JP2002017069A - Single phase induction motor and pump driven therewith - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a single phase induction motor capable of rotating in a prescribed direction alone by a mechanical control mechanism of simple structure, and an inexpensive pump using the motor for driving. SOLUTION: This motor is provided with a mechanical control mechanism 8 permitting rotation of a rotating shaft 6 in one prescribed direction and exerting repulsion on the rotary shaft in the reverse prescribed direction by blocking the rotation in the other direction, so that the rotation is blocked by the mechanical control mechanism and the rotation in the prescribed direction starts by receiving the repulsion even if a motor 7 starts operating in the reverse direction with power ON. Thus, this single phase induction motor rotates in the prescribed direction alone, thereby providing a pump capable of rotating in one direction alone.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a single-phase induction motor that rotates only in a predetermined direction and a pump using the motor for driving, particularly a tube pump.

[0002]

2. Description of the Related Art As is well known, a single-phase induction motor has a feature that its structure is relatively simple and its product price is low. However, since the rotation direction at the time of startup is not constant due to its principle, it rotates in a predetermined direction. Electrical measures such as providing a shading coil or using a starting capacitor as described above, and mechanical measures such as using a deceleration gear that rotates only in a certain direction are required. For this reason, there are problems that the cost of the final product including the motor and the entire system are increased while using a low-priced single-phase induction motor, and that the control circuit and the mechanical mechanism are complicated.

[0003]

SUMMARY OF THE INVENTION In view of the above problems, the present invention is directed to a single-phase induction motor in which the motor is rotated only in a predetermined direction by a mechanical control mechanism having a simple structure, and a drive of the motor. An object of the present invention is to provide a low-priced pump used for the purpose.

[0004]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a single-phase induction motor according to the present invention permits rotation of a rotating shaft in one predetermined direction and prevents rotation in another direction. Further, a mechanical control mechanism for applying a repulsive force in the predetermined direction to the rotation shaft is provided. This mechanical control mechanism
For example, a projecting piece is provided on one of a rotating side member such as a rotating plate attached to a rotating shaft and a fixed side member such as a fixed plate attached to a stator, and the other corresponding to this projecting piece. Is provided by providing a concave portion.

[0005] With such a configuration, when the electric motor is started in a predetermined rotation direction upon turning on the power, the motor can continue to rotate as it is, and when started in the opposite direction, the rotation is blocked by a mechanical control mechanism. At the same time, the revolving force in the predetermined direction instantaneously rotates the rotation axis in the predetermined direction, which triggers the rotation in the predetermined direction. Therefore, the rotation direction of the motor can be restricted to a desired direction only by adding a simple mechanism, and the added value of the single-phase induction motor can be increased.

In the pump according to the present invention, a single-phase induction motor is used for driving. The rotation shaft of the motor is allowed to rotate in one predetermined direction, and is prevented from rotating in the other direction. A mechanical control mechanism for applying a repulsive force in the direction of the rotation axis to the rotating shaft. Therefore, as in the case of the motor alone, when the motor is started in a predetermined direction, the rotation can be continued, and when the motor is started in the opposite direction, the rotation is prevented by the mechanical control mechanism. Then, the direction of rotation is reversed by the repulsive force in the predetermined direction, and the rotation in this direction starts and continues to rotate.

[0007] Such an invention can be applied to, for example, a tube pump. A tube pump has a structure in which a tube is arranged between a pressurizing member that moves eccentrically and an outer member having a circular inner periphery, and the tube is sequentially pressed by the pressurizing member in a longitudinal direction to deliver a fluid in the tube. The mechanical control mechanism can be provided between, for example, an eccentric drive body that rotates together with the rotating shaft and a ring-shaped pressing member that is driven by the eccentric drive body and moves eccentrically. This eliminates the need for a DC motor and a DC power supply for driving the motor, which are generally used in the related art, and makes it easy to reduce the price of the entire pump.

