DE102021102709A1 - HIGH PRESSURE PUMP - Google Patents

Abstract

Drive arrangement of a high-pressure pump with a pump piston guided in a receptacle and high-pressure pump with such a drive arrangement.

Description

The application relates to a drive arrangement of a high-pressure pump with a pump piston guided in a receptacle and a high-pressure pump with such a drive arrangement.

High-pressure pumps can be designed as plunger pumps, which are used, for example, in high-pressure water technology at pressures between 10 megapascals and 400 megapascals. From the DE 101 25 669 A1 a pump, in particular a plunger pump, is known which has a crank drive which drives a plunger arranged in a housing and guided in a receptacle in an oscillating manner, with a pump head fixed to the housing for conducting the pressurized fluid, the housing containing the crank drive and surrounds the plunger. The crank mechanism is driven by a pinion shaft, with the eccentric attachment of the connecting rod pins generating an oscillating movement of the plunger. In this case, a guide element is articulated on an axis on the connecting rod.

Converting a rotary movement of a crankshaft into a straight movement via a connecting rod and a crosshead leads to wear of the crosshead. One task can be seen as reducing or avoiding wear.

The object is achieved by a drive arrangement of a high-pressure pump according to claim 1 and a high-pressure pump according to claim 11. Possible embodiments are described in each case in the dependent claims.

The drive arrangement of a high-pressure pump has at least one pump piston guided in a receptacle and a rotationally driven camshaft, with at least one cam of the camshaft setting the pump piston in a linear stroke motion, with a stroke of the pump piston being at least 30 millimeters.

With the drive arrangement, a direct conversion of the rotational movement of the camshaft into the straight movement of the pump piston is achieved instead of an indirect diversion into the straight movement via a connecting rod. Compared to a drive arrangement with a crankshaft according to the prior art, a bearing shell between the crankshaft and the connecting rod, the connecting rod and the connecting rod pin can be omitted, so that wear is avoided. As a result, a significant reduction in frictional forces is achieved. This increases the efficiency of the drive arrangement.

One aspect relates to a high-pressure pump with such a drive arrangement, with a maximum operating pressure of the high-pressure pump being at least 300 megapascals, in particular at least 400 megapascals. It is, for example, a high-pressure pump whose maximum operating pressure can be up to 600 megapascals. A maximum volume flow of the high-pressure pump is at least 2000 liters, for example.

The high-pressure pump can have a housing in which the receptacle, the pump piston guided therein and the camshaft driven in rotation are arranged. The camshaft is driven, for example, by a drive shaft of an electric motor or internal combustion engine via at least one gear wheel of a countershaft transmission. A pump head with channels for conducting a fluid can be attached to the housing. To pump a fluid, fluid is sucked in from a suction chamber during a downward movement of the pump piston. As soon as the pump piston has passed its bottom dead center, the pump piston moves in the opposite direction. A valve closes access to the suction chamber. Another valve opens access to a pressure chamber. Due to the movement of the pump piston in the direction of its top dead center, the fluid is pumped into the pressure chamber and distributed via corresponding lines.

According to one embodiment of the drive arrangement, the stroke of the pump piston is at least 50 millimeters, in particular at least 60 millimeters. For example, the stroke of the pump piston is between 70 millimeters and 80 millimeters.

The stroke of the pump piston is defined as the path between the bottom dead center of the pump piston and the top dead center of the pump piston along a longitudinal axis of the receptacle of the pump piston, which can also be referred to as a cylinder. In relation to the cam, the stroke of the pump piston corresponds to a difference between a cam height and a base circle diameter of the cam. According to one embodiment, the cam height is at least 50 percent greater than the base circle diameter, in particular 75 percent greater than the base circle diameter. The cam height can be twice as large as the base circle diameter.

According to one embodiment of the drive arrangement, the cam can act directly on the pump piston, the pump piston sliding in sliding engagement on the cam. According to an alternative embodiment, the cam can be connected to the pump piston via a coupling means know Such a coupling means can be designed in the manner of a roller bearing connection. For example, the coupling means between the camshaft and the pump piston is designed as a roller shoe arrangement, with a roller on the pump piston following the cam in the roller follower.

According to a further embodiment of the drive arrangement, the pump piston can be prestressed in the direction of the camshaft by means of a compression spring. For example, the compression spring designed as a helical spring is arranged in such a way that it at least partially encloses the receptacle. If the pump piston is connected to the cam by the coupling means, the compression spring can be dispensed with.

According to a further embodiment of the drive arrangement, a plurality of cams can be arranged in different cam tracks along an axis of rotation of the camshaft in order to drive a corresponding number of pump pistons in a multi-cylinder arrangement.

• Fiq. 1 einen schematischen Längsschnitt einer Ausführungsform einer Hochdruckpumpe mit einer Antriebsanordnung;
• 2 eine schematische Darstellung einer Ausführungsform einer Antriebsanordnung einer Hochdruckpumpe in perspektivischer Ansicht;
• 3 eine schematische Darstellung einer weiteren Ausführungsform einer Antriebsanordnung einer Hochdruckpumpe in perspektivischer Ansicht.

