JP2904790B2 - Variable speed induction motor - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a variable speed induction motor, and more specifically, has a single rotor and a plurality of stators,
A voltage induced in a rotor conductor portion facing one of the plurality of stators by rotating an arbitrary stator and a corresponding conductor portion of the rotor facing the other stator. Causes a phase difference between the induced voltage and
The present invention relates to a variable speed induction motor having a so-called multiple stator configuration that can arbitrarily change the rotation speed and generated torque of a rotor.

[Conventional technology]

Methods for controlling the speed of the induction motor include a method of changing the power supply frequency, a method of switching the number of poles of a winding applied to a stator, and a method of controlling a primary voltage. In addition, Japanese Patent Publication No. 27-4357
In the technique described in the above publication, the stator is divided into two sets of a fixed stator and a movable stator, each of which has the same winding and is connected to the same power source. The conductors are connected by a wing-shaped conductor whose central portion is widened, and both ends are connected by a short-circuit ring, and the movable stator is rotated to a secondary induced voltage which is secondarily induced by the other fixed stator. On the other hand, it is a movable speed induction motor that generates a different-phase current in the same conductor so that the current of the two vectors passes through the rotor conductor as a secondary current and arbitrarily changes the speed of the motor. Since the movable stator is formed to be movable by being mounted on the slide bearing, the sliding friction force between the movable stator and the slide bearing is large, and the movable stator is rotated for controlling the speed of the rotor. Requires a large force when moving the The equivalent of a large load if an attempt automatic control by ter. For this reason, the use of a large-sized rotating motor becomes unavoidable, not only dissipating wasteful large power but also practically not being practical. This tendency became more remarkable as the size of the variable speed induction motor became larger.

[Problems to be solved by the invention]

In the rotor having the resistance material for short-circuiting the rotor conductor according to the present invention, any one of the plurality of stators is rotated to form a voltage phase shifter, which is generated by the voltage phase shifter. Due to the phase difference, a current flows through the resistance material connected to the rotor conductor, and the resistance of the rotor conductor is increased, so that a large torque can be generated. The stator formed rotatably by this expands, for example, by simply providing a sliding body on the inner peripheral surface of the machine frame and the outer peripheral surface of the stator, or sliding between the inner peripheral surface of the machine frame and the outer peripheral surface of the stator. In the case of a sliding bearing system with a ball bearing or roller bearing interposed, rotation was impossible. The present invention seeks to provide a technique for solving such a problem.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a method in which a plurality of rotor conductors are connected to each other on a plurality of rotor cores which are axially attached to the same rotating shaft at a fixed interval. A rotor integrally mounted and short-circuited by a resistance material between the plurality of rotor cores, and a stator core facing each rotor core of the rotor. A rotor and a plurality of stators arranged coaxially side by side in a machine frame; At least one of the plurality of stators is provided on its outer peripheral side with a sliding surface that is centered about a rotor axis, and is provided on an inner periphery of a machine frame that faces the at least one stator. A surface is provided with an outwardly facing sliding surface that slides on the facing sliding surface, and the at least one stator is rotatably formed concentrically with the stator.

. At least one of the plurality of stators has an outer peripheral side provided with a bearing surface that is centered around a rotor shaft, and is provided on an inner peripheral surface of a machine frame facing the at least one stator. An external bearing surface facing the central bearing surface, and a ball-shaped rolling element interposed between the central bearing surface and the external bearing surface, and the at least one stator is connected to the rotor. It is formed concentrically and freely rotatable.

As a result, a rotating stator is used to solve the problem.

Note that the variable speed induction motor of the present invention can be formed in any of a single phase or a three phase, and the rotor is formed in a normal cage shape,
It can be applied to any type such as double cage, deep groove cage and special cage.

