Electrical generator or motor structure – Dynamoelectric – Rotary
Reexamination Certificate
1999-06-09
2001-02-27
Ramirez, Nestor (Department: 2834)
Electrical generator or motor structure
Dynamoelectric
Rotary
C310S216006, C310S256000
Reexamination Certificate
active
06194806
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a compact cylindrical radial gap type motor having a rotor comprised of permanent magnets, and more particularly, to a DC brushless motor in which the motor characteristics are improved by appropriate establishment of the form of the salient poles for a motor with a concentrated winding armature structure using a bobbin for each of the salient poles, said salient poles having a distributed structure.
2. Description of the Prior Art
Patent Application 306115 of 1998 describes a laminated, inner rotor type brushless DC motor structure in which the armature is constructed of a ring section and multiple salient pole sections, where the length of each salient pole in the axial direction is practically the same as the length of its opposing rotor magnet.
The invention described in Japanese Patent Application 306115 of 1998 does not explain the dimensional relationship between the lead winding section and the opposing section of the salient pole magnet, nor does it explain the dimensional relationship between the width in the circumferential direction of the salient pole and the rotor magnetic pole pitch. Accordingly, it has the drawback that it does not clearly indicate which shape of salient pole improves the motor efficiency. As a result, even though a unique armature structure is presented, there is the drawback that a suitable effect cannot be obtained.
SUMMARY OF THE INVENTION
The objective of the present invention, in order to overcome the above problem, proposes an active iron core type compact cylindrical radial gap type motor having field magnetic poles generated by permanent magnets and, in opposition to these, salient poles generating a rotational magnetic field and arranged with their emission direction along the rotational axis, and which does not employ the conventional laminated structure with cores of practically the same shape laminated in the axial direction, but which instead, by using an armature constructed of a stator ring section and multiple salient poles constructed radially, provides a high efficiency motor by using an appropriate salient pole shape.
In order to overcome the above-mentioned problem, the main present invention provides an iron core type cylindrical radial gap type motor structure characterized by having field magnetic poles generated by permanent magnets and, in opposition to these, salient poles generating a rotational magnetic field and arranged with their emission direction along the rotational axis, the shape of said salient poles being approximately T-shaped in cross-section along the rotational axis direction, and I-shaped in cross-section at right angles to the rotational axis direction, the upper end of said T-shaped opposing the axial direction of the rotor magnets and the lower end being mechanically coupled and fixed to the stator ring, thus constructing the magnetic circuit of the armature, and where the relationship between the length L
1
of the said salient pole in the axial direction opposed to the field magnetic pole, and the length L
2
in the axial direction of the coil core section about which the coil is wrapped, satisfies the conditions 0.3*L
1
<L
2
<0.6*L
1
, and, furthermore, where the relationship between the thickness A
1
of the said salient pole in the circumferential direction, and the pitch P of the field magnetic pole, satisfies the conditions 0.4*P<A
1
<0.8*P.
The second invention of the present invention provides a compact cylindrical radial gap type motor structure as described in the above main invention, characterized by having salient poles made from electromagnetic steel plates laminated in the circumferential direction.
The third invention of the present invention provides a compact cylindrical radial gap type motor structure as described in the above main invention, characterized by having salient poles made from a soft magnetic substance composed of soft magnetic powder mixed into plastic resin.
The fourth invention of the present invention provides a compact cylindrical radial gap type motor structure as described in the above main invention, characterized by having field magnet poles made from permanent magnets which are formed from metallic alloy.
The fifth invention of the present invention provides a compact cylindrical radial gap type motor structure as described in the above main invention, characterized by having field magnet poles made from permanent magnets which are formed from a sintered magnetic substance.
The sixth invention of the present invention provides a compact cylindrical radial gap type motor structure as described in the above main invention, characterized by having field magnet poles made from permanent magnets which are formed from plastic magnets.
The seventh invention of the present invention provides a compact cylindrical radial gap type motor structure as described in above mentioned invention, characterized by having a rotor location detection magnet formed as a integrated with the field magnet poles, which are formed from plastic magnets.
The eighth invention of the present invention provides a compact cylindrical radial gap type motor structure as described in the above main invention, in which the motor has an inner rotor structure.
The ninth invention of the present invention provides a compact cylindrical radial gap type motor structure as described in the above main invention, in which the motor has an outer rotor structure.
REFERENCES:
patent: 2298388 (1942-10-01), Knobel
patent: 4503368 (1985-03-01), Sakamoto
patent: 4780636 (1988-10-01), Gandhi et al.
patent: 4947065 (1990-08-01), Ward et al.
patent: 5162684 (1992-11-01), Hayakawa
patent: 5369325 (1994-11-01), Nagate et al.
patent: 5493161 (1996-02-01), Uno et al.
patent: 5498917 (1996-03-01), Ninomiya et al.
patent: 5783880 (1998-07-01), Teshima et al.
Aono Yoshiyuki
Fujitani Sakae
Kagawa Masaki
Suzuki Yuzuru
Dinh Le Dang
Minebea Co., Limited
Ramirez Nestor
Staas & Halsey , LLP
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