Outboard motor with a charge air cooler

• US 6,408,832 B1
• Filed: 09/28/2001
• Issued: 06/25/2002
• Est. Priority Date: 03/26/2001
• Status: Expired due to Term

• Current Assignee: Brunswick Corporation
• Original Assignee: Brunswick Corporation
• Inventors: Christiansen, Erik J.
• Primary Examiner(s): Denion, Thomas
• Assistant Examiner(s): TRIEU, THAI BA
• Application Number:
  US09/966,017
• Time in Patent Office: 270 Days
• Field of Search: 123/564, 123/65.BA, 123/539.1, 123/311, 123/563, 605/99, 417/406, 440/88, 440/89
• US Class Current: 123/563
• CPC Class Codes: F02B 29/0418 the intake air cooler having a bypass or multiple flow paths within the heat exchanger to vary the effective heat transfer surface
• CPC Class Codes: F02B 29/0437 Liquid cooled heat exchangers
• CPC Class Codes: F02B 33/36 of positive-displacement type
• CPC Class Codes: F02B 33/446 having valves for admission of atmospheric air to engine, e.g. at starting
• CPC Class Codes: F02B 61/045 for outboard marine engines
• CPC Class Codes: F02M 69/044 for injecting into the intake conduit downstream of an air throttle valve
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies

Abstract

An outboard motor is provided with an engine having a screw compressor which provides a pressurized charge for the combustion chambers of the engine. The screw compression has first and second screw rotors arranged to rotate about vertical axes which are parallel to the axes of a crankshaft of the engine. A bypass valve regulates the flow of air through a bypass conduit extending from an outlet passage of the screw compressor to the inlet passage of the screw compressor. A charge air cooler is used in a preferred embodiment and the bypass conduit then extends between the cold side plenum of the charge air cooler and the inlet of the compressor. The charge air cooler improves the operating efficiency of the engine and avoids overheating the air as it passes through the supercharger after flowing through the bypass conduit. The bypass valve is controlled by an engine control module in order to improve power output from the engine at low engine speeds is while avoiding any violation of existing limits on the power of the engine at higher engine speeds.

Claims

1. An outboard motor, comprising:

an internal combustion engine having a plurality of cylinders, each of said plurality of cylinders each having one of a plurality of pistons slidably disposed therein for reciprocal movement;

a crankshaft driven by said plurality of pistons of said engine and supported within said engine for rotation about a vertical axis;

a supercharger having an inlet passage and an outlet passage, said supercharger being a screw compressor comprising a first screw rotor rotatable about a first rotor axis and a second screw rotor rotatable about a second rotor axis, said first and second rotor axes being parallel to said vertical axis, said screw compressor being connected in torque transmitting relation with said crankshaft;

a propulsor connected in torque transmitting relation with said crankshaft;

an air conduit connected in fluid communication with said plurality of cylinders to direct a flow of charge air from said supercharger to said plurality of cylinders, said outlet passage being connected in fluid communication with said air conduit;

a heat exchanger disposed in fluid communication with said air conduit between said supercharger and said plurality of cylinders and in thermal communication with said flow of charge air to reduce the temperature of said charge air prior to said flow of charge air entering said plurality of cylinders;

a bypass conduit disposed in fluid communication between said air conduit and said inlet passage of said supercharger; and

a bypass valve disposed within said bypass conduit to control the flow of air from said outlet passage to said inlet passage, said bypass conduit is disposed in fluid communication between said first conduit of said heat exchanger and said inlet passage of said supercharger.

2. The outboard motor of claim 1, wherein:

said heat exchanger is a charge air cooler comprising first and second conduits disposed in thermal communication with each other, said first conduit being configured to direct said flow of charge air through said charge air cooler and to said plurality of cylinders, said second conduit being configured to direct a flow of cooling water from a water inlet of said charge air cooler to a water outlet of said charge air cooler, said first and second being configured to separate said flow of cooling water from said flow of charge air.

3. The outboard motor of claim 2, wherein:

said first and second conduits are disposed within a housing of said charge air cooler.

4. The outboard motor of claim 1, wherein:

said internal combustion engine is a four cycle internal combustion engine.

