BUFFERING DEVICE FOR THE OPERATING MECHANISM OF A SWITCHGEAR, AND METHOD OF LUBRICATION THEREOF

摘要

A piston rod (15) and a first piston (13) are arranged in the interior of an external cylinder (11) and internal cylinder (12); a second piston for absorbing the change of volume of operating fluid (24) is also arranged therein. Also, a first return spring (18) for returning the piston rod (15) to the interruption position is provided and a second return spring (20) for returning the operating fluid 24 into the high-pressure chamber (25) by pressurizing the second piston (14) is provided. In addition, the air in the interior of the buffering device (10) is withdrawn by a vacuum pump (38), and operating fluid (24) is thus introduced in a degassed condition.

主权项

1. A buffering device employed in an operating mechanism whereby opening/closing action of a switchgear is performed by reciprocal drive of a moving body including an electrical contact between open and closed positions, for reducing the speed of said moving body in a vicinity of termination of an action of a switchgear, said buffering device comprising:
(1) an external cylinder and internal cylinder that are provided on a same central axis; (2) a first piston arranged within said internal cylinder, freely slidably arranged on said same central axis; (3) a second piston respectively arranged within said external cylinder freely slidably arranged on said same central axis; (4) a piston rod freely slidably arranged with respect to said first piston and said second piston; (5) a packing fixed in said second piston in a sliding portion of said external cylinder and said piston rod; (6) a first return spring seat that is fitted at an end of said piston rod, in order to restrict a range of movement of said first piston; (7) a first return spring that is arranged between an end of said internal cylinder and said first return spring seat; (8) a second return spring seat that is fixed on said same central axis within said external cylinder; (9) a second return spring that is arranged between said second piston and said second return spring seat; (10) an oil return path that is formed between said piston rod and said first return spring seat and one end of which is opened/closed by sliding action of said first piston; (11) a plurality of through-holes formed in an axial direction in said internal cylinder; (12) a plug having a packing, that is fixed at an end of said internal cylinder; (13) a high-pressure chamber formed by a space defined by said external cylinder, said internal cylinder, said plug, said second piston and said piston rod, said plug being linked with a drive portion of said operating mechanism; (14) an operating fluid that is sealed in said high-pressure chamber, constructed in such a way that braking force is generated by compression of said operating fluid by said piston rod being forced into said high-pressure chamber on drive of said operating mechanism, wherein gas such as air is removed from said operating fluid beforehand in an interior of a vacuum container.