Low-noise energy-saving electric drive

Invention relates to a power-driven tool equipped with a three-phase brushless electric motor, and more precisely to a control method of an output characteristic of the electric motor of the power-driven tool. The power-driven tool includes a brushless motor that includes a rotor with a constant magnet, a cylindrical stator and three-phase stator windings. Multiple slots are made on the inner surface of the stator at specified intervals in a circumferential direction. Each of the three stator windings is formed with multiple coils wound in the slots of the stator and connected to each other. Total number of coil turns wound in the slots of each phase is the same for three phases and is not divisible by the number of slots of each phase.

Combined winding of the induction machine with number of pole pairs 2p=4 and number of slots z=36 for number of parallel branches a=1 or 2 is made with pitch y=1-10 and contains 12 coils. Number of turns m_"з" of odd coils and number of turns m_"тр" of even coils comply with ratio $$m_{\text{'}\text{'}тр"}/m_{"з"}=\sqrt{3}.$$

Winding design for a rotating electrical machine includes the core with slots and a coil comprising the first and second windings combined by their intercrossing. Each straight section of the coil is inserted to one of two slots made with the preset interval so that the core is assembled at the core.

Invention enables to produce energy-efficient electrical machines, particularly high-performance, high-torque low-noise asynchronous motors. The disclosed integrated winding of an asynchronous machine with the number of pairs of poles 2p=2, with the number of grooves z=18 for the number of parallel braches a=1 is made with spacing y=1-10 and 6 has coils, wherein the number m_"з" of turns of odd coils and the number m_"тр" of turns of even coils satisfies the relationship $$m/m=\sqrt{3}.$$

In the middle of the first coil group (10a) there is a middle tooth (8a), which has the first MB width of the middle tooth. A stator (5) has the second group (10b) of coils. The first and second groups of coils are placed in the circumferential direction (U), directly in sequence one after another. Between the first and second groups of coils there is the first edge tooth (9), which has the first RB width of the edge tooth. In essence the first RB width of the edge tooth is equal to RB=a·ZB, and the first MB width of the middle tooth is equal to MB=(2-a)·ZB. The coefficient a is bigger than 0 and less than 1.

Invention is related to the sphere of electric equipment and may be used for production of rectifying asynchronous generators of stand-alone power plants. Technical result is attained by the reason that in a rectifying free-running asynchronous generator with capacitor excitation and a stator winding made of six coil group having outputs, according to this invention, the first output of the winding is taken from the united end of the fourth and beginning of the first coil groups, the second output of the winding is taken from the united end of the first and beginning of the second coil groups, the third output is taken from united end of the sixth and beginning of the third coil groups, the fourth output is taken from the united end of third and beginning of the fourth coil groups, the fifth output is taken from the united second and beginning of the fifth coil groups, the sixth output is taken from the united end of the fifth and beginning of the sixth coil groups, in parallel to the above stator windings there are six in-series delta connected excitation capacitors, which can connect these capacitors and outputs of the second, fourth and sixth capacitors as per the wye-wye connection scheme and the load is connected to these outputs in compliance with the voltage value and phase number matching the required load.

Invention is related to the sphere of electric equipment and may be used for production of asynchronous generators of stand-alone power plants. Technical result is attained by the reason that in a multifunctional free-running asynchronous generator with capacitor excitation and a stator winding made of six coil group having outputs the first output of the winding is taken from the united end of the fourth and beginning of the first coil groups, the second output of the winding is taken from the united end of the first and beginning of the second coil groups, the third output is taken from united end of the sixth and beginning of the third coil groups, the fourth output is taken from the united end of third and beginning of the fourth coil groups, the fifth output is taken from the united end of the second and beginning of the fifth coil groups, the sixth output is taken from the united end of the fifth and beginning of the sixth coil groups, in parallel to the above stator windings there are six in-series delta-connected excitation capacitors, which can connect these capacitors and outputs of the second, fourth and sixth capacitors as per the wye-wye connection scheme and the load is connected to these outputs in compliance with the voltage value and phase number matching the required load.

