JPH0223095A - Variable speed induction motor - Google Patents

Abstract

PURPOSE:To eliminate a trouble in the rotation of a stator even with a large heat generation by the operation of a long period or with a high torque by movably engaging a roll between the outer periphery of the stator and the inner periphery of a frame with a spring material. CONSTITUTION:A spring material 53 having a holding function is interposed between a roll 50 and the outer periphery of a rotating stator 12A. The roll 50 is brought into close contact with the inner periphery of a frame 10 by the material 53, and the roll 50 is interposed stably on the outer periphery of the stator 12A by the holding function of a retainer 52 and the material 53. Further, the part of the material 53 has a gap to become the outer periphery of the stator 12A, and the roll 50 is movably engaged with the outer periphery of the stator 12A while being held by the material 53. Thus, it prevents an engaging part from grating or fixing upon thermal expansion of the stator 12A due to the heat generated from the resistance material of a rotor conductor.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a variable speed induction motor, and more particularly, to a variable speed induction motor having a single rotor and a plurality of stators. By rotating the rotor, a voltage is induced in a rotor conductor portion facing one of the plurality of stators and a voltage is induced in a corresponding conductor portion of the rotor facing the other stator. The present invention relates to a so-called variable speed induction motor having a multi-stator configuration, which can create a phase difference between voltages and arbitrarily change the rotational speed and generated torque of a rotor.

(Prior art) Methods for controlling the speed of an induction motor include changing the power supply frequency, changing the number of poles of the winding on the stator, and controlling the -order voltage. -43
The technology described in Publication No. 57 divides the stator into two sets, a fixed stator and a movable stator, each with the same winding and connected to the same power supply, and also divides the rotor into two sets to prevent rotation. The child conductors are connected at the center by a separate conductor with a wide width, and at both ends by a short-circuit ring, and the movable stator is rotated to generate a secondary induced voltage induced by the other fixed stator. On the other hand, a variable speed induction motor generates different phase currents in the same conductor, so that the current of the sum of two vectors passes through the rotor conductor as a secondary current, and the speed of the motor can be arbitrarily varied. Since the movable stator is attached to a slide bearing and is configured to move, the sliding friction between the movable stator and the slide bearing is large, and the movable stator is rotated to control the speed of the rotor. This requires a large amount of force, and if the movable stator were to be automatically controlled by a small motor, it would result in a considerable load. For this reason, the use of a large rotation motor is unavoidable, which not only wastes a large amount of power and radiates heat, but is also practically impractical. This tendency became more pronounced as the variable speed induction motor became larger.

[Problem to be solved by the invention]

In the rotor having a resistive material that short-circuits the rotor conductors according to the present invention, any one of the plurality of stators is rotated to form a voltage phase shifting device, and the voltage generated by the voltage phase shifting device is Due to the phase difference, current flows through the resistor material connected to the rotor conductor, which increases the rotor conductor resistance and can generate a large torque, but on the other hand, the heat generation of the resistor material also has a large effect. This causes the rotatable stator to expand, making it impossible to rotate, for example in a sliding bearing system. The present invention aims to provide a technique to solve such problems.

[Means to solve the problem]

In order to achieve the above object, the present invention includes a plurality of rotor conductors installed in a continuous manner on a plurality of rotor cores that are pivotally attached to the same rotating wheel at regular intervals, and a plurality of rotor conductors are connected to each other. an integral rotor that is short-circuited and connected between the plurality of rotor cores by a resistive material; and a stator core that faces each rotor core of the rotor, and is arranged coaxially with the rotor. A plurality of stators are provided in the machine frame, and one of the plurality of stators is provided around the outer periphery of at least one of the plurality of stators such that a rolling element sandwiched between a spring material and a holding plate is loosely attached to the outer periphery of at least one stator. The second method is to install a roller clamped between a spring material and a press plate on the inner periphery of the machine frame facing at least one stator among the plurality of stators. The at least one stator is formed so as to be rotatable concentrically with the rotor by disposing a movable body around the rotor so as to freely attach the movable body to the outer periphery of the stator and press it against the outer circumference of the stator. This was used as a means of solving the problem.

The variable speed induction motor of the present invention can be formed into either a single-phase or three-phase type, and the rotor can be of a normal squirrel cage type, a double squirrel cage type, a deep groove cage type, a special squirrel cage type with 9 windings, etc. It can be applied to any type of conductor, and the conductor used in the explanation of the present invention refers to a conductor installed in a squirrel cage rotor core,
and each of the windings wound around the wire-wound rotor core.

