JPS5818868B2 - Cylindrical rotating field type rotor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cylindrical rotating field type rotor in which a conductor of a brake winding is disposed in a magnetic pole portion of a rotor body of a rotating electric machine.

A conventional cylindrical rotating field type rotor in which a braking conductor is not provided in the magnetic pole portion has a structure as shown in a perspective view showing the end side of the rotor body in FIG.

The figure shows a part of the coil end cut away, excluding the retaining ring at the end of the field coil. 1 is the rotor body, which constitutes the rotor core, is provided with a large number of coil slots 2, and is magnetic coil 3
It accommodates.

1a is a magnetic pole part, 1b is a rotating shaft part stepped down from both ends of the rotor body 1, and 1c is an end face of the body.

The field coil 3 has a coil end 3a shaped like an arc with respect to the axis, and is wound around both straight parts.

Ventilation holes 8 rising in the radial direction are provided on the inner circumferential surface on both sides of the coil end portion 3a, into which cooling gas serving as a cooling medium is pressurized as shown by arrow A.

9 is a ventilation hole provided in the circumferential direction in the coil end 3a;
A ventilation hole 8a extending from the ventilation hole 9 to the inner peripheral surface in the radial direction is provided in the middle portion of the coil end portion 3a.

Reference numeral 4 denotes a pair of partition plates on both sides that contact the outer circumference of the rotating shaft portion 1b, the inner circumference of the coil end portion 3a, and the body end surface 1c, respectively, and are provided at both ends of the partition plate 5 that partitions the inflow side of the cooling gas. The cooling gas coming out from the ventilation hole 8a of the coil end 3a as shown by arrow B is partitioned off, and a low pressure zone 11 is formed.

Reference numeral 14 denotes an annular cover plate which is applied to the outer end surface of the coil end portion 3a and whose inner circumference is in contact with the partition plate 5.

6 is an insulating spacing plate inserted between the field coils 3 of different polarities, 7
10 is an insulating spacer inserted between the coil ends 3a, and 10 is a ventilation groove provided at the end of the magnetic pole part 1a, which directs the cooling gas from the body end face 1c side to the outside of the magnetic pole part 1a in the direction of arrow C. Pass it to the circumferential side.

12 is a wedge of the coil slot 2, and 13 is a braking conductor placed under this wedge.

The ventilation of the cooling gas in the above device is as follows.

A part of the cooling gas press-injected into the coil end 3a side as shown by arrow A enters through the ventilation holes 8 on both sides, passes through the ventilation holes 9 in the radial direction, flows circumferentially through the ventilation holes 9, and flows from the ventilation holes 8a to the low pressure zone. Join 11.

This combined cooling gas flows through the ventilation groove 10 as shown by arrow C.
The air flows through the air gap to the outer circumferential side of the rotor body 1, and flows through the air gap to the other end of the rotor body 1 in the axial direction.

The other part of the cooling gas that is press-fitted into the coil end 3a side enters the ventilation holes 8 in the straight parts on both sides of the coil end 3a from below, passes through the straight parts of the coil in the axial direction, and then radially to the air gap.

The above conventional rotor has a wedge 12 in the coil slot 2.
The lower brake conductor 13 and the end side of this brake conductor are wedged 1
A brake winding is formed by a retaining ring (not shown) of the coil end 3a which is in pressure contact with the coil end 3a through the coil end 3a.

In recent large-capacity machines, it has become necessary to arrange the brake conductor of the brake winding also in the magnetic pole portion.

In this case, if the ventilation groove 10 is provided at the end of the magnetic pole portion 1a as shown in FIG. 1, it will be difficult to provide a slot for the braking conductor.

A conventional example in which magnetic pole slots for braking conductors are provided in the magnetic pole part 1a of the rotor body 1 shown in FIG. 1 is shown in FIGS. show.

The magnetic pole part 1a is provided with magnetic pole part slots 15 and 16 in the axial direction, avoiding the ventilation groove 10.

Wedge-shaped brake conductors 17 and 18 and connecting conductors 19 and 20 below these brake conductors are arranged in these pole slots.

This connecting conductor is connected to the wedge-shaped brake conductor 17.
．． Since the numeral 78 is divided into a plurality of parts in the axial direction, the purpose is to electrically connect the divided parts.

Providing the magnetic pole slots 15 and 16 at positions that avoid the ventilation groove 10 in this way would result in the braking conductors 17 and 18 not being provided with sufficiently large magnetic pole slots.
Also, it is not possible to make the cross-sectional area sufficient.

If the width of the ventilation grooves 10 is reduced or the number of ventilation grooves 10 is reduced in order to increase the magnetic pole thrower (15, 16), the cooling effect of the coil end portion 3a will be reduced, resulting in a disadvantage.

In this invention, in order to arrange the braking conductor in the magnetic pole part of the rotor body, a magnetic pole slot is provided in the axial direction through the ventilation groove at the end of the magnetic pole part, and the braking conductor is placed in the magnetic pole part slot. , the braking conductor located at the top of the ventilation groove is provided with radial ventilation holes to guide the cooling gas through the ventilation groove without obstruction, and the braking conductor with a sufficient cross-sectional area is provided at the magnetic pole part. The object is to provide a cylindrical rotating field type rotor.

