Turbocharged engine driven positive displacement blower having a bypass passage

• US 4,502,283 A
• Filed: 09/24/1982
• Issued: 03/05/1985
• Est. Priority Date: 09/24/1982
• Status: Expired due to Fees

• Current Assignee: General Motors Corporation (Motors Liquidation Co. GUC Trust)
• Original Assignee: General Motors Corporation (Motors Liquidation Co. GUC Trust)
• Inventors: Wandel, David M.
• Primary Examiner(s): KOCZO JR, MICHAEL
• Application Number:
  US06/422,892
• Time in Patent Office: 893 Days
• Field of Search: 60/609, 60/611, 60/610, 123/564, 417/301, 417/310, 417/253
• US Class Current: 60/609
• CPC Class Codes: F02B 37/04 Engines with exhaust drive and other drive of pumps, e.g. with exhaust-driven pump and mechanically-driven second pump
• CPC Class Codes: F02B 37/16 by bypassing charging air
• CPC Class Codes: F16L 37/26 in which the connection is made by transversely moving the parts together, with or without their subsequent rotation
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies

Abstract

A turbocharged internal combustion engine, preferably of the two-stroke cycle type, is provided with a Roots type positive displacement charging blower having a bypass passage in one end plate and controlled by a single plunger control valve responsive solely to blower outlet pressure to provide for bypassing air flow around the blower under various engine operating conditions either in reverse direction to reduce excess blower power or in the direction of flow to provide additional charging air.

Claims

1. The combination of an intake air supply system with an internal combustion engine having a cylinder charging air intake and an exhaust discharge, said intake air supply system including

an engine driven positive displacement blower having inlet and outlet means and an exhaust gas driven turbo-compressor connected in series whereby the compressor discharges to the blower inlet and the blower outlet discharges to the engine air intake,

a bypass passage connecting the blower inlet and outlet,

a pressure responsive control valve means in the bypass passage to control the flow of fluid through the bypass, and the improvement wherein said control valve means is operative to open and maintain open said bypass passage solely in response to the existence of predetermined superambient levels of pressure on the blower outlet side of the control valve means, whereby said control valve means permits bypass flow, substantially upon reaching or exceeding a predetermined blower discharge pressure, either (a) to recirculate air flow from the blower outlet to the inlet to reduce or limit the engine power absorbed by the blower or (b) to conduct additional air flow around the blower directly from the turbo-compressor to the engine intake to avoid the restriction of the blower to increased charging air flow, thereby providing a dual function capability in a single control valve means.

4. The combination of claim 1 wherein said control valve means comprises

a valve seat in the passage between said inlet and outlet, and

a reciprocable plunger slidable on an axis and biased toward and seatable on said valve seat, said plunger having an end wall transverse to said axis and exposed to blower outlet pressure on the far side of said valve seat, said plunger further having a side wall parallel with said axis and exposed to blower inlet pressure on the near side of said valve seat, whereby said control valve means is responsive solely to blower outlet pressure to open or close said bypass passage.

2. The combination of an intake air supply system with an internal combustion engine having a cylinder charging air intake and an exhaust discharge, said intake air supply system including

an engine driven positive displacement blower having inlet and outlet means and an exhaust gas driven turbo-compressor connected in series whereby the compressor discharges to the blower inlet and the blower outlet discharges to the engine air intake,

said blower having a housing rotatably supporting a pair of mating impellers in an enclosed chamber having inlet and outlet zones respectively connected with the compressor and the engine air intake and defined in part by an end plate at one end of the housing supporting adjacent ends of said impellers, and the improvement comprising

a bypass passage through the end plate and connecting the blower inlet and outlet zones to bypass air around the impellers, and

a pressure responsive control valve means in the bypass passage to control the flow of fluid through the bypass, said control valve means being operative to open and maintain open said bypass passage solely in response to predetermined superambient levels of pressure on the blower outlet side of the control valve means, whereby said control valve means permits bypass flow, substantially upon reaching of a predetermined blower discharge pressure, either (a) to recirculate air flow from the blower outlet to the inlet to reduce or limit the engine power absorbed by the blower or (b) to conduct additional air flow around the blower directly from the turbo-compressor to the engine intake to avoid the restriction of the blower to increased charging air flow, thereby providing a dual function capability in a single control valve means.

5. The combination of claim 2 wherein said control valve means comprises

a valve seat in the passage between said inlet and outlet zones, and

a reciprocable plunger slidable on an axis and biased toward and seatable on said valve seat, said plunger having an end wall transverse to said axis and exposed to blower outlet pressure on the far side of said valve seat, said plunger further having a side wall parallel with said axis and exposed to blower inlet pressure on the near side of said valve seat, whereby said control valve means is responsive solely to blower outlet pressure to open or close said bypass passage.

3. The combination with an internal combustion engine having an air intake of an air supply system comprising

an exhaust driven turbo-compressor supplying air to the engine air intake and

a Roots blower connected between the compressor and the air intake to supplement the supply of air thereto, said blower having

a housing defining an enclosed chamber in which a pair of mating impellers are rotatable on parallel axes to positively displace fluids from an inlet zone on one side of the chamber to an outlet zone on the other side thereof,

inlet and outlet openings into the housing at the inlet and outlet zones to respectively induct fluids to and discharge fluids from the chamber,

the housing including an end plate closing one end of the chamber and lying in close proximity with adjacent ends of said impellers, said end plate partially defining said chamber including portions of both said inlet and outlet zones,

a bypass passage in said end plate and extending between spaced openings to said inlet and outlet zones, said passage providing a bypass around the blower impellers, and

a pressure responsive control valve mounted in said end plate and extending into said bypass passage to control fluid flow therethrough, said control valve comprising

a valve seat in the passage between said passage openings, and

a reciprocable plunger slidable on an axis and biased toward and seatable on said valve seat, said plunger having an end wall transverse to said axis and exposed to blower outlet pressure on the far side of said valve seat, said plunger further having a side wall parallel with said axis and exposed to blower inlet pressure on the near side of said valve seat, whereby said control valve is responsive solely to blower outlet pressure to open or close said bypass passage.