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 comprising: a pressure-tight housing; an accumulator piston that protrudes into the housing and is axially movable in the housing between a first end of the housing and a second end of the housing, the accumulator piston comprising: a head having a first diameter; the head comprising a terminal surface facing towards the second end of the housing and a circumference peripherally connected with the terminal surface; a guide strip fastened to the circumference of the head, the guide strip having a second diameter greater than the first diameter, the guide strip configured to contact an inner wall of the housing during an operation of the accumulator module to maintain a gap between the circumference of the head and the inner wall, the inner wall having a third diameter greater than the first diameter; and at least one pressure-relief groove in the head, the at least one pressure-relief groove disposed around the circumference of the head; a closure cover that closes the first end of the housing in a pressure-tight manner; and a pair of connection ducts in the housing, for conveying a highly pressurized fluid to a high-pressure duct located outside the housing, such that the highly pressurized fluid is located in the gap between the inner wall of the housing and the head of the accumulator piston during the operation of the accumulator module, and such that the guide strip is maintained between the second end of the housing and the pair of connection ducts when the accumulator piston is in contact with the first end of the housing, the pair of connection ducts comprising a first connection duct maintained between the first end of the housing and the at least one pressure-relief groove during the entire operation of the accumulator module, and a second connection duct located between the second end of the housing and the at least one pressure-relief groove during a portion of the operation of the accumulator module, the guide strip fastened to the circumference of the head in between the terminal surface of the head and the at least one pressure-relief groove, the accumulator piston further comprising a single through-bore comprising an axial bore portion and a radial bore portion, the axial bore portion axially traversing into the terminal surface of the head and extending on a longitudinal axis of the accumulator piston, the radial bore portion radially traversing through the circumference of the head and not traversing into the at least one pressure-relief groove, the axial bore portion substantially perpendicular to the radial bore portion and in fluid communication with the axial bore portion, the axial bore portion configured to allow the highly pressurized fluid to flow between a base of the housing and the radial bore portion, the radial bore portion configured to allow the highly pressurized fluid to flow between the axial bore portion and the pair of connection ducts, and the at least one pressure-relief groove positioned in between the guide strip and the radial bore portion, so as to maintain the pressure-relief effect provided by the at least one pressure-relief groove.

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 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 guide strip is disposed so as to be parallel with the at least one pressure-relief groove.

4. The accumulator module as claimed in claim 1, wherein the guide strip comprises polytetrafluoroethylene.

5. The accumulator module as claimed in claim 1, 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 be disposed within the housing between the at least one pressure-relief groove and the second end of the housing.

6. The accumulator module as claimed in claim 1, wherein the closure cover is configured to axially guide the accumulator piston.

7. The accumulator module as claimed in claim 1, wherein a first distance between one of the pair of connection ducts and the closure cover is less than a second distance between the at least one pressure-relief groove and the closure cover during the operation of the accumulator module.

8. The accumulator module as claimed in claim 1, wherein the second connection duct is between the first end of the housing and the at least one pressure-relief groove during another portion of the operation of the accumulator module.

9. The accumulator module as claimed in claim 1, wherein the first connection duct of the pair of connection ducts is narrower than the second connection duct of the pair of connection ducts.

10. The accumulator module as claimed in claim 9, wherein the first connection duct is located between the second connection duct and the first end of the housing.

11. A hydromechanical spring-loaded drive comprising: 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 between a first end of the housing and a second end of the housing, the accumulator piston comprising: a head having a first diameter; the head comprising a terminal surface facing towards the second end of the housing and a circumference peripherally connected with the terminal surface; a guide strip fastened to the circumference of the head, the guide strip having a second diameter greater than the first diameter, the guide strip configured to contact an inner wall of the housing during an operation of the accumulator module to maintain a gap between the circumference of the head and the inner wall, the inner wall having a third diameter greater than the first diameter; and at least one pressure-relief groove in the head, the at least one pressure-relief groove disposed around the circumference of the head; a closure cover that closes the first end of the housing in a pressure-tight manner; a pair of connection ducts in the housing, for conveying a highly pressurized fluid to a high-pressure duct located outside the housing, such that the highly pressurized fluid is located in the gap between the inner wall of the housing and the head of the accumulator piston during the operation of the accumulator module, and such that the guide strip is maintained between the second end of the housing and the pair of connection ducts when the accumulator piston is in contact with the first end of the housing; and a spring accumulator coupled to the piston, the guide strip fastened to the circumference of the head in between the terminal surface of the head and the at least one pressure-relief groove, the accumulator piston further comprising a single through-bore comprising an axial bore portion and a radial bore portion, the axial bore portion axially traversing into the terminal surface of the head and extending on a longitudinal axis of the accumulator piston, the radial bore portion radially traversing through the circumference of the head and not traversing into the at least one pressure-relief groove, the axial bore portion substantially perpendicular to the radial bore portion and in fluid communication with the axial bore portion, the axial bore portion configured to allow the highly pressurized fluid to flow between a base of the housing and the radial bore portion, the radial bore portion configured to allow the highly pressurized fluid to flow between the axial bore portion and the pair of connection ducts, and the at least one pressure-relief groove positioned in between the guide strip and the radial bore portion, so as to maintain the pressure-relief effect provided by the at least one pressure-relief groove.

