Motor vehicle alternator and system for controlling the same

• US 5,763,977 A
• Filed: 07/19/1996
• Issued: 06/09/1998
• Est. Priority Date: 07/21/1995
• Status: Expired due to Fees

• Current Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company)
• Original Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company)
• Inventors: Kato, Hiroaki, Shimasaki, Yuichi, Tsuzuki, Shunichi
• Primary Examiner(s): Stephan, Steven L.
• Assistant Examiner(s): JONES, JUDSON
• Application Number:
  US08/683,956
• Time in Patent Office: 690 Days
• Field of Search: 310/51, 310/156, 310/162, 310/181, 310/191, 310/209, 318/115
• US Class Current: 310/191
• CPC Class Codes: H02K 21/024 Radial air gap machines

Abstract

A motor vehicle alternator connected to an output shaft of an internal combustion engine mounted on a vehicle, comprising a rotor made of a permanent magnet for producing a magnetic field, an armature (stator) having a coil placed opposite to the permanent magnet rotor and a belt drive mechanism for connecting one of the permanent magnet and the armature to the output shaft of the engine to bring them into a relative rotation such that the armature relatively moves in the magnetic field produced by the permanent magnet. In the alternator, there is provided an axial displacement mechanism for displacing at least one of the permanent magnet rotor and the armature in an axial direction of the relative rotation, whereby a magnetic flux passing through the armature is changed. The axial displacement mechanism comprises a solenoid, a plunger housed in the solenoid to be movable when the solenoid is energized and a lever connected to the plunger at one end and to a carrier that carries the armature such that it pivots about a fulcrum to displace the armature in the axial direction of the relative rotation. Other types of the mechanism using a rack and pinion, etc., are used. The operation of mechanism is controlled such that a desired electric power is generated.

Claims

1. A motor vehicle alternator connected to an output shaft of an internal combustion engine mounted on a vehicle, comprising:

a permanent magnet for producing a magnetic field;

an armature placed opposite to the permanent magnet;

a drive mechanism for connecting one of the permanent magnet and the armature to the output shaft of the engine to bring them into a relative rotation such that the armature relatively moves in the magnetic field produced by the permanent magnet; and

an axial displacement mechanism for displacing at least one of the permanent magnet and the armature in an axial direction of the relative rotation, whereby a magnetic flux passing through the armature is changed, said axial displacement mechanism comprising;

a pinion gear;

a motor connected to the pinion gear to rotate it; and

a toothed rack which meshes with the pinion gear and retaining the armature such that, when the pinion gear is rotated by the motor, it moves to displace the armature in the axial direction of the relative rotation, whereby the magnetic flux passing through the armature is changed, wherein the armature has a core-less coil, and the permanent magnet is carried on a carrier made of magnetic substance and having a rim such that the core-less coil of the armature is placed between the rim and the permanent magnet.

2. An alternator according to claim 1, wherein the carrier has a second rim projecting in a direction parallel with the axial direction of the relative rotation and the permanent magnet rests on the second rim.

3. A motor vehicle alternator connected to an output shaft of an internal combustion engine mounted on a vehicle, comprising:

a permanent magnet for producing a magnetic field;

an armature placed opposite to the permanent magnet;

a drive mechanism for connecting one of the permanent magnet and the armature to the output shaft of the engine to bring them into a relative rotation such that the armature relatively moves in the magnetic field produced by the permanent magnet; and

an axial displacement mechanism for displacing at least one of the permanent magnet and the armature in an axial direction of the relative rotation, whereby a magnetic flux passing through the armature is changed, said axial displacement mechanism comprising;

a screw;

a motor connected to the screw to rotate it; and

a retainer having a threaded hole to be meshed with the screw and retaining the armature such that, when the screw is rotated by the motor, it moves to displace the armature in the axial direction of the relative rotation, whereby the magnetic flux passing through the armature is changed,

wherein the armature has a core-less coil, and the permanent magnet is carried on a carrier made of magnetic substance and having a rim such that the core-less coil of the armature is placed between the rim and the permanent magnet.

