JPH04156246A - Rotary electric machine having shaft current stopping insulation - Google Patents

Abstract

PURPOSE:To maintain rigidity and strength and improve the looseness at a combined portion due to the deterioration of insulating materials by providing a vertical surface at the center and a conical surface at both the ends for the end surfaces of the aligned portion with shaft- center inner peripheral member of outer peripheral member aligned with an insulating member and also by placing an insulating member between them and connecting them with a connecting member. CONSTITUTION:A least one of the end lid 3 and bearing housing 8 is formed by a shaft-center inner peripheral member 201 concentric relative to a rotating shaft 10, an insulating member 24 and an outer peripheral member 202; an end face of an aligned portion with either one of the insulating member 24, the shaft-center inner peripheral member and the outer peripheral member 202 is made as a vertical face vertical to the rotating shaft 10 at the central portion; both end portion is made as a conical face having the same apex angle having the rotating shaft as center axis; and an insulating material is interlaid between both the conical faces and the vertical face and the aligned portion is connected with an insulation-treated jointing material. By doing this, the predetermined strength and rigidity required for the structural body can be realized and also the looseness of the aligned portion due to the deterioration of the insulating material after a long period of use can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Objective of the Invention (Industrial Application Field) The present invention relates to a rotating electrical machine having shaft current blocking insulation that blocks shaft current flowing through a bearing portion of a motor, a generator, or the like.

(Prior Art) Conventionally, the structure of one electric motor (hereinafter referred to as a rotating electric machine) of a railway vehicle is as shown in Fig. 7, and this figure is a longitudinal cross-sectional view showing a cross section passing through the center of the rotating shaft. be. In the figure, reference numeral 1 denotes a frame of a rotating electrical machine, and a stator core 4 is attached to the inner peripheral portion of the frame 1 by being pressed from both ends with stator core pressers 5. A stator is constructed by assembling stator coils 7 into a large number of slots 6 formed in the inner peripheral surface of this stator core 4. Further, bearings 9 are respectively attached to the housing 8 fitted to the side plate 2 at one end of the frame 1 of the stator and the mirror lid 3 at the other end, and the rotary shaft 10 is rotatably supported by both bearings 9. A rotor core 11 is fixed to this rotating shaft 10 by being pressed from both ends with rotor core pressers 12. A large number of slots 13 formed on the outer periphery of this rotor core 11
Assemble the rotor 7-14 to the rotor t<-
A ring-shaped short circuit ring 15 is welded to both ends of the squirrel cage rotor. Further, a fan 16 fitted to the rotating shaft 10 causes cooling air to flow into the rotating electric machine from the suction port 17 by the rotation of the rotating shaft 10, cools the stator filter 7, rotor bar 14, and short circuit ring 15, and then discharges the cooling air. It is discharged from the port 18.

In the rotating electric machine configured as described above, the rotor rotates when energized, and this rotational force is transmitted from the shaft end of the rotating shaft IO to the coupling 20 and the gear device 21 within the cart 19 configured as shown in FIG. The signal is transmitted to the wheels 22 through the vehicle, causing the vehicle to travel.

In recent years, there has been a strong demand for higher performance in vehicles, and for this reason, it has become necessary to increase the size of the stator coil 7, stator core 4, rotor bar 14, short circuit ring 15, rotor core 11, and fan 16. The rotating electric machine is installed between the bogie 19, wheels 22, and axle 23 by making the thickness in the direction of the center of the rotating shaft as thin as the strength allows, making it as compact as possible, and making the gap through which the cooling air passes as small as possible. It's becoming necessary.

By the way, the rotor rotated by energization generates unnecessary magnetic flux in the rotating shaft 10 due to the rotational movement. This magnetic flux becomes shaft linkage or axial magnetic flux to generate an axial voltage, which causes an axial current to flow.

