CN214366878U - Impeller for centrifugal pump - Google Patents

Abstract

An impeller for a centrifugal pump, the centrifugal pump comprising: motor element, pump shaft and pump body subassembly, wherein, pump body subassembly includes pump sleeve and the holding in a plurality of impeller stage group in the pump sleeve, and the impeller stage group includes: a support housing and a guide housing attached together in an axial direction to define an impeller cavity, and an impeller accommodated in the impeller cavity and driven by a pump shaft to rotate synchronously therewith, the impeller comprising: the pump includes a hub defining a central bore engaged with the pump shaft, and a tapered wall extending radially outward and axially upward from the hub, a vane extending helically from a lower surface of the tapered wall, and an impeller seat attached to an outer periphery of the vane, the impeller seat defining an outer support end surface at a lower end thereof and including an impeller reinforcement sleeve disposed on an outer peripheral surface of the impeller seat.

Description

Impeller for centrifugal pump

Technical Field

The present application relates to an impeller, in particular to an impeller for a centrifugal pump.

Background

The water pumps are of various types, and generally, the water pumps are three types, namely a low-pressure horizontal centrifugal pump, an air compressor and a centrifugal pump. The centrifugal water pump has simple structure, small volume, convenient assembly and disassembly, large water yield, uniform water outlet, quick start, easy water quantity adjustment and capability of sucking and delivering sand-containing water. But the suction lift is not large, is generally 7 to 9 meters, and is only suitable for wells with shallow underground water level. The air compressor has simple structure, is not limited by the height of the water level, can convey water containing sand, and does not influence water pumping when the well pipe is slightly bent. However, the working efficiency of the air compressor is only 15 to 25 percent generally, the power is wasted excessively, and the water outlet is not uniform enough. The deep well water pump can suck deep water and the water outlet is uniform. The selection of the water pump is mainly determined according to factors such as the static water level of underground water, the design water yield of a well, the water level drop, the caliber of a well pipe and the like.

The principle of the centrifugal pump is that a motor and a pump set are combined into a whole and immersed into an underground water well for pumping and water delivery. The centrifugal pump is widely applied to farmland irrigation and drainage, industrial and mining enterprises, urban water supply and drainage, sewage treatment and the like. The centrifugal pump has no special requirements for water pipes. Centrifugal pumps can be used for steel pipe wells, ash pipe wells and earth wells. As long as the pressure of the centrifugal pump head can be borne, no matter the steel pipe, the rubber pipe or the plastic pipe can be connected with the centrifugal pump. The centrifugal pump is convenient and simple to install, use and maintain, occupies small area and does not need to build a pump room. The light centrifugal pump at present has lighter weight and more convenient installation and movement.

The centrifugal pump works on a principle similar to a multistage pump, except that the motor of the centrifugal pump is arranged at the very bottom of the pump. Before the centrifugal pump is installed, the centrifugal pump is necessarily filled with water in advance. After the centrifugal pump is installed in place, the pump shaft and the impellers are driven by the motor to rotate at a high speed to generate attraction force, water around the water inlet is sucked into the pump body, and the nominal lift of the centrifugal pump is achieved through pumping of the impellers. The nominal lift of the centrifugal pump is formed by overlapping the lifts of a plurality of impellers.

The rotational speed of the motor of existing centrifugal pumps is typically less than 3000 rpm. In order to increase the pumping efficiency and the lift, it is necessary to increase the rotation speed of the motor. However, since the motor of a centrifugal pump generally directly transmits torque to the pump body by means of the output shaft, the rotational speed of the impeller assembly in the pump body is also high at high motor speeds. For the same impeller, the centrifugal force is proportional to the rotation speed. In the event that the centrifugal force of the impeller assembly exceeds its design limit, the impeller assembly is susceptible to damage during high speed rotation, thereby affecting the safety and useful life of the centrifugal pump.

SUMMERY OF THE UTILITY MODEL

In order to prevent the impeller from being damaged during high-speed rotation and to extend the safety and service life of the centrifugal pump, it is necessary to develop a reinforced impeller.

