JP2627790B2 - Variable speed induction motor - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a variable speed induction motor, and more particularly, to a single rotor, two stators, and a motor having two stators. A voltage phase shift that causes a phase difference between a voltage induced in a rotor conductor portion facing one of the stators and a voltage induced in a corresponding conductor portion of the rotor facing the other stator. The present invention relates to a variable speed induction motor having a so-called two-stator configuration, which can change a rotation speed and a generated torque of a rotor arbitrarily by adjusting a voltage phase shifter.

[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
As described in the 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 supply. Are connected to each other by a widened wing-shaped conductor at the center and connected at both ends by short-circuit rings, and to the secondary induction voltage induced by rotating the movable stator and secondarily induced by the other fixed stator. A variable-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 stator is mounted on the slide bearing so that it can move, the sliding friction between the movable stator and the slide bearing is large, and when the movable stator is rotated to control the speed of the rotor. Requires a large force to move the movable stator The equivalent of a large load if an attempt automatic control by over. 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 remarkable as the size of the variable speed induction motor increased.

[Problems to be solved by the invention]

In the rotor having a resistance material for short-circuiting the rotor conductor according to the present invention, the phase difference generated by the voltage phase shifter causes a current to flow through the resistance material so that the rotor conductor resistance increases and a large torque is generated. On the other hand, however, heat generated by the resistance material is large and the stator formed rotatably expands due to the influence of the heat. For example, the stator cannot be rotated in a sliding bearing system. The present invention seeks to provide a technique for solving such a problem.

[Means for solving the problem]

In order to achieve the above object, the present invention has two rotor cores that are axially attached to the same rotating shaft at a fixed interval,
A plurality of rotor conductors communicating with the rotor core are provided, and a plurality of rotor conductors are short-circuited to each other between the two rotor cores by a resistance material. And two stators each having a winding wound around two stator cores arranged concentrically with the rotor core, and at least one of the two stators is provided. In a variable speed induction motor in which a stator is formed so as to be rotatable concentrically with the rotor and is a rotatable stator that is rotated by a rotating mechanism, the rotatable stator has at least one fixed member. Attach the support on the side different from the side between the rotor cores of the child,
The support is fitted with a ball bearing or a roller bearing and is axially mounted on the rotating shaft to form the at least one stator rotatably concentrically with the rotor and to rotate the support. A solution is provided by providing a flexible material between the child cores and the inner periphery of the machine frame to absorb thermal expansion.

Alternatively, the rotating stator has a support mounted on a side of at least one stator on a side different from that between the rotor cores, and the support is fitted with a ball bearing or a roller bearing and the rotating shaft is , And the at least one stator is rotatably formed concentrically with the rotor, and the inner peripheral surface of the machine frame slides on a side of the support that is different from between the rotor cores. A moving sliding surface protrudes. Further, a sliding member that slides on the inner peripheral surface of the machine frame is provided between the rotor cores of the support.

(Operation)

The operation of the variable speed induction motor configured as described above is as follows. That is, a support is mounted on a side of the stator different from the side between the rotor cores, and the support is fitted with a ball bearing or a roller bearing, and is axially mounted on the rotating shaft, The rotation stator is rotatably mounted concentrically with the rotor by being axially mounted on the rotation shaft in a rolling bearing manner, so that the rotation stator can be rotated with a small force. This makes it possible to reduce the size of the driving device for rotation.

Further, the variable speed induction motor of the present invention can generate a large torque by the action of the resistance material, but generates a large amount of heat. For example, a ball bearing or a roller is provided on the outer peripheral portion of the stator to rotate the stator. In the case where the bearing is fitted and mounted on the machine frame, the rotatably formed stator expands, and a large force is applied to the ball bearing or the roller bearing, and a large force is also applied to the machine frame. If the expansion is large, the ball bearing or roller bearing may be damaged or the frame side may be damaged, or the point of contact of the ball bearing or roller bearing with the stator or the frame side may be worn due to the action of vibration during motor operation. However, in the present invention, the above-mentioned problems have been solved.

That is, in the present electric motor, heat is increased when a large torque is generated by increasing the phase difference. By sliding the surface, a more stable rotating stator can be provided in combination with the bearing fitted to the rotating shaft.

In addition, a flexible material is fixed to the outer peripheral surface of the support or the inner peripheral surface of the machine frame, and the expansion of the rotating stator caused by the heat generated by the resistance material is absorbed by the flexible material to support the support. Things.

〔Example〕

Hereinafter, a first embodiment will be described with reference to FIG.

