Controllable cascade electric drive
SUBSTANCE: invention relates to cascade electric rotary actuator drives and may be used for production of gearless drives with frequency adjusted from 0 to double nominal at stable nominal rotation speed including reversible and other type drives. The proposed controllable cascade electric drive contains two electric motors mounted coaxially on the housing. Each motor is composed of a rotor rigidly mounted on its shaft and a stator. The stator of one of the electric motors is designed as stationary and is mounted on the housing while the second motor stator is capable of free motion relative of the shaft. According to the invention concept, it additionally contains a fixture ring rigidly mounted on the shaft of the stationary stator motor. Mounted on the fixture ring are two e-magnetic clutches one of them capable of contact with the friction plate that has a projection fitting into the movable stator body concavity which is coaxial to the said projection. The other e-magnetic clutch is capable of contact with its friction plate and of connection, with the help of the said plate, to the movable stator electric motor shaft that has a splined recess for the friction plate to fit in. The working areas of the above two friction plates that come in contact with the above e-magnetic clutches are equal to provide for identical performance of the said e-magnetic clutches. Mounted on the drive housing is a third e-magnetic clutch capable of contact with a third friction plate that has a projection fitting into the movable stator body having a concavity which is coaxial to the said projection of the third friction plate.
EFFECT: extension of the range of the cascade electric drive adjustment due to provision for generation of high rotation speeds close to double the nominal one at constant torque value or possibility to generate a doubled torque value at constant rotation speed.
2 cl, 6 dwg
The invention relates to a cascade of electrical drives rotational motion, consisting mainly of two induction motors, and can be used to create direct-drive actuators with adjustable frequent rotation from 0 to twice rated at fixed time or drives with double the torque at a constant nominal speed of rotation, including reverse, and if you use any other types of electric drives.
Modern electric motors DC and AC squirrel cage or wound rotor have a high speed in modes that are close to the nominal. Low speed can be obtained in two ways. The first way is to use different gearboxes, which complicates the drive reduces its reliability and does not solve the problems of reducing the frequency of rotation. The frequency of rotation of the output gear may not be close to zero, the more change sign and implement the reverse drive. The second method requires the use of expensive frequency controlled drive, which in turn does not solve the problem of obtaining a very low rotational speeds that are close to 0, and get twice the synchronous speed at a constant time or double time at a constant Singh is Onna speed. The frequency converters pollute the mains harmonics of higher orders, resulting in waveform distortion voltage, i.e. reduce the quality of electricity.
Known asynchronous electric motor with squirrel cage rotor and stator phase windings [Kopylov I.P. Electrical machines: textbook. for universities / Ispropyl. - 2nd ed., Rev.): the High. HQ., Logo, 2000. - 607 S.] Such induction motor has a high frequency of rotation defined by the number of pairs of poles and the frequency and voltage of the supply network. However, the engine speed operating modes less synchronous, because the slope of the operating characteristics of the engine (its "stiffness") n=f(M) depends on the parameters of the engine, in particular from the internal resistance of the magnetic circuit of the rotor and the supply voltage.
This engine does not provide low speeds, as in this case, the mode of its operation will be unstable, in addition, in the case of application of the reduction gearbox, this engine provides a wide range of speed regulation, especially with a low limit, zero, and reverse. Also, this engine does not receive the doubled value of the torque on the shaft at a constant nominal speed of rotation or to get twice the values of the torque at a constant nominal speed.
The prototype is cascading electric drive consisting of two coaxially mounted electric motors, each including an inner magnetic core on the shaft and the outer magnetic core. One pair of same magnetic motors are connected rigidly, but one of the eponymous other pair of magnetic circuits installed still. While the other magnetic circuit of the other of the pair is mounted for rotation and an output element of the actuator. (U.S. Pat. No. 2050672, 1995)
And this device has disadvantages. The device produces a drive with high torque only at low speeds, and with a wide range of change of speed with a lower limit of zero. Receive the same high speeds of rotation, close to double the nominal constant value or receive a double point at a constant speed to get through this drive possible.
Object of the invention is the expansion of the range of regulatory cascade electric drive.
