CN211116812U

CN211116812U - Low-specific-speed canned motor pump

Info

Publication number: CN211116812U
Application number: CN201921901902.7U
Authority: CN
Inventors: 钱运德; 栾晓颖; 师勇; 黄昕昱
Original assignee: Dalian Jinshi Pump Co ltd
Current assignee: Dalian Jinshi Pump Co ltd
Priority date: 2019-11-06
Filing date: 2019-11-06
Publication date: 2020-07-28
Anticipated expiration: 2029-11-06

Abstract

The utility model provides a low specific speed canned motor pump, belongs to canned motor pump technical field, canned motor pump is from a left side to the right side and is pump body entry, stator, impeller, axle sleeve, pump cover, third cavity, supplementary impeller, first cavity, stator and rotor subassembly, second cavity, back bearing body, pump shaft in proper order, the circumference terminal surface of stator is seted up and is just facing the hole of pump body export, pump cover mid portion part is equipped with two inclined holes, the left end face of pump cover set up a radial hole and axial hole, the axle sleeve set up a radial hole, the hole of intercommunication second, four cavities is seted up to the back bearing body front end of canned motor pump rear end, the pump shaft set up an axial hole and a radial hole, the axial hole links to each other with radial hole, radial hole is just facing the radial hole of axle sleeve. The shield pump is used for conveying special media under special working conditions by opening a hole above the guide vane, arranging a radial hole and an axial hole on a pump shaft and arranging the auxiliary impeller in front.

Description

Low-specific-speed canned motor pump

Technical Field

The invention belongs to the technical field of canned motor pumps, and particularly relates to a canned motor pump with a low specific speed.

Background

The specific revolution number is a comprehensive characteristic number including flow, lift and revolution number derived on the basis of a similarity law, and is the basis for calculating the structural parameters of the pump. The specific revolution reflects the shape of the impeller, and the smaller the specific revolution, the larger the outer diameter of the impeller and the smaller the width, and the larger the outer diameter of the impeller, the higher the lift. The low specific speed centrifugal pump has the obvious characteristics of small flow and high lift, and is widely applied to various fields of petrochemical industry, water conservancy and electric power, aerospace and the like.

However, with the development of chemical industry and the increasing awareness of people about environment and safety, especially when flammable, explosive, volatile low-temperature media (such as liquefied petroleum gas) and toxic or expensive media are conveyed, the leakage-free pump with zero leakage becomes the first choice for users. The canned motor pump is one kind of no-leakage pump, and has motor with rotor and impeller fixed onto the same shaft, canned sleeve assembly to separate the rotor from the stator of the motor, rotor running in conveyed medium and power transmitted to the rotor via the magnetic field of the stator. Most of heat generated by a motor of the canned motor pump is taken away by the circulation of the medium, and the medium not only can take away part of heat generated by motor loss in the circulation process, but also can play a role in lubricating and cooling a sliding bearing assembly, so that a circulation passage of the medium is very important for the canned motor pump

In order to realize the characteristics that the canned motor pump has low specific speed, the centrifugal pump has small flow and high lift, the company develops a canned motor pump with low specific speed. However, the characteristic of small flow of the low-specific speed pump is very unfavorable for a circulation path of the shield pump, and the small flow is difficult to take away heat, so that the motor is overheated and burnt; too little flow may adversely lubricate the plain bearing assembly, easily resulting in starved dry grinding damage during pump operation. Further, the lower the specific speed of the pump, the smaller the flow rate, and the larger the impeller diameter relative to the motor, the more difficult it is to balance the axial force.

The invention content is as follows:

the utility model discloses combine low specific speed centrifugal pump because the special of impeller and make the motor in the inside of flow little, lift height and canned motor pump and the prior art that does not have the leakage combine, for solving new product circulation route and axial force problem, the utility model discloses it is leading at stator top trompil, pump shaft center trompil, supplementary impeller on the basis of above prior art, be used in carrying special medium under the special operating mode.

