CN214366679U

CN214366679U - Plunger and hydraulic pump

Info

Publication number: CN214366679U
Application number: CN202120225386.1U
Authority: CN
Inventors: 李彬; 马薇; 王丽平
Original assignee: Bosch Rexroth Beijing Hydraulic Co Ltd
Current assignee: Bosch Rexroth Beijing Hydraulic Co Ltd
Priority date: 2021-01-27
Filing date: 2021-01-27
Publication date: 2021-10-08
Anticipated expiration: 2031-01-27

Abstract

The utility model provides a plunger and hydraulic pump. The plunger includes: a housing including a peripheral wall including opposing first and second ends and a housing base connected to the first end of the peripheral wall; a core comprising a core base and an inner circumferential wall comprising opposing first and second ends, the core base being connected to the first end of the inner circumferential wall; wherein the core is engaged into the housing such that the outer peripheral wall surrounds the inner peripheral wall and a closed cavity is formed between the outer peripheral wall and the inner peripheral wall. According to the utility model discloses a plunger processing is convenient.

Description

Plunger and hydraulic pump

Technical Field

The present invention relates to a hydraulic pump, and more particularly, to a plunger and a hydraulic pump having the same.

Background

The hydraulic pump includes a plunger to draw in and deliver fluid out. Existing plungers include solid plungers and hollow plungers. Solid plungers can provide higher volumetric efficiency, however, are heavier and mechanically less efficient, and hollow plungers are lighter and mechanically more efficient, but less volumetrically efficient.

EP0808988a1 discloses a plunger comprising a base and a plunger housing welded together, including a closed cavity, which has good volumetric and mechanical efficiency, however the assembly of the base and the plunger housing by welding is complicated.

SUMMERY OF THE UTILITY MODEL

The utility model aims to solve or at least alleviate the problem that exists among the prior art.

In one aspect, a plunger is provided, comprising:

a housing including a peripheral wall including opposing first and second ends and a housing base connected to the first end of the peripheral wall;

a core comprising a core base and an inner circumferential wall comprising opposing first and second ends, the core base being connected to the first end of the inner circumferential wall;

wherein the core is engaged into the housing such that the outer peripheral wall surrounds the inner peripheral wall and a closed cavity S is formed between the outer peripheral wall and the inner peripheral wall.

In another aspect, a hydraulic pump is provided, the hydraulic pump comprising a plunger according to various embodiments.

According to the utility model discloses a plunger processing is convenient.

Drawings

The disclosure of the present invention will become more readily understood with reference to the accompanying drawings. As is readily understood by those skilled in the art: these drawings are for illustrative purposes only and are not intended to constitute a limitation on the scope of the present invention. Moreover, in the drawings, like numerals are used to indicate like parts, and in which:

fig. 1 is a cross-sectional view of a plunger according to an embodiment of the present invention; and

fig. 2 is a cross-sectional view of a plunger according to another embodiment of the present invention.

Detailed Description

A plunger according to one embodiment of the present invention is described with reference to fig. 1. The plunger includes: the housing 1, the housing 1 comprises a peripheral wall 12 and a housing base 11, the housing base 11 may be integrally formed with the peripheral wall 12 and located at a first end 121 of the peripheral wall 12, the peripheral wall further comprising a second end 122 opposite the first end 121, the second end 122 of the peripheral wall defining an open opening. The plunger further comprises a core 2, the core 2 comprising a core base 21 and an inner circumferential wall 22, the core base 21 being integrally formed with the inner circumferential wall 22 and located at a first end 221 of the inner circumferential wall 22, the inner circumferential wall further comprising a second end 222 opposite the first end 221. The core 2 is engaged into the housing 1, for example by inserting the inner circumferential wall 22 into the housing 1 from the open opening of the second end 122 of the outer circumferential wall 12, such that the outer circumferential wall 12 surrounds the inner circumferential wall 22 and a closed cavity S is formed between the outer circumferential wall 12 and the inner circumferential wall 22. The utility model discloses a joint of shell 1 and core 2 forms the plunger, wherein has closed cavity S in order to reduce the weight of plunger, reduces open cavity O' S volume simultaneously for the plunger has better mechanical efficiency and volumetric efficiency.