There are other causes of this shaft voltage, such as armature reaction of the irregular groove winding, static charge, and return current flowing into the rail, but all of these are caused by the rotation of the rotating bearing 9.
As shown in Figure 1, an electric current is generated, which breaks the slight oil film formed for lubrication, causing an arc to fly to the bearing rolling surface and roughening the surface (this is called "electrolytic corrosion"), Bearing 9
This will reduce the lifespan of the Metal friction powder is generated from the rough rolling surface, mixes with lubricating oil such as grease, and deteriorates the lubricating oil, causing the life of the bearing 9 to decrease at an accelerating rate, eventually resulting in burnout of the bearing 9 and rotor rotation. This will result in a locking accident that will make you incapacitated.

For this reason, the following measures have been taken in the past. This is a method of inserting an electrical insulator into a part of the electrical circuit to interrupt the current so that the generated shaft voltage does not flow through the bearing.

This will be explained using FIG. FIG. 8 is a drawing mainly showing the bearing section. In FIG. 8, the side plate 2 disposed at one end of the frame 1 is divided into an inner circumference side plate 201 and an outer circumference side plate 202, and the inner circumference side plate 201 and the outer circumference side plate 202 are separated.
A mirror cover 3 disposed between the frame 1 and the other end of the frame 1
is divided into an inner mirror lid 301 and an outer peripheral portion M302, and an insulator 24 is inserted between the inner mirror lid 301 and the outer mirror lid BD2.

The "A" section showing the details of this insulating part will be explained between the inner circumferential side plate 201 and the outer circumferential side plate 202 shown in FIG.

Note that the structure between the inner mirror cover 301 and the outer mirror cover 302 is also the same, so a description thereof will be omitted. Inner circumferential side plate 201 and outer circumferential side plate 2
An integrally formed insulator 24 having an L-shaped cross section is inserted into the fitting part 25 and bolts 26 to firmly tighten and fix the inner circumferential side plate 201, so that the inner circumferential side plate 201. The outer peripheral side plates 202 are integrally connected. Insulation between the bolt 26 and the inner circumferential side plate 201 is constructed by inserting and sandwiching a bobbin 28 made of an insulating material into a hole 27 formed in the inner circumferential side plate 201.

If an inorganic material such as ceramic, which exhibits little creep due to permanent compression deformation, is used as an insulator constructed in this way, it would be difficult to form or process it into the shape and dimensions shown in Figure 2, and it would be extremely expensive. Therefore, it was not practical. Furthermore, inorganic materials generally have the problem of being weak against vibration and impact and easily cracking. For this reason, the insulator is a mixture of inorganic and organic materials, and a material with as little creep as possible is used. Furthermore, in order to maintain the strength to withstand the fitting force due to the tightening margin and the tightening force of the bolt 26, the insulator should be aged sufficiently to prevent creep during use, and to prevent the occurrence of creep during use. Sufficient compressed surface area is ensured to prevent surface pressure from acting on the insulator.

With this configuration, the rigidity and strength of the inner circumferential side plate 201 and the outer circumferential side plate 202 can be maintained at the same level as the conventional structure, and electrical insulation is also performed, so that a rotating electrical machine having a structure to prevent electrolytic corrosion of the bearings can be realized.

(Issue II to be solved by the invention) However, the insulation structure of the bearing part for preventing electrolytic corrosion of the bearing mentioned above also has the following advantages. It was extremely difficult to use electrical equipment for long periods of time. The first
The reason for this is that by configuring the insulating part as shown in Figure tJ8, the thickness of the inner peripheral side plate 201 portion of the rotating electric machine increases by "L", so the bogie is In order to maintain the minimum clearance "G' between the wheel 22 and the wheel 22, which is a restricted dimension within the stator coil 7, the stator core 4, the rotor bar 14, the short-circuit ring 15, the rotor core 11, and the fan 16, must,
There has been a problem in that the performance of the rotating electric machine is lower than in the case where such an insulating part is not provided. Similarly, for the insulating part on the mirror cover side (drive side), as shown in Figs. 7 and 8, the gap "M" with the coupling 20 is maintained.
However, there was a problem in that the rotating electric machine had to be made smaller.