Invention is related to the sphere of electric equipment and may be used in asynchronous generators of stand-alone power plants. One part of a phase winding with a large vector sum of load and exciting currents is made with a heavy-gage wire, while the other part of the phase winding with a less vector sum of load and exciting currents is made with a wire of the lesser gage. In the suggested asynchronous generator with the eight-pole stator winding out of twenty four coil groups (from the first up to the twenty fourth) and excitation capacitors, according to the invention, the first output is taken from the united beginning of the first coil group and ending of the sixth one, the second output is taken from the united end of the second coil group and beginning of the third one, the third output is taken from the united end of the fourth coil group and beginning of the fifth one, the fourth output is taken from the united end of the nineteenth coil group and beginning of the twentieth coil group, the fifth output is taken from the united end of the twenty first coil group and beginning of the twenty second coil group, the sixth output is taken from the united end of the twenty third coil group and beginning of the twenty fourth coil group; at that the end of the first coil group is connected to the beginning of the seventh coil group, the beginning of the second group is connected to the end of the eighth group, the end of the third coil group is connected to the beginning of the ninth group, the beginning of the fourth group is connected to the end of the tenth group, the end of the fifth coil group is connected to the beginning of the eleventh group, the beginning of the sixth group is connected to the end of the twelfth group, the end of the seventh coil group is connected to the beginning of the thirteenth group, the beginning of the eighth group is connected to the end of the fourteenth group, the end of the ninth coil group is connected to the beginning of the fifteenth group, the beginning of the tenth group is connected to the end of the sixteenth group, the end of the eleventh coil group is connected to the beginning of the seventeenth coil group, the beginning of the twelfth group is connected to the end of the eighteenth group , the end of the thirteenth coil group is connected to the beginning of the nineteenth coil group, the beginning of the fourteenth group is connected to the end of the twentieth group, the end of the fifteenth coil group is connected to the beginning of the twenty first coil group, the beginning of the sixteenth group is connected to the end of the twenty second group, the end of the seventeenth coil group is connected to the beginning of the twenty third coil group, the beginning of the eighteenth group is connected to the end of the twenty fourth group, at that the excitation capacitors are connected to the first, second and third outputs and the generator load is connected to the fourth, fifth and sixth outputs.

Front links for connection of turn groups are arranged above the end surface of the tooth area of the core with that part of the slots, where the winding layer is available, rods of which they connect, places of connections of turn front links with rods of that layer of winding, above which there are front links for connection of turn groups, arranged at the side of centres of the core slots. Places of connections of at least most other front links with the rods of the upper layer of the winding are arranged at the side of the tooth surface of the core, and places of connections of these front links with rods of the lower layer of the winding are arranged at the side of the core back.

Stator winding includes three single-phase windings formed with equal number of coils arranged in slots. Coils are connected to each other as per equal schemed providing spatial displacement of axes of windings through 120 degrees. Each of the single-phase windings throughout double pole division of the stator is formed with 2Z/2pm coils that include Z/2pm groups with similar number of coils in groups. Each of the groups of coils has different width of coils included into it and different number of turns forming coils in comparison to other groups of coils. Besides, coils of one of the groups have minimum width with minimum number of turns. Width and number of coil turns of every next group have different width and number of coil turns of the previous group. Coils with larger width and larger number of turns are arranged concentrically relative to coils with minimum width and minimum number of turns. Some parts of the volume of slots, which remain free after laying of coils of this single-phase windings, are used for arrangement of coils of two other single-phase windings that are made in a similar way.

Frequency electric drive contains a three-phase electric motor the windings of which are connected in triangle and are connected to a voltage inverter. Poles of the inverter are connected to poles of the rectifier and filter designed as two series connected capacitors. The electric motor is fitted with leads from the middle of windings to which the terminals of the star connected three-phase capacitor battery are connected the zero point of which is connected to the middle point of series connected filter capacitors.

Proposed electric machine is characterised by forming winding of each stator out of concentric coils laid in one layer on the circle periphery of toroidal magnetic conductor in the A, C, B order. Rotor of split thickness consists of at least two discs separated by air gap and featuring slots for installation of common ferromagnetic inserts. Stators are positioned so that same phase coils of opposing stators are placed at three hundred sixty electrical degrees against each other.

Low noise induction motor comprises two mutually dependent combined windings, one of which is assembled as "star", and the second one - as "delta". These windings are laid into slots so that resulting vectors of induction of magnetic flows of pole pairs in identical phases of "star" and "delta" form an angle of 30 el. degrees between each other.

In three-phase asynchronous electric motor consisting of a stator including a housing, a hollow steel charged core attached from the inside to the housing and carrying the slots on inner cylindrical surface, and three-phase power winding laid in slots of charged core and made in the form of three single-phase windings with similar parameters and spatial shift of axes through 120 degrees, a rotor arranged inside the stator core with an air gap in relation to it, and end shields attached to the stator housing, in which the rotor shaft is installed, according to the invention, the stator includes an additional compensating three-phase winding laid into slots of the core and consisting of three single-phase windings with similar parameters, the axes of which are offset in space through 120 degrees; at that, additional compensating three-phase winding is isolated from three-phase power winding; its single-phase windings are connected to a star diagram, and phase beginnings are connected to capacitors connected to a triangle diagram, which are installed on the motor or beyond the motor.