FIG. 4 is a perspective view of the end portion of the rotor body showing an embodiment of the present invention, in which a portion of the end portion of the field coil is shown broken except for the retaining ring, 1 and 1a.

1b, 1c, 2, 3, 3a, 4-8, 8a, 9° 11-
14 is the same as the conventional device described above.

Reference numeral 21 denotes a ventilation groove that is rounded up in the axial direction from the body end face 1c to the outer circumferential surface of the end of the magnetic pole portion 1a; 22 is a magnetic pole slot that passes through the upper part of this ventilation groove and is provided in the axial direction;
Reference numeral 3 designates a wedge-shaped braking conductor driven into this magnetic pole slot, which is made of a good conductor, such as beryllium copper alloy, and is formed into a wedge shape.

The braking conductor 23 is divided into a plurality of parts in the axial direction, and a plurality of radial ventilation holes 24 communicating with the ventilation groove 21 are bored in the end conductor 23a of these parts.

Details of the end portion of the magnetic pole portion 1a into which the braking conductor 23 is driven are shown in a plan view in FIG. 5, a cross-sectional side view in FIG. 6, and a cross-sectional front view in FIG. 7.

Reference numeral 25 denotes a retaining ring for the coil end portion 3a, a pair of which is shrink-fitted to the outer circumference of both ends of the rotor body 1, and the coil slot 2
The braking conductor 13 of the magnetic pole part slot 22 and the braking conductor 23 of the magnetic pole part slot 22
Both ends of the coil are electrically connected to form an end ring, forming a squirrel-shaped damper winding.

The braking conductor 23 is divided into a plurality of parts in the axial direction, and the divided parts are electrically connected by the magnetic pole part 1a.

In order to further improve the electrical connection of this divided portion, a connecting conductor may be provided below the brake conductor 23.

In the device of the above embodiment, the magnetic pole slot 22 passes over the ventilation groove 21, and the cooling gas that has passed through the coil end 3a and entered the low pressure zone 11 passes through the ventilation groove 21 and enters the end conductor 23a. It passes through the ventilation hole 24 and is led to the outer circumferential side of the magnetic pole portion 1a.

In this way, even if the ventilation groove 21 is present, the braking conductor 23 having the required cross-sectional area can be provided in the magnetic pole portion 1a.

Note that since the end side of the magnetic pole slot 22 communicates with the ventilation groove '21, a part of the bottom surface is removed, but since the width of the slot is larger than the width of the ventilation groove 21, the wedge-shaped braking conductor 23 is maintained without any problem.

The dimensions and number of the magnetic pole slots 22 and ventilation grooves 21 are determined so that the electrical performance of the braking conductor 23 of the magnetic pole part 1a and the amount of cooling gas passing through the coil end 3a are satisfied.

As described above, according to the present invention, the magnetic pole slot is provided to pass over the ventilation groove at the end of the magnetic pole, and the end portion of the braking conductor placed in the magnetic pole slot has a radius that communicates with the ventilation groove. Since the ventilation holes are provided in both directions, a braking conductor of sufficient size can be disposed in the magnetic pole portion without obstructing the ventilation of the cooling gas.

[Brief explanation of drawings]

Figure 1 is a perspective view showing a conventional cylindrical rotor at the end of the rotor body, with the retaining ring removed and a part of the field coil end cut away. FIG. 1 is a cross-sectional front view and side view of an end of a rotor body showing an example in which a braking conductor is arranged in a magnetic pole part, and FIG. 4 is a rotor body showing a cylindrical rotor according to an embodiment of the present invention. 5 and 6 are perspective views showing the end of the field coil with a part of the field coil end cut away, excluding the retaining ring.
FIG. 7 is a plan view and a cross-sectional side view of the end side of the magnetic pole part in the figure, and FIG. 7 is a cross-sectional view taken along the line ■--■ in FIG. 1...Rotor body, 1a...Magnetic pole part,
1C... Body end face, 2... Coil slot, 13... Braking conductor, 21...
Ventilation groove, 22...Magnetic pole slot, 23...
... Wedge-shaped braking conductor, 23a ... End side conductor, 24 ... Ventilation hole. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Claims] 1. A large number of coil slots are provided in the axial direction in the rotor body forming the rotor core, and a straight part of the field coil is inserted into each of these slots, and the end of the field coil is connected to the body. The end portions and straight portions of the field coil are respectively cooled by the cooling medium that is brought out from the end face and press-fitted from the outside. In the rotor, a ventilation groove is formed in the circumferential surface in the axial direction, and the cooling medium cooled through the end of the coil is passed through the ventilation groove from the end surface side of the body and distributed in the radial direction. A magnetic pole part slot is provided in the magnetic pole part in the axial direction through the upper part of the ventilation groove, and a ventilation hole is formed in the magnetic pole part slot and communicates with the air gap side in the radial direction from the ventilation groove on the end side. What is claimed is: 1. A cylindrical rotating field type rotor comprising a braking conductor provided therein, the cooling medium entering the ventilation groove passing through the ventilation hole of the braking conductor and leading to the air gap side.