Hydraulic drive for a switchgear

Patent metadata

Field	Value
Publication number	US-10229799-B2
Application number	US-201615552590-A
Country	US
Kind code	B2
Filing date	Feb 10, 2016
Priority date	Mar 6, 2015
Publication date	Mar 12, 2019
Grant date	Mar 12, 2019

Abstract

A switchgear driving device has a rod coupled to a movable electrode; an operation piston connected to the rod; and an operation cylinder in which an operation piston slides. A main control valve controls the pressure of the hydraulic oil in the operation cylinder. A turning-on pressure accumulation piston slides inside a turning-on pressure accumulation chamber; and a turning-on pressure accumulation spring imparts a driving force to the turning-on pressure accumulation piston to pressurize the hydraulic oil within the turning-on pressure accumulation chamber. A turning-off pressure accumulation piston slides inside a turning-off pressure accumulation chamber. A turning-off pressure accumulation spring imparts a driving force to the turning-off pressure accumulation piston to pressurize the hydraulic oil in the turning-off pressure accumulation chamber. A spring case accommodates the turning-on pressure accumulation spring and the turning-off pressure accumulation spring, wherein the turning-off pressure accumulation spring is arranged inside the turning-on pressure accumulation spring.

First claim

The invention claimed is:

1. A switchgear driving device that effects turning-on/off of contacts including a stationary electrode and a movable electrode by using a hydraulic oil,
the switchgear driving device comprising:
a rod coupled to the movable electrode;
an operation piston connected to the rod;
a fluid pressure mechanism part including an operation cylinder in which the operation piston slides, a turning-on pressure accumulation chamber and a turning-off pressure accumulation chamber effecting pressure accumulation on the hydraulic oil for turning-on/off, and a main control valve controlling the pressure of the hydraulic oil in the operation cylinder;
a turning-on pressure accumulation piston sliding inside the turning-on pressure accumulation chamber;
a turning-on pressure accumulation spring that imparts a driving force to the turning-on pressure accumulation piston to pressurize the hydraulic oil within the turning-on pressure accumulation chamber;
a turning-off pressure accumulation piston sliding inside the turning-off pressure accumulation chamber;
a turning-off pressure accumulation spring that imparts a driving force to the turning-off pressure accumulation piston to pressurize the hydraulic oil in the turning-off pressure accumulation chamber; and
a spring case accommodating the turning-on pressure accumulation spring and the turning-off pressure accumulation spring,
wherein the turning-off pressure accumulation spring is arranged inside the turning-on pressure accumulation spring,
wherein the turning-on pressure accumulation spring and the turning-off pressure accumulation spring are constituted by coil springs that are arranged concentrically, and
wherein with a center of the turning-on pressure accumulation spring and of the turning-off pressure accumulation spring serving as a reference, the turning-off pressure accumulation chamber and the turning-off pressure accumulation piston are arranged on an inner side, and the turning-on pressure accumulation chamber and the turning-on pressure accumulation piston are arranged on an outer side.

2. The switchgear driving device according to claim 1 , wherein
the operation piston is configured such that an inside of the operation cylinder is divided into a small pressure receiving area chamber placed on a side of the contacts and a cylinder control chamber placed on a side opposite the small pressure receiving area chamber,
the turning-off pressure accumulation chamber is connected to the small pressure receiving area chamber via a path through which the hydraulic oil passes, and
the turning-off pressure accumulation piston is slidably arranged inside the turning-off pressure accumulation chamber, and the turning-off pressure accumulation spring is constructed such that an accumulated pressure of the turning-off pressure accumulation spring is imparted to the hydraulic oil in the turning-off pressure accumulation chamber via the turning-off pressure accumulation piston, and
the turning-on pressure accumulation piston is slidably arranged inside the turning-on pressure accumulation chamber, and the turning-on pressure accumulation spring is constructed such that an accumulated pressure of the turning-on pressure accumulation spring is imparted to the hydraulic oil in the turning-on pressure accumulation chamber via the turning-on pressure accumulation piston.

