Engine-generator set with integral gear reduction

• US 5,816,102 A
• Filed: 12/03/1996
• Issued: 10/06/1998
• Est. Priority Date: 12/03/1996
• Status: Expired due to Term

• Current Assignee: Generac Power Systems Incorporated (Generac Holdings Incorporated)
• Original Assignee: Generac Corporation
• Inventors: Kern, Robert D., Ruehlow, Gerald C.
• Primary Examiner(s): Bonck, Rodney H.
• Assistant Examiner(s): FENSTERMACHER, DAVID MORGAN
• Application Number:
  US08/758,359
• Time in Patent Office: 672 Days
• Field of Search: 74/412 R, 74/413, 464/74, 464/76, 290/1 R, 290/1 A, 123/2, 123/3
• US Class Current: 74/412.00R
• CPC Class Codes: F02B 63/04 for electric generators
• CPC Class Codes: F02B 75/007 having vertical crankshafts
• CPC Class Codes: F16H 1/08 the members having helical, herringbone, or like teeth
• CPC Class Codes: H02K 7/116 with gears
• CPC Class Codes: Y10T 74/19642 Directly cooperating gears
• CPC Class Codes: Y10T 74/19647 Parallel axes or shafts

Abstract

In an engine-generator set, the generator has a first shaft driving a generator armature and also has a second shaft in spaced relationship to the first shaft. The second shaft is coupled to the engine and there is a gear on each of the shafts which provides a "step-down" gear reduction for powering the generator at, e.g., 1800 rpm, where the engine speed is greater than 1800 rpm. Preferably, the engine is coupled to the generator armature shaft through a torsional coupling for isolating engine vibration from the generator.

Claims

1. In a stationary-mounted apparatus including an engine powering a generator, and wherein the generator includes a first shaft supported by a pair of bearings and concentric with and driving a generator armature, the improvement wherein:

the first shaft has a shaft end extending away from the bearings;

a first gear is concentrically mounted on the shaft end and has a first pitch diameter;

the generator includes a second shaft in spaced relationship to the first shaft;

the second shaft is concentric with and coupled to the engine crankshaft and has a second gear mounted thereon in engagement with the first gear; and

the second gear has a pitch diameter less than the pitch diameter of the first gear.

2. The apparatus of claim 1 wherein:

the generator has a housing;

the pair of bearings supporting the first shaft are in the housing.

3. The apparatus of claim 1 wherein:

the generator has a housing; and

the second shaft is supported by a pair of spaced shaft bearings mounted in the housing.

4. The apparatus of claim 1 wherein:

the engine has a flywheel; and

the second shaft is coupled to the engine flywheel by a driving member attached to the flywheel.

5. The apparatus of claim 4 wherein the flywheel is concave and includes a central portion and an outer perimeter extending away from the central portion, and wherein the second shaft protrudes into the flywheel.

6. In an apparatus including an engine powering a generator, and wherein the generator includes a first shaft driving a generator armature, the improvement wherein:

the first shaft is supported by inward and outward spaced-apart bearings mounted in the generator;

the first shaft has a cantilever shaft end protruding outwardly away from the outward bearing and toward the engine;

the cantilever shaft end has a first gear affixed thereto;

the apparatus includes a second shaft in spaced relationship to the first shaft;

the second shaft has a second gear affixed thereto, such second gear being in driving engagement with the first gear; and

the engine has a crankshaft and the second shaft is coupled to the engine in axial alignment with the crankshaft.

7. The apparatus of claim 6 wherein:

the generator has a housing;

the second shaft is supported for rotation by a pair of spaced-apart bearings; and

the bearings supporting the first shaft and the bearings supporting the second shaft are in the generator housing.

8. The apparatus of claim 7 wherein:

the engine includes a flywheel having a locating pocket formed therein; and

the second shaft is coupled to the flywheel through a torsional coupling having a driving member received in the locating pocket.

9. The apparatus of claim 8 wherein:

the flywheel has a ring gear mounted thereon for engine starting; and

the ring gear is spaced from the driving member.

10. The apparatus of claim 9 wherein:

the first gear has a first pitch diameter; and

the second gear has a second pitch diameter less than the first pitch diameter, thereby driving the first shaft at a rotational speed less than the rotational speed of the engine.