The technical result is achieved that ensures the high speeds of rotation, close to double the nominal constant value of time or getting doubled at constant sorostitute. Managed cascading electric drive containing two mounted in the housing coaxially of the motor, each of which consists of a rotor rigidly mounted on the shaft, and the stator, and the stator of one motor is stationary and fixed to the body, the stator of the other movable and is mounted with a possibility of rotation relative to the shaft, the retaining ring on the shaft of the motor with a fixed stator, a ring secured two electromagnetic couplings, one with the possibility of contact with the friction pad with a projection from the housing of the rolling stator having a hollow, coaxially with the ledge, the other with a possibility of contact with friction seal with the shaft of the motor a movable stator having a slotted recess under the friction lining, in addition, the working area of these friction pads in contact with the electromagnetic couplings made equal to provide the same performance electromagnetic coupling, and the third electromagnetic clutch mounted on the drive housing with the possibility of contact with the friction pad with a projection from the housing of the rolling stator having a hollow, coaxially with the guide clutches.
The proposed device are explained in the drawings: figure 1 shows a General view of the device, figure 2 shows characteristics asynchronos the engine, on fit shows characteristics of the actuator at different supply voltage, figure 4 shows the total characteristics of the electric drive at the same speeds, figure 5 shows a summary of the characteristics of the actuator at different speeds, figure 6 shows a diagram of the automatic speed control of the drive.
The device consists of an electromagnetic coupling 1, 2, mounted on the ring 3. The ring 3 is fixed on the shaft 4, for example, by welding and rotates with the shaft 4. The magnetic clutch 5 is fixed to the housing 6 and motionless. The stator 7 is stationary and fixed to the body 6, and the rotor 8 is stationary and rotates with the shaft 4 on bearings 9 regardless of the rotation of the shaft 10. The stator 12 rotates freely on the shaft 10, regardless of the rotation of the shaft in the bearings 13. The rotor 14 is rigidly fixed on the shaft 10 and rotates with the shaft on bearings 11 and 13. The electromagnetic clutch 5 acts on the stator housing 12 by means of a friction strip 15 having a protrusion extending into the stator housing 12. The electromagnetic clutch 1 is connected with the shaft 10 by means of the friction pads 16, and the electromagnetic clutch 2 is connected with the stator housing 12 by means of the friction pads 17. Moreover, the friction strip 17 has a protrusion extending into the body of the stator 12, and reacciona strip 16 is rigidly fixed to the spline shaft 10. Working area of friction pads 16 and 17 should be the same, for the same performance of the electromagnetic coupling 1 and 2. The stator housing 7 is rigidly fixed to the housing 6.
The principle of operation
To get twice the value of the torque at the same rotational speed must be controlled electromagnetic couplings in the following order. Serves the supply voltage to the electromagnetic clutch 1 and 5 and is detachable from the power supply to the electromagnetic clutch 2. When the rotor 8 rotates on the shaft 4 and the stator 12 remains stationary, since the electromagnetic clutch 5 inhibits the stator housing 12. By means of the electromagnetic clutch 1 is engaged and the rotor 14 rotating on the shaft 10. Finally we get double the torque on the shaft 10 between two asynchronous motors at the same speed.
To obtain the doubled value of the rotation speed with the same amount of torque necessary to produce the control electromagnetic couplings in the following order. Serves the supply voltage to the electromagnetic clutch 2 and turning off the electromagnetic clutch 1 and 5. When the rotor 8 rotates on the shaft 4 and transmits torque and speed on the stator 12 by means of an electromagnetic clutch 2. The rotor 14 rotates at asynchronous speed relative to the stator 12. The result on the shaft 10 double value of MSE is spine rotation with the same amount of torque.
Getting a smooth change, as well as low speed and reverse as follows.
Changing the supply voltage U on each of the drive motors, it is possible to change the inclination of the characteristics of each engine n=f(M,U). Consequently, it is possible to control the inclination of the working characteristics n=f(M) of the entire drive. For the same value of the synchronous frequency of the motor rotation this characteristic passes through the point M=0, n=0, figure 4. For different values of the synchronous rotation speed of the engine characteristic passes through the point M=0, n=ncI-ncII, 5.
Figure 2 shows typical characteristics of an induction motor, depending on the relative magnitude of the supply voltage. Figure 3, 4, 5 shows the principle of forming the aggregate characteristics of the actuator. It should be noted that the motor parameters, in particular the resistance of the rotor, effect on the stiffness characteristics, i.e. their angle. Figure 3 presents the characteristics of a cascade of two engines. Here the engine performance II relate to its output element (or to the stator in figure 1, or to the rotor in figure 1), the direction of rotation which is opposite to the one adopted for positive rotation. Respectively, and the torque of the motor II to the output element, also has the opposite napravleniya as when the drive motors I and II develop the same amount of points, their characteristics can be summarized, figure 4. It is seen that by changing the supply voltage, you can change the tilt of the operating characteristics of one of the motors and thereby it is possible to obtain the necessary resultant characteristic, consistent with the load characteristic of the working mechanism at a predetermined speed. It is also possible and simultaneously changing the voltage of both motors in opposite directions.