3. The switchgear driving device according to claim 2 , wherein
the spring case is formed in a cylindrical configuration having a bottom section, and is equipped with a fluid pressure driving part arranged so as to close the spring case on the side opposite the bottom section of the spring case, with the fluid pressure mechanism part being constructed from a pressure accumulation chamber part, a cylinder part, and a main control valve part;
the pressure accumulation chamber part is equipped with the at least one turning-on pressure accumulation chamber formed by a cylindrical hole section open to the spring case side, and the at least one turning-off pressure accumulation chamber formed by a cylindrical hole section open to the spring case side;
the cylinder part is fixed to the pressure accumulation chamber part and equipped with thereinside an operation cylinder in which the operation piston slides;
the operation cylinder is installed so as to be perpendicular to an operational direction of the turning-on pressure accumulation spring and/or the turning-off pressure accumulation spring, and the operation piston slides inside the operation cylinder in a direction perpendicular to the operational direction of the turning-on pressure accumulation spring and/or the turning-off pressure accumulation spring,
wherein the main control valve part operates through a change in the hydraulic oil pressure due to an operation of the main control valve, and allows a selective connection of the cylinder control chamber to the turning-on pressure accumulation chamber side or to a tank side.

4. The switchgear driving device according to claim 2 , wherein
the spring case is formed in a cylindrical configuration having a bottom section, and a hole section is provided at the bottom section of the spring case;
a cylinder accommodating part is fixed to the hole section; and
the fluid pressure mechanism part is fixed to the side opposite the bottom section of the spring case.

5. The switchgear driving device according to claim 4 , wherein
in the fluid pressure mechanism part, a main control valve including an opening main control valve and a closing main control valve, the turning-on pressure accumulation chamber, and piping connecting them to each other are arranged;
the closing main control valve is arranged halfway through a flow path communicating the cylinder control chamber with the turning-on pressure accumulation chamber to each other, with the flow path between them being opened and closed; and
the opening main control valve is arranged halfway through a flow path communicating the cylinder control chamber with the tank to each other, with the flow path between them being opened and closed.

6. The switchgear driving device according to claim 4 , wherein
the turning-on pressure accumulation chamber is formed as at least one chamber of a cylindrical configuration, and is formed so as to have an open section to the inner side of the spring case;
the turning-on pressure accumulation piston is equipped with a disk part having a hole formed at a center thereof, and at least one cylindrical part that is the same number as that of the turning-on pressure accumulation chamber, the cylindrical part having a configuration protruding toward the disk part;
the cylindrical parts are arranged so as to be capable of sliding inside the turning-on pressure accumulation chamber;
one end of the turning-on pressure accumulation spring is arranged in contact with the disk part on a side opposite the cylindrical parts of the turning-on pressure accumulation piston, and other end of the turning-on pressure accumulation spring is arranged in contact with the bottom section of the spring case,
wherein the turning-off pressure accumulation piston is equipped with a disk part, and at least one cylindrical part of a configuration protruding toward the disk part;
the cylindrical part is arranged so as to be slidable inside the turning-off pressure accumulation chamber;
one end of the turning-off pressure accumulation spring is arranged in contact with the fluid pressure mechanism part on an inner side of the turning-on pressure accumulation chamber with the center of the disk part as a reference, and other end thereof is arranged in contact with the turning-off pressure accumulation piston; and
the turning-off pressure accumulation spring is arranged so as to be capable of expanding and

Assignees

• Hitachi Ltd

Inventors

• Seto Shinji
• Ebisawa Daisuke
• Hashimoto Hiroaki

Classifications

• H01H33/302

  for fluid insulated switchgear, wherein the insulating fluid is also the working fluid · CPC title

• H01H3/24

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

• H01H33/30

  using fluid actuator · CPC title

• H01H33/34 Primary

  hydraulic · CPC title

• H01H3/3026

  in which the closing spring charges the opening spring or vice versa · CPC title