Brushless alternator

• US 4,918,343 A
• Filed: 10/13/1988
• Issued: 04/17/1990
• Est. Priority Date: 10/13/1988
• Status: Expired due to Fees

• Current Assignee: Kohler Company
• Original Assignee: Kohler Company
• Inventors: Heinrich, Martin W., Ten Hoven, James A.
• Primary Examiner(s): Salce, Patrick R.
• Assistant Examiner(s): LABALLE, CLAYTON E
• Application Number:
  US07/257,476
• Time in Patent Office: 551 Days
• Field of Search: 310/112, 310/113, 310/114, 310/65, 310/62, 310/63, 310/58, 310/258, 310/68 D, 310/59
• US Class Current: 310/58
• CPC Class Codes: H02K 1/185 to outer stators
• CPC Class Codes: H02K 19/38 Structural association of synchronous generators with exciting machines
• CPC Class Codes: H02K 9/06 with fans or impellers driven by the machine shaft

Abstract

A brushless alternator for an engine-generator set has a housing for mounting to the engine. Raised ribs define an internal bore of the housing, the bore having a constant diameter to mount the stator and the exciter field assembly, both of which have the same laminations. The ribs also define cooling air flow paths through the housing. A fan is mounted outside of the housing at the free end of the housing to draw air into the engine end, through the housing and out the free end.

Claims

1. A brushless alternator, comprising:

a housing having a free end and an engine end opposite from the free end;

housing mounting means at the engine end of the housing for mounting the housing to the engine;

a shaft coaxial with and extending through the housing;

means for mounting the shaft rotatably relative to the housing;

an exciter field assembly fixed to and inside of the housing, said exciter field assembly including a plurality of laminations which are stacked together;

an exciter armature which is mounted on the shaft to rotate with the shaft at an axial location in alignment with the exciter field assembly so that the exciter armature is radially inside of the exciter field assembly, said exciter armature including a plurality of laminations which are stacked together;

a rotor mounted on the shaft inside the housing, said rotor including a plurality of laminations which are stacked together;

a stator fixed to and inside of the housing at an axial location in alignment with the rotor so that the rotor is radially inside of the stator, said stator including a plurality of laminations which are stacked together; and

wherein;

the housing has integral raised ribs which extend axially and are circumferentially spaced apart around the interior of the housing, said ribs defining open spaces between them and defining an internal bore of the housing in which the stator and the exciter field assembly are mounted;

a fan is mounted on the shaft outside of the housing at the free end of the housing, said fan rotating with the shaft to draw cooling air into the housing through air intake slots located at the engine end of the housing and past the stator through the open spaces defined by the raised ribs, and to exhaust the cooling air out through the free end of the housing;

the housing is enlarged at the engine end to produce a bell shape;

the air intake slots are located in the enlarged portion of the housing; and

the raised ribs which define the internal bore of the housing extend into and become deeper in the enlarged portion of the housing.

2. A brushless alternator as in claim 1, wherein the exciter field assembly is secured inside the raised ribs at an axial location inside the enlarged portion of the housing.

3. A brushless alternator as in claim 1, wherein are the laminations of the stator and exciter field assembly are shaped to receive the raised ribs and form the open spaces between the raised ribs.

4. A brushless alternator, comprising:

a housing having an engine end and a free end opposite from the engine end;

housing mounting means at the engine end of the housing for mounting the housing to a prime mover;

a shaft coaxial with and extending through the housing;

means for mounting the shaft rotating relative to the housing;

an exciter field assembly fixed to and inside of the housing, said exciter field assembly including a plurality of laminations which are stacked together;

an exciter armature which is mounted on the shaft to rotate with the shaft at an axial location in alignment with the exciter field assembly so that the exciter armature is radially inside of the exciter field assembly, said exciter armature including a plurality of laminations which are stacked together;

a rotor mounted on the shaft inside the housing, said rotor including a plurality of laminations which are stacked together;

a stator fixed to and inside of the housing at an axial location in alignment with the rotor so that the rotor is radially inside of the stator, said stator including a plurality of laminations which are stacked together;

cooling air intake means at the engine end of the housing;

exhaust vent means at the free end of the housing;

fan means outside of the housing at the free end of the housing for drawing cooling air through the exhaust vent means;

means inside the housing for defining a cooling air flow path from the cooling air intake means to the exhaust vent means; and

wherein;

a drive hub is positioned on the shaft at the engine end of the housing to drivingly couple the shaft to a prime mover to which the housing is mounted; and

the drive hub is slip fit on the shaft and bolted to the exciter armature.

5. A brushless alternator as in claim 4, wherein the drive hub is replaceable with a drive hub of a different length to adapt the alternator to a different prime mover.