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 a rotor shaft 3 of the rotor 2 with a fixed interval therebetween. A non-magnetic core portion 2C is provided between the rotor cores 2A and 2B. A plurality of rotor conductors 4 are provided in a cage shape in a communication manner over the rotor cores 2A, 2B, and both ends thereof are short-circuited by short-circuit rings 5, 6. Non-magnetic core between rotor conductors 4
2C (between rotor cores) is interconnected (resistance short circuit) by the resistance material R. 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 7B.

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, the cylindrical machine frame 10 and the bearing plates 40A, 40B on both sides of the machine frame are provided with bolts 19A, 1B.
It is assembled integrally by tightening 9B. 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 has a support 50 of a size having a certain gap with the machine frame inner peripheral surface mounted on its side,
A bearing 51 fitted to a support 50, a small motor 15 and a gear 1
6,17. The support 50 of the stator 12A is the bearing 5
According to 1, the stator 12 </ b> A is formed to be rotatable concentrically with the rotating shaft 3, so that the stator 12 </ b> A is a rotating stator. The rotating stator 12A and the fixed stator 12B have ventilation holes 30A, 30B, and 30C, respectively. A blower 21 having an open top is fixedly surrounding the open air outlet 20 at the upper center of the machine frame 10, a fan motor 22 is supported by the blower 21, and a rotating shaft of the motor 22 is further rotated. The fan 23 is mounted on the shaft. A gear 17 is fitted on the outer peripheral surface of the stator core, and a 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 occurs in the voltage induced in the rotor conductor portions corresponding to the two stators of the rotor. That is, in the illustrated embodiment, this rotating mechanism constitutes the voltage phase shift device 18.
The stator windings 13A, 13B wound around the respective stators 12A, 12B
May be connected in series or in 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 bearing 51 is a commonly used ball bearing or roller bearing, and does not require a special bearing. Further, in this embodiment, a cantilever support method using a bearing is employed. However, due to the reaction of the rotating force received by the stator and the increase in the weight of the rotating stator due to the enlargement of the motor, the rotating stator is used. The flexible material 61 or the sliding material 62 on the flexible material
Is fixed on the outer peripheral surface of the support or on the inner peripheral surface of the machine frame, and the expansion of the rotating stator 12A due to the heat generation of the resistance material R is absorbed by the flexible material 61 to support the support. May support 50.

Next, a second embodiment will be described with reference to FIG. The description of the entire configuration overlapping with the first embodiment will be omitted.

A support 50 having a certain gap with the inner peripheral surface of the machine frame mounted on the side of the stator 12A is formed by a bearing 51 so as to be rotatable concentrically with the rotating shaft 3 and further fixedly rotated. A sliding surface 52 that slides on the inner peripheral surface of the machine frame or the machine frame bearing plate 40A side of the support 50 is provided on the support body 50 on a side different from the side facing between the rotor cores of the rotor. . This embodiment is an example in which a sliding surface is provided on the machine frame bearing plate 40A side. The bearing 51 is supported on the rotating shaft 3 by a support.
50 is fixed to the bearing 51 with stoppers 53 and 54, respectively. The sliding surface may be provided with a sliding material such as a metal coating or a dense material such as a resin. Further, as in the first embodiment, the flexible material 61 may be provided on the outer periphery of the support 50 in some cases.

In the above configuration, the rotating stator 12A supported by the rotatable support 50 formed concentrically with the rotor shaft 3 by the bearing 51 is adjusted and set by the small motor 15 of the voltage phase shifter 18. Is done. The rotation of the rotating stator 12A
The rotational speed of the rotor can be arbitrarily changed by causing a phase shift in the rotating magnetic field generated between the stators and controlling the voltage induced in the rotor conductor to increase or decrease. When the rotating stator 12A is further rotated, the rotor conductor 4 provided in a communicating manner between the rotors 2A and 2B has an integral structure short-circuited by the resistance material R. A current flows due to the phase difference, the resistance of the rotor conductor 4 increases, and a large torque can be generated.

The above-mentioned variable speed induction motor has a bearing 50 fitted on the support 50 and the support formed concentrically with the rotating shaft 3 so that the inner surface of the machine frame and the outer peripheral surface of the rotating stator are different from those of the prior art. The fitting surface pressure from the inner surface of the starting frame due to the fitting with the bearing interposed therebetween disappears, and the rotating stator can be rotated by the small motor. Also, when a large torque is generated in the variable speed motor, heat generation of the resistance material of the rotor conductor causes thermal expansion of the rotating stator.
Due to the thermal expansion of the rotating rotor, the squeezing or non-movability of the fitting portion is achieved by providing a gap between the supporting body of the rotating stator and the inner surface of the machine frame facing the rotating stator. Supporting the support makes it negligible. Further, by sliding the support with the inner peripheral surface of the machine frame on the bearing plate side where the thermal expansion is small, the rotation of the rotary stator by the support can be more smoothly and stabilized.

