SINGLE-PHASE PERMANENT MAGNET ROTOR ELECTRIC WATER PUMP ONLY ROTATING IN RIGHT DIRECTION AND ITS REALIZATION METHOD

Abstract

Disclosed are a single-phase permanent magnet rotor electric pump only rotating in a right direction and its realization method. The method comprises the following steps: controlling the size of a water chamber within a water pump body such that a space volume of the water chamber is 3 times or more than that of a space enclosed by each blade of an inner arc water impeller during rotation, and the diameter of the water chamber is 1.2 times or more than that of the water impeller at its common axis; designing the water pump body such that a portion of an inner wall of a water outlet pipe away from the central axis of the water chamber is parallelly deflected outward in a distance Δ from a tangent of the water chamber inner wall, thereby establishing a step structure; selecting a single-phase permanent magnet rotor or a proper torque to drive the arc water impeller within the water pump body, and limiting the fluctuation range of power supply voltage, thus ensuring that electric water pump rotates only in a right rotation direction and against the bending direction of the individual water blade. This method enables the water pump to rotate in the right direction under single-phase AC power supply condition where the fluctuation is up to 20% of the rated voltage.

Description

TECHNICAL FIELD

The present invention relates to a rotary non-variable capacity type pumping device and drag mechanism, in particular, relates to a method of enabling the forward and opposite rotating drag torque discrepancy of the arc-shaped water impeller for the said pumping device to increase, particularly involving the method and apparatus to enable the water pump dragged by the single-phase permanent magnet rotor motor to only have the right direction of rotation.

BACKGROUND ART

For the present technology, centrifugal water pumps are dragged by single-phase AC permanent magnet synchronous rotor motor, the said permanent magnet rotor and water impeller of the said centrifugal water pump are directly connected coaxially (see FIG. 3). It is simple in structure, light and small, and easy to produce, thus, cost is relatively lower, and it is widely and extensively used. Nevertheless, starting torque of the said single-phase permanent magnet synchronous rotor motor is almost zero, and any flow turbulence will affect and change the starting and running direction of the motor rotor, in other words, starting and running direction of the motor rotor are indeterminate and random. This is why in the earlier stages of the present technology, water impellers of straight-type blades of extremely low efficiency are adopted by such single-phase permanent magnet rotor electric water pumps and central part water discharge is adopted, namely, central axis of the drainage holes fall at radial direction of the water impeller and presents orthogonal relation with the central axis of the water impeller as is shown in FIG. 6. To improve effluent efficiency of water pumps, someone tries to use semiconductor integrated circuit and/or embedded software to control drag motor of the said water pump, enabling it to rotate towards the specified direction without being disturbed, for instance, technologies disclosed by European patent application EP 0 574 823 A2 and Chinese patent application 200710031484.6, therefore, highly effective arc-shaped water impeller whose water blades can be bent towards the same direction and tangential effluent form can be used as is shown in FIG. 5, thereby, electric water pumps can be energy-efficient. However, there are problems of obvious increase of cost, relative complicated structure and declining of reliability for all of the patented technologies disclosed above.

Under the circumstance of using high efficient water pump structure with arc-shaped water impeller whose water blades can be bent towards the same direction and tangential effluent form, the first and foremost thing shall be trying to enable the forward and opposite rotating drag torque discrepancy of the said arc-shaped water impeller to increase, thus, at starting state, when rotor assembly of the said electric water pump shakes a little, they will naturally rotate towards the direction where the drag torque is smaller, and rotate faster and faster till reaching the synchronous speed. Another issue to be considered shall be the fluctuation range of the power supply voltage. It is shown by analysis that if supply voltage of the drag motor deviates from the rated value, its drag torque will have greater deviation. Therefore, drag torque of the motor under maximum supply voltage smaller than opposite drag torque of the water impeller, while drag torque of the motor under minimum supply voltage greater than forward drag torque of the water impeller are naturally becoming essential conditions assuring the reliable operation of the said electric water pumps.

