Generator set and method

• US 4,835,405 A
• Filed: 11/30/1987
• Issued: 05/30/1989
• Est. Priority Date: 11/30/1987
• Status: Expired due to Fees

• Current Assignee: Cummins PowerGen IP, Inc. (Cummins Incorporated)
• Original Assignee: ONAN Corporation (Cummins Incorporated)
• Inventors: Hjelmstad, Stanely D., Miller, Michael C., Lent, Mark S., Clancey, Stephen M.
• Primary Examiner(s): Shoop, Jr., William M.
• Assistant Examiner(s): NOT, DEFINED
• Application Number:
  US07/126,923
• Time in Patent Office: 547 Days
• Field of Search: 290/1 R, 290/1 A, 290/1 B, 322/1, 123/2, 123/3
• US Class Current: 290/1.00A
• CPC Class Codes: F02B 63/04 for electric generators

Abstract

A generator set including an internal combustion engine which drives an alternator or generator to generate electricity. The engine and the generator are air cooled by air driven by a fan along two parallel air cooling circuits through the generator set. The components of the set are enclosed in a two-piece housing or enclosure having two openings, an air inlet and an air outlet.

Claims

1. A generator set, comprising:

(a) a horizontally disposed internal combustion engine including a drive shaft rotatable by the engine;

(b) generator means interconnected to a crankshaft of the engine for converting the mechanical rotational motion of the drive shaft into electrical energy;

(c) rotatable fan means rotated by the engine for cooling the generator set, the generator means being disposed intermediate of the fan means and the engine, the fan means including air flow separator means for separating air flow into a first air flow for cooling the engine and a second air flow for cooling the generator means;

(d) exhaust means for exhausting used gases which are byproducts of the combustion process, the exhaust means including a muffler means for deadening exhaust noise, the muffler means being located on a side of the engine opposite that of the generator means and the fan means; and

(e) a single enclosure enclosing the engine, generator means, fan means, and exhaust means, the enclosure including an air inlet and an air outlet, the air inlet being located on a side of the engine where the generator means and fan means are located, the air outlet being located on a side of the engine where the muffler means is located.

2. A generator set in accordance with claim 1, wherein a "line of sight" between noise generating sources inside the enclosure and the air inlet and the air outlet is blocked, thereby facilitating noise reduction.

3. A generator set in accordance with claim 2, wherein baffles are present for blocking the "line of sight" to the air outlet.

4. A generator set in accordance with claim 1, wherein the air flow separation means includes a shroud including first and second expanding radii, the first and second expanding radii including first and second cutoff means, respectively, for forcing the air along the first air flow path and the second air flow path, respectively.

5. A generator set in accordance with claim 4, wherein the fan means is interconnected to a rotatable extension of the generator means.

6. A generator set in accordance with claim 4, wherein the first air flow path is routed largely through the generator means and across an oil sump of the engine and the second air flow path is routed along the side of the generator means over a carburetor of the engine and across a finned portion and a cylinder head of the engine.

7. A generator set in accordance with claim 1, wherein polymeric acoustical foam and glass fiber are present in cooler areas of the generator set, and fibrous high temperature materials are present in hotter areas of the generator set.

8. A generator set in accordance with claim 1, wherein elastomeric mounts support the generator means and engine, a plurality of said elastomeric mounts being offset from a "rocking" line interconnecting a center of gravity of the generator means and a center of gravity of the engine, longitudinal axes of the offset elastomeric mounts extending roughly through the "rocking" line, at least one of the elastomeric mounts only supporting the generator means and engine when rocking about the "rocking" line exceeds a predetermined amount.

9. A generator set in accordance with claim 8, further including at least one elastomeric mount in substantial vertical alignment with the "rocking" line.

10. A generator set in accordance with claim 1, wherein the enclosure includes a base portion, a top portion, and a removable panel portion, the air outlet being located in the base portion.