Invention is aimed to enable electric energy transmission from a stationary source to a rotary receiver such as from a solar cell battery rotating round the space vehicle to such space vehicle as well as a rotary receiver drive. According to the invention, the double frequency electrical machine has two three-phase windings combined within a common stator core, the numbers of the windings pole pairs equal to p₁ and p₂; induced in the poles are EMPs with frequencies equal to f₁ and f₂ accordingly (f₁<f₂); there are terminals for connection of external electrical circuits; placed on the rotor is at least one phase winding having terminals for connection of external electrical circuits. Additionally, the double frequency electrical machine may have a rotor with magnetised poles or unmagnetised projections, their number equal to 2·p₁.

Bar wave winding of stator of asynchronous motor is single-layer, and winding bars are solid; at that, height of bar h_b, which is determined using the equations for damping factor k_d and relative current displacement factor ξ, which are calculated at maximum frequency value f of supply voltage on condition that damping factor k_d is at least by two times more than the value of the required control range of rotation frequency of asynchronous motor.

Low-speed asynchronous electric motor includes stator with multi-phase winding and rotor with interleaved core and short-circuited winding. Stator phases are made in the form of annular windings coaxial with rotor, each of which is located between two annular magnetic cores with teeth protruding in axial direction and which are opposite directed. At that, annular magnetic cores of the phase are offset relative to each other through π/z angle, and between them there arranged is toroidal magnetic core, and annular magnetic core of various phases are offset relative to each other through 2π/z·m angle, where z - the number of teeth of each annular magnetic core, and m - the number of phases.

Proposed invention can be used in hand-held electric arc welding devices. Induction welding generator has two-winding stator. Three-phase excitation winding 2 has terminals for excitation capacitors 3 to be connected thereto. Working winding 4 is a two-phase winding. Circuit of said winding each phase 4, 5, shifted through 90 degrees, incorporates compound capacitor 6, 7 and single-phase bridge rectifier 8, 9 shunted by shunting capacitors 10, 11. Output terminals of rectifiers 8, 9 are connected in parallel and welding electrode 12 is connected thereto.

Proposed short-circuited rotor with squirrel cage comprises shaft (1) and laminated core of sheet steel (2), in laminated core of sheet steel (2) there are rotor winding (3) rods located, which at both ends of laminated core of sheet steel (2) are pulled through openings (10) of each end plate (9) and closed by short-circuited ring (4), which, being electrically conducting, connects ends of rotor winding (3) rods on one side of short-circuited rotor to squirrel cage, besides each end plate (9) comprises circumferential ledge, which at least partially covers short-circuiting ring (4) with geometric closure at its outer side, besides each end plate (9) comprises part of rotor winding (3) rod and part of short-circuiting ring (4). At the same time, according to the present invention, end plates (9) are arranged as massive and are made of stronger material compared to rods of rotor winding (3) and short-circuiting rings (4), besides rods of rotor winding (3) have bulge at their ends with increased cross section of rod (7), moreover, at least part of rotor winding (3) rods bulge lies in openings (10) of end plates (9), besides transition between bulge and short-circuiting ring (4) is arranged in the form of rounding with transitional radius (8).

Present invention pertains to electric machine engineering. The invention seeks to simplify manufacturing and increase use of active materials, while reducing input of insulating materials and coefficient of differential scattering σ_d% m=3-phase 2p₁=6·k- and 2p₂=8·k- pole lap windings of a stator in z=144·k slots. The essence of the invention lies in that, the double-winding stator of an asynchronous motor has m=3-phase 2p₁=6·k- and 2p₂=8·k-pole lap windings in z=144·k slots, each of which is made symmetrical from m=6-zone from equally spaced coils, put into the slots in two layers. According to this invention: from K=z coils with numbers from 1K to (z)K, the 2p₁ pole winding relates to K/2 coils with odd numbers 1K, 3K,…(z-1)K, containing w_K1 turns and connected into 6p₁ coil semi-groups with q'₁=4 neighbouring coils in each. The 2p₂ pole winding relates to K/2 coils with even numbers 2K, 4K,…,(z)K, containing w_k2 turns and connected into 6p₂ coil semi-groups with q'₂=3 neighbouring coils in each. All coils have uneven spacing in the slots, equal to y_k=19, or y_k=21, where k=1, 2 given q'₁=z/12p₁ and q'₂=z/12p₂.

Stator and rotor contacting surfaces of motor-brake built around squirrel-cage induction motor are provided with taper thread; rotor shaft is supported on one end by radial bearing and on other one, by thrust bearing with spacer disk affording cohesion between stator and rotor threaded surfaces during reverse movement of rotor; shaft extension of the latter is splined.