JPH0382352A - Press fixing device for armature coil and compression amount measuring method - Google Patents

Abstract

PURPOSE:To facilitate measurement by replacing a deflection amount of a corrugated leaf spring with the other measuring amount. CONSTITUTION:In two streaks of upper and lower armature coils 2 housed in a slot 1a of an iron core 1, a spacer piece 3 is interposed mutually between the coils, and spacer pieces 4a, 4b are interposed on the side surface of the coil, while a corrugated leaf spring 16 is interposed, in a manner with its both sides interposed by wedge lower liners 14a, 14b, between 15 and the coil 2. The corrugated leaf spring 16, when the wedge 15 is driven into a wedge groove 1b of the slot 1a, is given a predetermined deflection, and a spring system is constituted such that both ends in the width direction of the wedge 15 are attached to the core and supported at two points and resiliently supported with a predetermined spring constant for the coil 2. By providing the non-linear characteristic in the characteristic of the spring 16, when a deflection amount is set to a value close to the maximum deflection value, deterioration of the deflection amount due to the aging of the dimension in the insulation coating or the like of the coil 2 is accurately obtained by measuring the natural frequency of the wedge 15.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a pressing fixing device for elastically fixing an armature coil in a slot of an iron core, and a method for measuring changes in pressing force over time.

[Conventional technology]

A known armature coil fixing device is shown in FIG. That is, the iron core 2, for example, the stator iron core 1, is provided with a slot 1a, and within the slot Ia, the armature coil 2 stacked in two stages is provided with a spacer piece 3'' t 3'b z 4a.
It is inserted with s 4d etc. interposed. Furthermore, a waveform leaf spring 6 and a wedge 5 are provided on the opening side of the slot 1a, and when the wedge 5 is pushed in, a pressing force P is applied to crush the waves of the waveform leaf spring 6 by a predetermined deflection amount 3. , the armature coil 2 is pressed and fixed toward the bottom of the slot Ia while maintaining elasticity.

In the fixing device configured in this way, the temperature of the armature coil 2 and iron core 1 rises due to thermal energy generated during operation of the rotating electrical machine, so the insulating coating of the armature coil 2 containing organic matter and the insulating material A so-called dimensional change occurs in which the dimension of the spacer piece shrinks over time, and the restoring force of the wave leaf spring 6 decreases accordingly. Furthermore, if the pressing force P applied to the armature coil decreases below a predetermined level due to a decrease in restoring force, the armature coil 2 will vibrate within the slot Ia due to the electromagnetic force that acts during one rotation, causing the insulation coating to wear out, etc. Because insulation damage occurs, it is necessary to monitor changes in the pressing force over time by regularly measuring the amount of deflection, and to carry out repairs when the pressing force P of the corrugated leaf spring falls below a predetermined level. .

FIG. 9 is a cross-sectional view of the main parts of a conventional fixing device that made it possible to measure the amount of compressive deformation of a wave-shaped leaf spring (1983-
(Refer to Publication No. 40583) In Fig. 0, a plurality of dimension measurement holes 7 are provided in the rust 5 between the wave pitch m of the waveform plate spring 6, and a dimension measurement gauge is installed in the dimension measurement holes 7. The structure is such that the remaining amount of deflection of the waveform leaf spring 6 can be measured by inserting the waveform leaf spring 6.

Figure 10 is a spring characteristic diagram showing the principle of measuring the remaining amount of deflection applied to a conventional device. The amount of deflection decreases to δ force, δ3, and along with this, the pressing force also decreases to P, , P. Therefore, if P3 is the lower limit of the required pressing force, then the remaining amount of deflection (]) m-
δ) by periodically measuring the lower limit of the pressing force P.
, it is possible to know whether the pressing force P has decreased on the casing.

FIG. 11 is an explanatory diagram showing a different conventional measurement method.
Apply a pressing load to the wedge 5 via the pressing jig A9 with the hydraulic cylinder 8 to give the waveform leaf spring 6 the maximum amount of deflection D■ (the amount of deflection when the waves of the leaf spring are completely crushed), and before applying the load. A method is known in which the deflection amount δ and the pressing force P are determined by measuring the dimensional changes after the dimensional change with the dial gauge 10.