The invention adopts the following technical scheme:

a low-specific-speed canned motor pump comprises a pump body inlet, a guide vane, an impeller, a shaft sleeve, a pump cover, a third chamber, an auxiliary impeller, a first chamber, a stator and rotor assembly, a second chamber, a rear bearing body and a pump shaft from left to right in sequence, the circumferential end surface of the guide vane is provided with a hole facing the outlet of the pump body, the middle part of the pump cover is separately provided with two inclined holes, the inclined hole is communicated with the outer end of the maximum diameter circle of the impeller and the third chamber, the left end surface of the pump cover is provided with a radial hole and an axial hole, the radial hole is communicated with the axial hole, the shaft sleeve is provided with a radial hole which is just opposite to the radial hole of the pump cover, the front end of the rear bearing body at the rear end of the canned motor pump is provided with a hole communicated with the second chamber and the fourth chamber, the pump shaft is provided with an axial hole and a radial hole, the axial hole is connected with the radial hole, and the radial hole is opposite to the radial hole of the shaft sleeve.

Further, the third chamber is connected with the first chamber, an auxiliary impeller 5 is arranged at the front end of the first chamber, a rotor assembly is arranged in the first chamber, a gap is reserved between the rotor and the stator and is called as a motor gap, the first chamber is connected with the second chamber, and the second chamber is connected with the fourth chamber.

The utility model discloses an advantage and effect do:

(1) the guide vane with the hole plays the role of a flow orifice plate, and the flow can be adjusted;

(2) the pressure drop generated by the front auxiliary impeller can balance part of the axial force;

(3) the ventilation cooling of the motor of the common centrifugal pump is changed into circulation cooling, the pump shaft is provided with a hole, the circulation path of the pump shaft is changed, a medium returns to the inlet of the impeller through the motor gap and the axial hole of the pump shaft under the action of the auxiliary impeller, and the circulation process not only lubricates and cools the sliding bearing assembly but also can take away most of heat generated by the motor.

Drawings

Fig. 1 is the structure schematic diagram of the low specific speed canned motor pump of the present invention.

The components in the figure: 1 is the pump body entry, 2 is the pump body export, 3 is the stator, 4 is the impeller, 5 is supplementary impeller, 6 is the housing subassembly, 7 is the back bearing body, 8 is the axle sleeve, 9 is first hole, 10 is the second hole, 11 is the third hole, 12 is the fourth hole, 13 is the first cavity, 14 is the second cavity, 15 is the motor gap, 16 is the pump cover, 17 is the third cavity, 18 rotor subassembly, 19 is the pump body, 20 is the stator, 21 is the fifth hole, 22 is the fourth cavity, 23 is the sixth hole, 24 is the seventh hole, 25 is the eighth hole, 26 is the ninth hole, 27 is the pump shaft.

Detailed Description

The present invention will be described in detail with reference to the accompanying drawings and examples.

The utility model discloses a trompil on the stator plays the effect of flow orifice plate throttle, thereby realizes the low discharge through the flow size of adjusting the stator export. A flow guide hole is formed in the position, close to the outer diameter of the impeller, of the pump cover, the outer circle of the maximum diameter of the impeller is connected with the third chamber through the flow guide hole, a front auxiliary impeller is additionally arranged, a flow guide hole is formed in the rear bearing body, a circulation passage of the pump shaft is changed through the hole in the pump shaft, and the medium returns to the inlet of the impeller from the shaft hole through the gap of the motor. When the pump operates, residual axial force points to the left side of the pump shaft along the pump shaft, the auxiliary impeller is arranged in front, partial pressure drop is generated when a medium passes through a motor gap, and force which points to the right side of the pump shaft along the pump shaft is generated, so that the balance of the whole axial force and the circulation of the medium are facilitated.