[For production]

The operation of the variable speed induction motor configured as described above is as follows. That is, the rolling elements are loosely attached between the outer circumferential surface of the stator and the inner circumferential surface of the machine frame by means of a spring material, and are formed to be rotatable concentrically with the rotor to form a rotating stator. It has become possible to rotate the rotary stator with a small force, and it has become possible to downsize the rotation drive device and the like.

In addition, although this variable speed induction motor can generate large torque due to the action of the resistive material, it also generates a large amount of heat. If the stator is fitted and mounted on the machine frame, the rotatable stator expands and a large force is applied to the ball bearing or 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 machine frame may be damaged.
The contact points of the ball bearing or roller bearing with the stator or the machine frame side were worn out due to the effect of vibration during operation of the electric motor, but the present invention has also solved the above-mentioned problems.

〔Example〕

Examples will be described below with reference to FIGS. 1 and 2.

First, the configuration of a variable speed induction motor 1 to which the present invention is applied will be schematically explained. 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 in the rotor core 2A, 28 pieces. A plurality of rotor conductors 4 are installed in a cage shape on the rotor cores 2A and 2B in communication between their outer ends, and both ends are connected to each other by short-circuit rings 5 and 6. Short circuited. The rotor conductor 4... is a non-magnetic core portion 2C and is made of a resistive material r.
are interconnected (resistive short circuit). The rotor 2 integrally constructed in this way has both ends bearing the bearings 7A.
, 7B, it becomes rotatable within the motor frame 10. Further, ventilation holes 25A and 25B are provided at appropriate locations in the rotor cores 2 and 3.

Stators 12A and 12B are arranged in parallel on the inner wall surface of the machine frame 10, facing each outer peripheral surface of the rotor cores 2A and 2B. Furthermore, as is clear from the drawings, the cylindrical machine frame 10 and the bearing plates 40A, 40B on both sides of the machine frame are connected to bolts 19A, 19B.
It can be assembled integrally by tightening. Further, ventilation holes 41A and 41B@ are opened in the bearing plates 40A and 40B.

In the case of this embodiment, the stator 12B is a fixed stator fixed to the inner wall surface of the machine frame. The stator 12A is constituted by a rolling element 50 interposed between the outer circumferential surface of the stator and the inner circumferential surface of the machine frame, a small motor 15, and gears 16 and 17, so that the stator 12A is concentric with the rotating shaft 3. Since it is configured to be rotatable, the stator 12A is a rotating stator.

Here, the surroundings of the rolling element 50 will be explained in detail. A spring material 53 having a holding function is interposed between the rolling element and the outer peripheral surface of the stator, and this spring material 53 allows the rolling element 50 to be held within the machine frame. The rolling elements 50 are held in close contact with the outer circumferential surface of the stator, and are stably held on the outer circumferential surface of the stator by the holding function of the presser plate 52 and the spring material 53.

Furthermore, a portion of the spring material 53 has a certain gap with the outer circumferential surface of the stator, so that the rolling elements are held by the spring material 53 and loosely attached to the outer circumferential surface of the stator.

Various shapes can be considered for the shape of the spring material as long as it has the function of allowing the rolling elements to loosely attach to the outer circumferential surface of the stator.

Further, reference numeral 51 denotes a holding body 51 that holds the rolling elements from the left and right sides.

In order to prevent dust from entering the sliding parts of the rolling elements, sealing materials 60 are provided on the outer periphery of both ends of the stator.

Furthermore, the symbol @61 is a stopper that prevents the stator from shifting from side to side.

In this embodiment, the rolling elements are loosely attached to the outer circumferential surface of the stator, but on the other hand, as shown in FIGS. 4 and 5, the rolling elements are loosely attached to the inner circumferential surface of the machine frame. However, the same effect can be obtained even if the spring material is brought into close contact with the outer circumferential surface of the stator. Furthermore, in the same manner as described above, the spring material 53 may have various shapes as long as it has the function of loosely attaching to the inner circumferential surface of the machine frame.

Furthermore, although there are two rows of surrounding rolling elements 50 in the drawings of this embodiment, it is easy to imagine that the number of rows may be increased or decreased as needed. Note that the rotating stator 12A and the fixed stator 12
B has ventilation holes 30A and 30B, respectively. An air exhaust port 2o is opened at the upper center of the machine frame 10.
A blower cylinder 21 with an open top is fixed to surround the air blower cylinder 21 , a fan motor 22 is supported on the blower cylinder 21 , and a fan 23 is rotatably attached to the rotating shaft of the motor 22 .

