JPS6037009Y2 - Brake winding connection support structure in salient pole type rotating electric machine - Google Patents

Description

[Detailed description of the invention] The present invention relates to an improvement of the connection support structure of the brake winding for a large-capacity salient pole type rotating electrical machine.The purpose of the present invention is to absorb thermal expansion of the brake winding conductor well, and The reason is that it maintains strength against centrifugal force.

As is well known, in a salient pole type synchronous machine, a damper winding is placed near the head surface of the salient magnetic pole for the purpose of preventing disturbances, etc., and this damper winding is inserted into a groove for each magnetic pole core and is inserted around the circumference. It is composed of a combination of winding conductors arranged in parallel in the direction and a short circuit ring connecting both ends of each winding conductor.

Such a brake winding is sometimes used for self-starting of synchronous phase modifiers and synchronous motors, and when starting using such a brake winding starting method, a large current flows through the brake winding, resulting in a rise in temperature. Thermal expansion occurs.

In particular, since the brake winding conductor is inserted into the groove of the magnetic pole core, heat dissipation is poor and the temperature rises, resulting in large thermal expansion.

On the other hand, the short-circuit ring located on the side of the magnetic pole core is heavy in large-capacity machines, and the short-circuit ring is usually held by a retaining ring to protect it from the centrifugal force that acts during operation.

A conventional connection support structure for such a brake winding is shown in FIG.

In the figure, 1 is a magnetic pole core, 2 is an end plate of the magnetic pole core 1, and 3 is a field winding.

The damper winding conductor 4 is inserted into the groove near the head surface of the magnetic pole core 1, and both ends of the brake winding conductor 4 protrude axially from the core 1 and are connected to the end plate 2.
A direct brazing connection is made to a shorting ring 5 arranged on the top surface of the holder.

A retaining ring 6 is lightly shrink-fitted to the outer periphery of this short-circuiting ring 5.

Note that 7 is an end plate 2 for maintaining centrifugal force against the field winding 3.
This is a retaining ring that is shrink-fitted to the outer periphery of the collar portion 2a.

Further, although not shown, a flexible connecting piece is interposed in the shorting ring 5 between each salient magnetic pole.

In the conventional structure described above, thermal expansion of the winding conductor 4 in the direction of arrow A caused by energization of the brake winding occurs when the rotating machine starts or slips during operation, and the short-circuiting ring 5 and the retaining ring 6 It is absorbed by sliding it in the axial direction on the upper surface of the end plate 2.

On the other hand, among the winding conductors 4 arranged in the circumferential direction for each magnetic pole core 1, the winding conductors located in the left and right outer regions of the magnetic pole are naturally the same as the winding conductors located in the central region of the magnetic pole. In comparison, the amount of interlinking magnetic flux is large, and therefore the flowing current, that is, the temperature rise is also large, and a relative thermal expansion difference occurs between the winding conductors.

However, as shown in Figure 1, each winding conductor 4 is directly connected to a short ring 5.
A structure in which the wires are brazed together cannot absorb the above-mentioned difference in thermal expansion between the winding conductors, and as a result, thermal stress is applied and there is a risk that the brazing portions may be damaged.

In order to deal with this problem, conventional methods have been implemented such as changing the material of the winding conductor 4, that is, the resistance value of the conductor 4, depending on the position of the conductor on the iron core 1, and balancing the current value, that is, thermal expansion. However, even with this method, it is difficult to match the resistance values, and in practice it is difficult to completely absorb the difference in thermal expansion between the winding conductors.

Some attempts have also been made to construct a structure in which all of the winding conductors 4 and the short-circuit ring 5 are connected via a flexible connecting piece.

However, the flexible connecting piece must be interposed between the winding conductor 4 and the shorting ring 5 in FIG. 1, which not only increases the axial dimension of the magnetic poles, but also increases the size of the rotating machine as a whole. In order to easily absorb the thermal expansion of the winding conductor only through the bending of the flexible connecting piece itself, the length of the flexible connecting piece must be large, and furthermore, due to frequent activation, the connecting piece is mechanically damaged. There is also the risk of fatigue and breakage.