[Problem to be solved by the invention]

With conventional fixing devices equipped with dimension measurement holes in the wedge, it is necessary to insert a dimension measurement gauge into the bottom of the wave of the wave spring to measure the deflection, so it is difficult to measure the number of kana between the wave pitch m. It is necessary to provide holes, and it is necessary to provide rows of measurement holes at multiple locations along the length of the wedge. For this reason, the processing cost of the dimension measurement holes increases, and the mechanical strength of the wedge decreases in the area of the measurement hole row, which requires reinforcement of the wedge to ensure the necessary mechanical strength. will occur. In addition, it is necessary to remove the rotor in order to insert the gauge into the dimension measurement hole, and there are problems in that the measurement work is large-scale and the work time is long because dimensions are to be measured at multiple locations. Furthermore, as shown in Figure 9, since the linear part of the waveform leaf spring characteristics is used, there is little decline in the pressing force due to changes in dimensions over time, but at the same time, the small change in dimensions allows for a high degree of dimensional measurement. There is also the problem that it is difficult to obtain.

On the other hand, with the conventional method of measuring the amount of residual deflection by applying a pressing load, there is no need to provide a measurement hole in the wedge, so there is no problem with a decrease in the mechanical strength of the wedge. This has the advantage that a certain amount of deflection can be obtained. However, as the inner diameter of the brushed stator core becomes larger, the hydraulic cylinder and its supporting structure become larger.
There is a problem that measurement preparation work is complicated and takes a long time.

The present invention aims to facilitate measurement by replacing the amount of deflection of a waveform leaf spring with another measured quantity, and to improve the spring characteristics of the waveform leaf spring commensurate with this measurement.

[Means to solve the problem]

In order to solve the above problems, according to the present invention, an armature coil inserted into a slot of an iron core, a wedge driven into the opening side of the slot, and a sliding material between the armature coil and the wedge. a waveform leaf spring interposed therebetween to press the armature coil toward the bottom of the slot, wherein the waveform leaf spring is made of a spring material having non-linear spring characteristics; It is assumed that the wedge is pressed in a non-linear region, and the change over time in the amount of compression of a wave-shaped leaf spring pressed in the non-linear region of the wedge spring characteristics is determined by measuring the natural frequency of the wedge.

[Effect]

In the above means, the spring characteristics of the waveform leaf spring are made to have nonlinear characteristics, and the initial amount of deflection applied to the waveform leaf spring by driving a wedge is placed near the upper limit of the nonlinear characteristic region, so that the spring characteristics of the waveform leaf spring become nonlinear due to aging of dimensions. The amount of deflection varies greatly within the area. When the amount of deflection of the waveform leaf spring in the housing changes, the natural frequency of the wedge, which is pressed and supported by the waveform leaf spring against the iron core, changes. Therefore, by attaching a small vibration sensor to the wedge and applying a mechanical impact force to the wedge, the natural frequency of the wedge can be converted into an electrical signal and easily detected. By comparing with the characteristic data obtained, it is possible to accurately determine the amount of deflection and the aging change in the pressing force of the wave-shaped leaf spring. According to this invention, there is no need to provide dimension measurement holes in the wedge, and if a small sensor such as a semiconductor gauge or a semiconductor pickup is used as a vibration sensor, a vibration sensor can be formed between the wedge on the stator side and the rotor. It is also possible to insert a 1 m armature coil fixing device, and it is possible to easily measure changes in dimensions over time without impairing the function required as a fixing device for a 1 m armature coil.

〔Example〕

The present invention will be explained below based on examples.

