DE202009003133U1 - Piston pump with several pistons - Google Patents

Abstract

Piston pump with a plurality of pistons which are driven by an eccentric, wherein the eccentric exerts only a compressive force on the pistons, characterized in that the pistons are connected to each other via an element which can absorb at least tensile forces during operation of the piston pump.

Description

State of the art

devices to promote of fluids, so of gases or liquids, such. B. pumps with several pistons or piston pumps, in which the pistons in a piston chamber are moved, are known in various configurations.

For example can the pistons over a driven rotatable or rotatable eccentric one continuously to carry out repetitive reciprocation. Especially with exactly an eccentric can two or more pistons are moved. The eccentric can through Acting on a contact surface on a piston this move away from a starting position or push off in a maximum position away from the starting position. The pressure force is in particular about the entire duration of a reciprocating motion applied to the piston. Subsequently The piston moves under a reversal of the direction of movement back to the starting position before he again reversing the direction of movement of the eccentric again pushed away becomes. The eccentric exercises only a pressure force on the piston. Usually the phases of movement of the two or more pistons are out of phase with each other. With two pistons running the forward movement of a piston advantageously simultaneously with the movement of the other piston and vice versa.

Purpose and advantages of the invention

task The present invention is to a piston pump of the introductory with regard to technical and economic aspects improve, in particular more reliably, easier or more compact to realize.

These The object is solved by claim 1.

In the dependent claims Advantageous developments of the invention are defined.

The Invention is based on a piston pump with multiple pistons, which via a Eccentric be driven, the eccentric on the pistons only exerts a compressive force. The essence of the invention is that the piston over a Element that absorb at least tensile forces during operation of the piston pump can, are interconnected. This can be a corresponding Piston pump particularly simple and space-saving realize.

In order to is particularly advantageous after a movement of the piston through whose pushing away means of the eccentric a reliable return movement realized. A piston, in a continuously repeatable Movement cycle one-way and a forward movement opposite Moving around, can over the element has a reset effect Experienced. With the element, the return of a piston during the Movement cycle set up. This also takes place continuously repeating, with the piston over the element in particular in a starting position at the end of the to-and-fro movement can be brought.

Especially are measures planned so far or return means, with which a backward move of the piston, replaceable by a comparatively clear simpler and more compact solution.

So So far, for example, spiral spring means as return means used, which permanently act on the piston under bias. This spring force, which also increases when the coil spring is compressed, must the eccentric while pushing away overcome the piston and exceed, to the desired To allow the piston to move forward. After elimination of the pressure of the eccentric on the piston, can the accordingly tensioned spring in the forward movement of the provision effect of the piston. A short strong push on the Piston, so that it is urged into a stop position, can with regard to wear and tear disturbing Sounds be disadvantageous.

Besides that is It is disadvantageous that this arrangement adds extra work for construction and assembly and also on parts means. In addition, mechanical Springs especially under changing loads in their spring function over time or can fatigue, if necessary, jam and / or tilt, causing the pump to fail.

Further It is proposed that there are two pistons which over the Eccentric perform a back and forth movement, the at least two pistons move over the element are displaceable to a starting position. So can after a maximum possible Moving a piston of this through the element back into the Starting position withdrawn become.

Especially It is advantageous that the element via a releasable connection with a Piston is connected. Thus, the arrangement and in particular the Element particularly easy to assemble and disassemble.

It is further proposed that the element is connected via a plug connection with a piston. A particular tool-free einrichtbare and releasable connector allows a fast and uncomplicated assembly or disassembly of the corresponding element.

Prefers the element is essentially designed as a rigid component. Thus, the element can be realized very stable.

Especially the element is advantageously designed in one piece. This too facilitates the assembly and disassembly of the piston pump.

It is further advantageous that the releasable connector such is formed, that the element in a direction transverse to the direction of movement of a Piston is inserted into the piston. This way you can prevent that by acting on the element during the movement of the piston personnel acts in the insertion direction of the element. Thus, the danger of an unwanted solving exclude the connector.

Prefers the element is designed as a pin element that a bent End portion, which in the installed state in one on the end portion coordinated reception opening is plugged in. This makes the element easy and inexpensive to deploy.

Especially It is advantageous that exactly two pistons are provided, which have a common U-shaped Element are connected. Thus, a coupling can be particularly advantageous the two pistons are reached. In particular, it is beneficial when the two pistons are aligned with their longitudinal axes and in between the eccentric sits. The directions of movement of the piston, so the Float, falls also with the longitudinal alignment the piston together. The element can be occupied by the eccentric Bridge area and couple the pistons together. The element can be parallel to the longitudinal direction the pistons are used in their extension, so to speak.

figure description

Based an embodiment of a piston pump according to the invention shown in FIGS further features and advantages of the invention explained.

in the Individual shows:

1 a longitudinal section through a piston pump according to the invention omitting individual parts z. B. a housing cover and

2 a section through the piston pump according to the invention along the line AA in 1 , where one in 1 not shown housing side in 2 not omitted.