CONTENT OF THE INVENTION

The invention is intended to solve the technical issues by means of avoiding the deficiencies of the above existing technology, and put forward a method and apparatus of enabling the centrifugal water pump dragged by the single-phase permanent magnet rotor motor to just have the right direction of rotation under the condition of no increase of cost, thus greatly promoting the energy efficiency of such water pumps, and applicable to regions whose supply network voltage fluctuation range is greater. The following technical proposal can be adopted for the purpose of addressing the said technical issues: put forward a method of enabling single-phase permanent magnet rotor motor to just have the right direction of rotation, including Step:

A. Control the dimension of the water chamber in the water pump, be sure to enable the space volume of the water chamber to be over 3 times of the tolerance space of all rotating water blades of the arc-shaped water impeller therein, meanwhile, diameter of the said water chamber shall be more than 1.2 times of the diameter of the water impeller therein, so as to increase the drag torque of the said arc-shaped water impeller rotating towards wrong direction;

B. During the designing of the water pump body, tangential water discharge shall be adopted, enabling the part where the inner wall of the outlet pipe (set at the radial side of the said water chamber and connected with the water chamber) is far away from the central axis of the said water chamber to deviate parallelly outside from the tangent line of the inner wall of the said water chamber for certain distance A, result in an abrupt structure, further increasing the drag torque of the said arc-shaped water impeller rotating towards wrong direction;

C. Choose single-phase permanent magnet rotor motor with appropriate torque to drag water impeller in the said water pump, limit the fluctuation range of the supply voltage, be sure to enable the drag torque M_max of the said motor under maximum supply voltage to be lower than the drag torque N_opp for the said water impeller rotating towards wrong direction, namely, rotating inversely, while, drag torque M_max under minimum supply voltage greater than forward rotating drag torque N_for of the said water impeller rotating towards right direction, the structural shape of the said water chamber and dimension of the said permanent magnet rotor have assured N_opp>>N_for, therefore:

• • M_max<N_opp, M_min>N_for,

Thereby, the said electric water pump rotating in right direction against the bending direction of the said water blades is assured; space volume of the water chamber stated in Step A refers to all space volume of the water chamber closed by the water chamber cover.

As to the said abrupt structure in the said Step B, geometrical relationship thereof satisfies

0.50≧Δ/d≧0.20, where d is the inner diameter of the said outlet pipe;

In the other preferred embodiment, geometrical relationship of the abrupt structure stated in the said Step B satisfies

0.30≧Δ/d≧0.20, where d is also the inner diameter of the said outlet pipe.

For another embodiment of the invention, the said method of enabling the single-phase permanent magnet rotor electric water pump to only have right direction of rotation also includes Step:

D. Increase at least one moveable baffle, which can rotate on inner wall of the water chamber along an axial axis; meanwhile, a base plate whose diameter is a little larger than that of the arc-shaped water impeller is set at the back of the said arc-shaped water impeller, when the water impeller rotates in opposite direction, water flow thrusts aside the movable baffle, enabling it to cock and withstand the verge of the said base plate, hindering the opposite rotation of the water impeller.

The invention has also put forward a high-efficient electric water pump only having right rotating direction, comprising pump body and a water chamber which is roughly cylindrical space therein, the water chamber cover assembled at the axial outer end of the water chamber has limited the space of the water chamber, arc-shaped water impeller on the rotor assembly is accommodated in the space of the said water chamber coaxially, dragged by the permanent magnet rotor of the single-phase synchronous motor (coaxially installed with the water impeller) to rotate; at the radial side of the said water chamber, outlet pipe connected with the water chamber is set; in particular, space volume of the said water chamber is more than 3 times of the tolerance space of rotating water blades of arc-shaped water impeller therein, meanwhile, diameter D of the said water chamber is more than 1.2 times of the diameter of the coaxial water impeller therein, space volume of the water chamber described here refers to all space volume of the water chamber closed by the water chamber cover;

The part where the inner wall of the said outlet pipe is far away from the central axis OO′ of the said water chamber deviates parallelly outside from the tangent line of the inner wall of the said water chamber for certain distance A, result in an abrupt structure.

For the said abrupt structure, the geometrical relationship wherein satisfies,

• • 0.50≧Δ/d≧0.20, where d is the inner diameter of the said outlet pipe.

In the other preferred embodiment, geometrical relationship of the abrupt structure stated in the said Step B satisfies,

• • 0.30≧Δ/d≧0.20, where d is the inner diameter of the said outlet pipe.

In the other preferred embodiment, high-efficient electric water pump for the invention with only right rotating direction also comprises at least one moveable baffle, which is set on the inner wall of the said water chamber and rotates around the axial axis on the inner wall of the water chamber, while a base plate whose diameter is a little greater than diameter Dy of the water impeller is set at the back of the said arc-shaped water impeller, if the water impeller rotates oppositely, water flow will thrust aside the moveable baffle, enabling it to cock and withstand the verge of the water impeller base plate, hindering the opposite rotation of the water impeller.