FIG. 1 is a sectional view showing an armature coil fixing device according to an embodiment of the present invention, and FIG. 2 is an enlarged sectional view of the A-A section in FIG. 1a
The upper and lower two armature coils 2 are housed in the upper and lower armature coils 2, with a spacer piece 3 between the coils. Spacing pieces 4a and 4b are interposed on the sides of the coil, and a corrugated plate spring 16 is installed between the wedge 15 and the coil 2, and the lower wedge liners 14a and 14bK are placed on both sides of the corrugated plate spring 16.
It is inserted in a sandwiched manner. The corrugated leaf spring 16 is a wedge 15
When driving the wedge 15L into the wedge groove 1b, a predetermined deflection δ is applied, and as shown in the equivalent circuit of the mechanical system in Fig. 3, both ends of the wedge 15 with a mass m in the width direction abut against the iron core. A spring system is constructed which is supported at two points and elastically supported by the coil 2 at a spring constant.

Figure 4 is a characteristic diagram showing an example of the spring characteristics of a waveform leaf spring.
5th rI! J is a dimensional drawing of the corrugated leaf spring used in FIG. 4. In FIG. 5, the corrugated plate 16 has a spring steel thickness t.
is 0.9trrm, the wave pitch m and the wave radius of curvature R
The wave height (maximum deflection amount) D- in the unloaded state is 3a and 1.8a, respectively, and the splash characteristics are determined by the pressing force P (N/mj) as shown in Figure 4. It has a nonlinear characteristic in which the amount of deflection δ tends to saturate as the amount of deflection δ increases.

FIG. 6 is a spring constant-deflection characteristic diagram of a waveform leaf spring, which was obtained from the slope of the curve in FIG. If the range of allowable deflection of the corrugated plate spring 16 having the characteristics shown in Figs. 4 and 5 is set as a nonlinear region from 1 mm to 1.8 m, the 1 δ curve will be in the range 8D of allowable deflection. It is greatly curved, and the repulsion constant changes depending on the change in the amount of deflection δ = ΔP
/Δδ changes significantly. Further, the natural frequency ωn of the wedge 15 shown in the spring system shown in FIG. 3 changes in proportion to the square root of the spring constant as shown by the following equation, where m is the mass of the wedge.

ωn = V777 (rad /see) =
(1) In the embodiment, since the spring characteristics of the corrugated leaf spring 16 are made to have non-linear characteristics, the amount of deflection initially given to the corrugated leaf spring by driving the wedge 15 is near the upper limit of the allowable deflection amount region, i.e. If the value is set close to the maximum deflection Dm, the decrease in the deflection δ due to later changes in the dimensions of the insulation coating of the armature coil 2 can be accurately determined by measuring the natural frequency of the wedge. .

FIG. 7 is an explanatory diagram showing a method for measuring the natural frequency of a wedge to be applied in an embodiment.
1 is fixed and a mechanical shock is applied to the wedge 15, the wedge 15 vibrates at a natural frequency determined by equation (1), so the vibration sensor 21 converts this into an electrical signal, and the measuring device 22, for example, records the vibration. Record it on the meter. In addition, if a small vibration sensor such as a semiconductor gauge or a semiconductor pickup is used, the vibration sensor 21 can be pushed into the gap between the wedge 15 on the stator side and the rotor and fixed to the surface of the wedge. In addition to being able to measure the natural frequency of a rotating electric machine without disassembling it, the measurement data is recorded on a recorder, which greatly simplifies the measurement process.

In addition, as a method of converting the obtained natural frequency ωn of the wedge into the deflection amount δ of the corrugated plate spring or the pressing force P, the thickness of the wedge lower liner 4 or the spacing piece 3, for example, at the time of manufacturing the rotary electric machine. The relationship between the amount of deflection δ and the natural frequency ωn of the waveform leaf spring is determined by a method such as changing the amount of deflection, and the deflection is calculated by comparing the obtained calibration curve with the measurement data of the natural frequency at each point. By determining the change in the amount δ, it is possible to accurately and easily manage the pressing force of the coil based on the amount δ of deflection of the waveform leaf spring.