In the case of a tube pump, the mechanical control mechanism includes a projecting piece having a spring property formed on the outer periphery of the eccentric driving body in a direction opposite to a predetermined rotation direction, and a projecting piece formed on the inner periphery of the pressing member. And a locking recess formed in such a shape that the front end of the front end abuts. In this case, an oil-impregnated material impregnated with lubricating oil can be arranged on the inner peripheral side of the protruding piece, and the lubricating oil is supplied to the periphery by deforming the protruding piece and pressing the oil-impregnated material. The above-mentioned projecting piece can be replaced with a spring piece attached to the eccentric drive body while projecting in the same direction.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of the present invention will be described with an example of a tube pump using a single-phase induction motor as a driving motor. FIG. 1 is a schematic front view of the whole pump, but the general structure of the tube pump itself is well known, so that it will be briefly described.

In FIG. 1, reference numeral 1 denotes an outer member having a cylindrical chamber 2 formed therein. The inner peripheral surface 2a of the cylindrical chamber 2 is circular and formed in a range larger than a semicircle and smaller than the entire circumference. 2
The portion where a is not formed is the opening 2b.
Reference numeral 3 denotes a tube, which is arranged in a ring shape along the inner peripheral surface 2a of the cylindrical chamber 2 and has both ends drawn out of the outer member 1 to form an inlet 3a and an outlet 3b. The outer member 1 is made of a rubber material such as NBR or ABS.
And the like. As the tube 3, a tube made of rubber or various synthetic resins is appropriately selected and used according to the fluid to be transferred. In general, an elastic material is used, but a material having no elasticity may be used.

Reference numeral 4 denotes a ring-shaped pressurizing member disposed inside the tube 3 and has a double structure of an inner ring 41 and an outer ring 42. The inner ring 41 is a rigid material having a small friction coefficient. For example, the outer ring 42 is made of a fluororesin synthetic resin molded product, and the outer ring 42 is made of an elastic material having a large friction coefficient such as rubber.

Reference numeral 5 denotes an eccentric drive unit disposed inside the pressing member 4, and reference numeral 6 denotes a rotary shaft to which the eccentric drive unit 5 is attached. The eccentric drive body 5 rotates while pressing the circular outer peripheral surface 5a in contact with the inner peripheral surface 4a of the pressing member 4, thereby causing the pressing member 4 to make a circular motion along the inner peripheral surface 2a. The tube 3 between the outer peripheral surface 4b and the inner peripheral surface 2a of the cylindrical chamber 2 is sequentially pressed toward the outlet 3b. Reference numeral 7 denotes a single-phase induction motor arranged on the back side of the outer member 1, and its rotating shaft becomes the rotating shaft 6 as it is or is connected to the rotating shaft 6 via an appropriate speed reducer.

A projection 8a is formed on the outer peripheral surface 5a of the eccentric driving body 5, and a locking recess 8b is formed on the inner peripheral surface 4a of the inner ring 41 of the pressing member 4 corresponding to the projection 8a. A mechanical control mechanism 8 according to the present invention is configured. In the case of FIG. 1, the predetermined rotation direction of the rotating shaft 6 is clockwise as indicated by an arrow, and the protruding piece 8a is protruded in a counterclockwise direction, and an external force is applied as shown in FIG. In the absence state, the tip 8c is formed in such a shape that it slightly protrudes from the circular outer peripheral surface 5a. Further, as described above, since the eccentric drive body 5 is a synthetic resin molded product, the protruding piece 8a has a certain degree of resilience. Correspondingly, the locking recess 8b formed in the pressing member 4 has a protruding piece 8 as shown in FIG.
It is formed in a shape having a stepped surface 8d against which the tip 8c of a abuts.

Reference numeral 5b denotes a connecting hole into which the rotating shaft 6 is inserted, and 5c denotes a key groove which engages with a key (not shown) provided on the rotating shaft 6, whereby the eccentric driving body 5 is integrated with the rotating shaft 6. Rotate. The inner ring 41 has a detent pin 4
1a is protruded and loosely inserted into a large engaging hole (not shown) provided in the outer member 1 to stop the rotation of the pressing member 4 from rotating. Reference numeral 11 denotes a tube pump configured as described above.

The mechanical control mechanism 8 is configured as described above. When the single-phase induction motor 7 is driven and the rotating shaft 6 starts rotating clockwise, for example, in a predetermined direction, the outer peripheral surface of the eccentric driving body 5 is rotated. 5 a rotates while sliding on the inner peripheral surface 4 a of the pressing member 4. In this case, since the protruding piece 8a passes through the locking recess 8b without any trouble, the eccentric driving body 5 rotates as it is, and the pressing member 4 performs a circular motion to perform the pumping operation.