If the rotational speed of the drive motors of the same, the resulting characteristics of the actuator passing through the point M=0, n=0 from any angle figure 4. If the slope is zero, the drive actually turns into a stop preventing rotation of the driven device under action of an external moment.
If the values of the frequencies of the drive motors are different, the resulting characteristic passes through the point M=0, n=ncI-ncIIand the slope of the combined performance is determined by the inclination of the motor characteristics. The resulting characteristic can be with positive slope, negative (falling characteristic) or with zero slope (rigid characteristic), in the latter case, the actuator rotates with a frequency of n=ncI-ncII.
From the graphs in figure 4, 5 it is seen that the actuator can develop maximum torque at low engine speeds. Important is to notice this point is close to the torque delivered by the motors at the nominal voltage values.
The actuator allows the reversal of rotation without switching phases. This is achieved by a corresponding change in the voltage on the motors I and II.
The speed control actuator can be solved, for example, the proposed scheme of automatic control devices presented on Fig.6. The system consists of a sensor 18 frequency of rotation of the output element of the drive Converter 19 current frequency nmrotation of the normalized signal. Element 20 compares the signals proportional to the given nassand the current nmthe values of rotation speed. The controller 21 generates the control action for a given control law (the proportional, integral, differential, or their combinations)that manages the switching of power phases one and pairs of poles of one of the engines, and also generates the control signals to the electromagnetic clutch 1, 2 and 5. The device 22 converts the control action in the power supply voltage of the motor (for example, using magnetic amplifiers).
The use of the proposed solutions will expand the control range of the drive. The rotation speed can be adjusted is connecting to is from 0 to twice rated in two-stage cascade. When increasing stages of the cascade will be possible to increase the speed and to extend the control range. Moreover, the components of the electric drive will always be working modes that are close to the nominal.
The invention will find application in industry, mechanical engineering, machine building, transport, etc.
1. Managed cascading electric drive with two electric motor mounted in the housing coaxially, each of which consists of a rotor rigidly mounted on the shaft, and the stator, and the stator of one motor is stationary and fixed to the body, and the stator another made movable and is mounted with the possibility of free rotation relative to the shaft, characterized in that it further includes a mounting ring fixed on the motor shaft with a fixed stator, a mounting ring secured two electromagnetic couplings, one of which has the possibility of contact with a friction pad having a protrusion extending into the hollow body the rolling stator, coaxially with the specified protrusion, the other of the electromagnetic clutch has a possibility of contact with the friction pad and the connection with its help with having a splined bore under this friction gasket shaft of the electric motor, the stator of which is movable, and working the horses of these two friction pads, contact with these electromagnetic clutches made equal to provide the same performance data of electromagnetic couplings, gear housing secured third electromagnetic clutch having contact with the third friction pad having a protrusion that comes in the case of the rolling stator having a hollow, coaxially with the specified protrusion of the third friction pads.
2. Managed cascading electric actuator according to claim 1, characterized in that the ring, which is fixed to the electromagnetic clutch fixed on the first shaft.
FIELD: electric engineering.
SUBSTANCE: invention is related to electric engineering, to electromagnet mechanisms, and more specifically, to contactless magnetic reducers, and may be used as transmission device in mechanical systems with high resource of operation under impact loads. Magnetic reducer has rotor of fast rotation with permanent magnets (1), magnetised tangentially, wedge-like pole tips (2) with convex profiled surfaces inverted to working gap, non-magnetic bush (3) for fitting onto shaft of fast rotation (4). Magnetic core (5) with evenly installed teeth inverted to working gap, is fixed to body (6), with which hollow cylinders (7) are mechanically connected by non-magnet ring (10), which have alternating ferromagnetic and non-magnet elements. Rotor of slow rotation represents hollow cylinders (8) mechanically connected to shaft of slow rotation (9) by means of non-magnet disk (11) and has alternating ferromagnetic and non-magnet elements. Due to introduction of hollow cylinders of stator and rotor of slow rotation, magnetic reducer is produced with high transmission torque from alternating ferromagnetic and non-magnetic elements.