11. A generator set in accordance with claim 10, wherein the muffler means has a vertical orientation.

12. A generator set in accordance with claim 1, wherein the generator set further includes control circuit means for regulating the voltage output of the generator set, the control circuit means including:

(a) a quadrature winding on the generator means;

(b) amplifier circuitry electrically interconnected to the quadrature winding, the quadrature winding providing an electrical input to the amplifier circuitry;

(c) voltage sensing circuitry electrically interconnected to the electrical output of the generator means, the voltage sensing means including means for converting AC voltage of the generator means electrical output to a low DC voltage output proportional to the electrical output AC voltage;

(d) reference circuitry means for providing a reference voltage output;

(e) comparator circuitry means electrically interconnected to the reference circuitry means and the voltage sensing circuitry for comparing the output of the reference circuitry means and the voltage sensing circuitry, the comparator circuitry means being electrically interconnected to the amplifier circuitry for outputting to the amplifier circuitry a signal representative of the difference between the voltage sensing circuitry output and the reference circuitry means;

(f) the amplifier circuitry including output means for outputting a pulse width modulated signal for driving exciter windings of the generator means; and

(g) crossover means electrically interconnected to the amplifier for determining the angle at which the amplifier output means is activated.

13. A generator set in accordance with claim 12, wherein the control circuit means includes a DC power source means for providing a voltage to the amplifier circuitry upon initial start-up of the generator set and further including capacitor means for providing additional current when excessive loads are placed on the generator set.

14. A method of making a generator set, comprising the steps of:

(a) mounting an engine with its cylinder in a horizontal orientation;

(b) interconnecting generator means to a crankshaft of the engine for rotation therewith;

(c) interconnecting fan means to a rotatable extension of the generator means for rotation therewith, the generator means being disposed intermediate of the engine and the fan means;

(d) interconnecting exhaust means to the engine for exhausting used gases, providing the exhaust means with muffler means for deadening exhaust noise, positioning the muffler means on a side of the engine opposite that of the generator means; and

(e) enclosing the engine, generator means, fan means, and exhaust means within a single enclosure including a top portion and a base portion, the enclosure including an air inlet on a side of the engine where the fan means and generator means are located and further including an air outlet on a side of the engine where the muffler means is located.

15. A method in accordance with claim 14, including blocking "line of sight" between the air inlet and the air outlet and noise generating sources inside the enclosure.

16. A method in accordance with claim 15, wherein the step of blocking the "line of sight" includes blocking the "line of sight" between the air inlet and the generator means and blocking the "line of sight" between the air outlet and the engine.

17. A method in accordance with claim 14, wherein the step of interconnecting the fan means includes the step of providing a structure for separating incoming air flow from the air inlet into first and second air flows, the first air flow cooling the engine and the second air flow cooling the generator means.

18. A method of making a generator set, comprising the steps of:

(a) mounting an engine with its cylinder in a horizontal orientation;

(b) interconnecting generator means to a crankshaft of the engine;

(c) interconnecting fan means to a shaft extension of the generator means for creating an air flow generally in a downstream direction so as to cool the generator set, the generator means being disposed intermediate of the engine and the fan means, providing the fan means with air flow separation means for separating the air flow generally into first and second air flows, the first air flow cooling the engine and the second air flow cooling the generator means;

(d) interconnecting exhaust means to the engine for exhausting used gases from the engine, the exhaust means including muffler means for deadening exhaust noise;

(e) positioning the muffler means downstream from the fan means and the generator means; and

(f) enclosing the engine, generator means, fan means and muffler means within an enclosure including an air inlet and an air outlet.

19. A method in accordance with claim 18, including the step of orienting the muffler means in a vertical orientation.

20. A method in accordance with claim 18, wherein the step of enclosing includes creating a two-piece enclosure having a base and a cover, forming the base from sheet metal and the cover from plastic, and placing gasket material along abutting surfaces of the base and cover.