A piston pump according to the invention 1 has as drive unit, for example, an electric motor 2 on, with which over here as a planetary gear 3 trained gear an eccentric 4 is rotationally driven. The eccentric 4 has a deep groove ball bearing on the outside 5 on, so the eccentric 4 outside by a circumferential outside of an outer race 5a of the deep groove ball bearing 5 is formed, the opposite an associated inner race 5b , with the rotating inner part 4a of the eccentric 4 rotatably connected, can perform a relative movement. This allows relative movements or friction between the outer side of the outer race 5a and an inside end face 6a or an inner end face 7a two oppositely positioned cylindrical piston 6 respectively. 7 be avoided or at least significantly reduced if the eccentric 4 the respective piston 6 respectively. 7 pushes. Pushing away the pistons 6 . 7 due to the rotation of the eccentric 4 changing effective radius of the respective outer portion of the outer race 5a , wherein the respective outer portion with the respective end face 6a respectively. 7a is in contact while pressure forces on the front page 6a respectively. 7a exercises. There is always only one piston 6 or 7 pushed away or on one of the end faces 6a . 7a Transmit pressure forces. The other piston 6 respectively. 7 In contrast, motion coupled again to the eccentric 4 used, which is explained below.

With the rotation of the eccentric 4 As described, the pistons 6 . 7 to the outside or from the eccentric 4 moved away. This movement of the pistons 6 . 7 outward is indicated by the arrow P1 for the piston 6 or by the arrow P2 for the piston 7 indicated. In accordance with 1 shown position is the piston 7 over the eccentric 4 pressed outward according to arrow P2. On the piston 6 is, however, from the eccentric 4 currently no pressure applied or is the end face 6a only touching on the outside of the outer race 5a at.

To reset the outward over the eccentric 4 pressed pistons 6 . 7 reach in a more inward position, so after a movement according to the arrows P1 and P2 an opposite direction, a movement of the piston 6 . 7 to enable is a reset element, which here as a clip 8th is formed, provided. If the eccentric 4 according to 1 continues to turn, the piston is 7 according to arrow P2 after it has moved to a maximum position to be reached, which is above the maximum value of the outer radius of the eccentric 4 is fixed, then pulled back in the opposite direction to P2, ie according to arrow P1, inward. This is about the clip 8th accomplished.

The clip 8th is designed here as a U-shaped bent metal pin, wherein the clip 8th with their ends bent over at the ends 8a respectively. 8b in corresponding openings 9 . 10 or through holes in the piston 6 or in the piston 7 is plugged in. The bent end section 8a is in the opening 9 in the piston 6 and the bent end portion 8b is in an opening 10 in the piston 7 plugged in. With this connection between the pistons 6 and 7 is the respective piston after a maximum movement to the outside according to the arrows P1 and P2 by the action of the eccentric 4 on the other piston, which is pushed away to the outside, back to the eccentric 4 attracted. When moving outward, the pistons become 6 . 7 acted upon by compressive forces and the subsequent moving inward, the piston 6 . 7 brought by tensile forces back into a starting position or in a furthest retracted position.

By the reciprocating motion of the two pistons 6 . 7 For example, a fluid, for example a hydraulic fluid of a hydraulic unit, can be conveyed in a known manner. This is about the movement of the piston 6 . 7 the hydraulic fluid conveyed, for example, in a pressure-side outgoing line.

In 1 is for example a hydraulic connection 11 for the connection of a hydraulic fluid line (not shown) shown.

1

piston pump

2

electric motor

3

planetary gear

4

eccentric

4a

inner part

5

Deep groove ball bearings

5a

Outer race

5b

Inner race

6

piston

6a

front

7

piston

7a

front

8th

clip

8a

end

8b

end

9

opening

10

opening

11

hydraulic connection

Claims (9)

Piston pump with a plurality of pistons which are driven by an eccentric, wherein the eccentric exerts only a compressive force on the pistons, characterized in that the pistons are connected to each other via an element which can absorb at least tensile forces during operation of the piston pump. Piston pump according to claim 1, characterized that there are two pistons which, via the eccentric, produce a and make a move, wherein the at least two pistons in the movement over the Element are displaceable to a starting position. Piston pump according to claim 1 or 2, characterized that element over a detachable one Connection is connected to a piston. Piston pump according to one of the preceding claims, characterized characterized in that the element via a releasable connector with a Piston is connected. Piston pump according to one of the preceding claims, characterized characterized in that the element substantially as a rigid component is trained. Piston pump according to one of the preceding claims, characterized characterized in that the element is designed in one piece Piston pump according to one of the preceding claims, characterized characterized in that the detachable Plug-in connection is designed such that the element in one Direction transverse to the direction of movement of a piston in the piston is pluggable. Piston pump according to one of the preceding claims, characterized characterized in that the element is designed as a pin element, having a bent end portion, the built-in Condition plugged into a matched to the end portion receiving opening is. Piston pump according to one of the preceding claims, characterized characterized in that exactly two pistons are provided, which have a common bow-shaped element are connected.