Accumulator Module for Hydromechanical Spring-Loaded Drive

Abstract

The invention relates to an accumulator module for a hydromechanical spring-loaded drive, wherein the spring-loaded drive is provided to actuate a high-voltage power switch (12), and wherein the accumulator module contains a pressure-tight housing (1), an accumulator piston (2) which protrudes into the housing (1) and is axially moveable in the housing (1), and a sealing cover (4) which seals the housing in an pressure-tight manner. In addition, at least one connecting channel (5, 6) is provided, which is introduced into the housing (1) for transporting a highly pressurised fluid present between the inner wall (7) of the housing and the head (3) of the accumulator piston to a high-pressure channel (11) of the spring-loaded drive, which channel is outside the housing. In order to increase the service life of the accumulator module, at least one pressure relief groove (8) is circumferentially applied to the head (3) of the accumulator piston.

Claims

1. An accumulator module for a hydromechanical spring-loaded drive, wherein the spring-loaded drive is provided for activating a high-voltage power switch, and wherein the accumulator module includes: pressure-tight housing; an accumulator piston that protrudes into the housing and is axially movable in the housing; a closure cover that closes the housing in a pressure-tight manner; at least one connection duct, incorporated in the housing, for conveying a highly pressurized fluid that in the operation of the accumulator module is located between an inner wall of the housing and a head of the accumulator piston to a high-pressure duct of the spring-loaded drive, said high-pressure duct being located outside the housing, wherein at least one pressure-relief groove is incorporated in the head of the accumulator piston in an encircling manner.

2. The accumulator module as claimed in claim 1, wherein the at least one pressure relief groove comprises at least two pressure-relief grooves of the same geometric design incorporated in the head of the accumulator piston, so as to run in a circumferential direction of said head and so as to have the same spacing from one another.

3. The accumulator module as claimed in claim 1, wherein the head of the accumulator piston has at least one through-bore through which the fluid that in the operation of the accumulator module is located between the inner wall of the housing and the head of the accumulator piston can flow to the at least one connection duct.

4. The accumulator module as claimed in claim 1, wherein grooves or notches, through which the fluid that in the operation of the accumulator module is located between the inner wall of the housing and the head of the accumulator piston can flow to the at least one connection duct, are disposed on an outside of the head of the accumulator piston.

5. The accumulator module as claimed in claim 1, wherein a guide strip is fastened to the circumference of the head of the accumulator piston.

6. The accumulator module as claimed in claim 5, wherein the guide strip is disposed so as to be parallel with the at least one pressure-relief groove.

7. The accumulator module as claimed in claim 5, wherein the guide strip is composed of polytetrafluoroethylene.

8. The accumulator module as claimed in claim 5, wherein the guide strip in relation to the at least one pressure-relief groove is disposed on the head of the accumulator piston so as to lead when the accumulator piston enters the housing.

9. The accumulator module as claimed in claim 5, wherein the guide strip in relation to the at least one pressure-relief groove is disposed on the head of the accumulator piston so as to trail when the accumulator piston enters the housing.

10. The accumulator module as claimed in claim 1, wherein the at least one pressure-relief groove is disposed in a helical manner along a circumference of the head of the accumulator piston.

11. The accumulator module as claimed in claim 1, wherein the closure cover axially guides the accumulator piston.

12. A hydromechanical spring-loaded drive having an accumulator module for activating a high-voltage power switch, wherein the accumulator module includes: a pressure-tight housing; an accumulator piston that protrudes into the housing and is axially movable in the housing; a closure cover that closes the housing in a pressure-tight manner; at least one connection duct, incorporated in the housing, for conveying a highly pressurized fluid that in the operation of the accumulator module is located between an inner wall of the housing and a head of the accumulator piston to a high-pressure duct of the spring-loaded drive, said high-pressure duct being located outside the housing, wherein at least one pressure-relief groove is incorporated in the head of the accumulator piston in an encircling manner.

13. The accumulator module as claimed in claim 12, wherein the at least one pressure relief groove comprises at least two pressure-relief grooves of the same geometric design incorporated in the head of the accumulator piston, so as to run in a circumferential direction of said head and so as to have the same spacing from one another.

14. The accumulator module as claimed in claim 12, wherein the head of the accumulator piston has at least one through-bore through which the fluid that in the operation of the accumulator module is located between the inner wall of the housing and the head of the accumulator piston can flow to the at least one connection duct.

15. The accumulator module as claimed in claim 12, wherein grooves or notches, through which the fluid that in the operation of the accumulator module is located between the inner wall of the housing and the head of the accumulator piston can flow to the at least one connection duct, are disposed on an outside of the head of the accumulator piston.

16. The accumulator module as claimed in claim 12, wherein a guide strip is fastened to the circumference of the head of the accumulator piston.

17. The accumulator module as claimed in claim 16, wherein the guide strip is disposed so as to be parallel with the at least one pressure-relief groove.

