Slip controlling belt tension system

Patent metadata

Field	Value
Publication number	US-2016007526-A1
Application number	US-201414772646-A
Country	US
Kind code	A1
Filing date	Mar 13, 2014
Priority date	Mar 13, 2013
Publication date	Jan 14, 2016
Grant date	—

Abstract

A yard maintenance device having a working assembly selectively rotatable based on operation of an engine of the device may include a belt drive system. The belt drive system may include at least one driven pulley operably coupled to the working assembly, a drive shaft operably coupled to the engine, a drive belt configured to selectively couple the drive shaft to the at least one driven pulley, a tension adjustment assembly, and a control unit. The tension adjustment assembly may be configured to operably couple to at least one component of the belt drive system to adjust a position thereof to modify tension of the drive belt. The control unit may be configured to provide electronic control of the tension adjustment assembly.

First claim

1 . A lawn care device comprising:
a cutting deck housing at least one blade; an engine configured to selectively provide for rotation of the at least one blade responsive to selective coupling of the engine to the at least one blade; and a PTO switch that is operable to engage or disengage a PTO clutch to provide the selective coupling between the engine and the at least one blade via a belt drive system, wherein the belt drive system comprises: at least one blade pulley operably coupled to the at least one blade; a drive shaft operably coupled to the engine; a drive belt configured, responsive to engagement of the PTO clutch, to couple the drive shaft to the at least one blade pulley; a tension adjustment assembly configured to operably couple to at least one component of the belt drive system to adjust a position thereof to modify tension of the drive belt; and a control unit configured to provide electronic control of the tension adjustment assembly.

2 . The lawn care device of claim 1 , wherein the control unit is configured to monitor engine RPM and blade RPM to determine a current slip value.

3 . The lawn care device of claim 2 , wherein the control unit is configured to perform a comparison of the current slip value to a slip setpoint and control the tension adjustment assembly based on the comparison.

4 . The lawn care device of claim 1 , wherein the control unit is configured to apply a gradual increase in the tension of the drive belt during a predetermined period of time after activation of the PTO switch.

5 . The lawn care device of claim 1 , wherein the control unit is configured to apply a pulsed increase in the tension of the drive belt during a predetermined period of time after activation of the PTO switch.

6 . The lawn care device of claim 1 , wherein the control unit is configured to apply a gradual increase in the tension of the drive belt to a slip setpoint.

7 . The lawn care device of claim 1 , wherein the control unit is configured to apply a pulsed increase in the tension of the drive belt to a slip setpoint.

8 . The lawn care device of claim 1 , wherein the drive shaft comprises a split pulley operably coupled to the at least one blade pulley via the drive belt, the split pulley being configured to change pulley diameter based on the tension of the drive belt.

9 . The lawn care device of claim 8 , wherein the split pulley comprises a first half and a second half biased to be drawn toward each other on a pulley axis by a biasing member.

10 . The lawn care device of claim 9 , wherein an increase in the tension of the drive belt causes the first half and the second half to move away from each other to decrease an effective pulley diameter of the split pulley to change a pulley ratio between the at least one blade pulley and the split pulley to correspondingly change a speed of rotation of the at least one blade.

11 . The lawn care device of claim 1 , wherein the belt drive system further comprises at least one idler pulley, and wherein the at least one idler pulley is the at least one component.

12 . The lawn care device of claim 11 , wherein the tension adjustment assembly comprises an electric motor and a winch cable operably coupled to the at least one idler pulley, the electric motor being operable to increase or decrease tension on the winch cable to adjust a position of the at least one idler pulley.

13 . The lawn care device of claim 12 , wherein the electric motor comprises a DC electric motor operable to increase or decrease tension on the winch cable to adjust a position of the at least one idler pulley, and wherein the DC electric motor is configured to operate to adjust a tension holder to a predetermined position, the tension holder being held at the predetermined position by a solenoid such that, responsive to a loss of power, the solenoid releases the tension holder to release tension on the drive belt.

14 . The lawn care device of claim 12 , wherein the electric motor comprises a linear actuator.

15 . The lawn care device of claim 1 , wherein blade RPM is detected using an optical sensor configured to detect a drain hole on the at least one blade pulley.

16 . The lawn care device of claim 1 , wherein the lawn care device is a riding lawn mower.

17 . A belt drive system for a yard maintenance device having a working assembly selectively rotatable based on engagement or disengagement of a PTO clutch to provide selective coupling between an engine and the working assembly via the belt drive system, the belt drive system comprising:
at least one driven pulley operably coupled to the working assembly; a drive shaft operably coupled to the engine; a drive belt configured to selectively couple the drive shaft to the at least one driven pulley; a tension adjustment assembly configured to operably couple to at least one component of the belt drive system to adjust a position thereof to modify tension of the drive belt; and a control unit configured to provide electronic control of the tension adjustment assembly.

18 . (canceled)

19 . The belt drive system of claim 17 , wherein the control unit is configured to monitor engine RPM and blade RPM to determine a current slip value,
wherein the control unit is configured to perform a comparison of the current slip value to a slip setpoint and control the tension adjustment assembly based on the comparison.

20 - 24 . (canceled)

25 . The belt drive system of claim 17 , wherein the drive shaft comprises a split pulley operably coupled to the at least one driven pulley via the drive belt, the split pulley being configured to change pulley diameter based on the tension of the drive belt.

26 . (canceled)

27 . (canceled)

28 . The belt drive system of claim 17 , wherein the belt drive system further comprises at least one idler pulley, wherein the at least one idler pulley is the at least one component, and wherein the tension adjustment assembly comprises an electric motor and a winch cable operably coupled to the at least one idler pulley, the electric motor being operable to increase or decrease tension on the winch cable to adjust a position of the at least one idler pulley.

29 - 32 . (canceled)

Assignees

• Husqvarna Ab

Inventors

• Greulich Douglas
• Albinger Matthew
• Dwyer Sean

Classifications

• A01D34/008 Primary

  for automated or remotely controlled operation · CPC title

• F16H2007/0865

  Pulleys · CPC title

• A01D34/64

  mounted on a vehicle, e.g. a tractor, or drawn by an animal or a vehicle (A01D34/695 takes precedence) · CPC title

• F16H7/02

  with belts; with V-belts · CPC title

• A01D69/002

  driven by power take-off · CPC title