To this end, the present application proposes an impeller for a centrifugal pump comprising: a motor assembly providing rotational motion, a pump shaft driven by an output shaft of the motor assembly, and a pump body assembly, wherein the pump body assembly includes a pump sleeve and a plurality of impeller stage sets housed within the pump sleeve, the impeller stage sets comprising: a support housing and a guide housing attached together in an axial direction to define an impeller cavity, and an impeller accommodated in the impeller cavity and driven by a pump shaft to rotate synchronously therewith, the impeller comprising: the pump includes a hub defining a central bore engaged with the pump shaft, and a tapered wall extending radially outward and axially upward from the hub, a vane extending helically from a lower surface of the tapered wall, and an impeller seat attached to an outer periphery of the vane, the impeller seat defining an outer support end surface at a lower end thereof and including an impeller reinforcement sleeve disposed on an outer peripheral surface of the impeller seat.

According to an alternative embodiment, the impeller seat comprises a tapered portion and a vertical portion connected at the end of the tapered portion having the smaller outer diameter.

According to an alternative embodiment, the reinforcement sleeve comprises a conical sleeve portion extending along the tapered portion and a vertical sleeve portion extending along the vertical portion.

According to an alternative embodiment, the hardness of the reinforcing sleeve is greater than the hardness of the impeller seat.

According to an alternative embodiment, the reinforcing sleeve is made of cemented carbide.

According to an alternative embodiment, the reinforcement sleeve is attached to the impeller seat by means of ultrasonic welding.

According to an alternative embodiment, the impeller is fixed to the impeller seat by means of ultrasonic welding.

According to an alternative embodiment, the guide casing of the impeller stage set comprises a central portion having a central bore allowing the pump shaft to extend therethrough, a peripheral portion axially engaged with the support casing and guide vanes extending helically between the central portion and the peripheral portion, the central portion, the peripheral portion and the guide vanes defining the guide passage of the impeller stage set.

According to an alternative embodiment, the impeller seat, the conical wall and the blades define a centrifugal channel, the hub defines a central support end surface perpendicular to the axial direction, the central support end surface is defined by the hub of the impeller or a central movable sealing ring embedded at the lower end of the hub, the flow guiding housing comprises a central abutting end surface in constant abutting contact with the central support end surface, and the flow guiding channel is in fluid communication with the centrifugal channel.

According to an alternative embodiment, the central dynamic sealing ring is made of tungsten steel.

According to the impeller of the application, the reinforcing sleeve made of the material with higher hardness is configured, the problem that the impeller is easily damaged in the high-speed rotating process and can be generally prevented in the prior art can be effectively solved, and therefore the safety and the service life of the centrifugal pump are effectively prolonged.

Drawings

The foregoing and other features, advantages and benefits of the present application will be described in detail below with reference to the drawings, in conjunction with exemplary embodiments of the present application. It is to be understood that the drawings are not to scale and are merely illustrative of the principles of the application and are not intended to limit the application to the embodiments illustrated.

FIG. 1 is a longitudinal section of an exemplary centrifugal pump of the present application; and

FIG. 2 is a longitudinal sectional view of the impeller stage set of the centrifugal pump of FIG. 1.

Detailed Description

The embodiments of the present application described herein are defined as impellers, which may be put into practice in the embodiments described below. These embodiments may, however, be exemplified and implemented in many different forms and are not limited to the embodiments set forth herein. The present application is not limited to the disclosed embodiments. Rather, these illustrative examples of implementations are provided so that this disclosure will be thorough and complete.

It is to be understood that the drawings are designed solely for the purposes of illustration and not as a definition of the limits of the embodiments disclosed herein. Furthermore, the drawings are not necessarily to scale and, unless otherwise indicated, they are merely intended to conceptually illustrate the structures described herein.