EFFECT: improvement of mass and dimensional parameters.
SUBSTANCE: invention relates to electrical engineering and is meant for generating electrical energy using an electromechanically actuated contra-rotating generator. A rotor and the contra-rotating generator are connected by two oppositely rotating disc rotors larger than the radius of a high-speed linear motor. Two oppositely rotating steps in form of double blocks are formed, lying coaxially and with a common axis of rotation. The inductor of the high-speed linear motor is immovably attached to the housing of the device and transmits counterrotation with angular acceleration to secondary elements through steps. As a result of this opposite rotation, two velocities and two moments are combined. The method is safe and cheap. The device is distinguished by high reliability, high power at low weight, low price, easier manufacture and operation.
EFFECT: increased power and efficiency.
2 cl, 1 dwg
SUBSTANCE: invention relates to electrical engineering and may be used as electromechanical converter of mechanical power supplied to the mechanical input of the machine and electrical DC power supplied to the other electrical input of the machine to the total electrical AC power. The two-dimensional axial electric machine-generator contains armature with winding and brush-commutating set of DC machine. The rotor is implemented with squirrel cage winding. The armature and rotor can freely rotate with regard to each other and are axial. In addition, AC generator winding is coiled in the armature grooves with the output being connected to AC mains by means of the three contact rings and three brushes.
EFFECT: summation and conversion of mechanical power, for example wind power, and electrical DC power, for example solar power supplied from photoelectric converter, to electrical power of phase direct current but with more stable output parameters as compared to conventional electromechanical converters.
SUBSTANCE: present invention pertains to electrical engineering and can be used in parametric machines in the electrical energy industry as electric generators and electric motors, for example on electrical power stations. The synchronous generator-compensator is a combined electrical machine, the circuit of which has an electronic frequency converter, with power corresponding to an asynchronous motor. On one axle of the synchronous generator-compensator there are series-arranged rotors of the drive motor, synchronous generator with a thyristor-type self-triggering system, and the asynchronous motor with a short-circuited rotor. The rotor of the asynchronous motor is in form of a flywheel with a large diameter, radius R and mass, which matches up the radius r and mass of the rotor of the synchronous generator, respectively, calculated using the mechanical resonance formula. The ratio R/r is chosen in accordance with the Fibonacci number sequence. The output of the synchronous generator and the input of the stator of the asynchronous motor are connected through a frequency converter, supplying the asynchronous motor with current, with discrete synchronisation of the frequency of current from the synchronous generator and frequency of the angular impulse of the asynchronous motor. The circuit of the frequency converter has massive capacitors, with provision for mechanical positive feedback from the rotor of the asynchronous motor to the rotor of the synchronous generator due to the single axle of the rotor of the asynchronous motor and the synchronous generator. The rotor of the asynchronous motor has ratio of the width to its radius in accordance with the Fibonacci number sequence, in succession to the chosen ration R/r. The diameter of the asynchronous motor is increased, corresponding to the rotor, with provision for clearance between the stator and the rotor of 1-3 mm. The method of operation of the synchronous generator-compensator is implemented, as is described in the material of the claim.
EFFECT: increased fuel saving in the drive motor, due to increase in moment of inertia on the system axle.
3 cl, 3 dwg
SUBSTANCE: invention can be used as electromechanical converter of mechanical energy delivered to one machine input (mechanical) and dc electric energy simultaneously delivered to its other input (electrical) into integrated dc electric energy. In electrical machine containing armature with winding and brush-collector unit of dc machine and rotor with short-circuited winding, over rotor winding of asynchronous motors that are able to rotate around each other, according to this invention a generator winding is additionally laid in armature slots. Output of this winding is connected by means of contact rings and brushes with net of alternating current consumers.
EFFECT: implementation of summing and converting of mechanical and dc electrical energy into electrical energy with simultaneous improvement of electrical energy parameters stability at output.
SUBSTANCE: rotor winding is performed as rotor windings of asynchronous machines with phase rotor in the circuit of which three-phase full-wave regulating thyristor rectifier unit is included. At that, output of this rectifier unit is connected in series with armature circuit using keys of switch unit that is able to perform either serial-additive or serial-subtractive connection with armature circuit depending on sign of armature rotation frequency change direction.
EFFECT: providing control for output rotation speed of two-dimensional electric machine and for frequency of generated by it voltage when input signals are continuously and indeterminantly varying.
