parallel. . When the motor rises to about 80% of the synchronous speed, the low speed switch SW1 composed of a centrifugal switch etc. is turned off as shown in Fig. 2, and the auxiliary coil 2 is powered only from the operating capacitor CR. When supplied, the rotation of the elevator becomes steady and the lift of the elevator rises.

When the lift stops and descends, when a not-shown descending switch is turned on, the rotation direction selector switch SW3 is switched to the descending side, and the protection switch SW4 interlocking therewith is turned off, but the low speed switch is used. SW1 remains on. As a result, when the power supply 4 is supplied to the motor, the polarities of the auxiliary coil 2 with respect to the main coil 1 of the motor are reversed, so that the conveyed object begins to descend, and it descends even after the low speed switch SW1 is turned off. to continue. In this case, when the power supply switch SW is turned off and the power supply 4 is cut off, the motor switch SW2 which is interlocked with this is also turned off and the brake 3 is automatically operated to brake the motor.

Even if the power supply 4 is cut off when the motor speed is faster than the synchronous speed, since the protection switch SW4 is turned off and the operation capacitor CR is opened, the voltage shown by the broken line in FIG. 9 is generated. In most cases, no voltage is applied to the brake 3 and the brake 3 is brought into a braking state.

When the lowering switch is turned on and the protection switch SW4 interlocked with the lowering switch is turned off, the brake 3 operates automatically when a power failure occurs while the power switch SW remains on. However, it is conceivable that the motor connected by a gear descends due to its own weight and is forced to rotate by an external force. Even if the motor is forcibly rotated at a speed faster than the synchronous speed by the external force, the protection switch SW4 is turned off and the circuit of the driving capacitor CR is opened, so that almost no voltage is generated and the brake 3 is braked. It remains safe and safe.

FIG. 4 shows another embodiment of the present invention, in which the contact on the descending side of the switch connecting the operating capacitor CR of the rotation direction changeover switch SW3 and the motor switch SW2 is not connected to the power source 4 side. The structure may also be used as a protection switch SW4.

In the above embodiment, the protection switch SW4 is interlocked with the rotation direction changeover switch SW3. However, when the motor is rotated at a speed faster than the synchronous speed by an external force, this is detected. The structure may be such that the protection switch SW4 turns off automatically. In the above embodiment, the capacitor-operated motor in which the brake 3 is connected in parallel has been described, but the invention can be applied to the case where the brake 3 is connected to another device such as an axial flow pump.

[0021]

[Effect of device]

 As described above, according to the capacitor operation type motor of the present invention, when the power is cut off while the motor is rotated by the external force, the power generation is stopped and the other devices connected to the motor are stopped. Safety can be improved by stopping the application of voltage.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing a capacitor-operated motor in which brakes are connected in parallel according to an embodiment of the present invention.

FIG. 2 is a circuit diagram showing a steady rotation state of a capacitor operation type motor in which the brakes of FIG. 1 are connected in parallel.

FIG. 3 is a circuit diagram showing a state in which the brakes of FIG. 1 are rotated by an external force of a capacitor driving type motor connected in parallel.

FIG. 4 is a circuit diagram showing a capacitor driving type motor in which brakes are connected in parallel according to another embodiment of the present invention.

FIG. 5 is a circuit diagram showing a conventional capacitor operation type motor.

FIG. 6 is a circuit diagram showing a conventional capacitor-operated motor in which brakes are connected in parallel.

FIG. 7 is a graph showing a rotational speed-torque curve of a capacitor operation type motor.

FIG. 8 is a graph showing a speed-generated voltage / torque curve of a capacitor driving type motor when the power supply is cut off.

FIG. 9 is a graph showing a relationship between torque, load torque, and changes in generated voltage according to rotation speed.

[Explanation of sign]

 1 Main coil 2 Auxiliary coil 3 Brake 4 Power supply CS Starting capacitor CR Operating capacitor SW Power switch SW1 Low speed switch SW2 Motor switch SW3 Rotation direction selector switch SW4 Protection switch

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masumi Kameyama 1-24-30 Nanami Station, Nakamura-ku, Nagoya, Aichi Prefecture, Chuo Branch Office, Toshiba Corporation (72) Tomio Fujiba, Chiba Fukushima City Tennohara No. 9 within Kita-Shiba Electric Co., Ltd.

Claims (1)

[Scope of utility model registration request] 1. A main coil and an auxiliary coil are connected in parallel,
In a capacitor-operated motor in which a circuit in which a starting capacitor connected in series with a low speed switch is connected in parallel with an operating capacitor is connected in series with the auxiliary coil, protection that cuts when the motor is rotated by an external force A capacitor operation type motor characterized in that a switch is provided in series with an operation capacitor.