6. A brushless alternator as in claim 4, wherein the cooling air intake means admit air to the interior of the housing past the outside of the exciter field assembly.

7. A brushless alternator, comprising:

a housing having an engine end and a free end opposite from the engine end;

housing mounting means at the engine end of the housing for mounting the housing to a prime mover;

a shaft coaxial with and extending through the housing;

means for mounting the shaft rotatably relative to the housing;

an exciter field assembly fixed to and inside of the housing, said exciter field assembly including a plurality of laminations which are stacked together;

an exciter armature which is mounted on the shaft to rotate with the shaft at an axial location in alignment with the exciter field assembly so that the exciter armature is radially inside of the exciter field assembly, said exciter armature including a plurality of laminations which are stacked together;

a rotor mounted on the shaft inside the housing, said rotor including a plurality of laminations which are stacked together;

a stator fixed to and inside of the housing at an axial location in alignment with the rotor so that the rotor is radially inside of the stator, said stator including a plurality of laminations which are stacked together;

cooling air intake means at the engine end of the housing;

exhaust vent means at the free end of the housing;

fan means outside of the housing at the free end of the housing to draw cooling air through the exhaust vent means;

means inside the housing for defining a cooling air flow path from the cooling air intake means to the exhaust vent means; and

wherein;

a drive hub is positioned on the shaft at the engine end of the housing to drivingly couple the shaft to a prime mover to which the housing is mounted;

the drive hub is bolted to the exciter armature;

the shaft has a flange which is integral with the shaft; and

the drive hub is slip fit onto the shaft and is also bolted to the flange.

8. A brushless alternator as in claim 7, wherein the exciter armature is slip fit onto the shaft and is sandwiched between the drive hub and the flange.

9. A brushless alternator, comprising:

a housing having an engine end and a free end opposite from the engine end;

housing mounting means at the engine end of the housing for mounting the housing to a prime mover;

a shaft coaxial with and extending through the housing;

means for mounting the shaft rotatably relative to the housing;

an exciter field assembly fixed to and inside the housing, said exciter field assembly including a plurality of laminations which are stacked together;

an exciter armature which is mounted on the shaft to rotate with the shaft at an axial location in alignment with the exciter field assembly so that the exciter armature is radially inside of the exciter field assembly, said exciter armature including a plurality of laminations which are stacked together;

a rotor mounted on the shaft inside the housing, said rotor including a plurality of laminations which are stacked together;

a stator fixed to and inside of the housing at an axial location in alignment with the rotor so that the rotor is radially inside of the stator, said stator including a plurality of laminations which are stacked together;

cooling air intake means at the engine end of the housing;

exhaust vent means at the free end of the housing;

fan means outside of the housing at the free end of the housing to draw cooling air through the exhaust vent means;

means inside the housing for defining a cooling air flow path from the cooling air intake means to the exhaust vent means; and

wherein;

a drive hub is positioned on the shaft at the engine end of the housing to drivingly couple the shaft to a prime mover to which the housing is mounted;

the drive hub is bolted to the exciter armature;

the shaft has a flange which is integral with the shaft;

the exciter armature is slip fit on the shaft;

the drive hub is slip fit onto the shaft; and

the exciter armature and the drive hub are fastened to the flange.

10. A brushless alternator, comprising:

a housing having an engine end and a free end opposite from the engine end;

housing mounting means at the engine end of the housing for mounting the housing to a prime mover;

a shaft coaxial with and extending through the housing;

means for mounting the shaft rotatably relative to the housing;

an exciter field assembly fixed to and inside of the housing, said exciter field assembly including a plurality of laminations which are stacked together;

an exciter armature which is mounted on the shaft to rotate with the shaft at an axial location in alignment with the exciter field assembly so that the exciter armature is radially inside of the exciter field assembly, said exciter armature including a plurality of laminations which are stacked together;

a rotor mounted on the shaft inside the housing, said rotor including a plurality of laminations which are stacked together;

a stator fixed to and inside of the housing at an axial locations in alignment with the rotor so that the rotor is radially inside of the stator, said stator including a plurality of laminations which are stacked together;

cooling air intake means at the engine end of the housing;

exhaust vent means at the free end of the housing;

fan means outside of the housing at the free end of the housing to draw cooling air through the exhaust vent means;

means inside the housing for defining a cooling air flow path from the cooling air intake means to the exhaust vent means; and

wherein;

the cooling air intake means admit air to the interior of the housing pas the outside of the exciter field assembly; and

the cooling air intake means are slots in the housing which extend axially away from the exciter field assembly toward the stator.