JPH02221688A - Electrically-driven compressor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention has a compressor main body at one end of the compressor housing, a permanent magnet type electric motor part in the middle part of the compressor housing, and a permanent magnet type electric motor part in close contact with the housing, and the gas is passed through the motor part at the other end. This is related to the structure of an electric compressor that discharges .

[Conventional technology]

Regarding the expansion of the gas flow area of the compressor,
As described in Japanese Patent No. 0311, a blow gas (
Some have a passage for the oil (oil).

[Problem to be solved by the invention]

In the above technology, in order to secure the magnetic passage at the back of the core, gas passages are provided at the radial outer edge between the slots, so it is difficult to expand the passage area, and the outer periphery of the core is gear-shaped, making it difficult to handle. There were some problems, such as difficulty.

An object of the present invention is to provide an electric compressor using a permanent magnet motor with gas flow passages in the entire area near the outer periphery of the core and in the slot teeth in an iron core with a small number of slots, thereby increasing the gas passage area as much as possible. The purpose is to

[Means to solve the problem]

In order to achieve the above objective, it is necessary to secure a slot for inserting the coil, a magnetic path, a gas flow path, a compressor,
It is also necessary to secure the contact surface of the core. Among these, effective use of slots, especially in the overall configuration, leads to improved overall balance. An effective means for this is to reduce the number of coils (number of slots).In addition, in a permanent magnet motor, in order to use rotor magnets and stator windings, it is necessary to reduce the number of slots for each pole and each phase. q=z/
It is appropriate to set (pXm)=1 and not to cross each phase coil by 2π/p.

Further, motor loss mainly consists of copper loss and iron loss value mechanical loss, but in order to reduce iron loss, it is desirable to equalize the magnetic flux of the stator core as much as possible. Therefore, by setting the wall thickness of the back of the slot to wXeXk/πp (k=0.9 to 1.1), the originally intended magnetic flux can be made uniform. moreover,
Laminated cores are generally used in electric motors, but for punching gas flow passages, due to the deformation of the core during pressing and the strength of the outer circumferential surface of the core, the distance between the air hole and the outer circumference of the core must be at least twice the plate thickness. is desirable.

Furthermore, the stator core is in close contact with the compressor housing,
It is held by the tightening force of the housing, but in order to receive this holding force, in order to increase the air hole area, if the shape is long, the corner radius on the outer circumferential side should be made large, and the corner radius on the inner circumferential side should be increased. Making it smaller is effective in securing the strength area.

Also, as mentioned earlier, when the number of slots is reduced, the teeth can generally be made wider by the number of slots, so it is necessary to provide a notch at the inner peripheral end of the slot tooth to allow gas to pass through the inner peripheral surface of the stator. This is effective in increasing the gas flow area.

Furthermore, when the slot tooth width is increased to less than 0.9, slits can be provided in the slot teeth, which is effective in increasing the gas flow area.

[Effect]

Reducing the number of slots means that the radial sidewall ratio of the slots becomes 1/z, which reduces the slot insulation cross-sectional area per slot area, thereby increasing the effective area of the slots into which the coil can be inserted. Further, in order to magnetize a permanent magnet rotor incorporated in a compressor, it is desirable that the stator magnetic poles have full pitch coils, and it is preferable that the coils in the slots have one coil per slot. Similarly, if the number of slots increases, the slot teeth will naturally become smaller, but considering the coil insertion surface, the wider the teeth, the smaller the slot teeth will be.
It is preferable in terms of strength, and based on these conditions, it is suitable for an electric compressor using a permanent magnet periodic motor.

By effectively utilizing the slots, the utilization rate of the stator core can be improved, the back area of the core can be increased, or the slot tooth width can be increased, and as mentioned above, the gas flow area passing through the stator can be increased. By reducing the gas flow resistance within the compressor and increasing the gas flow rate, compressor efficiency and output can be improved.

〔Example〕

Embodiments of the present invention will be described with reference to FIGS. 1 to 6. 1st
The figure is an overall cross-sectional view of an electric compressor to which embodiments 1 to 3 of the present invention are applied, and the coil 6 shows an example of the arrangement of a three-phase, four-pole motor. In the figure, the number of slots for each pole and each phase q=
12/ (4X3) = 1, and each phase coil is arranged at 2π/4 knee π (90”).As can be seen from the figure, with 1 coil in 1 slot, each coil is arranged at the full pitch of the stator magnetic poles. The conductor cross section of the coil can be made large with a small number of slots, and the iron core 1 can be used effectively.

