EP4137701A1

EP4137701A1 - Pump capable of delivering heated fluid

Info

Publication number: EP4137701A1
Application number: EP22187217.9A
Authority: EP
Inventors: Yukun Wang; Jin Lu; Liangdong LI
Original assignee: BSH Hausgeraete GmbH
Current assignee: BSH Hausgeraete GmbH
Priority date: 2021-08-16
Filing date: 2022-07-27
Publication date: 2023-02-22
Also published as: CN216111302U

Abstract

The invention discloses a pump capable of delivering a heated liquid. The pump includes a driving portion, an impeller portion, and a cover portion that are sequentially connected. A fluid inlet and a fluid outlet are provided on the cover portion, the driving portion includes a first housing, the impeller portion includes an impeller and a second housing, the first housing, the second housing, and the cover portion are sequentially fixedly connected to define an impeller cavity for mounting the impeller, and the second housing and the impeller are respectively made of materials having same or similar thermal expansion coefficients. Therefore, size changes of the second housing and the impeller after thermal expansion are close, so that a risk of blocking or excessive friction is reduced.

Description

The invention relates to a pump, and in particular, to a pump capable of delivering a heated fluid.
A pump generally includes an impeller arranged in an impeller cavity. During operation, the impeller is driven by a motor to rotate at a high speed, to drive a fluid to flow. To cause the impeller to better drive the fluid, the impeller cavity may be made as small as possible, and therefore there is a quite small gap between the impeller and a wall of the impeller cavity. The impeller of the pump is usually made of plastic. A shell part of the pump and the wall of the impeller cavity are sometimes made of metal, to provide high strength and heat resistance. When this type of pump is used to deliver a heated fluid, especially when a temperature of the fluid is high, for example, 50°C or more, because the plastic-made impeller and the metal-made wall of the impeller cavity have different thermal expansion coefficients, and the thermal expansion coefficient of the impeller is larger, a degree by which the size of the impeller is increased is larger, and the gap between the impeller and the wall of the impeller cavity is compressed. As a result, the impeller is blocked or excessively worn out.
An objective of the invention is to provide an improved pump, to overcome shortcomings of the related art.
Embodiments of the invention include: a pump capable of delivering a heated liquid, including a driving portion, an impeller portion, and a cover portion that are sequentially connected, where a fluid inlet and a fluid outlet are provided on the cover portion, the driving portion includes a first housing, the impeller portion includes an impeller and a second housing, the first housing, the second housing, and the cover portion are sequentially fixedly connected to define an impeller cavity for mounting the impeller, and the second housing and the impeller are respectively made of materials having same or similar thermal expansion coefficients.
In some embodiments, the second housing and the impeller are both made of plastic.
In some embodiments, the second housing and the impeller are made of a same material. Beneficial improvements further include that the second housing is located on a radial outer side of the impeller and extends in an axial direction.
Beneficial improvements further include that the second housing includes a first flange and a second flange that are located at two ends in the axial direction and a cylindrical peripheral wall located between the first flange and the second flange, and the first flange and the second flange are fixedly connected to the first housing and the cover portion respectively.
Beneficial improvements further include that the first housing and the cover portion are respectively made of metal.
Beneficial improvements further include that an axial depth of the impeller cavity is slightly greater than an axial thickness of the impeller, and a size difference between the axial depth and the axial thickness is less than 1 mm.
In various embodiments of the invention, size changes of the second housing and the impeller after thermal expansion are close, so that a risk of blocking or excessive friction is reduced. The following describes specific implementations of the invention with reference to the accompanying drawings.

FIG. 1 is an exploded view of a pump; and
FIG. 2 is a partial cross-sectional view of the pump.

