Electrical generator or motor structure – Dynamoelectric – Rotary
Patent
1991-12-13
1993-10-12
Stephan, Steven L.
Electrical generator or motor structure
Dynamoelectric
Rotary
H02K 348
Patent
active
052528774
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
The present invention relates to slot insulating magnetic wedges inserted in stator slots of a motor.
RELATED ART
In order to improve the efficiency and the power factor of a motor or to reduce electromagnetic vibration sound thereof, magnetic wedges are usually inserted into opening portions of stator slots. With the magnetic wedges inserted, a magnetic unbalance between the opening portions of the stators and the tooth portions thereof is removed. Thereby, the strain of magnetic flux in magnetic air gaps is decreased and a loss due to higher harmonic magnetic flux which takes place in the stator is suppressed. Consequently, various characteristics of the motor are improved.
FIG. 5 is a partial view showing principal portions of a motor using conventional magnetic wedges. In the figure, a stator slot 1 of the motor has an opening (1a) against a rotor 2. In the opening portion 1a, a magnetic wedge 3 with a trapezoidal section is inserted. This magnetic wedge is made of a substance where for example iron powder or ferrite powder is bound with resin or the like. The stator slot 1 houses a coil 4. Thus, the stator slot 1 also has a function for preventing the coil 4 from protruding therefrom.
The characteristics of the motor are generally improved in proportion to the amount of coil 4 housed in the slot 1. Thus, with respect to the magnetic wedge 3 with the trapezoidal section does nor have an effective sectional area of the slot 1 and thereby the effect of the magnetic wedge 3 being inserted cannot be satisfactorily obtained. In addition, since the magnetic wedge which is made up of a substance where magnetic powder is bound with resin or the like does not have an enough mechanical strength, it has a problem with respect to reliability thereof because of a chip and a crack when it is inserted in the stator slot or it is used.
To solve the above mentioned problems, as shown in FIG. 6, a unified construction of the magnetic wedge 5 where a ferrite 5b, which is a magnetic material, is coated on an insulating thin leaf shaped material 5a, which is used as a wedge material, has been proposed (refer to Japanese Utility Model Laid-Open Publication No. SHO 59(1984)-18548). In this construction, the effect of the magnetic wedge is fulfilled and the amount of coil which is housed in the slot is equal to that where the non-magnetic thin leaf shaped material is used as the wedge. In addition, in this construction, the wedge can also be automatically inserted into the stator slot.
However, the magnetic wedge, where the magnetic material such as ferrite is coated on the thin leaf shaped material, tends to peel off depending on the thickness of the coating layer or tends to chip or crack when it is inserted into the stator slot or it is used like the magnetic wedge made of a substance where magnetic powder is bound. In addition, with respect to the accomplishment of the high efficiency of the motor, the above mentioned construction does not provide an enough result. Thus, from such a viewpoint as well as the above mentioned problems, it was strongly desired to modify the above mentioned magnetic wedges.
On the other hand, magnetic wedges using an amorphous alloy thin strip as a magnetic material are disclosed in Japanese Patent Laid-Open Publication Nos. SHO 58(1983)-19138, SHO 58(1983)-22554, SHO 59(1984)-175350, and so forth. However, these magnetic wedges have the following problems. The Japanese Patent Laid-Open Publication No. SHO 58(1983)-19138 discloses a magnetic wedge 6 where a plurality of amorphous alloy thin strips 6a are laminated in a manner that the long side thereof is nearly parallel to the coil in the slot, while the short side thereof is nearly parallel to the center line of the section of the iron core. This magnetic wedge requires many steps to produce. In addition, since the mechanical strength required as the wedge should be obtained only with the adhesive strength of the lamination, the above mentioned wedge cannot provide enough strength. In addition, like the above mentioned ma
REFERENCES:
patent: 4928382 (1990-05-01), Fujiwava et al.
patent: 5124607 (1992-06-01), Rieber et al.
Hibino Sadayoshi
Kimura Tadatomo
Mochizuki Motoyasu
Ozawa Shigeo
Sakata Yasuo
Kabushiki Kaisha Toshiba
LaBalle C.
Stephan Steven L.
LandOfFree
Slot insulating magnetic wedges does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Slot insulating magnetic wedges, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Slot insulating magnetic wedges will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1907019