Further exemplary embodiments and advantages are presented in more detail below with reference to the figures. It shows:

• figure 1 shows a schematic longitudinal section of an embodiment of a high-pressure pump with a drive arrangement;
• 2 a schematic representation of an embodiment of a drive arrangement of a high-pressure pump in a perspective view;
• 3 a schematic representation of a further embodiment of a drive arrangement of a high-pressure pump in a perspective view.

In the 1 a high-pressure pump with a drive arrangement is shown in a schematic longitudinal section. A pump head 7 is arranged schematically on a housing 1 of the drive arrangement and has channels (not shown) for conducting a fluid. A maximum operating pressure of the high-pressure pump can be at least 300 megapascals and a maximum volume flow of the high-pressure pump can be at least 2000 liters. The drive arrangement of the high-pressure pump has a pump piston 4 guided in a receptacle 6 . A cam 3 of a camshaft 2 driven in rotation deflects the pump piston 4 and sets it in an oscillating linear stroke movement. The stroke of the pump piston, ie the path between a bottom dead center (UT) of the pump piston 4 and a top dead center (OT) of the pump piston 4 along a longitudinal axis L of the mount 6 is at least 30 millimeters. The schematic representation is not to scale in this regard. The pump piston 4 is moved from its top dead center back towards the bottom dead center, for example by means of a compression spring 8 prestressed in the direction of the camshaft 2 . The compression spring 8 embodied, for example, as a helical spring encloses the receptacle 6 here. The receptacle 6 , the pump piston 4 guided therein and the camshaft 2 driven in rotation are arranged in the housing 1 of the high-pressure pump. The camshaft 2 is driven, for example, by a drive shaft of an electric motor or an internal combustion engine, for example via a reduction gear (not shown). A plurality of cams 3 can be arranged in different cam tracks along an axis of rotation R of the camshaft 2 in order to drive a corresponding number of pump pistons 4 in a multi-cylinder arrangement.

In the 2 an exemplary embodiment of the drive arrangement is shown schematically in a perspective view. The cam 3 can act directly on the pump piston 4 or via a coupling means 5. In the exemplary embodiment shown, the coupling means 5 between the camshaft 2 and the pump piston 4 is designed as a roller shoe arrangement, for example with a roller bearing. In the exemplary embodiment shown, the cam 3 has a circular segment with a constant height of the cam 3 extending over an angle of approximately 45 degrees of one revolution of the camshaft 2 . While the coupling means 5 of the pump piston 4 rolls along this circular segment, the pump piston is held at top dead center. The cam 3 can also be referred to as a control disc. The pump piston 4 can be moved by means of the compression spring (8, 1 ) are moved back from its top dead center in the direction of bottom dead center as soon as the coupling means 5 reaches the end of the circle segment with constant height of the cam 3.

In the 3 a further exemplary embodiment of the drive arrangement is shown schematically in a perspective view. The pump piston 4 is connected here to the cam 3 by the coupling means 5, so that the restoring spring can be omitted. The cam 3 pulls the pump piston 4 from top dead center to bottom dead center. Furthermore, a double cam is shown in the exemplary embodiment, which brings about two strokes of the pump piston 4 per revolution of the camshaft 2 .

reference list

1

Housing

2

camshaft

3

cam, control disk

4

pump piston, plunger

5

coupling arrangement

6

recording, cylinder

7

pump head

8th

compression spring

L

longitudinal axis

R

axis of rotation

QUOTES INCLUDED IN DESCRIPTION

This list of the documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• DE 10125669 A1 [0002]

Claims (12)

Drive arrangement of a high-pressure pump with a pump piston (4) guided in a receptacle (6) and with a rotationally driven camshaft (2), the cam (3) of which sets the pump piston (4) into a linear stroke movement, with a stroke of the pump piston (4) is at least 30 millimeters. Drive arrangement according to claim 1 , characterized in that the cam (3) acts directly on the pump piston (4). Drive arrangement according to claim 1 , characterized in that the cam (3) acts on the pump piston (4) via a coupling means (5). Drive arrangement according to claim 3 , characterized in that the coupling means between the camshaft (2) and the pump piston (4) is designed as a roller shoe arrangement (5). Drive arrangement according to one of the preceding claims, characterized in that the pump piston (4) is prestressed in the direction of the camshaft (2) by means of a compression spring (12). Drive arrangement according to claim 5 , characterized in that designed as a helical spring compression spring (12) is arranged at least partially enclosing the receptacle (6). Drive arrangement according to claim 3 , characterized in that the pump piston (4) is connected to the cam (3) by the coupling means. Drive arrangement according to one of the preceding claims, characterized in that a plurality of cams (3) are arranged in different cam tracks along an axis of rotation of the camshaft (2) for driving a corresponding number of pump pistons (4) in a multi-cylinder arrangement. Drive arrangement according to claim 1 , characterized in that the stroke of the pump piston (4) is at least 50 millimeters. Drive arrangement according to claim 1 , characterized in that the stroke of the pump piston (4) is between 70 millimeters and 80 millimeters. High-pressure pump with a drive arrangement according to one of the preceding claims, characterized in that an operating pressure of the high-pressure pump is at least 300 megapascals. high pressure pump claim 11 , characterized in that a volume flow of the high-pressure pump is at least 2000 liters.

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