Compared to the present technology, beneficial effects of the electric water pump for the invention lie in: high-efficient water pump only rotating in right direction under single-phase AC power supply condition with the nominal voltage whose fluctuation range is up to 20%.

DESCRIPTION OF FIGURES

FIG. 1 is the orthogonal projection diagram for the overall appearance of the preferred embodiment of the single-phase permanent magnet rotor electric water pump of the invention, of which, FIG. 1-1 is the front view, A-A sectional view of FIG. 1-2; and FIG. 1-2 is the top view;

FIG. 2 is the axonometric projection diagram for the overall appearance of the said preferred embodiment, of which, FIG. 2-1 is the decomposition state diagram; and FIG. 2-2 is the post-assembly axonometric projection diagram;

FIG. 3 is the axonometric projection diagram for rotor assembly 4 of the said electric centrifugal pump, including FIG. 3-1 the decomposition state diagram; and FIG. 3-2 is the post-assembly axonometric projection diagram;

FIG. 4 is the orthogonal projection diagram for the overall appearance of the other preferred embodiment of the single-phase permanent magnet rotor electric water pump of the invention, in which, FIG. 4-1 is the sectional view (front view) of the arc-shaped water impeller during forward rotation, at this moment, moveable baffle 33 sinks to the bottom and lies horizontally, FIG. 4-2 is the sectional view (front view) of the arc-shaped water impeller during opposite direction rotation, at this moment the moveable baffle 33 is erected, both of the two Figures are the A-A sectional view of FIG. 4-3; and FIG. 4-3 is the top view;

FIG. 5 is the orthogonal projection diagram for the overall appearance of the single-phase permanent magnet rotor electric water pump (arc-shaped water impeller) of the existing technology, of which, FIG. 5-1 is the front view, FIG. 5-2 is A-A sectional view; and FIG. 5-2 is the top view;

FIG. 6 is the orthogonal projection diagram for the overall appearance of the single-phase permanent magnet rotor electric water pump (straight-shaped water impeller) of the existing technology in the early stage, of which, FIG. 6-1 is the front view, FIG. 6-2 is A-A sectional view; and FIG. 6-2 is the top view.

MODE OF CARRYING OUT THE INVENTION MODEL

To further illustrate the principle and structure of the invention, the invention is further described in detail in accordance with the preferable embodiments shown in the figures.

For the invention, the method of enabling single-phase permanent magnet rotor electric water pump to only rotate in right direction includes Step A: control the dimension of the water chamber in the water pump, be sure to enable the space volume of the water chamber to be over 3 times of the tolerance space of all rotating water blades of the arc-shaped water impeller therein, meanwhile, diameter of the said water chamber shall be more than 1.2 times of the diameter of the water impeller therein, so as to increase the drag torque of the said arc-shaped water impeller rotating towards wrong direction;

B. During the designing of the water pump body, tangential water discharge form shall be adopted, enabling the part where the inner wall of the outlet pipe (set at the radial side of the said water chamber and connected with the water chamber) is far away from the central axis of the said water chamber to deviate parallelly outside from the tangent line of the inner wall of the said water chamber for certain distance A, result in an abrupt structure, result in an abrupt structure, further increasing the drag torque of the said arc-shaped water impeller rotating towards wrong direction;

C. Choose single-phase permanent magnet rotor motor with appropriate torque to drag the water impeller inside of the said water pump body, limit the fluctuation range of the supply voltage, be sure to enable the drag torque M_max of the said motor under maximum supply voltage to be lower than the drag torque N_opp of the said water impeller rotating towards wrong direction, namely rotating oppositely; while drag torque M_min of said motor under minimum supply voltage to be grater than the drag torque N_for of the said water impeller rotating towards right direction, namely rotating forward, besides N_opp>>N_for, therefore,

• • M_max<N_opp, M_min>N_for,

Thereby, only right direction of rotation against the bending direction of the said water blades within the whole supply voltage fluctuation range for the said electric water pump is assured.

Space volume of the said water chamber in Step A refers to the all space volume of the water chamber after being closed by the water chamber cover.

As to the abrupt structure in the said Step B, geometric relationship therein satisfies,

0.50≧Δ/d≧0.20, where d refers to the inner diameter of the said outlet pipes.

In the other preferred embodiment, geometrical relationship of the said abrupt structure in the said Step B satisfies

0.30≧Δ/d≧0.20, where d is also the inner diameter of the said outlet pipe.