FIELD: electrical engineering and power-driven transport; driving vehicles of all kinds.
SUBSTANCE: proposed electrodynamic propulsion unit has inductor, armature, and ac power supply. In addition, it has electronic device with three pairs of electrodes. Inductor is made in the form of wound magnetic circuit with armature-accommodating gap. One of windings is connected to armature; leads of other winding are connected to polarizing electrodes. Its midpoint is connected to cathode and grounded. Its symmetrical taps are connected to orthogonal electric field electrodes and in phase opposition, to polarizing electrodes. Third winding is connected to ac power supply and through voltage changer, to electric arc electrodes, and also through capacitors, to second-winding leads.
EFFECT: reduced cost; reduced adverse effect of electromagnetic field onto environment; enhanced efficiency.
1 cl, 1 dwg
FIELD: electrical engineering.
SUBSTANCE: proposed energy conservation electric drive that can be used for rotary boring, measurement of liquid discharges through large-diameter pipelines, and pump delivery regulation in main pipelines has at least one ac squirrel-cage actuating motor incorporating two independent windings of which one is connected in delta and other one, in star; three-phase generator that functions as three-phase power supply coupled with prime mover, such as diesel engine or electric motor; and automation system incorporating rectifier for varying parameters of dc current from control system, its output being connected to leads of three-phase generator inductor windings, as well as comparison device that generates control signal and is connected through its output to rectifier input and through inputs, to controlled variable setting element and sensor installed on controlled entity, such as on motor shaft. Eliminating operating instability zone and enhancing shaft starting torque, as well as extending range of shaft speed variation have made it possible to improve mechanical characteristics of electric drive.
EFFECT: enhanced efficiency and operating reliability, reduced mass and maintenance charges.
7 cl, 4 dwg, 1 tbl
FIELD: electrical engineering; specific electrical machines for off-line power supplies.
SUBSTANCE: proposed self-excited induction generator designed for operation under abnormal environmental conditions and in hermetically sealed power-generating units has squirrel-cage rotor and core-shaped stator with Z teeth whose slots receive stator winding, as well as field capacitors; novelty is that stator winding is made in the form of Z bars closed on one end by means of end ring. Generator also has additional magnetic core with slots receiving three-phase winding and conducting bars connected on one end with Z bars of stator winding and on other end they are closed by means of other end ring to form Z-phase winding.
EFFECT: enhanced reliability, reduced mass and size of induction generator.
5 cl, 3 dwg
SUBSTANCE: electrical machine comprises stator with winding, inner rotor with output shaft installed in bearings, intermediate rotor covering inner rotor, on inner surface of intermediate rotor there are windings arranged, shaft of intermediate rotor is arranged as hollow, inside there is inner rotor shaft, besides bearings arranged on shafts of inner and intermediate rotors are arranged coaxially to their axis of rotation. On outer surface of intermediate rotor there are groups of permanent magnets arranged with alternating polarity, and generator winding of stator is multi-phased.
EFFECT: increased efficiency of device operation in wide range of inner rotor output shaft rotation speed change due to controlled redistribution of coaxial rotors rotation speeds, production of permanent output power with control of its rotation speed, and expansion of functional capabilities.
SUBSTANCE: asynchronous motor with hollow short-circuit rotor includes hollow rotor and external stator with core and winding, as well as additional rotor installed on the shaft in the zone restricted with stator with possibility of rotation irrespective of hollow rotor, made from ring-shaped magnet radially magnetised with the number of pairs of poles, which is equal to the number of pairs of poles of stator winding, on which there pressed is thin-wall sleeve from conducting material, and hollow rotor is made in the form of thin-wall shell from conducting material.
EFFECT: increasing power coefficient and efficiency of asynchronous motor with hollow rotor without deterioration of its dynamic characteristics.
3 cl, 2 dwg
SUBSTANCE: in electrical machine containing the device for creation of magnetic field and device for conversion of one kind of energy to the other, according to the invention, in device for creation of magnetic field (stator) the slots formed with magnetic conductor, which are through in axial direction, are also through in radial direction, and above external part of open slots which are through in radial direction there installed is external rotor enveloping the external part of stator (magnetic field creation device). Thus, electrical machine has inner rotor with which the main magnetic flow interacts, and outer rotor with which leakage flux interacts.
EFFECT: use of leakage flux in electric motors for creation of torque moment Mt, and in current generators for obtaining electric power, and as a result, increasing operating efficiency of electrical machines.