Leakage gas recirculation system for use in stirling engine

• US 4,197,707 A
• Filed: 07/03/1978
• Issued: 04/15/1980
• Est. Priority Date: 07/06/1977
• Status: Expired due to Term

• Current Assignee: Nippon Piston Ring Company Limited
• Original Assignee: Nippon Piston Ring Company Limited
• Inventors: Asano, Kenji
• Primary Examiner(s): Ostrager, Allen M.
• Application Number:
  US05/921,678
• Time in Patent Office: 652 Days
• Field of Search: 60/517, 60/521, 60/522, 60/525, 62/6
• US Class Current: 60/517
• CPC Class Codes: F02B 1/04 with fuel-air mixture admission into cylinder
• CPC Class Codes: F02G 1/0535 Seals or sealing arrangements
• CPC Class Codes: F02G 2253/03 Stem seals
• CPC Class Codes: F02G 2270/90 Valves
• CPC Class Codes: F16J 15/004 forming of recuperation chamber for the leaking fluid

Abstract

A leakage gas return device for a Stirling engine includes a pumping cylinder divided into first and second chambers by a piston, one of the chambers for receiving leakage gas from the block seal through a first one way valve and returning the leakage gas to the engine cylinder through a second one way valve. The other chamber is first connected to a low pressure oil source to permit expansion of the first chamber by the leakage gas, and at bottom dead center the second chamber is connected to a high pressure oil source to thereby force the leakage gas back into the engine cylinder.

Claims

1. A leakage gas return device for use in a Stirling engine having a block seal portion to form a seal between a cylinder of the Stirling engine and a piston rod, wherein the improvement is characterized in that said return device comprises:

(a) a pumping cylinder and a piston disposed in said pumping cylinder and having at least one seal means for dividing said pumping cylinder into first and second chambers, said piston being slidable between a bottom dead center position at which the volume of said first chamber is a maximum and a top dead center position at which the volume of said second chamber is a maximum;

(b) a leakage gas intake passage for providing leakage gas from said block seal portion into said first chamber through a first one way valve;

(c) a leakage gas discharge passage for providing the leakage gas in said first chamber into a Stirling engine cylinder through a second one way valve;

(d) a fluid intake and discharge passage connected to said second chamber and selectively communicating with a low pressure fluid source and a high pressure fluid source;

(e) control means for providing communication between said fluid intake and discharge passage and said low pressure fluid source in response to a first control signal and providing communication between said fluid intake and discharge passage and said high pressure fluid source in response to a second control signal; and

(f) switch means switchable between a first position when said piston reaches top dead center and a second position when said piston reaches bottom dead center, said switch means generating said first and second control signals when in its first and second positions, respectively, so that leakage gas from said leakage gas intake passage forces said piston to its bottom dead center position at which time high pressure fluid introduced into said second chamber forces the leakage gas out of said first chamber into said Stirling engine cylinder until said piston reaches top dead center.

2. A leakage gas return device as claimed in claim 1, wherein said fluid is oil.

3. A leakage gas return device as claimed in claims 1 or 2, wherein said control means comprises a solenoid-operated valve having for providing said selective connections between said intake and discharge passage and said low and high pressure fluid sources, and wherein said switch means comprises switches positioned at either end of said pumping cylinder and connected to said solenoid operated valve for providing said first and second control signals.

4. A leakage gas return device as claimed in claim 3, wherein said switches are proximity switches.