From this point of view, the thermal expansion of each winding conductor itself and the relative thermal expansion difference between the winding conductors can be well absorbed with a simple configuration, and the strength against centrifugal force can be maintained. Therefore, it is desired to improve the connection support structure of the damper winding.

In view of these points, the present invention makes maximum use of the upper surface area of the magnetic pole tip plate, supports the short-circuited ring of the magnetic pole tip plate and the brake winding by centrifugal force with the retaining ring, and reduces the thermal expansion of the brake winding conductor itself and the winding. The purpose of this invention is to provide a highly reliable connection support structure for damper windings that can satisfactorily absorb the relative thermal expansion difference between conductors through a clever configuration. This will be explained in detail based on examples.

In FIGS. 2 to 5, the short-circuit ring 5 is located at the axial end side area of the flange portion 2a of the magnetic pole end plate 2, facing each of the winding conductors 4 arranged in the circumferential direction of the magnetic pole core 1 and installed through the groove. It is located so that it is located at

In the range between this short circuit ring 5 and the magnetic pole core 1, the end plate 2
On the upper surface of the holder, comb tooth-like protrusions 8 are arranged circumferentially.

The arrangement pitch of the comb teeth is set in accordance with the arrangement pitch of the brake winding conductor 4, and a groove 9 is defined between each comb tooth.

Further, connection pieces 10 and 11 are inserted between each winding conductor 4 and the short-circuit ring 5 through the groove 9, and the space between them is brazed.

Furthermore, the winding conductors located in most areas of each winding conductor 4 excluding the left and right ends of the magnetic pole core are connected to the short circuit ring 5 via the rigid connecting piece 10, while the winding conductors located in the remaining left and right end areas Only a part of the winding conductor is connected to the shorting ring 5 via a flexible connecting piece 11 which is made of laminated thin plates and curved, for example.

The height of each connecting piece 10.11 is selected to be smaller than the height of the comb teeth 8.

Further, a common retaining ring 12 is fitted on the outer periphery of both the shorting ring 5 and the end plate 2 to maintain the strength of the connecting conductor and the shorting ring against centrifugal force.

This retaining ring 12 lightly contacts the outer circumferential surface of the short-circuit ring 5, and is firmly shrink-fitted onto the upper surface of the comb tooth-like protrusion 8 of the end plate 2.

Therefore, each connecting piece 10.11 fitted into the groove 9 is not directly pressurized and restrained by the retaining ring 12 between it and the end plate 2.

Although not shown, an insulating material is wound around each connection piece 10.11.

According to the above configuration, at the time of starting based on the brake winding starting method or when a slip occurs during steady operation, heat generation due to energization of the brake winding conductor 4 and thermal expansion due to temperature rise are prevented by the rigid connecting piece 10. This is absorbed by sliding the shorting ring 5 against the retaining ring 12 via the .

At this time, the flexible connecting piece 11 also moves following the movement of the shorting ring 5.

Furthermore, only a slight difference in relative thermal expansion occurring between the winding conductors located at both left and right end areas and the center area of the magnetic pole core 1 is absorbed by the bending of the ears of the flexible connecting piece 11. As a result, the brazing of each connecting piece 10.11 is able to absorb thermal expansion completely without undue thermal stress at the location.

Note that the short circuit ring 5 is located at the flange portion 2a at the axial end plate of the end plate 2.
are located on the upper surface of each connecting piece 10, 11 . In particular, the flexible connecting piece 11, which requires a relatively long dimension in order to absorb thermal expansion due to bending, is also made to maximize the upper surface area of the end plate 2 to specifically increase the axial dimension of the end plate. It can be placed without any problem.