On the other hand, when the rotating shaft 6 starts rotating counterclockwise, when the eccentric drive body 5 rotates and the protruding piece 8a reaches the position of the locking recess 8b, the step surface of the locking recess 8b is formed. The tip 8c of the protruding piece 8a abuts on 8d. However, the pressing member 4
Is in a state in which a part of the tube 3 is pressurized, and a certain amount of force is required to rotate the tube 3. Therefore, the tip 8c does not rotate immediately even when the tip 8c hits, but is eccentrically driven at the moment when the tip 8c hits. The rotation of the body 5 is stopped, and a repulsive force in the clockwise direction is given to the protruding piece 8a by the impact. For this reason, the eccentric drive 5
Is momentarily slightly rotated clockwise, and this rotation is also transmitted from the rotation shaft 6 to the rotor of the electric motor 7, and the rotation direction of the rotor causes the rotation shaft 6 to rotate clockwise. Then, the eccentric drive 5 is rotated clockwise in the same manner as described above.

During the rotation of the eccentric drive 5, a small clicking sound is generated each time the projection 8a comes to the position of the locking recess 8b. In addition, since the eccentric driving body 5 rotates while sliding in contact with the pressing member 4, the sliding surface must always be kept in a lubricated state. FIG. 4 is an example considering such points.
An oil-impregnated material 9 is arranged on the inner peripheral side of the protruding piece 8a. Oil impregnated material 9
, Which functions as an oil reservoir, for example, felt or sponge impregnated with lubricating oil is used. Each time the projecting piece 8a of the eccentric driving body 5 comes to the position of the locking recess 8b, it comes out of the outer peripheral surface 5a slightly, and again the pressing member 4
The operation of being pressed by the inner peripheral surface 4a is repeated, so that each time the oil-containing material 9 is pressed, lubricating oil is supplied to the periphery. Therefore, the above-mentioned click noise is reduced, and the lubricating action is automatically performed on the sliding surface, so that a tube pump having a low operating noise and a long life can be obtained.

FIG. 5 shows an example in which a spring piece 8e is attached in place of the protruding piece 8a integrally formed with the eccentric drive body 5, and the spring piece 8e is made of, for example, a 0.3 mm thick vinyl chloride plate. . FIG. 5 (a) shows a case where only the spring piece 8e is provided,
(b) shows an oil-impregnated material 9 arranged on the inner peripheral side of a spring piece 8e, and the operation itself is the same as that of the case where the above-mentioned projection 8a is provided.

The mechanical control mechanism 8 according to the present invention has a function similar to a one-way clutch, but not only permits rotation in a predetermined direction, but also reverses the direction for rotation in the opposite direction. This is different from a normal clutch in that the clutch has a function of causing the clutch to operate. The illustrated embodiment is an example of a tube pump driven by a single-phase induction motor. A mechanical control mechanism is provided between an eccentric drive unit 5 and a pressurizing member 4 which are essential members of the tube pump. 8, there is no need to use another member for the mechanical control mechanism 8. Therefore, the structure is not complicated, and a low-priced single-phase induction motor can be used. Therefore, there is no need for a DC power supply as in the case of using a DC motor, and an inexpensive tube pump can be obtained.

The present invention is not limited to the above-described tube pump, but can be applied to various pumps having a fixed rotation direction. The mechanical control mechanism may be provided not on the pump side but on the electric motor side. it can. Further, the single-phase induction motor of the present invention is provided with a mechanical control mechanism in the motor alone, and can be used as a prime mover for various devices as well as a pump.

[0021]

As is apparent from the above description, the single-phase induction motor of the present invention allows the rotation shaft to rotate in one predetermined direction, prevents the rotation in the other direction, and prevents the rotation shaft from rotating in the other direction. A mechanical control mechanism for applying a repulsive force in the direction of the arrow to the rotating shaft is provided. Therefore, for example, a mechanical control mechanism having a simple structure in which a protruding piece is provided on one of the rotating side member and the fixed side member, and a concave portion is provided on the other member corresponding to this protruding piece is merely added. Thus, the rotation direction can be restricted to a desired direction, and a single-phase induction motor suitable for various types of prime movers can be provided at low cost.

