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AssigneeKollmorgen Technologies Corporation
InventorsJohn V. Byrne, Francis McMullin, Francis Devitt, Jeremiah O'Dwyer
Estimating the term…
A drive system includes a reluctance motor, driving a load. The motor has stator and rotor poles and magnetizing windings for each stator pole. The airgap is small so that saturation occurs during pole overlap, and the poles are constructed so that there is torque overlap between phases as successive phases are energized during rotor rotation. A sensor provides a rotor position input to a reference waveform generator. The output of the generator is determined by rotor position and is applied to a power converter through a current controller. Accordingly the waveform generator establishes a relative magnitude for motor phase current for every position of the rotor during the period of energization of a motor phase. A further input may be applied to the system to determine the absolute magnitude of the phase current, subject to the waveform pattern established by the generator. The rotor poles may be skewed to modify the static torque versus rotor angle characteristic of the motor, the skew being between one-quarter and one-half of rotor pole arcuate extent.
A drive system comprising a saturable variable reluctance electrical motor, said motor comprising a stationary or driving member having a plurality of salient driving poles, a magnetizing winding for each driving pole, and a movable or driven member having a plurality of salient driven poles, the number of driven poles being less than the number of driving poles, and a plurality of airgaps, the airgap between each driving pole and a driven pole positioned in alignment therewith being small relative to the dimensions of the poles transverse to said airgap and at least the driven poles being formed so that in operation of the motor magnetic saturation occurs substantially in a region of the mechanically variable interface or overlap between the driving and driven poles, and the extents and dispositions of the driven poles being related to those of the driving poles so that in operation of the motor, a force-producing increment of driven member displacement resulting from the mechanical interface or overlap of each driven pole with a driving pole overlaps a force-producing increment of driven member displacement resulting from the overlap of another driven pole with a further driving pole, and the system also comprising power supply means including voltage source means for connection across the driving pole windings, said windings being connectible across said voltage source means in a predetermined sequence during driven member displacement and each driving pole winding being thus connectible for a predetermined increment of driven member displacement, so that the driving poles may be sequentially energized for displacement of the driven member between successive minimum reluctance positions, and driven member position-sensing means for generating at least one signal, the instantaneous value of which is dependent on the position of the driven member for providing driven member position information at a succession of intervals within each said predetermined increment of driven member displacement during which a driving pole winding is connectible to said voltage source means, and the power supply means also including means for regulating the instantaneous magnitude of the current in a driving pole winding when connected to said voltage source means, said current-regulating means being responsive to said at least one driven member position-dependent signal of the driven-member position-sensing means to regulate said current magnitude so that the instantaneous value of said current set by said regulating means at any position of the driven member within said increment of driven member displacement during which the winding is connectible to said voltage source means relative to its value at any other said position is substantially determined by the instantaneous position of the driven member within said increment.
A drive system comprising a saturable variable reluctance electrical motor, said motor comprising a stator having a plurality of salient stator poles, a magnetizing winding for each stator pole, and a rotor having a plurality of salient rotor poles, the number of rotor poles being less than the number of stator poles, a radial airgap between each stator pole and a rotor pole positioned in alignment therewith being small relative to the dimensions of the poles transverse to said airgap and at least the rotor poles being formed so that in operation of the motor, magnetic saturation occurs substantially in a region of the mechanically variable interface or overlap between the stator and rotor poles, and the arcuate extents and dispositions of the rotor poles being related to those of the stator poles so that in operation of the motor, a torque-producing angular increment of rotor rotation resulting from the mechanical interface or overlap of each rotor pole with a stator pole overlaps a torque-producing angular increment of rotor rotation resulting from the overlap of another rotor pole with a further stator pole, and the system also comprising power supply means including voltage source means for connection across the stator pole windings, said windings being connectible across said voltage source means in a predetermined sequence during rotor rotation and each stator pole winding being thus connectible for a predetermined angular increment of rotor rotation, so that the stator poles may be sequentially energized for rotation of the rotor between successive minimum reluctance positions, and rotor position-sensing means for generating at least one signal, the instantaneous value of which is dependent on the position of the rotor for providing rotor position information at a succession of intervals within each said predetermined angular increment of rotor rotation during which a stator pole winding is connectible to said voltage source means, and the power supply means also including means for regulating the instantaneous magnitude of the current in the stator winding when connected to said voltage source means, said current-regulating means being responsive to said at least one rotor position-dependent signal of the rotor position-sensing means to regulate said current magnitude so that the instantaneous value of said current set by said regulating means at any angular position of the rotor within said angular increment of rotor rotation during which the winding is connectible to said voltage source means relative to its value at any other said angular position is substantially determined by the instantaneous angular position of the rotor within said angular increment.