The second reason is that even if a material with low creep is used as the insulator, surface pressure is reduced, and sufficient aging is performed, after long-term use, the insulator will always wither and thinning will occur, resulting in poor fitting. Gaps and loosening occur in the parts, reducing the rigidity and strength of the side plate 2 and mirror cover 3. To recover from this, it is necessary to replace the insulator or replace the side plate 2 and mirror cover 3 with new ones. As a result, maintenance work is extremely time-consuming and maintenance costs are extremely high.

The present invention has been made in view of the above-mentioned problems, and has a structure that has a certain level of strength and rigidity, and also improves and recovers the loosening of the joints due to deterioration of the insulators caused by long-term use. An object of the present invention is to provide a rotating electric machine having functional shaft current blocking insulation.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above-mentioned object, the present invention provides a structure in which a mirror cover is disassembled at one end of a segmental frame provided with a stator, and a bearing housing is disassembled at the other end. It is attached by a suitable coupling means, and the mirror cover and the bearing no.
In a rotating electric machine, in which a rotor corresponding to the stator is rotatably supported by a rotary shaft, at least one of the mirror cover and the bearing housing is arranged as an axially inner circumferential member concentric with the rotary shaft. , an insulating member, and an outer circumferential member, and the end face of the connecting portion between the insulating member and either the axis inner circumferential member or the outer circumferential member is a vertical plane perpendicular to the rotation axis, and both ends are The part is a conical surface having the same apex angle with the rotation axis as the central axis, and the joining part is connected to the double conical surface and the vertical surface using a bonding material insulated by interposing an insulating material. .

(Function) According to the above configuration, the tightening force due to the binding material is applied to the vertical surface, and the area of the vertical surface of the joint can be set without any particular restriction so that creep does not occur in the insulation material, and it can be used for a long period of time. Even if the insulating material deteriorates, by tightening the bonding material, both end faces of the joint become conical surfaces with the same apex angle around the rotation axis, creating a wedge effect, resulting in deterioration. It is possible to maintain the rigidity and strength of the side panels and mirror cover by reducing gaps and looseness.

(Example) Examples of the present invention will be explained below with reference to the drawings. 1st
The figure shows a first embodiment of the present invention, and shows details of part A in FIG. 8.

Note that this embodiment and the embodiments shown below show cases in which the bearing housing 8 is provided on the side plate 2 of the bearing housing 8 shown in FIGS. shall be. In FIG. 1, an inner circumferential side plate 201 constituting an axial inner circumferential member and an outer circumferential side plate 202 constituting an outer circumferential member are formed concentrically with respect to the rotation axis lO, and the fitting portions Xa, Xb and the trunked portion Y It is joined to the inner peripheral side plate 201 by an insulated bolt 28 via a bobbin 28 with an insulator 24 interposed therebetween. The shape of the fitting parts Xa and xb is a conical surface having the same apex angle θ with the rotating shaft 10 as the central axis, and by tightening the bolts 26, the inner peripheral side plate 201 and the outer peripheral side plate 202 are moved in the radial direction of the side plate 2. are configured to be separated from each other. The compressed surface area of the insulator 24 is the fitting portion Xa.

In xb, the length of the conventional example shown in FIG. 2 is the same as that of the first embodiment shown in FIG. However, the total thickness of the inner circumferential side plate 201 and the outer circumferential side plate 202 can be made thinner than the conventional example shown in FIG. It is possible to maintain the same performance as the conventional rotating electric machine shown in FIG. 7 which does not have the structure of the insulator 24. Furthermore, if the insulator 24 begins to wither after long-term use and the fitting force of the fitting parts Xa, The tightening force can be easily recovered and the rigidity and strength at the time of manufacture can be maintained. In addition, since the fitting parts Xa and Xbfd are formed at both ends of the trunked part Y, it has more stable support than the conventional structure shown in FIG.

Next, a tJ2 embodiment is shown in FIG. This diagram shows the insulator 24
This figure shows a shape in which the tapered fitting part of the first embodiment and the conventional fitting part shown in FIG. 2 are used together.

FIG. 4 shows a third embodiment, and this embodiment is constructed by combining tapered inclinations.