In some embodiments, when the housing 1 is engaged with the core 2, the core base 21 is connected to the second end 122 of the outer peripheral wall 12 of the housing 1, and the second end 222 of the inner peripheral wall 22 of the core 2 is connected to the base 11 of the housing 1. In other embodiments, the core 2 may be engaged with the housing 1 in other ways.

In the embodiment of fig. 1, the outer ring of the core base 21 has an external thread and it engages with an internal thread at the second end 122 of the peripheral wall 12 of the housing 1, and a thread glue a may be applied between the core base 21 and the second end 122 of the peripheral wall 12 of the housing 1 to provide a seal between the core base 21 and the second end 122 of the peripheral wall 12 of the housing 1 to prevent fluid from entering the closed cavity S. In other embodiments, a sealing ring may be used instead of thread glue. In an alternative embodiment, the core base 21 may be joined to the second end 122 of the peripheral wall 12 of the housing 1 by interference fit, with a sealant or sealing member also being provided therebetween.

Furthermore, in the embodiment shown in fig. 1, a sealing ring 42 may be provided between the end surface 223 of the second end 222 of the inner circumferential wall 22 of the core 2 and the stop surface 111 of the base portion 11 of the housing 1, which sealing ring 42 is compressed when the base portion 21 of the core 2 is screwed to the outer circumferential wall 12 of the housing 1, thereby providing a seal between the second end 222 of the inner circumferential wall 22 and the base portion 11 of the housing 1, preventing fluid from entering the closed cavity S. The second end 222 of the inner circumferential wall 22 may also be engaged and sealed with the base 11 of the housing 1 by any other suitable means. Based on this, both ends of the closed cavity S of the plunger shown in fig. 1 are completely sealed.

With continued reference to fig. 2, another embodiment in accordance with the present invention is described. In the embodiment shown in fig. 2, the core base 21 has a flange 211, and a sealing ring 41 is provided between the stop surface 2111 of the flange 211 of the core base 21 and the end surface 1221 of the second end 122 of the peripheral wall 12 of the housing 1, thereby providing a seal between the core base 21 and the second end 122 of the peripheral wall 12 of the housing 1. In this embodiment, there may or may not be a threaded connection between the core base 21 and the second end 122 of the peripheral wall 12 of the housing 1.

In the embodiment shown in fig. 2, the second end 222 of the inner circumferential wall 22 of the core 2 is externally threaded and engages with the internal threads of the base 11 of the housing 1, and there may be a thread compound B between the second end 222 of the inner circumferential wall 22 and the base 11 of the housing, thereby providing a seal between the second end 222 of the inner circumferential wall 22 of the core 2 and the base 11 of the housing 1. Alternatively, the second end 222 of the inner circumferential wall 22 of the core 2 may be interference fitted into the base 11 of the housing 1.

Thus, the second end 122 of the peripheral wall 12 of the housing 1 is sealingly connected to the core base 21 at a location that may be sealingly connected by thread-on-thread glue, thread-on-seal, interference fit-on-seal glue or interference fit-on-seal or any other suitable means. Similarly, the second end 222 of the inner peripheral wall 22 of the core 2 is sealingly connected to the base 11 of the housing 1, which may be sealingly connected by means of thread-on-thread glue, thread-on-seal, interference fit-on-seal glue or interference fit-on-seal or any other suitable means.

In addition, in all embodiments, the base 11 of the housing 1 may have a spherical plunger coupling portion 14 on the outside for coupling with a plunger driver. The plunger driver pulls the plunger to reciprocate. In all embodiments, the base 11 of the housing 1 defines a first portion 31 of the fluid passage, the inner peripheral wall 22 of the core 2 defines a second portion 32 of the fluid passage inside, the first portion 31 of the fluid passage and the second portion 32 of the fluid passage communicating when the core 2 is engaged in the housing 1, thereby collectively defining an open cavity O. In some embodiments, the outer peripheral wall 12 and the inner peripheral wall 22 are cylindrical and the first portion 31 of the fluid passage extends to the top end 13 of the spherical plunger coupling 14 to provide a portion of the fluid between the base 11 of the housing 1 and the plunger driver to form a liquid film, such as an oil film.

