Differential cylinder for a hydromechanical drive for electrical circuit breakers

Patent metadata

Field	Value
Publication number	US-9714645-B2
Application number	US-201414171505-A
Country	US
Kind code	B2
Filing date	Feb 3, 2014
Priority date	Aug 3, 2011
Publication date	Jul 25, 2017
Grant date	Jul 25, 2017

Abstract

A differential cylinder for a hydro-mechanical drive for actuating an electric switch, for example, a high-voltage switch, can include a first pressure area to be loaded with an operating pressure, a second pressure area, and a piston which can be moved in a movement range as a function of the pressure difference between the first and second pressure area. A damping device is provided which, during a movement of the piston in the direction of the second pressure area in one section of the movement range, provides damping against the movement of the piston, wherein the damping is adjustable.

First claim

What is claimed is:

1. A differential cylinder for a hydromechanical drive for actuating an electrical switch, comprising:
a first pressure region for supplying with a working pressure;
a second pressure region;
a piston, having a range of movement and which is movable depending on a pressure difference between the first and second pressure regions;
a damping device which, in an event of a movement of the piston in a direction of the second pressure region, provides damping with respect to the movement of the piston in a section of the range of movement, the damping being set automatically, the damping device including:
a damping chamber, having a side wall and a bottom wall;
a plurality of oil passages arranged in the bottom wall, the plurality of oil passages including a first oil passage and a second oil passage; and
a first closure element provided for regulating a damping pressure, the first closure element being clamped securely in place at an end of the plurality of oil passages facing away from the damping chamber such that the first closure element partially closes the first oil passage and closes the second oil passage until the damping pressure in the second oil passage increases, the first closure element having spring properties for regulating the damping pressure.

2. The differential cylinder as claimed in claim 1 , wherein the first closure element clamped securely in place is a spring washer.

3. The differential cylinder as claimed in claim 1 , wherein the damping chamber is arranged at an opposite end of the second pressure region from the piston, and wherein the damping device comprises:
a damping pin projecting on the piston in the direction of the second pressure region, wherein the damping pin and the damping chamber are arranged such that the damping pin projects into the damping chamber in the section of the range of movement and thus separates the second pressure region from the damping chamber.

4. The differential cylinder as claimed in claim 3 , wherein the damping pin and the damping chamber are arranged such that, after the penetration of the damping pin into the damping chamber, there remains a residual gap, which has a predetermined passage cross section.

5. The differential cylinder as claimed in claim 4 , wherein the predetermined passage cross section is arranged such that it brings about a predetermined maximum damping with respect to the movement of the piston.

6. The differential cylinder as claimed in claim 5 , wherein the second closure element and the oil passages, which is fully or partially closed by the first closure element, act as check valves.

7. The differential cylinder as claimed in claim 5 , further comprising:
a second closure element wherein a cross section of the first oil passage is arranged such that, in the event of a movement of the piston in the direction of the second pressure region, the second closure element closes the first oil passage, and wherein a cross section of the second oil passage is arranged such that the second closure element does not fully close the second oil passage and forms a gap through which hydraulic fluid flows.

8. The differential cylinder as claimed in claim 7 , wherein the second closure element and the oil passages, which are fully or partially closed by the first closure element, act as check valves.

9. The differential cylinder as claimed in claim 3 further comprising:
a hydraulic fluid container arranged at the end of the plurality of oil passages facing away from the damping chamber; and
a hydraulic line fluidly connecting the second pressure region to the hydraulic fluid container;
wherein, when the damping pin projects into the damping chamber, the damping pin also separates the damping chamber from the hydraulic line.

10. The differential cylinder as claimed in claim 1 , wherein the spring properties of the first closure element enable the first closure element to bend downwardly away from the second oil passage and expose a cross section through which hydraulic fluid flows when the damping pressure in the second oil passage increases, wherein a size of the cross section increases as the damping pressure increases.

11. A hydromechanical drive for a high-voltage circuit breaker comprising:
a differential cylinder for activating an electrical switch, the differential cylinder including:
a first pressure region for supplying with a working pressure;
a second pressure region;
a piston, having a range of movement and which is movable depending on a pressure difference between the first and second pressure regions;
a damping device which, in an event of a movement of the piston in a direction of the second pressure region, provides damping with respect to the movement of the piston in a section of the range of movement, the damping being set automatically, the damping device including:
a damping chamber, having a side wall and a bottom wall;
a plurality of oil passages arranged in the bottom wall, the plurality of oil passages including a first oil passage and a second oil passage; and
a first closure element provided for regulating a damping pressure, the first closure element being clamped securely in place at an end of the plurality of oil passages facing away from the damping chamber such that the first closure element partially closes the first oil passage and closes the second oil passage until the damping pressure in the second oil passage increases, the first closure element having spring properties for regulating the damping pressure.

12. The hydromechanical drive as claimed in claim 11 , wherein the first closure element clamped securely in place is a spring washer.

13. The hydromechanical drive as claimed in claim 11 , wherein a damping chamber is arranged at an opposite end of the second pressure region from the piston, and wherein the damping device comprises:
a damping pin projecting on the piston in the direction of the second pressure region, wherein the damping pin and the damping chamber are arranged such that the damping pin projects into the damping chamber in the section of the range of movement and thus separates the second pressure region from the damping chamber.

14. The hydromechanical drive as claimed in claim 13 , wherein the damping pin and the damping chamber are arranged such that, after the penetration of the damping pin into the damping chamber, there remains a residual gap, which has a predetermined passage cross section.

15. The hydromechanical drive as claimed in claim 14 , wherein the predetermined passage cross section is arranged such that it brings about a predetermined maximum damping with respect to the movement of the piston.

16. The hydromechanical drive as claimed in claim 15 , wherein the second closure element and the oil passages, which is fully or partially closed by the first closure element, act as check valves.

17. The hydromechanical drive as claimed in claim 15 , comprising:
a second closure element wherein a cross section of the first oil passage is arranged such that, in the event of a movement of the piston in the direction of the second pressure region, the second closure element closes the first oil passage, and wherein a cross section of the second oil passage is arranged such that the second closure element does not fully close the second oil passage and forms a gap through which hydraulic fluid flows.

18. The hydromechanical drive as claimed in claim 15 , wherein the second closure element and the oil passages, which are fully or partially closed by the first closure element, act as ch

Assignees

• Abb Technology Ag
• Abb Schweiz Ag

Inventors

• Schmidt Matthias

Classifications

• F04B19/22 Primary

  of reciprocating-piston type · CPC title

• H01H3/605

  making use of a fluid damper · CPC title

• H01H3/24

  using pneumatic or hydraulic actuator {(for storing energy in a spring motor H01H3/301)} · CPC title

• H01H33/34 Primary

  hydraulic · CPC title

• F16F9/49

  Stops limiting fluid passage, e.g. hydraulic stops {or elastomeric elements inside the cylinder which contribute to changes in fluid damping (fluid-actuated displacement devices with means for accelerating or decelerating the stroke F15B15/22)} · CPC title