4. An alternator according to claim 3, wherein the carrier has a second rim projecting in a direction parallel with the axial direction of the relative rotation, and the permanent magnet rests on the second rim.

5. A motor vehicle alternator connected to an output shaft of an internal combustion engine mounted on a vehicle, comprising:

a permanent magnet for producing a magnetic field;

an armature placed opposite to the permanent magnet;

a drive mechanism for connecting one of the permanent magnet and the armature to the output shaft of the engine to bring them into a relative rotation such that the armature relatively moves in the magnetic field produced by the permanent magnet; and

an axial displacement mechanism for displacing at least one of the permanent magnet and the armature in an axial direction of the relative rotation, whereby a magnetic flux passing through the armature is changed, said axial displacement mechanism comprising;

a worm gear; and

a rack meshed with the worm gear and retaining the armature such that, when the worm gear is rotated, it moves to displace the armature in the axial direction of the relative rotation, whereby the magnetic flux passing through the armature is changed,

wherein the armature has a core-less coil, and the permanent magnet is carried on a carrier made of magnetic substance and having a rim such that the core-less coil of the armature is placed between the rim and the permanent magnet.

6. An alternator according to claim 5, wherein the carrier has a second rim projecting in a direction parallel with the axial direction of the relative rotation, and the permanent magnet rests on the second rim.

7. A system for controlling electric power generated by an alternator connected to an output shaft of an internal combustion engine mounted on a vehicle, the engine including an exhaust system with a catalytic convertor therein, with the catalytic convertor having a heater connected to the alternator, and being supplied with current from the alternator, said system comprising:

a permanent magnet for producing a magnetic field;

an armature placed opposite to the permanent magnet;

a drive mechanism for connecting one of the permanent magnet and the armature to the output shaft of the engine to bring them into a relative rotation such that the armature relatively moves in the magnetic field produced by the permanent magnet; and

a magnetic flux changing mechanism for changing a magnetic flux through the armature;

heater current supply determining means for determining whether the current should be provided from the alternator to the heater;

desired electric power determining means for determining a desired amount of electric power to be generated by the alternator in response to the determination of the heater current supply determining means; and

means for controlling the magnetic flux changing mechanism such that the desired amount of electric power is generated.

8. A system according to claim 7, further including:

engine operating condition detecting means for detecting parameters indicative of operating conditions of the engine;

wherein said desired electric power determining means determines the desired amount of electric power in response to the determination of the heater current supply determining means and the detected parameters.

9. A system according to claim 7, wherein the magnetic flux changing mechanism co rises an axial displacement mechanism for displacing at least one of the permanent magnet and the armature in an axial direction of the relative rotation, whereby a magnetic flux passing through the armature is changed.

10. A method for controlling electric power generated by an alternator connected to an output shaft of an internal combustion engine mounted on a vehicle, the engine including an exhaust system with a catalytic convertor therein, with the catalytic convertor having a heater connected to the alternator, and being supplied with current from the alternator, said method comprising the steps of:

a permanent magnet for producing a magnetic field;

an armature placed opposite to the permanent magnet;

a drive mechanism for connecting one of the permanent magnet and the armature to the output shaft of the engine to bring them into a relative rotation such that the armature relatively moves in the magnetic field produced by the permanent magnet; and

a magnetic flux changing mechanism for a changing magnetic flux passing through the armature;

determining whether the current should be supplied from the alternator to the heater;

determining a desired amount of electric power to be generated by the alternator in response to the determination of whether the current should be supplied to the heater; and

controlling the magnetic flux changing mechanism such that the desired amount of electric power is generated.

12. A method according to claim 10, wherein the magnetic flux changing mechanism comprises an axial displacement mechanism for displacing at least one of the permanent magnet and the armature in an axial direction of the relative rotation, whereby a magnetic flux passing through the armature is changed.

11. A method according to claim 19, further including:

detecting parameters indicative of operating conditions of the engine; and

determining the desired amount of electric power in response to the determination of the heater current supply determining means and the detected parameters.