(Operation)

The operation of the variable speed induction motor configured as described above is as follows. That is, the rotating stator is provided between the facing sliding surface or bearing surface provided on the outer peripheral side of the stator and the facing sliding surface or bearing surface provided on the inner periphery of the machine frame. Because of the sliding of the bearing and the rotation with the ball-shaped rolling elements interposed on the bearing surface, heat generated when a large torque is generated by the action of the resistive material as in the variable speed induction motor, and an abnormal temperature rise Even if the bearing expands, the facing surface of the bearing of the rotating stator expands outward, and the facing surface of the bearing inscribed in the machine frame expands inward, and the gap between the facing surface and the facing surface expands. The effect on the surface bearing by the bearing is neglected, and a sliding body is provided on the outer circumference of the stator and the inner circumference of the machine frame for the rotation of the stator as in the conventional example, or the ball bearing is mounted on the outer circumference of the stator. Or, in the case where the roller bearing is fitted and mounted on the machine frame, the rotatable member is formed. If the expansion expands, a large force is applied to the ball bearings or roller bearings, and a large force is applied to the machine frame.If the expansion is large, the sliding surface will stick, the ball bearings or roller bearings will be damaged, or the machine frame will be damaged. The present invention has solved the problem of the occurrence of damage to the sliding surface and the abrasion of the sliding surface and the contact point between the ball bearing or the roller bearing and the stator or the machine frame side in combination with the action of vibration during operation of the motor.

Embodiment An embodiment will be described below with reference to FIGS. 1 and 2.

First, the configuration of the variable speed induction motor 1 to which the present invention is applied will be schematically described. Rotor cores 2A and 2B are mounted on the rotor shaft 3 of the rotor 2 at regular intervals. A non-magnetic core portion 2C is provided between the rotor cores 2A and 2B. On the rotor cores 2A and 2B, a plurality of rotor conductors 4 are provided in a cage shape so as to communicate with each other between outer end portions thereof, and both end portions are mutually short-circuited by short-circuit rings 5 and 6. You. The rotor conductors 4 are interconnected (resistance short-circuit) by the resistance material r in the nonmagnetic core portion 2C. The rotor 2 integrally formed in this manner is rotatable in the motor frame 10 because both ends thereof are supported by bearings 7A and 4B. In addition, ventilation holes 25A and 25B are opened at appropriate positions of the rotor cores 2 and 3.

The stators 12A and 12B are arranged side by side on the inner wall surface of the machine frame 10 so as to face the respective outer peripheral surfaces of the rotor cores 2A and 2B. Further, as is apparent from the drawings, a cylindrical machine frame 10 and bearing plates on both sides of the machine frame
40A and 40B are assembled integrally by tightening bolts 19A and 19B. Further, ventilation holes 41A, 41B are formed in the bearing plates 40A, 40B.

In the case of the present embodiment, the stator 12B is a fixed stator fixed to the inner wall surface of the machine frame. The stator 12A includes bearings 50, 51 fixed or fitted on the outer peripheral surface of the stator and the inner peripheral surface of the machine frame, respectively.
, Ball bearing 54, small motor 15 and gears 16,1
7, the rotor 12A is configured to be rotatable concentrically with the rotor shaft 3, so that the stator 12A is a rotating stator with respect to the stator 12B. (The bearing will be described later.) The rotary stator 12A and the fixed stator 12B have ventilation holes 30A and 30B, respectively. A blower cylinder 21 having an open top is fixedly surrounding the open air outlet 20 at the upper center of the machine frame 10, and a fan motor 22 is attached to the blower cylinder 21.
, And a fan 23 is axially mounted on the rotation shaft of the motor 22.

The gear 17 is fitted on the outer peripheral surface of the rotating stator 12A, and the rotating mechanism 18 is formed by the gear 16 and the small motor 15. Thereby, it can rotate relatively to the fixed stator 12B. By operating this rotating mechanism, specifically, by rotating the small motor 15 by an arbitrary amount, a phase difference is generated between the rotor conductor portions corresponding to the respective stators of the rotor. That is, in the illustrated embodiment, this rotating mechanism constitutes the voltage phase shift device 18.

Reference numeral 60 denotes a solenoid for controlling the movement of the projecting piece in and out. The solenoid 60 is mounted on the machine frame 14 and the projecting piece is rotated by the rotating stator 12A.
The rotation stator 12A is fixed so that it does not rotate except when necessary, by being freely attached to the gear 17 fitted to the gear 17.

The stator windings 13A, 13A wound around the stators 12A, 12B, respectively.
The connection to the power supply of 3B may be either serial or parallel. In addition, although the voltage phase shifter is shown by a rotating mechanism, it may be a combination of pure electric means such as interposing a phase shifter of a connection switching type of a stator winding and a rotating mechanism. .