Fig. 1 is a longitudinal section of an exemplary centrifugal pump of the present application. Generally, a centrifugal pump includes a motor assembly and a pump body assembly 20. The motor assembly includes a motor housing and a motor, such as an electric motor, accommodated in the motor housing and capable of outputting a high rotational speed. An auxiliary system, such as a cooling system, that provides auxiliary functions for the operation of the motor is also provided within the motor housing. The pump block assembly 20 includes a pump sleeve 22 and a plurality of impeller stage sets 200 housed within the pump sleeve 22. The output shaft of the motor drives the impeller 70 of each impeller stage set 200 in the centrifugal pump to rotate via the pump shaft 11 of the centrifugal pump. In the illustrated embodiment, the pump shaft 11 is a six-tooth pump shaft.

In the present application, for convenience of description, the direction in which the pump shaft 11 extends is defined as an axial direction, and the circumferential direction extends around the axial direction. The centrifugal pump of the present application is normally placed vertically during use, so the axial direction is also referred to as the vertical direction, the direction/end in the axial direction towards the motor assembly is referred to as the lower/lower end, the opposite direction/end is referred to as the upper/upper end. In a plane perpendicular to the axial direction, a direction from the pump sleeve 22 toward the central axis of the pump shaft 11 is referred to as radially inward, and conversely, a direction from the central axis of the pump shaft 11 toward the pump sleeve 22 is referred to as radially outward, with reference to the central axis of the pump shaft 11 defining the axial direction.

Referring back to fig. 1, the pump body assembly 20 includes, in order in an axial direction, from bottom to top, a water intake section 30, an impeller section 50 composed of a plurality of impeller stage sets, and a water outlet section 40, the structures of which are described in detail below.

In the water inlet section 30, water inlet holes 32 distributed in the circumferential direction are provided on the pump sleeve 22, and in the water inlet section 30, a cone housing 34 is provided inside the pump sleeve 22. The cone housing 34 is configured as an inverted cone that opens toward the motor assembly, including a central bore that allows the pump shaft 11 to pass through. A pump shaft connection portion that connects the pump shaft 11 to an output shaft of the motor assembly and supports the pump shaft 11 is disposed within a space 33 formed by an inner surface 37 of the cone housing 34 facing the motor assembly. An opposite outer surface 39 of cone housing 34 and pump sleeve 22 define a water space 35 in fluid communication with inlet opening 32 for receiving water entering through inlet opening 32 from outside the centrifugal pump. According to the present application, the water inlet 32 includes a plurality of water inlet groups spaced apart in the circumferential direction of the pump sleeve 22, each water inlet group including a plurality of water inlet holes densely distributed.

The following describes a plurality of impeller stage sets 200 included with the impeller section 50 mounted within the pump sleeve 22. The impeller section 50 of the illustrated centrifugal pump comprises 4 impeller stage sets 200, although the number of impeller stage sets of the centrifugal pump is not limited to 4, but may vary according to actual requirements.

The impeller stage set 200 in the impeller section 50 includes a stationary support housing 60 and a flow directing housing 250. In the axial direction, the inducer housing 250 is closer to the motor assembly and the water intake section 30 than the support housing 60, that is, the inducer housing 250 is located below the support housing 60 during use of the centrifugal pump in the vertical configuration. The support and guide housings 60, 250 in an impeller stage set 200 engage each other in the axial direction, are attached together, together defining an impeller cavity running through in the axial direction, and the guide housing 250 of the last impeller stage set 200 and the support housing 60 of the next impeller stage set 200 in two impeller stage sets 200 arranged adjacent to each other in the vertical direction are attached together. The impeller stage set 200 also includes an impeller 70 located within the impeller cavity, the impeller 70 being engaged with the pump shaft 11 and driven for synchronous rotation by the pump shaft 11. In the field of centrifugal pumps, the impeller 70 and the pump shaft 11 are typically joined together by means of a splined engagement, the pump shaft 11 comprising six key teeth 111 evenly distributed in the circumferential direction.