However, in this case, if the thickness t of the tapered insulator 24 in the direction of the rotating shaft is made the same, the tightening effect by additional tightening becomes effective.

FIG. 5 shows a fourth embodiment, in which the tapered fitting portion is curved, and the same effects as the above-mentioned embodiments can be expected.

FIG. 6 shows a fifth embodiment, in which the length of the insulator 24 is increased and the compressed surface area of the insulator 24 is further increased. Note that if there is sufficient space in the direction of the rotation axis, the tapered fitting part is not provided on both the side plate 2 and the mirror cover 3, but is provided on either one, and
The length of All shown in the figure may be configured as the thickness I of the outer peripheral side plate 202.

[Effects of the Invention] As is clear from the above description, the present invention comprises a side plate of a rotating electric machine consisting of an axial side plate, an insulating side plate, and an outer circumferential side plate, and the insulating side plate is connected to the axial center side plate or the outer circumferential side plate. The end faces of the joining part are a vertical face in the center, and both ends are conical faces having the same apex angle with the rotation axis as the central axis, and an insulating material is interposed between these vertical faces and the conical face, and the bonding material is insulated. This not only cuts off shaft current and prevents electrolytic corrosion of the bearings, but also maintains rigidity and strength and prevents reduction in dimensions that would degrade the performance of rotating electrical machines.
It is possible to provide a rotating electric machine having shaft current blocking insulation that can easily prevent loosening by retightening the binding material when the insulation material deteriorates due to aging and creep etc. occur and the joint becomes loose. can.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing the details of the insulation part of the first embodiment of the rotating electric machine of the present invention, Fig. 2 is a diagram showing the details of the insulation part of the conventional example, and Fig. 3 is a diagram showing the shape of the insulation part of the second embodiment. 4 is a diagram showing the shape of the insulating part of the third embodiment, FIG. 5 is a diagram showing the shape of the insulating part of the fourth embodiment, and FIG. 6 is a diagram showing the shape of the insulating part of the fifth embodiment. Fig. 7 is a longitudinal cross-sectional view of the rotating electrical machine, Fig. 8 is a diagram showing the side plate and mirror cover surroundings of the conventional example in which the shaft current blocking insulating part is provided in Fig. 7, and Fig. 9 is a diagram showing the rotating electrical machine as the drive source of the vehicle. FIG. 10 is a sectional view taken along line BB in FIG. 9, and FIG. 11 is a diagram showing a path through which an axial current flows when the rotating electric machine is not provided with an insulating section. Frame, 2. Side plate, 3.. [i4.. Stator core, 5. Stator core holder, 6.. Stator slot, 7. Stator coil, 8.. Housing, 9.. Bearing 10.. Rotating shaft, 11. Rotor core, 12. Rotor core holder, 13. Rotor slot, 14. Rotor bar, 15. Short circuit ring,
16...Fan, 24...Insulator, 26...Bolt, 28...Bobbin, 201...Inner peripheral side plate, 20
2... Outer circumference side plate, 801... Inner circumference mirror cover, 302.
...Outer mirror cover. Applicant's representative Patent attorney Takehiko Suzue Figure 3 Figure 4 Figure 5 Figure 6 Figure 9 Figure 10 @ 11 @

Claims (1)

[Claims] A mirror cover is attached to one end of a cylindrical frame provided with a stator, and a bearing housing is attached to the other end by removable coupling means, and the mirror cover and the bearing housing each correspond to the stator via bearings. In a rotating electric machine that rotatably supports a rotor and a rotary shaft, at least one of the mirror cover and the bearing housing includes an axial inner peripheral member, an insulating member, and an outer peripheral member that are concentric with the rotary shaft. The end face of the connecting part between the insulating member and either the shaft inner peripheral member or the outer peripheral member is a vertical plane perpendicular to the rotational axis in the center, and both ends are perpendicular to the rotational axis. A conical surface having the same apex angle as the central axis,
A rotating electric machine having axial current blocking insulation, characterized in that the connecting portion is connected by a bonding material which is insulated by interposing an insulating material between both conical surfaces and the vertical surface.