293results about "Salient poles" patented technology

A low inductance electrical machine which may be used as an alternator or motor with low armature inductance is disclosed. Arrangements of complementary armature windings are presented in which the fluxes induced by currents in the armature windings effectively cancel leading to low magnetic energy storage within the machine. This leads to low net flux levels, low core losses, low inductance and reduced tendency toward magnetic saturation. Separately excited field arrangements are disclosed that allow rotor motion to effect brushless alternator or brushless motor operation. An exemplary geometry includes a stator including two toroidal rings and a concentric field coil together with a rotor structure separated from the stator by four air gaps. An alternate embodiment allows for counter-rotation of two rotor elements for use as a flywheel energy storage system in which the external gyroscopic effects cancel.

A high power low RPM direct current electric motor is disclosed whereby the high power output is achieved in one of two ways or both. In the first case, the need for cooling is reduced simultaneously along with an increase in the utilization of the magnetic field present in the motor permanent magnets. This is achieved by wrapping the electromagnet core with windings that are capable of demagnetizing the rotor permanent magnets under stall conditions. Interlocking motor circuitry is provided which prevents the full activation of these motor windings until motor RPM values reach a safe level. This increases motor power while decreasing resistive losses in electromagnet windings. In the second case, the rotary portion consists of a large diameter relatively flat rotor containing permanent magnets and having built in vanes for moving air over the electromagnet stator windings providing forced air cooling.

The present invention relates to a two-phase brushless DC motor which can increase a pemerance coefficient of a rotor to the maximum to thereby improve efficiency and starting feature of the motor, and to reduce torque ripple and noise thereof. The brushless motor of the present invention includes a two-phase winding stator having 4×n winding poles and auxiliary poles provided between the winding poles, and a rotor constituted by 6×n permanent magnet rotating poles having divided angle. Auxiliary poles between the stator poles can be provided. The two-phase brushless motor of the present invention can be driven by a control device for the two-phase motor which can transform electric power and rectify electronically.

A permanent-magnet motor including a rotor having permanent magnets disposed therein, and a stator, wherein an outer circumferential surface of the rotor is opposite to an inner circumferential surface of the stator, and one or both of the outer circumferential surface of the rotor and the inner circumferential surface of the stator are varied in a radial direction so as to provide a non-uniform gap between the two surfaces to approximate sinusoidal change in magnetic flux.

An electric system that includes a single-phase permanent-magnet electric machine and a control system for driving the electric machine under load at speeds in excess of 60 krpm. Additionally, a product that includes the electric system.

The object of the present invention is to increase thrust generation of a linear motor, and to achieve miniaturization and the low price of a linear motor by improving a magnetic circuit. In order to achieve the object, the present invention provides a linear motor including a magnetic yoke for the north pole 8 which is commonly connected to the magnetic pole N of permanent magnets 4, a magnetic yoke for the south pole 9 which is commonly connected to the pole S of permanent magnets 4, a magnetic north pole 5 forming a part of magnetic yoke for the north pole 8 and being mounted on the surface of a slider 3, a magnetic south pole 6 forming a part of magnetic yoke for the south pole 9 and being mounted on the surface of a slider 3 so as to be alternately located in a traverse direction of the slider 3 with the magnetic north pole 5.

The armature of a motor comprises a core constituted by assembling a plurality of split core members. Each split core member has at least two teeth. The method for manufacturing the armature comprises the steps of: winding a conductive wire on each tooth of each split core member to form a first coil on the teeth; spanning the conductive wire extending from a winding finishing end of the first coil from each tooth to the other tooth; winding the conductive wire on the tooth to which the conductive wire is spanned to form a second coil on the first coil; joining a winding starting end of the first coil and a winding finishing end of the second coil in each tooth to form a single coil; and mutually assembling the plurality of split core members each comprising the coils. As a result, productivity is improved, while reducing size.

A brushless electric motor system comprises a rotor and a stator comprising poles. Electrical phase windings have coils (U1-6, V1-6, W1-6) wound around the poles. Power switches (T1-24) controlled by a control device supply electric current the windings from positive and negative rails connected to power supply. For each phase at least one group of four power switches arranged in a H-bridge configuration is provided. The coils of each phase winding are preferably divided into winding group (U1-3, Ua-6, V1-3, V4-6, W1-3, W4-6) and the electric conductor of each winding group is then electrically conductor of the other winding groups. Then four power switches arranged in an H-configuration is provided for each winding group. The use of power switches in H-bridge configurations allows the faulty windings or winding groups to be disabled and that the rest of the windings or coils can be used for driving the rotor, this giving the motor system a high reliability. The current supplied to other windings or winding groups can then be increased to compensate for the faulty group. The coil groups can be separated from other coil groups by unwound stator poles. Current sensors (303) can sense the current in each winding group and be used to detect whether the currents are too high. The sensed currents can be used to identify fault conditions in the system so that then suitable switches can be disabled, disconnecting a faulty winding group.