The armature coil fixing device and compression amount measuring method of the present invention can be applied to either the stator side or the two rotor sides. In addition, the spring characteristics of a corrugated leaf spring vary depending on its material and dimensions, and it is not limited to the waveform leaf springs shown in Figures 4 and 5, and is compatible with its usage conditions. A corrugated leaf spring may be used and the non-linearity of its spring characteristics may therefore be chosen arbitrarily.

〔Effect of the invention〕

As described above, this invention uses a corrugated leaf spring having non-linear spring characteristics, gives the corrugated leaf spring an initial deflection close to the upper limit of the non-linear region by driving a wedge, and at the same time gives the corrugated leaf spring an initial deflection close to the upper limit of the non-linear region. The system was designed to calculate the decrease in deflection caused by changes in later years by measuring the natural frequency of the wedge. As a result, by imparting nonlinear characteristics to the corrugated plate spring, changes in the amount of deflection that occur over one year, as well as changes in the spring constant, are significantly greater than those of conventional fixing devices that utilize a linear region. Therefore, the amount of deflection can be accurately measured using the natural frequency of the wedge, which changes in proportion to the square root of the spring constant.

In addition, since the natural vibration of the wedge is detected using a small vibration sensor and recorded on a recorder, problems such as a reduction in the mechanical strength of the wedge and increased processing costs caused by providing a dimension measurement hole in the wedge can be avoided. Also, it does not require large-scale equipment unlike the conventional method of applying a pressing load to the wedge and measuring the remaining deflection, making it much easier to measure and manage changes in dimensions over time than with the conventional method. You can get the advantage of being able to

Furthermore, in order to miniaturize the vibration sensor, it is easy to insert the vibration sensor into the gap between the stator and rotor and crimp the vibration sensor to the wedge surface, so it is possible to easily rotate the vibration sensor to measure later changes in dimensions. It will save you from having to disassemble the electrical equipment.
This provides the advantage of further simplifying the management of the fixed state of the armature coil.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing an armature coil fixing device according to an embodiment of the present invention, Fig. 2 is an enlarged sectional view of the section A-A in Fig. 1, and Fig. 3 is a sectional view of a spring system applied to the embodiment. equivalent circuit diagram,
Fig. 4 is a spring characteristic diagram showing an example of the waveform leaf spring in the example, Fig. 5 is a dimensional specification diagram showing an example of the waveform leaf spring in the example, and Fig. 6 is the waveform in the example. A characteristic diagram showing an example of the spring constant vs. deflection t characteristic of a leaf spring, Fig. 7 is an explanatory diagram showing a method for measuring the natural frequency of a wedge applied to an embodiment, and Fig. 8 is a sectional view showing a conventional fixing device. , FIG. 9 is a sectional view of the main parts of a conventional fixing device that makes it possible to measure the amount of deflection of a wave-shaped leaf spring, and FIG. 10 is a spring characteristic diagram showing the principle of measuring the amount of deflection in the device of FIG. 9. FIG. 11 is an explanatory diagram of a different conventional method for measuring the amount of deflection. 1... Iron core, la... slot, 2... armature coil 3.3a, 3b... spacing piece, 5, 15-<rust,
6゜16... Waveform plate spring, 21... Vibration sensor, 2
2...Measuring instrument, δ...Deflection, Dm...Maximum deflection, D...Allowable range of deflection, P...Pushing force, k.
...Spring constant. 1. Figure 4. Pressure force (N/myn). Figure 5. 6121.

Claims (1)

[Claims] 1) An armature coil inserted into a slot of an iron core, a wedge driven into the opening side of the slot, and a sliding material interposed between the armature coil and the wedge. and a waveform leaf spring that presses the armature coil toward the bottom of the slot, wherein the waveform leaf spring is made of a spring material having nonlinear spring characteristics, and is pressed into a nonlinear region of the spring characteristics. An armature coil press fixing device characterized by: 2) The armature coil pressing and fixing device according to claim 1, wherein the change over time in the amount of compression of the waveform leaf spring pressed into a nonlinear region of spring characteristics is determined by measuring the natural frequency of the wedge. How to measure compression amount.