Pulse actuated hydraulic pump

• US 4,773,218 A
• Filed: 06/18/1986
• Issued: 09/27/1988
• Est. Priority Date: 06/18/1985
• Status: Expired due to Term

• Current Assignee: NGK Spark PLUG Company Limited (Niterra Co., Ltd.)
• Original Assignee: NGK Spark PLUG Company Limited (Niterra Co., Ltd.)
• Inventors: Okuda, Makoto, Ohya, Kanji, Kuwata, Masatoshi, Wakita, Naomasa, Hattori, Shuzo
• Primary Examiner(s): Stout, Donald E.
• Application Number:
  US06/875,690
• Time in Patent Office: 832 Days
• Field of Search: 417/412, 417/322, 417/505, 417/315, 417/472, 60/473, 60/476, 60/493
• US Class Current: 60/476
• CPC Class Codes: F04B 43/095 Piezoelectric drive

Abstract

A pulse-actuated hydraulic pump includes a hydraulic chamber with a bellows having a volume increased or decreased by the selective application a force in an axial direction thereof by a piezoelectric actuator. Control means control electrically-driven valves to selective discharge fluid from the bellows in precisely controllable volumes through a first pumping port or a second pumping port.

Claims

1. A pulse-actuated rotary driving gear comprising:

a bellows hydraulic chamber having a fluid capacity that may be decreased or increased by the selective application of a force applied in the axial direction thereof;

a piezoelectric actuator for applying said force in the axial direction of said bellows hydraulic chamber;

a first pumping port and a second pumping port;

a first electrically-driven valve installed between said bellows hydraulic chamber and said first pumping port having a valve lever and a piezoelectric actuator for displacing said valve lever to open and shut said valve;

a second electrically-driven valve installed between said bellows hydraulic chamber and said second pumping port having a valve lever and a piezoelectric actuator for displacing said valve lever to open and shut said valve;

a pulse supply for applying a pulse voltage to said piezoelectric actuator to generate pressure in the axial direction of said hydraulic chamber; and

control means for implementing a first driving mode including a first discharge step for discharging fluid from said chamber through said first pumping port by opening said first electrically-driven valve and shutting said second electrically-driven valve substantially synchronously with the selective control of said force on said chamber to decrease the capacity of said bellows hydraulic chamber and a first suction step for intaking fluid into said chamber through said second pumping port by shutting said first electrically-driven valve and opening said second electrically-driven valve substantially synchronously with the selective control of said force on said chamber to increase the capacity of said bellows hydraulic chamber, and a second driving mode including a second discharge step for discharging fluid out of said second pumping port by opening said second electrically-driven valve and shutting said first electrically-driven valve substantially synchronously with the selective control of said force on said chamber to decrease the capacity of said bellows hydraulic chamber, and a second suction step for intaking fluid into said first pumping port by shutting said second electrically-driven valve and opening said first electrically-driven valve substantially synchronously with the selective control of said force on said chamber to increase the capacity of said bellows hydraulic chamber;

a first bellows actuator coupled to said first pumping port;

a second bellows actuator coupled to said second pumping port;

a circular piece having a first end connected to said first bellows actuator and a second end connected to said second bellows actuator; and

a rotary shaft driven by said circular piece whereby said shaft is incrementally rotated by said control means operable in said first driving mode or said second driving mode.

2. A pulse-actuated linear reciprocating driving gear comprising:

a bellows hydraulic chamber having a fluid capacity that may be decreased or increased by the selective application of a force applied in the axial direction thereof;

a piezoelectric actuator for applying said force in the axial direction of said bellows hydraulic chamber;

a first pumping port and a second pumping port;

a first electrically-driven valve installed between said bellows hydraulic chamber and said first pumping port having a valve lever and a piezoelectric actuator for displacing said valve lever to open and shut said valve;

a second electrically-driven valve installed between said bellows hydraulic chamber and said second pumping port having a valve lever and a piezoelectric actuator for displacing said valve lever to open and shut said valve;

a pulse supply for applying a pulse voltage to said piezoelectric actuator to generate pressure in the axial direction of said hydraulic chamber; and

control means for implementing a first driving mode including a first discharge step for discharing fluid from said chamber through said first pumping port by opening said first electrically-driven valve and shutting said second electrically-driven valve substantially synchronously with the selective control of said force on said chamber to decrease the capacity of said bellows hydraulic chamber and a first suction step for intaking fluid into said chamber through said second pumping port by shutting said first electrically-driven valve and opening said second electrically-driven valve substantially synchronously with the selective control of said force on said chamber to increase the capacity of said bellows hydraulic chamber, and a second driving mode including a second discharge step for discharging fluid out of said second pumping port by opening said second electrically-driven valve and shutting said first electrically-driven valve substantially synchronously with the selective control of said force on said chamber to decrease the capacity of said bellows hydraulic chamber, and a second suction step for intaking fluid into said first pumping port by shutting said second electrically-driven valve and opening said first electrically-driven valve substantially synchronously with the selective control of said force on said chamber to increase the capacity of said bellows hydraulic chamber;

a first bellows actuator coupled to said first pumping port;

a second bellows actuator coupled to said second pumping port in such a manner that said first and second bellows actuators are linearly arranged and have respective operating ends facing each other; and

a linear travel body arranged between said first and second bellows actuators and having a first end connected to said operating end of said first bellows actuator and a second end connected to said operating end of said second bellows actuator.