Transmission and constant speed accessory drive

• US 7,396,311 B2
• Filed: 02/14/2006
• Issued: 07/08/2008
• Est. Priority Date: 02/18/2004
• Status: Expired due to Fees

• Current Assignee: Gates Corporation The
• Original Assignee: Gates Corporation The
• Inventors: Serkh, Alexander, Ali, Imtiaz
• Primary Examiner(s): Lewis; Tisha D
• Application Number:
  US11/353,426
• Publication Number:
  US 20060154775A1
• Time in Patent Office: 875 Days
• Field of Search: 475/257, 475/346
• US Class Current: 475/257
• CPC Class Codes: F02B 2275/06 Endless member is a belt
• CPC Class Codes: F02B 67/06 driven by means of chains, belts, or like endless members
• CPC Class Codes: F16H 15/503 in which two members co-operate by means of balls or rollers of uniform effective diameter, not mounted on shafts
• CPC Class Codes: F16H 61/6648 controlling of shifting being influenced by a signal derived from the engine and the main coupling
• CPC Class Codes: F16H 63/062 electric or electro-mechanical actuating means

Abstract

An infinitely variable speed ratio planetary ball transmission comprising planetary members in rolling contact with moveable inner and outer races and a constant speed accessory drive system utilizing the transmission. The transmission is infinitely variable between ratios of approximately 0.3 and 1.0. A transmission input shaft is connected to a prime mover such as a vehicle engine crankshaft by a drive belt. The transmission comprises at least one output shaft that is coaxial with the input shaft. An output pulley is attached to the output shaft. A belt is engaged between the output pulley and various engine accessories. A second end of the transmission output shaft may be directly coupled to an engine accessory mounted on the transmission. An included control system senses a crankshaft speed. A processor analyses the crankshaft speed and accordingly adjusts the transmission ratio using a stepper motor connected to a worm drive to maintain a constant output speed regardless of crankshaft speed.

Claims

1. A method of operating a belt drive accessory system comprising the steps of:

transmitting a torque with a first endless member from a driver member to a planetary ball transmission input;

transmitting a torque by a second endless member from the planetary ball transmission output to a driven accessory;

selecting a speed ratio of the planetary ball transmission according to a driver member rotational speed;

calculating an error between a desired driven accessory speed and an actual driven accessory speed;

adjusting the speed ratio until no substantial error is generated; and

locking the speed ratio of the planetary ball transmission when the driver member speed is constant.

2. The method as in claim 1 comprising the step of connecting a driven member directly to a planetary ball transmission second output.

3. The method as in claim 1 comprising the step of tensioning the second endless member with a tensioner.

4. The method as in claim 3 comprising the step of damping an oscillation of the second endless member.

5. The method as in claim 1 comprising the step of tensioning the first endless drive member with a tensioning member.

6. The method as in claim 1 comprising the step of damping an oscillation of the first endless member.

7. The method as in claim 1 comprising the step of a one-way clutching action for a driven accessory overrunning condition.