In addition, each connecting piece 10, 11 is housed in a groove 9 defined between the comb teeth 8, and can freely expand thermally without interfering with the retaining ring 12 fitted on the outer periphery of the end plate 2. Can be absorbed.

Also, during operation, the shorting ring 5 is pressed against the holding ring 12 by centrifugal force, but in this case also, the shorting ring 5 is not restrained by the thermal expansion of the winding conductor 4 and smoothly moves between the shorting ring 5 and the holding ring 12. In order to enable sliding, a lubricant 13 is applied to both sliding surfaces as shown in FIG.

As this lubricant, for example, an insulating powder lubricant is used.

By applying this lubricant, it is possible to more effectively absorb thermal expansion.

As described above, according to the present invention, most of the damper winding conductors, excluding some of the winding conductors located at the left and right end areas of the magnetic pole core, are connected to the short-circuit ring via the rigid connection piece. Thermal expansion is absorbed by sliding the shorting ring, which is displaced by the stress acting through the rigid connecting piece, overcoming the centrifugal friction between it and the retaining ring.

Furthermore, only some of the winding conductors located at the left and right end areas of the magnetic pole core are connected to the short circuit ring via flexible connecting pieces, and the mutual relationship between the winding conductors due to the difference in position on the magnetic pole core is The difference in thermal expansion can be absorbed by the deflection of the flexible connecting piece itself without imparting undue thermal stress to various parts.

Moreover, the flexible connecting piece does not absorb the entire amount of thermal expansion of the winding conductors through its own bending, but only absorbs a slight difference in thermal expansion relative to each other between the winding conductors. Even if the flexible connecting piece is repeatedly started and stopped, the mechanical fatigue of the flexible connecting piece is small, and there is no risk of accidents such as breakage.

In addition, each connection piece is housed in a groove between the comb teeth formed on the top surface of the end plate, and its movement is not restricted by the shrink-fitted retaining ring, which helps absorb thermal expansion. Accordingly, it is possible to provide a brake winding connection support device that provides excellent performance against centrifugal force and high reliability against centrifugal force.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of the main parts showing a conventional brake winding connection support structure, FIGS. 2 to 5 show an embodiment of the present invention, and FIG. 2 is a longitudinal sectional side view of the main parts. 3 is a plan view of the magnetic pole with the retaining ring removed, FIG. 4 is a sectional view taken along the line IV-TV in FIG. 2, and FIG. 5 is a partially cutaway perspective view. 1: Magnetic pole iron core, 2: Magnetic end plate, 3: Field winding, 4: Brake winding conductor, 5: Short circuit ring, 8: Comb teeth, 9: Groove between the comb teeth, 10: Rigidity Connection piece, 11: Flexible connection piece, 12: Retaining ring, 13: Lubricant.

Claims (1)

[Scope of Claim for Utility Model Registration] 1. Brake winding conductors arranged circumferentially at the head of a magnetic pole core and inserted into grooves of the core, a short-circuit ring disposed on the upper surface of the magnetic pole tip plate, and the short-circuit ring. One of the brake winding conductors located on the right and left outer regions of the magnetic pole is passed through each groove defined between the circumferentially arranged comb-like protrusions provided on the upper surface of the magnetic pole end plate between the magnetic pole iron core and the magnetic pole iron core. A flexible connecting piece connects the damper winding conductor and the short-circuit ring in the remaining half area, and a rigid connecting piece connects the brake winding conductor and the short-circuit ring located in the remaining half area, and the short-circuit ring and A brake winding in a salient pole type rotating electric machine, characterized in that the brake winding is comprised of the short-circuit ring spanning the comb-tooth-like protrusions and a retaining ring for supporting centrifugal force slidably attached to the outer periphery of the comb-tooth-like protrusions. Connection support structure. 2. In the braking winding connection and support structure as set forth in claim 1 of the utility model registration, a salient pole type rotation characterized in that a sliding surface between the short-circuit ring and the retaining ring is coated with a lubricant. Brake winding connection support structure in electrical machinery.