〔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. This has made it possible to smoothly operate a variable speed induction motor with no trouble and excellent torque characteristics and efficiency.

[Brief description of the drawings]

FIG. 1 is a side sectional view of a variable speed induction motor according to a first embodiment of the present invention, FIG. 2 is a side sectional view of a variable speed induction motor according to a second embodiment of the present invention, and FIG. Example of the flexible material provided. In the figure, 2 ... rotor, 2A, 2B ... rotor core, 2C
… Non-magnetic core part, 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, 16,17 ... Gear, 18 ... Voltage phase shifter, 19A, 19B ... Bolt, 20 …… Outlet, 21…
... Blower, 22 ... Fan motor, 23 ... Fan, 30A,
30B, 30C, 40A, 40B ... Bearing plate, 41A, 41B ... Vent, 50 ...
... Support, 51 ... Bearing, 52 ... Sliding surface, 53 ... Stopper, 54 ... Stopper, 61 ... Flexible material, 62 ... Sliding material.

 ──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-52-45009 (JP, A) JP-A-58-130704 (JP, A) JP-A-62-44045 (JP, A) JP-A 50-450 155914 (JP, A) JP-A-51-134814 (JP, A) JP-A-51-12601 (JP, A) JP-A-55-125061 (JP, U) JP-B-47-45761 (JP, B1) Jikken 39-38133 (JP, Y1)

Claims (3)

(57) [Claims] A rotor having a plurality of rotor cores fixedly mounted on the same rotating shaft at regular intervals, a plurality of rotor conductors communicating with the two rotor cores being provided, and An integral cage rotor in which the plurality of rotor conductors are short-circuited to each other by a resistance material between two rotor cores; and a two-pole cage concentrically provided with the two rotor cores. And two stators each having a winding wound on each of the stator cores, and at least one of the two stators is rotatably formed concentrically with the rotor. And a voltage induced on a conductor portion of the rotor facing one of the stators by the rotation of the stator, and a rotation facing the other stator. Providing a voltage phase shifter for generating a phase difference between the voltage induced in the conductor portion of the child,
In the variable speed induction motor in which the phase difference is controlled by the voltage phase shift device to change the torque characteristic and control the rotation speed over a wide range, the rotating stator is a stator core, and the voltage phase shift device A support is mounted on a different side between the rotor cores that are not affected by the heat generated by the resistance material when a large phase difference is provided, and a ball bearing or a roller bearing is fitted on the different side of the support. A variable speed induction motor characterized in that a flexible material that is attached to a rotating shaft and that absorbs thermal expansion is provided between the support and the inner periphery of the machine frame between rotor cores. 2. A method according to claim 1, further comprising: two rotor cores fixedly mounted on the same rotating shaft at fixed intervals, a plurality of rotor conductors communicating with said two rotor cores being provided, and An integral cage rotor in which the plurality of rotor conductors are short-circuited to each other by a resistance material between two rotor cores; and a two-pole cage concentrically provided with the two rotor cores. And two stators each having a winding wound on each of the stator cores, and at least one of the two stators is rotatably formed concentrically with the rotor. And a voltage induced on a conductor portion of the rotor facing one of the stators by the rotation of the stator, and a rotation facing the other stator. Providing a voltage phase shifter for generating a phase difference between the voltage induced in the conductor portion of the child,
In the variable speed induction motor in which the phase difference is controlled by the voltage phase shift device to change the torque characteristic and control the rotation speed over a wide range, the rotating stator is a stator core, and the voltage phase shift device A support is mounted on a different side between the rotor cores that are not affected by the heat generated by the resistance material when a large phase difference is provided, and a ball bearing or a roller bearing is fitted on the different side of the support. A variable-speed induction motor, wherein a sliding surface that slides on an inner peripheral surface of a machine frame is provided on a side of the support that is different from the space between the rotor cores, the projection being provided on the rotating shaft. 3. The variable speed induction according to claim 2, wherein a flexible material that slides on the inner peripheral surface of the machine frame and absorbs thermal expansion is provided on the support body between the rotor cores. Electric motor.