A drive system comprising a saturable variable reluctance electrical motor, said motor comprising a stator having a plurality of salient stator poles, a magnetizing winding for each stator pole, and a rotor having a plurality of salient rotor poles, the number of rotor poles being less than the number of stator poles, a radial airgap between each stator pole and a rotor pole positioned in alignment therewith being small relative to the dimensions of the poles transverse to said airgap and at least the rotor poles being formed so that in operation of the motor magnetic saturation occurs substantially in a region of the mechanically variable interface or overlap between the stator and rotor poles, and the arcuate extents and dispositions of the rotor poles being related to those of the stator poles so that in operation of the motor, a torque-producing angular increment of rotor rotation resulting from the mechanical interface or overlap of each rotor pole with a stator pole overlaps a torque-producing angular increment of rotor rotation resulting from the overlap of another rotor pole with a further stator pole, and the system also comprising rotor position-sensing means for generating at least one signal, the instantaneous value of which is dependent on the angular position of the rotor, and power supply means including voltage source means for connection across the stator pole windings, said windings being connectible across said voltage source means in a predetermined sequence during rotor rotation and each stator pole winding being thus connectible for a predetermined angular increment of rotor rotation, and the power supply means also including means for regulating the instantaneous magnitude of the current in a stator winding when connected to said voltage source means, said current-regulating means being responsive to said at least one rotor position-dependent signal of the rotor position-sensing means to regulate said current magnitude so that the instantaneous value of said current set by said regulating means at any angular position of the rotor within said angular increment of rotor rotation during which the winding is connectible to said voltage source means relative to its value at any other said angular position is substantially determined by the instantaneous angular position of the rotor, each rotor pole and each stator pole having circumferentially spaced apart edge regions, the circumferential spacing of said edge regions of each pole being substantially constant throughout the axial extent of the pole and one axial end of each of said edge regions of at least each rotor pole having a circumferential displacement relative to the other axial end of the same edge region of the pole of between one quarter of the constant circumferential spacing of the edge regions of the pole and a value equal to said spacing, so that said edge region is skewed relative to the axis of rotation of the rotor.
A drive system comprising a saturable variable reluctance electrical machine, said electrical machine comprising a stator having a plurality of salient stator poles, a winding for each stator pole, and a rotor having a plurality of salient rotor poles, the number of rotor poles being less than the number of stator poles, a radial airgap between each stator pole and a rotor pole positioned in alignment therewith being small relative to the dimensions of the poles transverse to said airgap and at least the rotor poles being formed so that in operation of the machine, magnetic saturation occurs substantially in, a region of the mechanically variable interface or overlap between the stator and rotor poles, and the arcuate extents and dispositions of the rotor poles being related to those of the stator poles so that in operation of the machine, a torque-producing angular increment of rotor rotation resulting from the mechanical interface or overlap of each rotor pole with a stator pole overlaps a torque-producing angular increment of rotor rotation resulting from the overlap of another rotor pole with a further stator pole, and the system also comprising voltage source means connectible across stator pole windings, said windings being connectible across said voltage source means in a predetermined sequence during rotor rotation and each stator pole winding being thus connectible for a predetermined angular increment of rotor rotation, and rotor position-sensing means for generating at least one signal, the instantaneous value of which is dependent on the position of the rotor for providing rotor position information at a succession of intervals within each said predetermined angular increment of rotor rotation during which a stator pole winding is connectible to said voltage source means, and said windings also being connectible across an electrical load during rotor rotation, also in a predetermined sequence, and each stator pole winding being thus connectible for a predetermined further angular increment of rotor rotation.
A saturable variable reluctance electrical machine comprising a stationary or driving member having a plurality of salient driving poles, a winding for each driving pole, a movable or driven member having a plurality of driven poles, the number of driven poles being less than the number of driving poles, and a plurality of airgaps, the airgap between each driving pole and a driven pole positioned in alignment therewith being small relative to the dimensions of the poles transverse to said airgap and at least the driven poles being formed so that in operation of the machine, magnetic saturation occurs substantially in a region of the mechanically variable interface or overlap between the driving and driven poles, the extents and dispositions of the driven poles being related to those of the driving poles so that in operation of the machine, a force-producing increment of driven member displacement resulting from the mechanical interface or overlap of each driven pole with a driving pole overlaps a force-producing increment of driven member displacement resulting from the overlap of another driven pole with a further driving pole, each driven pole and each driving pole having edge regions spaced apart in the direction of relative displacement of the driven and driving members, said spacing of said edge regions being substantially constant throughout the extent of the pole in a direction transverse to said direction of relative displacement and one transverse end of each said edge region of at least each driven pole being displaced in said direction of relative displacement with respect to the other transverse end of said edge region by between one quarter of the constant extent of the pole in said direction of relative displacement and a value equal to said extent so that said edge region is skewed relative to said direction of relative displacement.
A saturable variable reluctance electrical machine comprising a stator having a plurality of salient stator poles, a winding for each stator pole, a rotor having a plurality of rotor poles, the number of rotor poles being less than the number of stator poles, a radial airgap between each stator pole and a rotor pole positioned in alignment therewith being small relative to the dimensions of the poles transverse to said airgap and at least the rotor poles being formed so that in operation of the machine, magnetic saturation occurs substantially in a region of the mechanically variable interface or overlap between the stator and rotor poles, the arcuate extents and dispositions of the rotor poles being related to those of the stator poles so that in operation of the machine, a torque-producing angular increment of rotor rotation resulting from the mechanical interface or overlap of each rotor pole with a stator pole overlaps a torque-producing angular increment of rotor rotation resulting from the overlap of another rotor pole with a further stator pole, each rotor pole and each stator pole having respective circumferentially spaced apart edge regions, the circumferential spacings of said edge regions being substantially constant throughout the axial extent of the pole and one axial end of each said edge region of at least each rotor pole being circumferentially displaced relative to the other axial end of said edge region by between one quarter of the constant arcuate extent of the pole and a value equal to said arcuate extent so that said edge region is skewed relative to the axis of rotation of the machine.
Dependencies are inferred from the claim text.