Rectifying motor lap-wound magnetic winding with adjustable commutating angle

Abstract: This invention relates to a commutation motor having a lap-wound field winding with adjustable commutating angle that may enable composite polar axis center in continuous angle movement adjustment relatively by means of employing different excitation current upon different windings to facilitate commutation, not only applicable to unilaterial model but also especially suitable to model required for positive-reversal rotation.

Description: Conventional AC/DC rectifying motors, whether of the shunt excitation, series excitation or compound-excitation type, all include commutating magnetic poles or brushes and a magnetic polar axis, the maximum load being determined by the commutating angle. DC-C-235,089 discloses a motor having main stator windings m and n and auxiliary stator windings p and q. The orientation of the magnetic axis can be controlled by varying the current in the auxiliary windings which may in series or parallel. WO-A-89/06454 discloses a reversible motor or generator comprising a plurality of series-connected lap-wound field windings and a reversing switch connected to said field windings. The present invention provides a reversible motor or generator as disclosed above in WO-A-89/06454 characterised in that said field windings comprise a main field winding and a first and second mutually overlapping auxiliary field windings, one of said auxiliary field windings being angularly offset in one direction relative to said main field winding and the other of said auxiliary field windings being angularly offset in the opposite direction relative to said main field winding and said reversing switch has a first switching position in which the armature of the motor or generator is connected in parallel with the first auxiliary field winding and the main auxiliary field winding, and a second switching position in which the armature of the motor or generator is connected in parallel with the second auxiliary field winding and in series with the first auxiliary field winding and the main field winding. A preferred embodiment of the invention is described below by way of example only with reference to Figures 1 and 2 of the accompanying drawings, wherein Figure 1 shows a winding arrangement comprising a central main field winding and right and left lap-wound windings, and Figure 2 is a circuit diagram showing the winding arrangement of Figure 1 applied to a compound -excitation and reversible motor. Referring to Figure 1, the pole arrangement comprises at least three tooth-shaped pole pieces T 0 , T 1 and T 2 . Auxiliary pole pieces T 1 and T 2 may be the same size or of different sizes when necessary and the central pole piece T 0 may be larger, smaller or the same size as the pole pieces on either side. A main winding W 0 is wound around the three pole pieces W 0 to W 2 . The left auxiliary winding W 1 is wound around pole pieces T 0 and T 1 and the right auxiliary winding W 2 is wound around pole pieces T 0 and T 2 . The above arrangement is incorporated in the reversible motor shown in Figure 2, wherein control switch SW1 is a double knife switch having common connection terminals P3, P4 connected to the ends of armature AO. In one switch position (as shown in figure 2) the switch connects the terminals P3 and P4 to terminals P1 and P5 respectively which in turn are connected across the ends of auxiliary winding W1. In this configuration the winding W1 and armature AO are connected in parallel and the parallel combination is connected in series with windings W0 and W2. The motor can be reversed by switching switch SW1 to a position in which terminals P3 and P4 are connected to terminals P2 and P6 respectively, which are connected across the ends of auxiliary winding W2. The series-connected windings are connected between power supply terminals A and B. In conclusion, the lap wound field winding arrangement of the present invention provides an adjustable commutation angle. Furthermore the excitation of an independent winding (not shown) may be changed in order to change the commutation angle continuously rather than discontinuously.

Claims: A reversible motor or generator comprising a plurality of series-connected lap-wound field windings (W 0 , W 1 , W 2 ) and a reversing switch (SW 1 ) connected to said field windings, characterised in that said field windings comprise a main field winding (W 0 ) and first and second mutually overlapping auxiliary field windings (W 1 , W 2 ) one of said auxiliary field windings being angularly offset in one direction relative to said main field winding and the other of said auxiliary field windings being angularly offset in the opposite direction relative to the said main field winding and said reversing switch has a first switching position in which the armature of the motor or generator is connected in parallel with the first auxiliary field winding and in series with the second auxiliary field winding and the main auxiliary field winding, and a second switching position in which the armature of the motor or generator is connected in parallel with the second auxiliary field winding and in series with the first auxiliary field winding and the main field winding. A reversible motor or generator according to claim 1 which is a DC motor or a generator and wherein the commutation angle is adjustable.

Inventors: YANG TAI-HER, YANG, TAI-HER
Applicants: YANG TAI HER, YANG, TAI-HER
Application year: 1991
Main classification: H02K23
IPC codes: H02P7, H02K23