An electric machine (10; 100) comprises a rotor (14) having permanent magnets (24) and a stator (12) having coils (22) wound on stator bars (16) for interaction with the magnets across an air gap (26a, b) defined between them. The rotor has two stages (14a, b) arranged one at either end of the bars. The bars have a shoe (18a, 8) at each end of each bar that links magnetic flux through the bars with said magnets on each stage. Adjacent shoes facing the same stage of the rotor have a high-reluctance shoe gap (27) between them; adjacent magnets on each stage of the rotor have a high-reluctance magnet gap (25) between them; and the shoe and magnet gaps (25, 27) are angled with respect to each other such that they engage progressively as the rotor rotates. Alternatively, the shoes facing each stage are in a ring of connected shoes such that the magnets experience a continuous reluctance that is at least 90% constant as a function of rotor position. The bars (16) and shoes (18) are formed separately from one another and at least a part of each is formed by moulding soft-iron particles so that the particles have a short dimension that is arranged transverse a reluctance-plane. The bars and shoes are assembled so that the reluctance-plane of the bar is parallel a longitudinal axis (16a) of the bar and said reluctance-plane of the shoe is transverse said longitudinal axis.

An electric system that includes a single-phase permanent-magnet electric machine and a control system for driving the electric machine. The control system sequentially excites and freewheels a winding of the electric machine so as maintain substantially constant power over an operating speed range spanning at least 10 krpm and/or an excitation voltage range extending between a minimum voltage and a maximum voltage, the minimum voltage being less than 80% of the maximum voltage. Additionally, a product comprising the electric system.

An apparatus for stabilizing the spin axis of a rotating system, the rotating system having a rotor and motor means to cause rotation of the rotor about the spin axis and a magnet, windings, a source of drive current and an actuator combined with the motor means and forming a source of actuator current energizing the windings to generate a radial force which stabilizes the position of the spin axis and dampens other than rotational movements of the rotor.

A method, apparatus, article of manufacture and system for producing a field pole member for electrodynamic machinery are disclosed to, among other things, reduce magnetic flux path lengths and to eliminate back-iron for increasing torque and/or efficiency per unit size (or unit weight) and for reducing manufacturing costs. For example, a field pole member structure can either reduce the length of magnetic flux paths or substantially straighten those paths through the field pole members, or both. In one embodiment, a method provides for the construction of field pole members for electrodynamic machines.

A method, apparatus, article of manufacture and system for producing a field pole member for electrodynamic machinery are disclosed to, among other things, reduce magnetic flux path lengths and to eliminate back-iron for increasing torque and/or efficiency per unit size (or unit weight) and for reducing manufacturing costs. For example, a field pole member structure can either reduce the length of magnetic flux paths or substantially straighten those paths through the field pole members, or both. In one embodiment, a method provides for the construction of field pole members for electrodynamic machines.

A rotary electric machine comprising a stator body (ST in FIG. 1) which includes a winding configured of a plurality of coils (2), and a power supply section (PS) which includes conductive members (4, 5 and 6) for connecting the coils (2) to one another, and a holding member (11) for holding the conductive members (4, 5 and 6), wherein the power supply section (PS) is configured by employing the holding member (11) which is common to different connection structures such as a Y-connection and a delta connection. The rotary electric machine is advantageous in the points of the fabrication and supply of components owing to the common use of the components.

The brushless motor has a first and second drive member. The first drive member is equipped with M phase coil groups each having N electromagnetic coils where M is an integer of 1 or greater and N is an integer of 1 or greater. The second drive member has a plurality of permanent magnets, and is able to move relative to the first drive member. The first drive member has 2 (M×N) magnetic body cores. Each phase electromagnetic coil is coiled on a periodically selected magnetic body core at a ratio of 1 to 2M from among the arrangement of 2 (M×N) magnetic body cores.

A laminated core block includes a plurality of core members made of magnetic sheets stacked one on top of another, the plurality of core members including first and second core members which adjoin in a laminating direction, and a thermoplastic resin strand placed between the first and second core members. The thermoplastic resin strand is arranged to pass along one side surface of the first core member, between the first and second core members and along a side surface of the second core member on a side opposite to the aforementioned side surface of the first core member in this order. The first and second core members are bonded to each other by melting and curing the thermoplastic resin strand.

A stator for use in a two rotor single stator type electric motor includes a stator core including a plurality of stator teeth that are circumferentially arranged around a common axis leaving a plurality of identical spaces each being defined between adjacent two of the stator teeth. Each stator tooth includes a plurality of flat magnetic steel plates that are aligned along the common axis. A plurality of coils are put around the stator teeth respectively. Bolts extend through identical spaces of the stator core for combining the flat magnetic steel plates to have a fixed structure of the stator core. A molded plastic fills the identical spaces of the stator core. A plurality of elongate plate bars extend in the identical spaces through the molded plastic respectively. Each elongate plate bar extends in parallel with the common axis and is constructed of a magnetic material that has an electric resistance higher than the bolts.

In order to achieve high machine utilization with the magnetic fields having an approximately sinusoidal profile, an electrical synchronous machine is proposed having the following features:

• • a stator and a rotor with the stator having a three-phase winding (3) and the rotor being fitted with permanent magnets,
  • the three-phase winding (3) is arranged in slots in the stator,
  • the slots in the stator are formed by essentially axially running teeth (7, 8) which have at least two different tooth pitch widths τ_zb and which are arranged alternately in the circumferential direction of the stator, with their number in each case being identical,
  • only the teeth (7) with a tooth pitch width which is greater than other teeth (8) are at least partially surrounded by a winding (3).