The first of the bearings 50 and 51 will be described with reference to FIGS.
An example will be described.

Opposing bearing surface 57 fixed to the outer periphery of the rotating stator 12A
The bearing 50 having the bearing 50 and the bearing 51 having the outward bearing surface 58 provided on the inner peripheral surface of the machine frame facing the rotating stator 12A are provided with the bearing surface 57 facing the center of the bearing 50 and the bearing 51 facing outward. With the ball bearing interposed between the bearing and the bearing surface 58, the rotating stator 12A is rotatable concentrically with the rotor 2. At this time, the bearing 50 and the bearing
Reference numeral 51 denotes a contact between only the bearing surface 57 facing the center and the bearing surface 58 facing outward with the ball bearing interposed therebetween, and the other portions have a certain gap therebetween.

Next, a second embodiment of the bearings 50 and 51 will be described with reference to FIGS. A bearing 50 having an opposed sliding surface 61 fixed to the outer periphery of the rotating stator 12A, and the sliding surface 6 provided on an inner peripheral surface of the machine frame facing the rotating stator 12A.
By sliding with the bearing 51 having the outwardly facing sliding surface 62 that slides in 1, the rotating stator 12A becomes rotatable concentrically with the rotor 2. At this time, the bearing 50 and the bearing 51 are only in contact with the sliding surface 60 facing the center and the sliding surface 61 facing the outside, and the other portions have a certain gap therebetween.

The gear 17 may be fitted on the outer periphery of the bearing 50, or the gear 17 may be formed on the bearing 50 itself. The bearing 51 is screwed into the bearing 51A and the machine casing 10, and the bearing 51A is
And fixed with a plurality of stoppers 53 and set screws 56. On the other hand, the bearing 51B is formed integrally with the machine frame 10 (third
However, in addition to the present embodiment, a method similar to that of the bearing 51A (FIG. 4) or a method of press-fitting the bearing 51B into the machine frame (FIG. 5)
Figure) is taken.

The stopper 53 is fixed to the inner periphery of the machine frame by bolts 52A from the outer periphery of the machine frame, and the bolt 52B is screwed into the stopper 53,
The bearing 51A is fixed.

Coating or the like may be applied to the outer bearing surface 58 and the outer sliding surface 62 of the bearing 51 and the outer bearing surface 57 and the opposite sliding surface 61 of the bearing 50 for the purpose of improving durability. Conceivable.

The bearing having the above-described structure involves heat expansion due to heat generation from the resistance material and the stator and abnormal temperature rise at the time of generation of high torque and at the time of start-up and long-time operation of the variable speed induction motor according to the present invention. The bearings 50 and 51 also expand. Here, in the case of the present invention, the rotation fixing in which a ball-shaped rolling element is interposed between the facing bearing surface 57 provided on the outer peripheral side of the stator and the outward bearing surface 58 provided on the inner peripheral surface of the machine frame. Or a rotating stator formed by sliding a facing sliding surface 61 provided on the outer peripheral portion of the stator and a facing sliding surface 62 provided on the inner peripheral surface of the machine frame. As shown in FIGS. 6 and 8, the expansion of 50 and 51 is caused by the bearing surface 57 or the sliding surface 61 facing the center of the rotating stator and the bearing surface 58 inwardly facing the machine frame or the sliding surface facing outward. The gap with the surface 62 is widened, and the non-movability of the bearing due to the conventional fitting pressure with the machine frame can be ignored.

In the above configuration, the rotatable rotary stator 12A formed concentrically with the rotor shaft 3 is adjusted and set by the small motor 15 of the voltage phase shifter 18. The rotation of the rotating stator 12A causes a phase shift in a rotating magnetic field generated between the rotor and the stator, thereby increasing or decreasing the voltage induced in the rotor conductor, thereby increasing the rotational speed of the rotor. Can be changed arbitrarily. When the rotating stator 12A is further rotated, the rotors 2A and 2B
Since the rotor conductor 4 provided in communication between them has an integral structure short-circuited by a resistor r, a current due to a phase difference flows through the resistor r, and the resistance of the rotor conductor 4 increases. As a result, a large torque can be generated.