Example 1

The middle part of the pump cover 16 is provided with a first hole 9 and a second hole 10 of two inclined holes, the first hole 9 and the second hole 10 respectively connect the maximum diameter outer circle end of the impeller 4 with the third chamber 17, the left end surface of the pump cover 16 is provided with a sixth hole 23 of an axial hole, a seventh hole 24 of a radial hole, and the sixth hole 23 is connected with the seventh hole 24; an axial hole, a third hole 11 and a radial hole, a ninth hole 26 are formed in the pump shaft 27, and the third hole 11 is connected with the ninth hole 26; an eighth hole 25 of a radial hole is formed in the shaft sleeve 8; seventh hole 24 is opposite eighth hole 25, eighth hole 25 is opposite ninth hole 26; the rear bearing body 7 is provided with a third hole 11 at the front end, and the third hole 11 is communicated with the second chamber 14 and the fourth chamber 22.

The canned motor is characterized in that the canned motor is provided with a motor cover, a motor cover and a motor cover, the motor cover is arranged on the. The circulation loop of the impeller is changed by opening holes on the front part of the auxiliary impeller and the pump shaft, and the impeller mainly has two circulation paths. A first circulation path: when the medium flows from the pump body inlet 1 to the pump body outlet 2, the guide vane 3 plays a role in determining the small flow, the guide vane 3 is placed on the left side of the impeller, a fifth hole 21 is formed in the circumferential end face of the guide vane 3, and the direction of the fifth hole 21 is opposite to the pump body outlet 2. The size and number of the holes are determined by calculation, and the discharge flow rate of the pump body outlet 2 is determined. A second circulation path: the medium flows to the third chamber 17 through the first hole 9 and the second hole 10, flows to the first chamber 1 through the auxiliary impeller 5, is pressurized inside the auxiliary impeller 5 to accelerate the medium flow rate, leads the medium in the first chamber 13 into the second chamber 14 through the motor gap 15, flows into the fourth chamber 22 through the third hole 11, and returns to the impeller inlet through the fourth hole 12, the eighth hole 25, the seventh hole 24 and the sixth hole 23. This circulation will take away part of the heat generated by the motor and lubricate and cool the plain bearing assembly. The auxiliary impeller 5 is arranged in front, medium flows to the second chamber 14 from the first chamber 13 through the motor gap 15, partial pressure drop is generated in the process, the pressure borne by the left end face of the rotor assembly 18 is larger than the pressure borne by the right end face, and the auxiliary impeller generates a force which points to the right side of the pump shaft along the pump shaft to the rotor assembly 18; if the auxiliary impeller is set back, the direction of the force is reversed. The utility model discloses the product is leading to be used for balanced partial axial force with supplementary impeller. The shield pump is used for conveying special media under special working conditions by opening a hole above the guide vane 3, arranging a radial hole and an axial hole on the pump shaft 27 and arranging the auxiliary impeller 5 in front.

Claims

1. A low specific speed canned motor pump characterized in that: the canned motor pump is characterized in that the canned motor pump sequentially comprises a pump body inlet (1), a guide vane (3), an impeller (4), a shaft sleeve (8), a pump cover (16), a third cavity (17), an auxiliary impeller (5), a first cavity (13), a stator (20), a rotor assembly (18), a second cavity (14), a rear bearing body (7) and a pump shaft (27) from left to right, a hole facing a pump body outlet (2) is formed in the circumferential end face of the guide vane (3), two inclined holes are formed in the middle of the pump cover (16), the inclined holes are communicated with the outer end of a maximum diameter circle of the impeller (4) and the third cavity, a radial hole and an axial hole are formed in the left end face of the pump cover (16), the radial hole is communicated with the axial hole, the shaft sleeve (8) is provided with a radial hole facing the pump cover (16), and the front end of the rear bearing body (7) at the rear end of the canned motor pump is provided with the, The pump shaft (27) is provided with an axial hole and a radial hole, the axial hole is connected with the radial hole, and the radial hole is opposite to the radial hole of the shaft sleeve (8).

2. A low specific speed canned motor pump according to claim 1, characterized in that: the motor rotor comprises a rotor assembly, a stator and a third cavity, wherein the third cavity is connected with the first cavity, an auxiliary impeller (5) is arranged at the front end of the first cavity, the rotor assembly is arranged in the first cavity, a gap is reserved between the rotor and the stator and is called a motor gap, the first cavity is connected with the second cavity, and the second cavity is connected with the fourth cavity.