18. The accumulator module as claimed in claim 16, wherein the guide strip is composed of polytetrafluoroethylene.

19. The accumulator module as claimed in claim 16, wherein the guide strip in relation to the at least one pressure-relief groove is disposed on the head of the accumulator piston so as to lead when the accumulator piston enters the housing.

20. The accumulator module as claimed in claim 16, wherein the guide strip in relation to the at least one pressure-relief groove is disposed on the head of the accumulator piston so as to trail when the accumulator piston enters the housing.

21. The accumulator module as claimed in claim 12, wherein the at least one pressure-relief groove is disposed in a helical manner along a circumference of the head of the accumulator piston.

22. The accumulator module as claimed in claim 12, wherein the closure cover axially guides the accumulator piston.

Description

[0015] The invention and a potential design embodiment will be explained and described in more detail by means of the figures hereunder.

[0016] In the figures:

[0017] FIG. 1 shows an accumulator module having pressure-relief grooves in the case of a charged spring accumulator and of a closed high-voltage power switch; and

[0018] FIG. 2 shows the accumulator module from FIG. 1 in the case of a discharged spring accumulator and of an opened high-voltage power switch.

[0019] An accumulator module for a hydromechanical spring-loaded drive can be seen in FIG. 1. The spring-loaded drive herein is provided for activating a high-voltage power switch 12 and includes one or else a plurality of the accumulator module illustrated in FIG. 1. The spring-loaded drive moreover includes a hydraulically activated piston/cylinder assembly 16, indicated in FIG. 1, which mechanically acts directly on the high-voltage power switch 12 and exerts on the latter a closing force or opening force F, respectively. The hydraulic activation of the piston/cylinder assembly 16 is performed by way of a hydraulic system which is part of the spring-loaded drive and which comprises at least one high-pressure duct 11. A spring accumulator 14 which in FIG. 1 is illustrated as a coil spring is furthermore part of the spring-loaded drive. Alternatively, other types of springs such as, for example, disk springs, can also be used. The spring accumulator 14 here is in the charged state, that is to say the compressed state, wherein the coil spring is pressed against a stationary bearing face 15.

[0020] The accumulator module of FIG. 1 includes a pressure-tight housing 1, an accumulator piston 2 which protrudes into the housing 1 and is movable axially (along the longitudinal axis of said accumulator piston 2) in the housing 1, a closure cover 4 which axially guides the accumulator piston 2 and closes the housing in a pressure-tight manner, and two connection ducts 5, 6, incorporated in the housing 1, for conveying a highly pressurized fluid that is located between the inner wall 7 of the housing and the head 3 of the accumulator piston to the high-pressure duct 11 of the spring-loaded drive, said high-pressure duct 11 being located outside the housing. The fluid is preferably hydraulic oil. A total of three pressure-relief grooves 8 are attached in an encircling manner on the head 3 of the accumulator piston. The three pressure-relief grooves 8 of the same geometric design embodiment herein run along the circumferential direction of the head 3 of the accumulator piston so as to have the same spacing from one another.

[0021] The tip of the reference arrow of reference sign 7 in FIG. 1 not only points toward the inner wall of the housing 1 but at the same time also toward the inner wall of the housing base. Since the connection ducts 5 and 6 are located as a significant distance from the housing base, a hydraulic connection toward said connection ducts 5 and 6 has to be provided in order for the fluid to be able to escape from the space between the inner wall 7 and the head 3 of the accumulator piston when the accumulator piston 2 moves into the housing 1. For this purpose, the head 3 of the accumulator piston has a through bore 9 which is designed in a T shape.

[0022] A guide strip 10 which is composed of PTFE (polytetrafluoroethylene) and runs so as to be parallel with the pressure-relief grooves 8 is fastened to the circumference of the head 3 of the accumulator piston in the circumferential direction. It is prevented by virtue of the existing pressure-relief grooves 8 that pressure differentials within the housing 1, between the zones located above the axis A and close to the connection ducts 5, 6, and the zones that are located below the axis A and thus at the opposite side of the accumulator piston 2, are formed. Since the pressure conditions on either side of the axis A are thus balanced, the head 3 of the accumulator piston 2 is no longer urged from the central position such that any wear on the guide strip 10 is avoided.

[0023] By contrast to FIG. 1, FIG. 2 shows the high-voltage power switch 12 in the opened position. The spring accumulator 14 is discharged during the opening of the high-voltage power switch 12, so as to provide additional opening energy. The coil spring is relaxed when the spring accumulator 14 is being discharged, on account of which the accumulator piston 2 is moved into the housing 1. The highly pressurized fluid herein is moved through the through bore 9 in the direction of the connection ducts 5 and 6, and from there is conveyed in the direction of the high-pressure duct 11 where said fluid acts on the piston/cylinder assembly so that the opening procedure of the high-voltage power switch 12 is accelerated. The accumulator module in FIG. 2 is shown at the end of the opening procedure, when the head 3 of the accumulator piston 2 has reached the housing base, that is to say when the accumulator piston 2 has been fully retracted into the housing 1.