JPH0431817Y2 - - Google Patents

Description

[Detailed description of the invention] [Technical field to which the invention pertains] This invention relates to the configuration of a ground connection part of a telemeter device such as an FM transmitter incorporated in the excitation circuit of a brushless rotating electric machine.

[Prior art and its problems]

Conventionally, voltage and current measurements in the excitation circuit of brushless rotating electric machines and detection of ground faults have been carried out through brushes rather than measurement slip rings.

However, recently, in order to achieve maintenance-free operation and improve measurement accuracy, a telemeter device such as an FM transmitter has been incorporated into the rotor's excitation circuit, and the FM transmitter radio waves are received to measure the excitation voltage and current and detect ground faults. began to be carried out. Figure 3 is an electrical circuit diagram of a brushless rotating electrical machine equipped with a telemeter device, where 1 is a stationary armature, 2 is a rotor, and the rotor has a field winding 3, a rectifying element 4, and an exciter armature winding. A strong electric circuit is formed by the wire 5, and the field winding 3 is excited by the current from the exciter armature winding 5. Reference numeral 6 denotes the telemeter device described above, which is connected to the excitation circuit (field winding 3) and grounded via the grounding connection 7, and at the same time, the entire rotor 2 is also grounded.

In this circuit for detecting ground faults in the rotor, it is necessary to ground one end of the telemeter device 6 via the ground connection 7 as shown in Fig. 3, but the ground must be disconnected during the voltage withstand test of the circuit. If this is done without doing so, the telemeter device, which is a weak current circuit, will be instantly destroyed. Megger voltage also destroys insulation resistance measurements that are normally performed during maintenance. Therefore, when carrying out insulation resistance measurements and withstand voltage tests, the earth connection 7 must be opened and the telemeter device 6 must be disconnected from earth.

In the conventional structure of the earth connection section 7 for turning on and off the earth as shown in FIG. 4, the earth connection of the circuit was carried out using bolts. In FIG. 4, the telemeter device 6 and the rotor 2 are grounded.
The structure of the ground connection part 7 provided between the telemeter device 6 and the ground terminal 6b is that the ground terminal 6b at the tip of the ground wire 6a of the telemeter device 6 is connected to the rotor (ground side )2 is fixed with screws. That is, the figure shows a state in which the telemeter device 6 is grounded, and when disconnecting the ground connection, the troublesome work of loosening the bolt 9 and removing the ground terminal 6b from the connection base 10 and the stator 2 is involved. Therefore, there was a risk of forgetting to disconnect the ground connection and accidentally connecting the megger to perform a test, which was extremely dangerous to the telemeter device.

[Purpose of invention]

In view of the above-mentioned circumstances, it is an object of this invention to provide a rotating electric machine having a ground connection part in which it is impossible to make a mistake in disconnecting the ground connection.

[Key points of the idea]

Focusing on the fact that the ground connection must be disconnected when performing insulation resistance measurements or withstand voltage tests that are carried out during normal maintenance, and this is done while the rotor is stopped, we decided to The ground connection part is composed of a contact piece and a movable contact that opens when the rotor is stationary and closes due to centrifugal force when rotating.The telemeter device is disconnected from the ground when the rotor is stopped, and is connected to the ground when the rotor is rotating. I made it.

[Example of idea]

FIG. 1 shows an embodiment of this invention, and is a side sectional view of a switch operated by centrifugal force employed in the ground connection. Earth wire 6 of telemeter device 6
A fixed contact 11 is provided at the tip of the ground terminal 6b at the tip of a, and the ground terminal 6b is held between an insulating pedestal 12 and an insulating support piece 13, and fixed to the rotor (earth side) 2 with a bolt 14. . A movable contact 15 that comes into contact with and separates from the fixed contact 11 is provided at the other end of a movable contact piece 17 whose one end is electrically conductively fixed to the rotor (earth side) 2 with a bolt 16 .

In a switch with such a structure, when the rotor is stopped, the movable contact piece 17 is in the position shown by the solid line, and the contact 1 is in the position shown by the solid line.
1 and 15 are open and the telemeter device is not grounded, so the withstand voltage test of the rotating electrical machine,
Even if insulation resistance measurements are carried out, the telemeter device will not be destroyed. Further, when the rotor rotates, the movable contact piece is deformed by the centrifugal force thereof, so that the movable contact piece 15 comes into contact with the stationary contact 11 as indicated by a dashed line 17', and the telemeter device 6 is grounded.

FIG. 2 shows another embodiment of this invention, and is a sectional view of a switch using a coil spring operated by centrifugal force. The structure of this switch is that a conductive spring receiver 19 is provided in a conductive casing 18 that is screwed onto the rotor 2, and a tension type coil spring 20 is housed in the spring receiver 19. A movable contactor 21A is connected. An annular plate-shaped earth terminal 6b that comes into contact with and separates from the movable contact 21 is attached to an insulating terminal seat 22 and housed in the casing 18, and is attached to a cap 23.
As a result, the casing 18 is closed. The ground wire 6a of the telemeter device 6 passes through the casing 18 and the insulating terminal seat 22, and its tip is connected to the ground terminal 6b. This switch is in the state shown in FIG. 2 when the rotor is stopped, and the telemeter device is not grounded. However, when the rotor rotates, the coil spring 20 is expanded due to centrifugal force, and the movable contact 21 is connected to the ground terminal 6b. come into contact with. At this time, the telemeter device 6 is grounded to the rotor 2 through the ground wire 6a→movable contact 21→coil spring 20→spring receiver 19→casing 18.

[Effect of idea]

If a rotor with a telemeter device is to be tested for insulation resistance or withstand voltage during normal maintenance, the bolt at the ground connection must be removed to disconnect the telemeter device while the rotor is stopped, which is cumbersome. However, by using a switch operated by centrifugal force in the ground connection part as in the present invention, the rotor is connected to the ground while it is rotating, and when it stops, it is automatically connected. The telemetering device is protected from human error since the ground connection is permanently disconnected.

[Brief explanation of the drawing]

1 and 2 are side sectional views of the ground connection part of a telemeter device showing an embodiment of this invention, FIG. 3 is an electric circuit diagram of a brushless rotating electric machine having a telemeter device, and FIG. 4 is the same as that shown in FIG. FIG. 2 is a side cross-sectional view showing a conventional structure of a ground connection part. 2...Rotor, 6...Telemeter device, 7...
Earth connection portion, 11...fixed contact, 15...movable contact, 17, 17'...contact piece.

Claims (1)

[Scope of utility model registration request] In a rotating electric machine that is equipped with a telemeter device such as an FM transmitter in the excitation circuit of the rotor, and has a ground connection part that connects one end of the telemeter device to the rotating shaft and grounds it, the rotor is connected to the telemeter device and has an insulating material. a contact piece having a fixed contact fixed to the rotating shaft via a bolt, and a movable contact having one end fixed to the rotating shaft via a bolt to open the circuit when it is stationary and close the circuit by contacting the fixed contact due to centrifugal force when rotating; A ground connection part of a telemeter device for a rotating electrical machine, characterized by comprising: