JP3241947B2 - Rotating electric machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to improvement of vibration characteristics of a rotating electric machine having a heat exchanger or a wind tunnel.

[0002]

2. Description of the Related Art An electric motor with a heat exchanger shown in FIGS. In FIG. 8, 1 is a stator core.
It is stored in frame 2. Reference numeral 3 denotes a rotor core fitted on the shaft 4, supported by bearings 5, 5a, and mounted on the frame 2 via bearing brackets 6, 6a. 7
Is a heat exchanger and a hard rubber 8 on the frame 2 as shown in FIG.
And is fixed with a bolt 9. In particular, the number of bolts for mounting the heat exchanger 7 and the frame 2 is determined so that there is no problem in strength, and the bolts are always tightened by the designed number.

[0003] Generally, the motor is manufactured so that the imbalance of the rotating shaft 4 is corrected in order to operate quietly, and the exciting force of the rotating frequency component is reduced as much as possible. However, in reality, a slight imbalance remains, so that there is some excitation force of the rotational speed component.

On the other hand, when the natural frequency of the entire motor system coincides with the rotation frequency, the vibration response sensitivity increases, and the operating vibration of the motor increases. Therefore, a design is performed in which the natural frequency is detuned from the rotation frequency, and the natural frequency is measured on the foundation of the factory at the time of shipment from the factory to confirm that the detuning has been performed before shipment.

[0005]

However, it is often the case that the rigidity of the motor to be shipped is different from the rigidity of the evaluation foundation in the factory. In particular, due to recent trends in reduction in size and weight of materials and reduction in material costs, the motor installation base at the shipping destination has become soft, and the natural frequency of the motor installation system tends to decrease. Therefore, despite the design in which the natural frequency and the excitation frequency are detuned, depending on the installation state of the motor at the destination, the natural frequency coincides with the excitation frequency of the motor and becomes a resonance state. Operating vibration of the vehicle may increase. In such a case, as a means for keeping the operation of the motor quiet, it is necessary to reinforce the motor installation base or to reinforce the motor frame 2 to change the natural frequency of the motor installation system. However, these reinforcements require significant design changes and welding of members, and have the problem of loss of change cost and period. Therefore, resonance phenomena are easily avoided to reduce the operating vibration of the motor. A way was desired.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and provides a motor having a structure capable of changing the natural frequency of the entire motor system and capable of avoiding a resonance state and operating quietly. The purpose is to do.

[0007]

A first aspect of the present invention is a circuit for a circuit.
Wind tunnel or heat exchange through hard rubber on the frame of converter
With the container placed and tightened and fixed at multiple locations with tightening bolts
In a rotary electric machine, the
On the wind tunnel or heat exchanger frame at several places,
Place a fixing device having a plurality of drill holes, and
Insert the tightening bolt into one of the
And tighten the mounting rigidity adjustment
And tighten the screws to the wind tunnel or heat exchanger frame
It is characterized by being fixed . Claim 2 is the fixing device.
Between the tightening bolt and the mounting rigidity adjustment bolt
One pair, the number of fastening and fixing points, this one pair is a small number and tighten
It is characterized in that the number of fastenings with only bolts is increased . A third aspect of the present invention provides a fastening bolt through the fixing device.
A pair of rigidity adjustment bolts with a wind tunnel or heat exchange
At the four corners of the frame at the place where
The above-mentioned pair is arranged and tightened and fixed.
It is characterized in that it is fastened and fixed only with a mounting bolt .

[0008]

According to the rotating electric machine of the first aspect , the fixing device is
Through the tightening bolt and the mounting rigidity adjustment bolt
What, in Frame and wind tunnel or heat exchanger of the motor
Is fixed . Adjusting the mounting rigidity of the tightening part within the tightening location
By removing the bolts , the motor frame and wind tunnel or
Clamping state between frames of the heat exchanger changes, during which
Required natural vibration that deviates from resonance due to change in rigidity
Can be changed to a number. According to the rotating electric machine according to claims 2 and 3, the frame of the electric motor and the wind tunnel or the heat exchanger
Many correction setting positions can be selected for tightening points between frames.
Therefore, this means that a large number of natural frequencies can be set.
The effect of increasing the degree of freedom to change the natural frequency
is there.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a cross-sectional view showing a main part of a joint portion between a frame of a heat exchanger and a motor frame as viewed from a direction perpendicular to a rotation axis, and FIG. is there. In the figure, 12 is a frame of the electric motor, 17
Is a frame of the heat exchanger, which is a connecting portion of the frame 17 of the heat exchanger fixed to the frame 12 (a circular portion 30 surrounded by a dashed line in FIG. 8). The heat exchanger is tightened by means of bolts 19 via the metal spacer 20 of which the height has been adjusted and the fixing device 21 of the heat exchanger, using the screw holes 22 provided in the frame 12 of the electric motor. The fixing device 21 has two drill holes 24 in addition to the drill hole 23 through which the fastening bolt 19 passes.
24a is provided, and mounting rigidity adjusting bolts 26, 26a are tightened in screw holes 25, 25a provided in the frame 17 of the heat exchanger. In addition, these connecting parts are provided at several places on both sides of the heat exchanger symmetrically with respect to the axial length of the shaft 4 on each side (the four corners are fixed in principle). And
The motor is shipped in this state.

According to the above configuration, the heat exchanger is vertically
Attachment part when displacing downward (Electric including the fixing device 21
Connection between the machine frame 12 and the heat exchanger frame 17)
Is the rigidity of the spacer 20 and the flexure of the fixing device 21.
Stiffness and tensile stiffness of mounting stiffness adjusting bolts 26, 26a
Has high rigidity due to the deformation of metal parts
It will be. Conversely, if the heat exchanger is displaced upward,
The fixing rigidity is determined by the tensile rigidity of the tightening bolt 19 and the rigidity of the heat exchanger.
This is a composite of the bending stiffness of the setting device 21 and is basically made of gold.
It has high rigidity due to deformation of the metal part. By the way, when trying to displace the natural frequency of the motor,
Some mounting rigidity adjustment bolts 2 installed at several locations
Remove 6, 26a and adjust . When removing the mounting rigidity adjusting bolts 26 and 26a, the mounting rigidity hardly changes when the heat exchanger is displaced upward. However, the rigidity when displacing downward is determined by the mounting rigidity adjusting bolts 26 and 26a.
Is eliminated, so that the fixing device 21 and the heat exchanger
The number of fixed portions with the rubber 17 decreases, and the state of relatively high rigidity due to deformation of the metal changes to a state of relatively low rigidity supported by the hard rubber 18. Therefore, the rigidity of the mounting portion is reduced as a whole, and the natural frequency of the entire motor system can be changed.

Next, an electric motor with a heat exchanger shipped from a factory
Explains an example where the machine changed the natural frequency at the installation site
I will tell. FIG. 3 is a calculation model for evaluating the vibration characteristics of the motor with a heat exchanger. Symbols in the figure are: m1: weight of a frame including a stator core and a bearing bracket; m2: weight of a heat exchanger; m3 : Rotor weight, k 1: motor installation rigidity, k 2: heat exchanger mounting rigidity, k 3: rotor supporting rigidity. FIGS. 4 to 6 show the results of calculating the natural frequency of the entire electric motor based on the well-known equation of motion of the mass using this model.

FIG. 4 shows an example of evaluation at a factory, where m 1 = 4000 [kgf] and m 2 = 500 [k].
gf], m3 = 700 [kgf], k1 = 100000 [kgf / mm],
The modes from the first to the third order are shown as k 2 = 4500 [kgf / mm] and k2 = 10000 [kgf / mm]. The frame 12 of the motor, the frame 17 of the heat exchanger, and the rotor are respectively This is shown in a diagrammatic manner assuming that it is a mass point. Figure 4
The number in parentheses is (4-1-0), for example, and the left number 4
Represents FIG. 4, the central numeral 1 represents the mode, and the right numeral 0 represents
Represent the foundation. Hereinafter, the number 1 on the right indicates the motor frame,
2 represents a heat exchanger and 3 represents a rotor. Next,
The axis represents the basic axis of the foundation, on which the motor frame
12, heat exchanger frame 17, rotor does not tilt
If attached, each mass point is located on the basic axis, but 1s
(4-1-2) indicated by t MODE is the natural vibration mode of the heat exchanger.
Represents the code. In this embodiment, (4-1-2), (4-
Heat exchangers such as (2-2) and (4-3-2);
1), (4-2-1), (4-3-1), etc.
Modify the vibration system by changing the mounting rigidity between the frames.
This changes the natural frequency.

The 2nd mode diagram of FIG. 4 will be described. The mass point 4-2-1 representing the frame 2 including the stator core 1 and the bearing brackets 6 and 6a is indicated by a spring having a motor installation rigidity K1 with respect to the foundation 4-2-0.

The mass point 4-2-2 representing the heat exchanger is connected to the mass point 4-2-1 by a spring having a mounting rigidity K2 of the heat exchanger. The mass point 4-2-3 representing the rotor is connected to the mass point 4-2-1 by a spring having a rotor supporting rigidity K3.

For example, in a two-pole motor in which vibration is particularly problematic, the excitation frequency component of the rotational imbalance is 50 or 60 [Hz], but the data at the time of factory evaluation shown in FIG. The number is 45.3 [H] in the first mode.
It can be seen that the frequency is detuned from the excitation frequencies of 50 and 60 [Hz], which are 55.5 [Hz] for z] and 2nd, and 88 [Hz] for 3rd mode.