In another aspect, a hydraulic pump is provided, comprising a cylinder and a plunger located in the cylinder according to various embodiments of the present invention.

According to the utility model discloses a plunger provides good volumetric efficiency and mechanical efficiency, and its equipment is convenient simultaneously.

The foregoing description of the specific embodiments has been presented only to illustrate the principles of the invention more clearly, and to show or describe various components clearly so that the principles of the invention may be understood more readily. Various modifications or changes may be readily made by those skilled in the art without departing from the scope of the present invention. It is to be understood that such modifications and variations are intended to be included within the scope of the present invention.

Claims

1. A plunger, comprising:

a housing (1), the housing (1) comprising a peripheral wall (12) and a housing base (11), the peripheral wall (12) comprising opposing first and second ends (121, 122), the housing base (11) being connected to the first end (121) of the peripheral wall (12);

a core (2), the core (2) comprising a core base (21) and an inner circumferential wall (22), the inner circumferential wall (22) comprising opposing first and second ends (221, 222), the core base (21) being connected to the first end (221) of the inner circumferential wall (22);

wherein the core (2) is joined into the housing (1) such that the outer circumferential wall (12) surrounds the inner circumferential wall (22) and a closed cavity (S) is formed between the outer circumferential wall (12) and the inner circumferential wall (22).

2. The plunger according to claim 1, wherein the core (2) is engaged to the housing (1) by inserting an inner circumferential wall (22) into the housing (1) from an open opening of the second end (122) of the outer circumferential wall (12) of the housing (1), the core base (21) being connected to the second end (122) of the outer circumferential wall (12) of the housing (1), and the second end (222) of the inner circumferential wall (22) of the core (2) being connected to the housing base (11).

3. Plunger according to claim 2, characterized in that the core base (21) has an external thread and engages with an internal thread at the second end (122) of the peripheral wall (12) of the housing (1) and/or that a thread glue (a) is applied between the core base (21) and the second end (122) of the peripheral wall (12) of the housing (1).

4. The plunger of claim 2, wherein the core base (21) is interference fitted to the second end (122) of the peripheral wall (12) of the housing (1).

5. Plunger according to claim 2, characterized in that the core base (21) has a flange (211), a sealing ring (41) being provided between the flange (211) of the core base (21) and an end face (1221) of the second end (122) of the peripheral wall (12) of the housing (1).

6. Plunger according to claim 2, characterized in that the second end (222) of the inner circumferential wall (22) of the core (2) is externally threaded and engages with an internal thread of the base (11) of the housing (1) and/or that there is a thread glue (B) between the second end (222) of the inner circumferential wall (22) and the base (11) of the housing (1).

7. Plunger according to claim 2, characterized in that a sealing ring (42) is arranged between the end surface (223) of the second end (222) of the inner circumferential wall (22) of the core (2) and the stop (111) of the base (11) of the housing (1).

8. The plunger according to claim 2, characterized in that the second end (222) of the inner circumferential wall (22) of the core (2) is interference fitted to the base (11) of the housing (1).

9. The plunger according to any one of claims 1-8, characterized in that the base (11) of the housing (1) has a spherically shaped plunger connection (14) on the outside, the base (11) of the housing (1) defining a first part (31) of a fluid channel, the inner circumferential wall (22) of the core (2) defining a second part (32) of a fluid channel on the inside, the first part (31) of the fluid channel and the second part (32) of the fluid channel communicating to form an open cavity (O) when the core (2) is engaged in the housing (1), the first part (31) of the fluid channel extending to the top end (13) of the spherically shaped plunger connection (14), the outer circumferential wall (12) and the inner circumferential wall (22) being cylindrical.

10. A hydraulic pump, characterized in that the hydraulic pump comprises a plunger according to any one of claims 1-9.