For another embodiment of the invention, the said method of enabling the single-phase permanent magnet rotor electric water pump to only have right direction of rotation also includes Step D. Increase at least one moveable baffle, which can rotate on the inner wall of the water chamber around the axial axis; meanwhile, a base plate is set at the back of the said arc-shaped water impeller, whose diameter is a slightly greater than the diameter of the arc-shaped water impeller, when the water impeller rotates oppositely, water flow thrusts aside the moveable baffle, enabling it to cock and withstand the verge of the said base plate, hindering the opposite rotation of the water impeller.

For the invention, see FIG. 1 to FIG. 3 for single-phase permanent magnet rotor electric water pump only rotating in right direction, which comprises pump body 2, and water chamber 3 which is roughly cylindrical space therein, water chamber cover 8 which is assembled at the axial lateral end of the water chamber 3 has limited the space of the water chamber 3, arc-shaped water impeller 42 on the rotor assembly 4 is accommodated in the space of the said water chamber 3 coaxially, dragged to rotate by the permanent magnet rotor 41 of the single-phase synchronous motor (coaxially installed with the water impeller 42; outlet pipe 7 which is connected with the water chamber 3 is set at the radial side of the said water chamber 3; in particular, inner wall 71 of the said outlet pipe 7 is far away from the part where central axis OO′ of the said water chamber 3 is located, moved outward in parallelly to deviate from the tangent line of the inner wall 31 of the said water chamber 3 for a distance A, result in an abrupt structure 6, thus, further increasing the resistance of the said arc-shaped water impeller 42 rotating towards wrong direction (namely rotating oppositely), so as to assure that the high-efficient water pump rotates merely in the right direction against the bending direction of the said water blades 45 (namely rotating forward).

Space volume of the said water chamber 3 is more than 3 times of the tolerance space of all water blades 45 for arc-shaped water impeller 42 therein during rotation, meanwhile, diameter D of the said water chamber is more than 1.2 times of diameter Dy of the coaxial water impeller therein, space volume of the said water chamber 3 herein refers to all space volume of the water chamber 3 after being closed by the water chamber cover 8;

For the said abrupt structure 6, the geometrical relationship therein satisfies,

• • 0.50≧Δ/d≧0.20, where d is the inner diameter of the said outlet pipe 7.

In the other preferred embodiment, geometrical relationship of the said abrupt structure satisfies,

• • 0.30≧Δ/d≧0.20, where d is the inner diameter of the said outlet pipe.

In another preferred embodiment as is shown in FIG. 4, single-phase permanent magnet rotor electric water rotating only in right direction also comprises at least one moveable baffle 33 which is set on the inner wall of the said water chamber and rotates around an axial axis on the inner wall 31 of the water chamber, while a base plate 43 is set at the back of the said arc-shaped water impeller 42, whose diameter is a slightly larger than the diameter Dy water impeller 42, if the water impeller 42 rotates oppositely, water flow thrusts aside the said moveable baffle 33, enabling it to cock and withstand the verge of the base plate 43 of the water impeller, hindering the water impeller 42 to rotate oppositely.

See FIG. 5 and FIG. 6 for the existing technology for single-phase permanent magnet rotor electric water pump, thereof, arc-shaped water impeller and tangential water discharge are adopted by FIG. 5, while water impeller with straight-shaped blades and intermediate water outlet are adopted by FIG. 6. In FIG. 5, 2 is pump body, 3 is water chamber, 31 is inner wall of the water chamber, 32 is tangential outlet pipe, 45 is arc-shaped water blade. In FIG. 6, 2 is pump body, 3 is water chamber, 10 is straight-shaped water impeller, 11 is intermediate outlet pipe. Compared to the existing technology, problems for the existing single-phase permanent magnet rotor electric water pump are high in cost, complicated in structure, and low in reliability.