Further, the pump of the present invention uses a single-phase induction motor for driving and is provided with the above-mentioned mechanical control mechanism, and provides various pumps having a constant rotation direction at low cost. Becomes possible.

In the tube pump to which the present invention is applied, the above-mentioned mechanical control mechanism includes, for example, an eccentric drive body that rotates together with a rotary shaft, and a ring-shaped pressurizing apparatus that is driven by the eccentric drive body to perform eccentric movement. It is provided between members, the structure is simple and no additional parts for the mechanical control mechanism are required, and there is no need to use a DC power supply for driving as in the case of a DC motor, It is easy to reduce the price of the entire pump.

Further, in the tube pump, the mechanical control mechanism as described above includes a projecting piece or a spring piece formed on the outer periphery of the eccentric drive body in a direction opposite to a predetermined rotation direction and having a spring property, and a pressure member. With a locking recess formed in such a shape that the tip of the protruding piece abuts on the inner circumference, the structure is extremely simple and the operation is reliable, and lubricating oil is provided on the inner circumference side of the protruding piece and spring piece. By arranging the oil-impregnated material impregnated with, it is possible to constantly supply lubricating oil to the periphery thereof, and it is possible to obtain a tube pump having a low operating noise and a long life.

[Brief description of the drawings]

FIG. 1 is a schematic front view of a tube pump according to an embodiment of the present invention.

FIG. 2 is a front view and a cross-sectional view of the eccentric drive body according to the first embodiment.

FIG. 3 is a front view and a side view of an inner ring of the pressing member according to the first embodiment.

FIG. 4 is a front view of a modified example of the eccentric driving body.

FIG. 5 is a front view of another modified example of the eccentric driving body.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Outer member 3 Tube 4 Pressure member 41 Inner ring 5 Eccentric drive body 6 Rotating shaft 7 Single-phase induction motor 8 Mechanical control mechanism 8a Projection piece 8b Locking concave part 8e Spring piece 9 Oil-impregnated material 11 Tube pump

Claims (9)

[Claims] 1. A mechanical control mechanism which permits rotation of a rotating shaft in a predetermined direction, prevents rotation in the other direction, and applies a repulsive force in the predetermined direction to the rotating shaft. A single-phase induction motor characterized in that: 2. The mechanical control mechanism according to claim 1, further comprising: a protrusion provided on one of the member on the rotating shaft side and the member on the fixed side; and a recess provided on the other corresponding to the protrusion. 2. The single-phase induction motor according to claim 1, wherein the projection engages with the concave portion to prevent rotation when rotating in the other direction, and generates a repulsive force in a predetermined direction. 3. A single-phase induction motor is used for driving. The single-phase induction motor permits rotation of the rotating shaft of the motor in one predetermined direction, prevents rotation in the other direction, and moves in the predetermined direction. A mechanical control mechanism for applying a repulsive force to the rotating shaft. 4. The pump according to claim 1, wherein a tube is arranged between the eccentrically moving pressing member and an outer member having a circular inner periphery, and the pressing member sequentially presses the tube in the longitudinal direction so that the inside of the tube is compressed. 4. The pump according to claim 3, wherein the pump is a tube pump configured to deliver a fluid. 5. The mechanical control mechanism is provided between an eccentric drive body that rotates together with a rotating shaft and a ring-shaped pressing member that is driven by the eccentric drive body and moves eccentrically. The described pump. 6. The mechanical control mechanism according to claim 1, wherein the eccentric drive body has a spring-like projection formed on the outer periphery of the eccentric drive body in a direction opposite to a predetermined rotation direction, and a tip end of the projection on the inner periphery of the pressing member. 6. The pump according to claim 5, comprising a locking recess formed in an abutting shape. 7. The pump according to claim 6, wherein an oil-impregnated material impregnated with lubricating oil is disposed on the inner peripheral side of the projecting piece. 8. The mechanical control mechanism includes a spring piece mounted on the outer circumference of the eccentric drive body so as to protrude in a direction opposite to a predetermined rotation direction, and a tip of the spring piece on an inner circumference of the pressing member. 6. The pump according to claim 5, comprising a locking recess formed in an abutting shape. 9. The pump according to claim 8, wherein an oil-impregnated material impregnated with lubricating oil is disposed on the inner peripheral side of the spring piece.