A generator system for a portable, residential or small business generator includes an engine, an alternator, a continuously variable transmission pulley system and a governor. The engine includes a drive shaft and a throttle. The alternator includes a rotor disposed on a rotor shaft. The continuously variable transmission pulley system includes a drive pulley coupled to the drive shaft, a driven pulley coupled to the rotor shaft, and a belt configured to engage the drive pulley and the driven pulley. The governor adjusts the engine throttle to control the speed of the engine in response to a speed of the rotor shaft.
1. A generator system, comprising:
an engine having a drive shaft and a throttle;
an alternator having a rotor disposed on a rotor shaft;
a continuously variable transmission pulley system, comprising:
a drive pulley coupled to the drive shaft and having a variable drive pulley effective diameter,
a driven pulley coupled to the rotor shaft and having a variable driven pulley effective diameter, the driven pulley effective diameter increasing in response to an increase in torque on the rotor shaft, and
a belt configured to engage the drive pulley and the driven pulley and having a belt tension, wherein the drive pulley effective diameter varies in response to the belt tension; and
a governor configured to adjust the throttle to control the speed of the engine in response to a speed of the rotor shaft.
2. The generator system of claim 1 , wherein the driven pulley comprises:
a first sheave having a first surface configured to engage the belt; and
a second sheave having a second surface configured to engage the belt;
wherein at least one of the first sheave and the second sheave include a cam surface configured such that the second sheave is moveable axially and rotatably with respect to the first sheave in response to a torque on the rotor shaft.
3. The generator system of claim 2 , further comprising a spring configured to bias the second sheave toward the first sheave.
4. The generator system of claim 3 , wherein the spring includes an axial compression spring.
5. The generator system of claim 3 , wherein the spring includes a torsional spring.
6. The generator system of claim 2 , wherein the drive pulley comprises:
a third sheave having a third surface configured to engage the belt; and
a fourth sheave configured to move axially relative to the drive shaft, the fourth sheave having a fourth surface configured to engage the belt.
7. The generator system of claim 6 , further comprising a second spring configured to bias the fourth sheave toward the third sheave.
8. The generator system of claim 7 , wherein the second spring includes an axial compression spring.
9. The generator system of claim 1 , wherein the belt includes a V-belt having a tapered width configured to engage the surfaces of the pulleys.
10. A generator system, comprising:
an engine having a drive shaft and a throttle;
an alternator having a rotor disposed on a rotor shaft;
a continuously variable transmission pulley system, comprising:
a drive pulley coupled to the drive shaft,
a driven pulley coupled to the rotor shaft and having a variable driven pulley effective diameter, the driven pulley effective diameter increasing in response to an increase in torque on the rotor shaft,
a belt configured to engage the drive pulley and the driven pulley and having a belt tension, and
a belt tensioner engaged with the belt and movable in response to the belt tension to maintain the belt tension at a desired level; and
a governor configured to adjust the throttle to control the speed of the engine in response to a speed of the rotor shaft.
11. The generator system of claim 10 , wherein the belt tensioner includes a tensioner pulley separate from the drive pulley and the driven pulley.
12. The generator system of claim 11 , wherein the drive pulley and the driven pulley rotate about a drive axis and driven axis respectively, wherein the drive axis and the driven axis are fixedly spaced apart and are substantially parallel to one another, and wherein the tensioner pulley is rotatable about a tensioner axis that is substantially parallel to the drive axis and is movable with respect to the drive axis.
13. The generator system of claim 10 , wherein the drive pulley has a variable effective diameter.
14. The generator system of claim 13 , wherein the drive pulley effective diameter varies in response to the belt tension.
15. A generator system, comprising:
an engine having a drive shaft and a throttle;
an alternator having a rotor disposed on a rotor shaft;
a governor configured to adjust the throttle to control the speed of the engine in response to a speed of the rotor shaft;
a continuous belt having a belt tension;
a driven member coupled to the rotor shaft for co-rotation, the continuous belt coupled to the driven member such that the driven member operates to vary a first pitch radius of the belt at the rotor shaft in response to variations in a torque on the rotor shaft; and
a drive member coupled to the drive shaft for co-rotation, the continuous belt coupled to the drive member such that the drive member operates to vary a second pitch radius of the belt at the drive shaft in response to variations in the belt tension.
16. The generator system of claim 15 , wherein the driven member includes a variable diameter driven pulley and the drive member includes a variable diameter drive pulley.
17. The generator system of claim 16 , wherein the driven pulley comprises:
a first sheave having a first surface configured to engage the belt; and
a second sheave having a second surface configured to engage the belt;
wherein at least one of the first sheave and the second sheave include a cam surface configured such that the second sheave is moveable axially and rotatably with respect to the first sheave in response to a torque on the rotor shaft.
18. The generator system of claim 15 , wherein an increase in torque on the rotor shaft produces an increase in the first pitch radius and a corresponding decrease in the second pitch radius.
19. The generator system of claim 15 , wherein a decrease in torque on the rotor shaft produces a decrease in the first pitch radius and a corresponding increase in the second pitch radius.