5. The outboard motor of claim 1, wherein:

said bypass conduit is disposed in fluid communication between a charge air outlet of said first conduit of said heat exchanger and said inlet passage of said supercharger.

6. The outboard motor of claim 1, wherein:

said screw compressor is attached to said internal combustion engine at a front side of said internal combustion engine.

7. The outboard motor of claim 1, wherein:

said screw compressor is connected in torque transmitting relation with said crankshaft by an arrangement of two pulleys and an interconnecting belt.

8. The outboard motor of claim 1, wherein:

said screw compressor is attached to said internal combustion engine at a front side of said internal combustion engine.

9. The outboard motor of claim 8, wherein:

said screw compressor is connected in torque transmitting relation with said crank shaft by an arrangement of two pulleys and an interconnecting belt.

10. An outboard motor, comprising:

an internal combustion engine having a plurality of cylinders, each of said plurality of cylinders each having one of a plurality of pistons slidably disposed therein for reciprocal movement;

a crankshaft driven by said plurality of pistons of said engine and supported within said engine for rotation about a vertical axis;

a propulsor connected in torque transmitting relation with said crankshaft;

a supercharger having an inlet passage and an outlet passage, said supercharger is a screw compressor comprising a first screw rotor rotatable about a first rotor axis and a second screw rotor rotatable about a second rotor axis, said first and second rotor axes being parallel to said vertical axis, said screw compressor being attached to said internal combustion engine at a front side of said internal combustion engine, said screw compressor being connected in torque transmitting relation with said crankshaft;

an air conduit connected in fluid communication with said plurality of cylinders to direct a flow of charge air from said supercharger to said plurality of cylinders, said outlet passage being connected in fluid communication with said air conduit; and

a heat exchanger disposed in fluid communication with said air conduit between said supercharger and said plurality of cylinders and in thermal communication with said flow of charge air to reduce the temperature of said charge air prior to said flow of charge air entering said plurality of cylinders, said heat exchanger is a charge air cooler comprising first and second conduits disposed within a housing of said charge air cooler and in thermal communication with each other, said first conduit being configured to direct said flow of charge air through said charge air cooler and to said plurality of cylinders, said second conduit being configured to direct a flow of cooling water from a water inlet of said charge air cooler to a water outlet of said charge air cooler, said first and second being configured to separate said flow of cooling water from said flow of charge air.

11. The outboard motor of claim 10, wherein:

said internal combustion engine is a four cycle internal combustion engine.

12. An outboard motor, comprising:

a four cycle internal combustion engine having a plurality of cylinders, each of said plurality of cylinders each having one of a plurality of pistons slidably disposed therein for reciprocal movement;

a crankshaft driven by said plurality of pistons of said engine and supported within said engine for rotation about a vertical axis;

a propulsor connected in torque transmitting relation with said crankshaft;

an air conduit connected in fluid communication with said plurality of cylinders to direct a flow of charge air to said plurality of cylinders;

a heat exchanger disposed in fluid communication with said air conduit and in thermal communication with said flow of charge air to reduce the temperature of said charge air prior to said flow of charge air entering said plurality of cylinders; and

a supercharger having an inlet passage and an outlet passage, said outlet passage being connected in fluid communication with said air conduit said supercharger being a screw compressor comprising a first screw rotor rotatable about a first rotor axis and a second screw rotor rotatable about a second rotor axis, said first and second rotor axes being parallel to said vertical axis, said screw compressor being connected in torque transmitting relation with said crankshaft.

13. The outboard motor of claim 12, wherein:

said heat exchanger is a charge air cooler comprising first and second conduits disposed in thermal communication with each other, said first and second conduits being disposed within a housing of said charge air cooler, said first conduit being configured to direct said flow of charge air through said charge air cooler and to said plurality of cylinders, said second conduit being configured to direct a flow of cooling water from a water inlet of said charge air cooler to a water outlet of said charge air cooler, said first and second being configured to separate said flow of cooling water from said flow of charge air.

14. The outboard motor of claim 13, further comprising:

a bypass conduit disposed in fluid communication between a charge air outlet of said first conduit of said heat exchanger and said inlet passage of said supercharger, said screw compressor being attached to said internal combustion engine at a front side of said internal combustion engine; and

a bypass valve disposed within said bypass conduit to control the flow of air from said outlet passage to said inlet passage.