Further, as shown in the example of FIG.
, gas flow hole 4 in the iron core, gap 1 between the stator and rotor
7 and is discharged to the outside from the discharge port 14. Here, the stator core is held closely to the housing,
Enlarging the cut 5 in the iron core to increase the gas flow rate reduces this deep holding strength. Also, for this reason,
If the gas flow holes are irregularly formed in the iron core, the magnetic path of the motor will become non-uniform, and the magnetic flux density will become non-uniform at various parts, leading to deterioration of motor characteristics. To counter this, as shown in the example in Figure 3, the thickness of the back of the core is made uniform, and the thickness is made uniform across the gold scraps.
The characteristics of the motor are maintained by providing gas circulation holes,
A large gas distribution area can also be obtained. In addition, if the distance between the outer periphery of the gas circulation hole and the core outer diameter is more than twice the laminated core plate thickness t normally used in motors, deformation during core punching may occur.
Strength against deformation during handling can be ensured. FIG. 3 is a partially enlarged view showing the relationship between the contents described above. Roughly' IJ4 diagram shows the iron core part of claim 3 which is made asymmetrical by making the corner radius on the outer circumferential side large in order to make the gas flow hole large and to increase the holding strength to the housing when it is made into an elongated shape. An enlarged view is shown.

Figures 5 and 6 show that by setting the number of slots, the utilization rate of the core can be improved and the slot tooth width can be increased. A slit 8 can be provided.

〔Effect of the invention〕

According to the present invention, since the utilization rate of the iron core can be improved, the flow rate of gas can be expanded without impairing the motor characteristics of the electric compressor. The motor can be cooled uniformly by allowing gas to flow through the motor. In addition, by winding the coils at full pitch, the permanent magnet rotor can be magnetized by energizing the stator windings, making it possible to magnetize the compressor from outside. Compared to the case where the compressor is upright, it is possible to reduce the amount of foreign matter such as iron powder being brought into the compressor due to adsorption.

[Brief explanation of the drawing]

Fig. 1 is an overall cross-sectional view of an electric compressor to which an embodiment of the present invention is applied, Fig. 2 is a cross-sectional view showing the electric compressor and the motor in a fixed state, and Fig. 3 is a partially enlarged view of a different embodiment. , FIG. 4 is a partially enlarged view of the embodiment shown in FIG. 3, and FIGS. 5 and 6 are partially enlarged views of further different embodiments. 1...Motor stator, 2...Slot, 3...
Slot tooth portion, 4... Gas circulation hole, 5... Stator core cut, 6-... Motor coil, 7... Inner diameter notch provided in slot tooth, 8... Slit in slot tooth, 9... ... Permanent magnet rotor, 10... Compressor housing, 11... Compressor body, 12... Gas flow, 1
3...Gas suction port, 14...Gas discharge port, 15...
・Compressor main body valve, 17...Stator rotor gap diagram B-WxZ xk/Ip <k-a, 9-t, l) diagram diagram

Claims (1)

[Claims] 1. At one end of the compressor housing, the compressor main body is attached to the housing wall, the number of slots for each pole and each phase q = number of slots z/(
The stator has a stator that straddles each phase coil at 2π/p with the number of poles p x the number of phases m) = 1, and the compressor shaft has a permanent magnet rotor, and the compressed gas is passed through this electric motor. , an electric compressor discharging from the other end of the housing. 2. At the bottom of the slot of the stator, B = slot tooth width w
×z×k/πp (k = 0.9 to 1.1), which has a substantially uniform core thickness, and a core thickness of c = laminated core plate thickness × 2 or more from the core outer diameter. 2. The electric compressor according to claim 1, further comprising a plurality of air holes passing through in the axial direction over the entire circumference in a range sandwiched between the inner circumference and the inner circumference of the electric compressor. 3. The electric compressor according to claim 2, wherein the shape of the air hole is elongated, and the R of the corner portion is set such that the outer circumferential side is larger than the inner circumferential side. 4. The electric compressor according to claim 1, wherein a notch is provided on the inner peripheral side of the slot tooth portion of the stator to increase the flow rate of gas. 5. The electric compressor according to claim 1, wherein the slot tooth width is set to k=less than 0.9, and slits are provided in the slot teeth to increase the gas flow rate.