The gear 17 is fitted onto the outer circumferential surface of the stator core, and the gear 16
A rotation mechanism 18 is formed by a small motor 15 and a small motor 15 . This allows rotation relative to the fixed stator 12B. By operating this rotation mechanism, specifically by rotating the small motor 15 by an arbitrary amount, a phase difference is generated between the rotor conductor portions corresponding to each stator of the rotor. That is, in the illustrated embodiment, this rotating mechanism constitutes the voltage phase shifting device M18. In addition, each stator 12A, 12
The stator windings 13A and 13B wound around B may be connected to the power source either in series or in parallel. In addition, although a voltage phase shifting device using a rotating mechanism is shown, a combination of purely electrical means such as a phase shifter that switches the connection of the stator winding and a rotating mechanism may also be used. . The rolling element may be either roller-shaped or ball-shaped, and its material may be steel (JIS 5LJJ 1~
5LIJ3). In the above configuration, the rotatable rotary stator 12A, which is formed concentrically with the rotor QI13, is adjusted and set by the small motor 15 of the voltage phase shifter 18. The rotation of the rotary stator 12A causes a phase shift in the rotating magnetic field generated between the rotor and stator, and the voltage induced in the rotor conductor is controlled to increase or decrease, thereby increasing the rotation speed of the rotor. Can be changed arbitrarily. When the rotary stator 12A is further rotated, the rotor conductor 4 installed in communication between the rotors 2A and 2B is connected to the resistive material R. A current flows through r due to the phase difference, and the resistance of the rotor conductor 4 increases, making it possible to generate a large torque.

In the variable speed induction motor described above, the fitting surface pressure from the inner surface of the machine frame due to the fitting between the inner surface of the machine frame and the outer peripheral surface of the rotary stator with a bearing interposed between the inner surface of the machine frame and the outer peripheral surface of the rotary stator as in the conventional example is absorbed by the spring material. The rotary stator can be rotated using a small motor. In addition, when a large torque is generated in a variable speed motor, the rotary stator is thermally expanded due to the heat generated by the resistive material of the rotor conductor. Immobility can be accommodated by supporting the stator as detailed above.

〔Effect of the invention〕

Since the present invention is constructed as described above, the stator can be rotated with a small force, and even if the stator is operated for a long time or at high torque and generates a large amount of heat, the stator does not rotate at all. This made it possible to smoothly operate a variable speed induction motor with excellent torque characteristics and efficiency without any problems.

[Brief explanation of the drawing]

Figure 1 is a side sectional view of a variable speed induction motor according to the present invention, Figure 2 is a front sectional view, Figure 3 is a detailed view of section A in Figure 2, and Figure 4 is a detailed view of section A in Figure 2.
The figure is a front sectional view of the second embodiment, and FIG. 5 is a detailed view of section B in FIG. 4.

Claims (2)

[Claims] (1) A plurality of rotor conductors are installed in a continuous manner on a plurality of rotor cores that are mounted on the same rotating shaft at regular intervals, and the rotor conductors are connected to the plurality of rotor cores. An integral rotor whose child cores are short-circuited by a resistive material, and a plurality of stators arranged in parallel coaxially with the rotor, each having a stator core facing each of the rotor cores of the rotor. and provided within the machine frame, at least one of the plurality of stators
A rolling element sandwiched between a spring material and a presser plate is loosely installed around the outer periphery of each stator, and is brought into pressure contact with the inner surface of the machine frame, and the at least one stator is arranged concentrically with the rotor. A variable speed induction motor characterized by having a rotatable stator formed to be freely rotatable. (2) A plurality of rotor conductors are installed in a continuous manner on a plurality of rotor cores that are mounted on the same rotating shaft at regular intervals, and the rotor conductors are connected to the plurality of stator cores. An integral rotor short-circuited by a resistive material between them, and a plurality of stators arranged in parallel coaxially with the rotor, each having a stator core facing each rotor core of the rotor. and a rolling element sandwiched between a spring material and a presser plate is loosely installed around the inner periphery of the machine frame facing at least one stator among the plurality of stators, and A variable speed induction motor, characterized in that the at least one stator is press-contacted to the outer periphery of the stator, and the at least one stator is rotatably formed concentrically with the stator to form a rotating stator.