The above-described variable speed induction motor generates a large fitting surface pressure from the machine frame inner surface due to the fitting between the machine frame inner surface and the rotating stator outer peripheral surface as in the conventional example, and a large torque to the variable speed induction motor. When the resistance material of the rotor conductor generates heat or when the temperature of the rotor rises abnormally, the rotating stator is thermally expanded. Can be ignored by supporting the stator as detailed above.

〔The invention's effect〕

Since the present invention is configured as described above, the rotation of the stator can be performed with a small force, and even if the stator is rotated for a long time or at a high torque and generates a large amount of heat, the rotation of the stator is completely impossible. There is no hindrance, and the phase difference can be set to be large or 180 ° at start-up, and can be used as small or 0 ° after start-up, and the phase difference can be increased continuously or stepwise from start to rotation. As a result, the motor is started with a large starting torque and smoothly shifts to a steady rotation, so that the variable speed induction motor having excellent torque characteristics and efficiency can be smoothly operated.

[Brief description of the drawings]

1 is a side sectional view of a variable speed induction motor according to the present invention, FIG. 2 is a front sectional view, FIG. 3 is a detailed view of a first embodiment of a portion A in FIG. 2, and FIG. FIG. 5 is another embodiment of part A, FIG. 6 is a detailed view of part B in FIG. 3, FIG. 7 is a second embodiment of part A in FIG. FIG. 8 is a detailed view of a portion B in FIG. In the figure, 1 ... variable speed induction motor, 2 ... rotor,
2A, 2B: rotor core, 2C: non-magnetic core, 3 ...
Rotor shaft, 4 ... Rotor conductor, 5,6 ... Short-circuit ring, 7A, 7B ...
… Bearing, 10… Machine frame, 12A… Rotating stator, 12B …… Fixed stator, 13A, 13B …… Stator winding, 15 …… Small motor, 1
6, 17 ... gear, 18 ... voltage phase shifter, 19A, 19B ... bolt, 20 ... exhaust outlet, 21 ... blower, 22 ... fan motor, 23 ... fan, 25A, 25B, 30A , 30B, 30C, 40A, 40B ……
Vent holes, 50, 51A, 51B …… Bearing, 52A, 52B …… Bolt, 53
… Stopper, 54… Ball bearing, 55… Seal, 56… Set screw, 57… Centered bearing surface, 58… Outside bearing surface, 60… Solenoid, 61… Centered slide Moving surface, 62: sliding surface facing outward, r: resistance material.

Claims (2)

(57) [Claims] 1. A plurality of rotor conductors are provided in communication with each other on a plurality of rotor cores fixedly mounted on the same rotation shaft at fixed intervals, and the plurality of rotor conductors are connected to the plurality of rotor cores. An integrated rotor short-circuited by a resistance material between cores, and a plurality of stators having a stator core facing each rotor core of the rotor and being coaxially arranged with the rotor. A sliding surface that is provided in a machine frame, and is provided on an outer peripheral side of at least one of the plurality of stators so as to be centered on a rotor axis, and is provided on the at least one stator. An outwardly facing sliding surface that slides on the opposed centered sliding surface is provided on the inner peripheral surface of the facing machine frame, and the at least one of the at least two sliding surfaces is provided by sliding between the opposed centered sliding surface and the outwardly facing sliding surface. A variable stator wherein one stator is rotatably formed concentrically with the rotor to form a rotating stator. Induction motor. 2. A plurality of rotor conductors are provided in communication with each other on a plurality of rotor cores fixedly mounted on the same rotation shaft at fixed intervals, and the plurality of rotor conductors are connected to the plurality of rotor cores. An integral rotor short-circuited and connected by a resistance material between cores, and a plurality of stators having stator cores facing the respective rotor cores of the rotor and being coaxially arranged with the rotor. Is provided in a machine frame, and a bearing surface is provided on an outer peripheral side of at least one of the plurality of stators so as to be centered about a rotor shaft, and faces the at least one stator. A bearing surface having an outwardly facing surface having a radius relatively smaller than a radius formed by the opposed bearing surface and facing the opposed bearing surface, is provided on an inner peripheral surface of the machine frame; The at least one stator is moved forward with a ball-shaped rolling element interposed on the bearing surface facing outward. Variable speed induction motor, characterized in that the rotating stator with Katachi設 freely rotor concentrically with the rotation.