Electricity: motive power systems – Open-loop stepping motor control systems
Patent
1994-12-21
1995-12-19
Ip, Paul
Electricity: motive power systems
Open-loop stepping motor control systems
318135, 318685, 318687, 310 49R, H02K 3700
Patent
active
054771200
DESCRIPTION:
BRIEF SUMMARY
PRIOR ART
The present invention relates to an improved method of driving a 5-phase hybrid stepping motor.
BACKGROUND OF THE INVENTION
Hybrid stepping motors have been well known for over a quarter of the century as actuators appropriated for highly accurate positioning movements. The hybrid stepping motors are widely used in various machine tools, e.g. with fully automated production lines, as well as computer related instruments including printers, plotters, facsimile machines, and disk drive units.
For increasing the versatility in use, there is made an attempt to minimize the step angle of such a hybrid stepping motor. To this respect, four- and five-phase types of the stepping motor are now commonly provided.
The conventional four- or five-phase stepping motors however have some disadvantages that torque stiffness is unstable, that static torque is varied depending on the stop position, and that the step angle is not at a high accuracy. It is an object of the present invention to eliminate the foregoing disadvantages.
SUMMARY OF THE INVENTION
For achievement of the above object, a method of driving a multi-phase hybrid type stepping motor which has a rotor provided with one or more permanent magnets magnetized in the rotating direction of a rotary shaft, according to the present invention, is characterized by a two pole caps mounted to both ends of the permanent magnet respectively, each the pole cap made of a soft magnetic material and having a plurality (NR) of teeth arranged at equal intervals on the circumferential surface thereof, the teeth of the two pole caps being displaced by 1/2 of the teeth pitch (1/2 Tp) from each other, a plurality of stator segments of an asymmetrical form disposed around the rotor, each the asymmetrical stator segment having ten fixed magnetic poles thereof extending inwardly and radially, each the fixed magnetic pole having a winding wound thereon with no taps and being provided with two or more small teeth arranged at equal intervals of the same pitch as of the teeth of the rotor, the total number (NS) of the small teeth of the asymmetrical stator segment being determined by NS=5.times.(n0+n1), where n0 is the number of the small teeth on each of five of the ten fixed magnetic poles and n1 is the number of the small teeth on each of the remaining five fixed magnetic poles, the fixed magnetic poles with the n1 small teeth being arranged alternate with the fixed magnetic poles with the n0 small teeth, the n1 small teeth pole and the n0 small teeth pole being disposed opposite to each other about the axis of the rotary shaft, the relation between the total number (NR) of the teeth of the rotor and the total number (NS) of the small teeth of the stator segment being expressed by NS2420.8-NR (NS being greater than or equal to 0.8-NR), a difference between NR and NS being calculated from NR-NS=K(S0-S1)+10(S1-1+B) where K is an integer from 2 to 5, S0 and S1 are smallest possible integers or may be equal, and B is a fraction of 1 so that 10B (ten times of B) is always an integer, the ten stator windings on their respective fixed magnetic poles being coupled to one another in a circular order of P1, P6, P2, P7, P3 P8, P4, P9, P5, and P10, five terminals disposed between P1 and P10, P6 and P2, P7 and P3, P8 and P4, and P9 and P5 respectively, and by polarization of the ten fixed magnetic poles at each step of the rotating movement, N and S poles of the same number being generated.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross sectional view showing one embodiment of the present invention;
FIG. 2 is a longitudinal sectional view of time embodiment of time present invention;
FIG. 3 is a front view of a stator system another embodiment of the present invention;
FIG. 4 is a vector diagram of a rotor in the embodiment of time present invention;
FIG. 5 is a wiring diagram according to the embodiment of the present invention;
FIG. 6 is a chart showing the magnetic shift at fixed magnetic poles in full-step mode; and
FIG. 7 is a chart showing the magnetic shift at the f
REFERENCES:
patent: 4675564 (1987-06-01), Isozaki
patent: 4712028 (1987-12-01), Horber
patent: 4713570 (1987-12-01), Mastromattei
patent: 4873462 (1989-10-01), Harned
patent: 4890024 (1989-12-01), Hashimoto et al.
patent: 5128570 (1992-07-01), Isozaki
patent: 5283486 (1994-02-01), Kobori
patent: 5289064 (1994-02-01), Sakamoto
patent: 5309051 (1994-05-01), Kobori
patent: 5315192 (1994-05-01), Satomi
patent: 5386161 (1995-01-01), Sakamoto
Yoshida Kenji
Yoshimura Noriyuki
Ip Paul
Minebea Co. Ltd.
LandOfFree
Method for driving stepping motor of multiphase hybrid type does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method for driving stepping motor of multiphase hybrid type, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method for driving stepping motor of multiphase hybrid type will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-993945