Claims

1. A method of enabling single-phase permanent magnet rotor electric water pump to rotate only in right direction, including Step: A. control the dimension of the water chamber in the water pump, be sure to enable the space volume of the water chamber to be over 3 times of the tolerance space of all rotating water blades of the arc-shaped water impeller therein, meanwhile, diameter of the said water chamber shall be more than 1.2 times of the diameter of the water impeller therein, so as to increase the drag torque of the said arc-shaped water impeller rotating towards wrong direction;B. during the designing of the said water pump body, tangential water discharge is adopted, enabling the part where the inner wall of the outlet pipe (set at the radial side of the said water chamber and connected with the water chamber) is far away from the central axis of the said water chamber to deviate parallelly outside from the tangent line of the inner wall of the said water chamber for certain distance A, result in an abrupt structure, further increasing the drag torque of the said arc-shaped water impeller rotating towards wrong direction;C. choose single-phase permanent magnet rotor motor with appropriate torque to drag arc-shaped water impeller in the said water pump, limit the fluctuation range of the supply voltage, be sure to enable the drag torque Mmax of the said motor under maximum supply voltage to be lower than the drag torque Nopp for the said water impeller rotating towards wrong direction, namely, rotating oppositely, while, drag torque Mmin under minimum supply voltage greater than forward rotating drag torque Nfor of the said arc-shaped water impeller rotating towards right direction, namely rotating forward, the structural shape of the said water chamber and dimension of the said permanent magnet rotor have assured Nopp>>Nfor, therefore:Mmax<Nopp, Mmin >Nfor,thereby, the said electric water pump rotating in right direction against the bending direction of the said water blades is assured; space volume of the said water chamber in Step A refers to all space volume of the water chamber closed by the water chamber cover.

2. The method of enabling single-phase permanent magnet rotor electric water pump to rotate only in right direction according to claim 1 is characterized in that: for the abrupt structure stated in Step B, geometrical relationship thereof satisfies,0.50≧Δ/d≧0.20, where d is the inner diameter of the said outlet pipe.

3. The method of enabling single-phase permanent magnet rotor electric water pump to rotate only in right direction according to claim 1 is characterized in that: for the abrupt structure stated in Step B, geometrical relationship thereof satisfies,0.30≧Δ/d≧0.20, where d is the inner diameter of the said outlet pipe.

4. The method of enabling single-phase permanent magnet rotor electric water pump to rotate only in right direction according to claim 1 is characterized in that: it includes Step,D. increase at least one moveable baffle, which can rotate on inner wall of the water chamber around an axial axis; meanwhile, a base plate whose diameter is a little larger than that of the arc-shaped water impeller is set at the back of the said arc-shaped water impeller, when the water impeller rotates oppositely, water flow thrusts aside the movable baffle, enabling it to cock and withstand the verge of the said base plate, hindering the opposite rotating of the water impeller.

5. Single-phase permanent magnet rotor electric water pump rotating only in right direction comprises pump body and water chamber which is roughly cylindrical space therein, water chamber cover assembled at the axial outside end of the water chamber has limited the space of the water chamber, arc-shaped water impeller on the rotor assembly is coaxially accommodated in the space of the said water chamber, dragged to rotate by the permanent magnet rotor of the single-phase synchronous motor coaxially installed with the water impeller; outlet pipe which is connected with the water chamber is set at the radial side of the said water chamber; it features that: space volume of the said water chamber is more than 3 times of the tolerance space of all water blades for arc-shaped water impeller therein during rotation, meanwhile, diameter D of the said water chamber is more than 1.2 times of the diameter Dy of the coaxial water impeller therein, space volume of the said water chamber herein refers to all space volume of the water chamber after being closed by the water chamber cover;the part where the inner wall of the said outlet pipe is far away from the central axis OO′ of the said water chamber deviates parallelly outside from the tangent line of the inner wall of the said water chamber for certain distance A, result in the abrupt structure.

6. The Single-phase permanent magnet rotor electric water pump rotating only in right direction according to claim 5 is characterized in that: for the said abrupt structure, the geometrical relationship therein satisfies, 0.50≧Δ/d≧0.20, where d is the inner diameter of the said outlet pipe.

7. The Single-phase permanent magnet rotor electric water pump rotating only in right direction according to claim 5 is characterized in that: for the said abrupt structure, the geometrical relationship wherein satisfies, 0.30≧Δ/d≧0.20, where d is the inner diameter of the said outlet pipe.

8. The Single-phase permanent magnet rotor electric water pump rotating only in right direction according to claim 5 is characterized in that: it also comprises at least one moveable baffle which is set on the inner wall of the said water chamber and rotates around an axial axis on the inner wall of the water chamber, while a base plate is set at the back of the said arc-shaped water impeller whose diameter is a slightly greater than the diameter Dy of the water impeller, if the water impeller rotates oppositely, water flow thrusts aside the said moveable baffle, enabling it to cock and withstand the verge of the base plate of the water impeller, hindering the opposite rotation of the water impeller.