FIG. 2 is a longitudinal sectional view of the impeller stage set of the centrifugal pump of FIG. 1. The impeller 70 includes a cylindrical hub portion 72 and a tapered wall 74 extending radially outward and axially upward from the hub portion 72, e.g., near an upper end thereof (opposite to the direction of extension of the cone housing 34, and thus also referred to as a "forward tapered wall"), a vane 76 extending spirally from a lower surface 79 of the tapered wall 74, and an impeller seat 78 fixedly attached to an outer periphery of the vane 76. The hub 72, conical wall 74, vanes 76 and impeller seat 78 of the impeller 70 collectively define a centrifugal passage 75 that allows water to flow therethrough. The impeller seat 78 and the rest of the impeller 70 may be integrally formed or may be separately formed and later attached together by any suitable method, such as ultrasonic welding, in accordance with the principles of the present application. The impeller seat 78 of the impeller 70 includes a cylindrical base 782 and a forward tapered wall 784 extending obliquely radially outward and axially upward from an upper end of the cylindrical base 782.

The hub portion 72 defines a central bore 71, and the central bore 71 is adapted to be splined to the pump shaft 11 such that the pump shaft 11 drives the impeller 70 such that the impeller 70 rotates synchronously with the pump shaft 11. The lower end of the hub 72 defines an axially downward, i.e. towards the central support end surface 73, and the impeller seat 78, in particular the cylindrical base 782 thereof, defines an outer support end surface 77. The outer support end surface 77 includes one radial end surface parallel to the axial direction and two axial end surfaces perpendicular to the axial direction.

The impeller 70 further includes an impeller reinforcement sleeve 781 provided on the outer peripheral surface of the impeller seat 78. Reinforcing sleeve 781 includes a tapered sleeve portion extending along positively tapered wall 784 and a vertical sleeve portion extending along cylindrical base 782. The hardness of the reinforcing sleeve 781 is greater than the hardness of the impeller seat 78. The reinforcement sleeve 781 is made of cemented carbide, such as stainless steel, and is attached to the impeller seat 78 by means of ultrasonic welding. The reinforcing sleeve 781 is made of hard alloy with high hardness, so that the shape of the impeller seat 78 can be maintained, and then the shape of the impeller 70 is maintained, so that the problem that an impeller assembly is easily damaged in a high-speed rotating process is effectively solved, and the safety and the service life of the centrifugal pump are effectively prolonged.

The flow guide housing 250 of the impeller stage set 200 includes a central portion 252 having a central bore that allows the pump shaft 11 to extend therethrough, an outer peripheral portion 254, and vanes 256 extending radially between the central portion 252 and the outer peripheral portion 254. The flow guide passage 55 is defined by a central portion 252 and an outer peripheral portion 254 of the flow guide housing 250 and the adjacent outer static seal ring 98.

In the upward direction toward the impeller 70, the center portion 252 of the baffle housing 250 defines a center abutting end surface 262, and the center abutting end surface 262 is configured to be always in abutting contact with the center support end surface 73.

In the non-operational state of the centrifugal pump, the impeller 70 fits within an axial impeller cavity defined by the support housing 60 and the inducer housing 250. The central support end surface 73 is in abutting contact with the central abutment end surface 262 such that the guide housing 250 provides a support for the impeller 70.

In the operating state of the centrifugal pump, the impeller 70 rotates at a high speed along with the pump shaft 11 (not shown in fig. 2), and water is drawn in from the guide passage defined by the guide housing 250 by the centrifugal force generated by the rotation of the impeller 70, enters the centrifugal passage 75 of the impeller 70, and is then thrown into the guide passage 55 of the next impeller stage group 200.

An annular gap for allowing impurities, such as silt, in the water to settle downward is defined between the outer circumference of the impeller seat 78 of the impeller 70, specifically, the upper end outer circumference of the forward tapered wall 784 thereof, and the support housing 60. Silt in the water stream flowing in the centrifugal channel 75 passes through the annular gap and enters the impurity collection space defined by the support housing 60, the guide housing 250 and the impeller seat 78 of the impeller stage set 200.