12. The hydromechanical spring-loaded drive as claimed in claim 11, wherein the at least one pressure-relief groove comprises at least two pressure-relief grooves of the same geometric design 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.

13. The hydromechanical spring-loaded drive as claimed in claim 11, 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 be disposed within the housing between the at least one pressure-relief groove and the second end of the housing.

14. The hydromechanical spring-loaded drive as claimed in claim 11, wherein the closure cover is configured to axially guide the accumulator piston.

15. The hydromechanical spring-loaded drive as claimed in claim 11, wherein a first distance between one of the pair of connection ducts and the closure cover is less than a second distance between the at least one pressure-relief groove and the closure cover during the operation of the accumulator module.

16. The hydromechanical spring-loaded drive as claimed in claim 11, wherein one of the pair of connection ducts is maintained between the first end of the housing and the at least one pressure-relief groove during the entire operation of the accumulator module, and the other of the pair of connection ducts is located between the second end of the housing and the at least one pressure-relief groove during a portion of the operation of the accumulator module.

17. The hydromechanical spring-loaded drive as claimed in claim 16, wherein the other of the pair of connection ducts is between the first end of the housing and the at least one pressure-relief groove during another portion of the operation of the accumulator module.

18. An accumulator module comprising: a pressure-tight housing; an accumulator piston that protrudes into the housing and is axially movable in the housing between a first end of the housing and a second end of the housing, the accumulator piston comprising: a head having a first diameter; the head comprising a terminal surface facing towards the second end of the housing and a circumference peripherally connected with the terminal surface; a guide strip fastened to the circumference of the head, the guide strip having a second diameter greater than the first diameter, the guide strip configured to contact an inner wall of the housing during an operation of the accumulator module to maintain a gap between the circumference of the head and the inner wall, the inner wall having a third diameter greater than the first diameter; and at least one pressure-relief groove in the head, the at least one pressure-relief groove disposed around the circumference of the head; a closure cover that closes the first end of the housing in a pressure-tight manner; and a pair of connection ducts in the housing, for conveying a highly pressurized fluid to a high-pressure duct located outside the housing, such that the highly pressurized fluid is located in the gap between the inner wall of the housing and the head of the accumulator piston during the operation of the accumulator module, and such that the guide strip is maintained between the second end of the housing and the pair of connection ducts when the accumulator piston is in contact with the first end of the housing, the pair of connection ducts comprising a first connection duct and a second connection duct that is narrower than the first connection duct, the guide strip fastened to the circumference of the head in between the terminal surface of the head and the at least one pressure-relief groove, the accumulator piston further comprising a single through-bore comprising an axial bore portion and a radial bore portion, the axial bore portion axially traversing into the terminal surface of the head and extending on a longitudinal axis of the accumulator piston, the radial bore portion radially traversing through the circumference of the head and not traversing into the at least one pressure-relief groove, the axial bore portion substantially perpendicular to the radial bore portion and in fluid communication with the axial bore portion, the axial bore portion configured to allow the highly pressurized fluid to flow between a base of the housing and the radial bore portion, the radial bore portion configured to allow the highly pressurized fluid to flow between the axial bore portion and the pair of connection ducts, and the at least one pressure-relief groove positioned in between the guide strip and the radial bore portion, so as to maintain the pressure-relief effect provided by the at least one pressure-relief groove.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention and a potential design embodiment will be explained and described in more detail by means of the figures hereunder.

(2) In the figures:

(3) 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

(4) 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.

DETAILED DESCRIPTION OF THE DRAWINGS

(5) 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.

(6) 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.

(7) 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. In this example, connection duct 6 is narrower than connection duct 5. For this purpose, the head 3 of the accumulator piston has a through bore 9 which is designed in a T shape.

(8) 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 2 in the circumferential direction. By virtue of the pressure-relief grooves 8, 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 prevented. 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 wear on the guide strip 10 is avoided.

(9) 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.