Next, assuming that this electric motor is installed on a relatively flexible base at the shipping destination, k1 = 5000 [k
gf / mm] (the other parameters are the same) and FIG. 5 shows the result of calculating the natural frequency of the entire motor system. In this state, the natural frequency of the second mode is 49.7 [Hz].
In the 50 [Hz] region, a resonance state occurs and the operation vibration increases, resulting in a dangerous state.

In order to avoid this resonance state, the state where the mounting rigidity adjusting bolts 26 and 26a of the heat exchanger are removed is calculated.
Then, k1 = 100000 [kgf / mm ], k2 = 4500 [kgf / mm] ( the other parameters calculated and the same FIG. 4), and the secondary mode 49. 7 [Hz] is 38.6 [Hz]
And resonance can be avoided. No resonance at the natural frequency of another mode occurs. As a result, resonance
The motor can rotate quietly.

[0018] As described above, in the present exemplary embodiment has been described with reference to heat exchanger with an electric motor, it can also be applied to a motor having a wind tunnel for drawing outside air. Further, the present invention can be applied not only to a motor but also to a general rotating electric machine such as a generator. Furthermore, although each arranged mounting rigidity adjusting bolt 26,26a relative fastening bolt 19 for mounting the heat exchanger in the present embodiment, fastening bolts 19
And the mounting rigidity adjusting bolts 26 and 26a
And belt, of the position Bolt tightening in this pair volt
Tighten the bolts without using the fixing device 21
Tightening only with the bolt 19
The ratio is 1: 2, 1: 3, 1: 4. Or one-to-one
Bolts are used to tighten the four corners of the motor frame 12
Then use the tightening bolt 19 in the center between the four corners ,
Or a pair of bolts 1 in the center between the four corners
The ratio with 9 may be used as 1: 2, 1: 3, and 1: 4. This is the degree of freedom to change the natural frequency (natural frequency
Increase the range of change in the number).
You.

[0019]

According to the present invention, the factory mounting
By removing the rigidity adjusting bolt, it is possible to easily change the natural frequency of the electric motive entire system, providing an electric motor which can quiet operation to avoid resonance state in response to mounting state of the shipping destination can do.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a main part of a joint between a heat exchanger and a rotating electric machine frame according to the present invention;

FIG. 2 is a cross-sectional view showing a main part of a joint between the heat exchanger and the rotating electric machine frame according to the present invention;

FIG. 3 is a diagram showing a vibration characteristic evaluation model of a rotary electric machine with a heat exchanger;

FIG. 4 is a diagram showing results of evaluating vibration characteristics of a rotating electric machine during a factory test;

FIG. 5 is a diagram showing a vibration characteristic evaluation result of a rotating electric machine on a relatively flexible structure base at a shipping destination,

FIG. 6 is a diagram showing a vibration characteristic evaluation result after adjusting the mounting rigidity according to the present invention, with respect to FIG. 5;

FIG. 7 is a cross-sectional view of a state where a portion where a fastening bolt according to the present invention is removed is covered.

FIG. 8 is a cross-sectional view of a conventional rotating electric machine.

FIG. 9 is a diagram corresponding to FIG. 1 of a conventional example.

[Explanation of symbols]

12: frame, 17: heat exchanger frame,
18: hard rubber, 19: tightening bolt, 2
1: Fixing device for heat exchanger, 23, 24, 24a: drilled hole, 26, 26a: mounting rigidity adjusting bolt.

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-63-219932 (JP, A) JP-A-5-118381 (JP, A) JP-A-8-33096 (JP, A) 159149 (JP, U) Fully open sho 59-81265 (JP, U) Fully open sho 61-99699 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) H02K 5/24 H02K 5 / 00

Claims (3)

(57) [Claims] 1. A hard rubber is interposed on a frame of a rotating electric machine.
Place the wind tunnel or heat exchanger on the
In the rotating electric machine that is tightened and fixed by
The wind tunnel or heat exchanger at several locations
A plate-shaped fixing device with multiple drill holes
And insert a tightening bolt into one of the drilled holes to
Tighten the screw to the machine frame and other multiple holes
Into the wind tunnel or heat exchanger.
A rotating electric machine fixed to a frame by screws . 2. A fastening bolt and mounting through said fixing device.
Set the combination of rigidity adjustment bolts as one pair bolts and tighten
The number of bolts should be small, and only one bolt should be used.
The rotating electric machine according to claim 1 , wherein the number of tightening is large . 3. A tightening bolt and mounting via said fixing device.
Combination of rigidity adjustment bolts is set as one pair bolt, wind tunnel or heat
At the place where the exchanger and the rotating electrical machine are tightened and fixed,
Place the pair of bolts at each of the four corners and tighten and secure.
2. The rotating electric machine according to claim 1 , wherein the attachment portion is fixed by tightening only with a tightening bolt .