In the high-speed operation state of the centrifugal pump, the center support end surface 73 and the center abutting end surface 262 are always in abutting contact. In addition to providing support to the impeller 70, this abutment also receives an axial force from the impeller 70, and the transmission of the axial force causes friction between the two end faces 73 and 262 in contact with each other. To reduce the effect of this friction on the power and efficiency of the centrifugal pump, any surface treatment of the end faces 73 and 262 may be applied. In one embodiment, an anti-friction coating may be applied to the end surfaces 73 and 262. In the illustrated embodiment, rather than simply applying an anti-friction coating to the surface, additional components made of anti-friction material are provided to the impeller 70 and the inducer housing 250, respectively, to provide the end surfaces 73 and 262. For example, in FIG. 2, a central dynamic seal ring 92 made of ceramic is embedded within the hub 72 to provide the friction face 73 and a central static seal ring 94 made of tungsten steel is embedded within the deflector housing 250 to provide the friction surface 262.

As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items. As used herein, the term "or" is to be interpreted as a mathematical or, i.e., an inclusive disjunction; unless explicitly stated otherwise, it is not treated as a mathematical exclusive or (XOR). In addition, the singular forms "a", "an" and "the" should be construed as "at least one" and thus may include a plurality of the same kind of entities unless expressly stated otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, actions, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, actions, integers, steps, operations, elements, components, and/or groups thereof. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

Claims (10)

1. An impeller for a centrifugal pump, the centrifugal pump comprising:

a motor assembly for providing a rotational movement of the motor,

a pump shaft (11) driven by the output shaft of the motor assembly, an

A pump body component (20),

wherein the pump body assembly comprises a pump sleeve (22) and a plurality of impeller stage sets (200) housed within the pump sleeve (22), the impeller stage sets (200) comprising: a support housing (60) and a guide housing (250) attached together in an axial direction to define an impeller cavity, and an impeller (70) accommodated in the impeller cavity to be driven by the pump shaft to rotate synchronously therewith,

it is characterized in that the preparation method is characterized in that,

the impeller (70) comprises: a hub portion (72) defining a central bore for engagement with a pump shaft, and a tapered wall (74) extending radially outward and axially upward from the hub portion, a vane (76) extending helically from a lower surface of the tapered wall, and an impeller seat (78) attached to an outer periphery of the vane (76), the impeller seat (78) defining an outer support end surface (77) at a lower end thereof and including an impeller reinforcing sleeve (781) disposed on an outer peripheral surface of the impeller seat (78).

2. The impeller according to claim 1,

the impeller seat (78) includes a cylindrical base (782) and a forward tapered wall (784) extending obliquely radially outward and axially upward from an upper end of the cylindrical base (782).

3. The impeller according to claim 2,

the reinforcing sleeve (781) includes a tapered sleeve portion extending along the positively tapered wall (784) and a vertical sleeve portion extending along the cylindrical base (782).

4. The impeller according to any one of claims 1 to 3,

the hardness of the reinforcing sleeve (781) is greater than that of the impeller seat (78).

5. The impeller according to claim 4,

the reinforcing sleeve (781) is made of hard alloy.

6. The impeller according to any one of claims 1 to 3,

the reinforcing sleeve (781) is attached to the impeller seat (78) by means of ultrasonic welding.

7. The impeller according to any one of claims 1 to 3,

the impeller (70) is fixed to the impeller seat (78) by means of ultrasonic welding.

8. The impeller according to any one of claims 1 to 3,

the flow guide housing (250) of the impeller stage set (200) includes a central portion (252) having a central bore allowing a pump shaft to extend therethrough, a peripheral portion (254) axially engaged with the support housing (60), and a guide vane (256) extending helically between the central portion (252) and the peripheral portion (254), the central portion (252), the peripheral portion (254), and the guide vane (256) defining a flow guide channel (55) of the impeller stage set (200).

9. The impeller according to claim 8,

the impeller seat (78), the tapered wall (74) and the blades (76) define a centrifugal passage (75), the hub portion (72) defines a central support end surface (73) perpendicular to the axial direction, the central support end surface (73) is defined by the hub portion (72) of the impeller (70) or a central movable sealing ring (92) embedded at the lower end of the hub portion (72),

the flow guiding housing (250) comprises a central abutting end surface (262) which is always in abutting contact with the central supporting end surface (73), and

the flow directing channel (55) is in fluid communication with the centrifugal channel (75).

10. The impeller according to claim 9, characterized in that said central sealing ring (92) is made of tungsten steel.

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