As shown in FIG. 1, a pump 100 may be configured to deliver a heated fluid, such as heated water and/or air. For example, a heating temperature exceeds 40°C. The pump 100 may be applied to washing products such as a washing machine or a dishwasher. In the washing products, water usually needs to be heated to remove dirt. In some washing products, the pump 100 even needs to pump out at least some air.
As shown in FIG. 1 and FIG. 2, the pump 100 includes a driving portion 10, an impeller portion 20, and a cover portion 30 that are sequentially connected. The driving portion 10 includes a first housing 11 and a motor (not shown) located in the first housing 11. The impeller portion 20 includes a second housing 21 and an impeller 22 located in the second housing 21. A fluid inlet 31 and a fluid outlet 32 are provided on the cover portion 30. The first housing 11, the second housing 21, and the cover portion 30 are sequentially fixedly connected to define an impeller cavity 23 for mounting the impeller 22. The first housing 11 and the cover portion 30 respectively define end portions of the impeller cavity 23 in an axial direction, and the second housing 21 defines a circumferential boundary of the impeller cavity 23. The fluid inlet 31 and the fluid outlet 32 are respectively in spatial communication with the impeller cavity 23.
The second housing 21 is located on a radial outer side of the impeller 22 and extends in an axial direction. Specifically, the second housing 21 includes a first flange 24 and a second flange 25 that are located at two ends in the axial direction and a cylindrical peripheral wall 26 located between the first flange 24 and the second flange 25. The first flange 24 is fixedly connected to the first housing 11. The second flange 25 is fixedly connected to the cover portion 30.
As shown in FIG. 2, an axial depth of the impeller cavity 23 is slightly greater than an axial thickness of the impeller 22, so that there are gaps 4 between the impeller 22 and the end portions of the impeller cavity 23. A size difference between the axial depth of the impeller cavity 23 and the axial thickness of the impeller 22 is less than 1 mm. Therefore, a size sum of the gaps 4 between the impeller 22 and the end portions of the impeller cavity 23 is less than 1 mm. Due to the small gaps, the impeller 22 can easily come into contact with an inner wall of the impeller cavity 23 after thermal expansion, leading to strong friction or even blocking. Therefore, the second housing 21 and the impeller 22 are respectively made of materials having same or similar thermal expansion coefficients. Because the impeller 22 is usually made of plastic, the second housing 21 is also made of plastic. Alternatively, the second housing 21 and the impeller 22 are made of a same material. A material that is required to meet related parameters of both the second housing 21 and the impeller 22 is selected. Therefore, the thermal expansion coefficients of the second housing and the impeller can be ensured to be consistent. The second housing 21 mainly extends in the axial direction, and an axial length is also extended after t thermal expansion. The axial length of the second housing 21 and the axial thickness of the impeller 22 are relatively close, so that size changes thereof are also close. Therefore, the gaps between the impeller 22 and the end portions of the impeller cavity 23 maintain stable, and the impeller 22 is not prone to blocking or excessive friction.
To maintain the entire strength and the thermal deformation resistance of the pump 100, the first housing 11 and the cover portion 30 can be respectively made of metal.
The various specific implementations described above and shown in the accompanying drawings are only used to illustrate the invention, but are not all of the invention. Any variation made by a person of ordinary skill in the art to the invention within the scope of the basic technical concept of the invention shall fall within the protection scope of the invention.

Claims

A pump capable of delivering a heated fluid, comprising a driving portion (10), an impeller portion (20), and a cover portion (30) that are sequentially connected, wherein a fluid inlet (31) and a fluid outlet (32) are provided on the cover portion, the driving portion comprises a first housing (11), the impeller portion comprises an impeller (22) and a second housing (21), and the first housing, the second housing, and the cover portion are sequentially fixedly connected to define an impeller cavity (23) for mounting the impeller, characterized in that the second housing and the impeller are respectively made of materials having same or similar thermal expansion coefficients.
The pump according to claim 1, characterized in that the second housing and the impeller are both made of plastic.
The pump according to claim 1, characterized in that the second housing and the impeller are made of a same material.
The pump according to claim 1, characterized in that the second housing is located on a radial outer side of the impeller and extends in an axial direction.
The pump according to claim 4, characterized in that the second housing comprises a first flange (24) and a second flange (25) that are located at two ends in the axial direction and a cylindrical peripheral wall (26) located between the first flange and the second flange, and the first flange and the second flange are fixedly connected to the first housing and the cover portion respectively.
The pump according to claim 1, characterized in that the first housing and the cover portion are respectively made of metal.
The pump according to claim 1, characterized in that an axial depth of the impeller cavity is slightly greater than an axial thickness of the impeller, and a size difference between the axial depth and the axial thickness is less than 1 mm.