Control system and method using multiple inputs for controlling cooling fan speed of outdoor power equipment unit

Patent metadata

Field	Value
Publication number	US-11293333-B2
Application number	US-201615215758-A
Country	US
Kind code	B2
Filing date	Jul 21, 2016
Priority date	Jul 21, 2015
Publication date	Apr 5, 2022
Grant date	Apr 5, 2022

Abstract

An outdoor unit has a frame that carries a ground grooming or working implement, a traction drive, and a cooling fan, all of which comprises loads on a prime mover. A power management controller automatically reduces an operational speed of the traction drive when prime mover droop is present. The cooling fan cools two cooling fluids. The controller stores data representing variable fan speeds for cooling each cooling fluid in both normal and above normal temperature ranges and for use when prime mover droop is present. The controller uses the highest fan speed required for cooling the cooling fluids in the normal range unless the droop fan speed is lower in which case the lower droop fan speed is used but only to the extent that the lower droop fan speed is not lower than the highest fan speed required for cooling the cooling fluids in the above normal temperature range.

First claim

The invention claimed is:

1. An outdoor power equipment unit, which comprises:
(a) a frame that carries a prime mover, a ground grooming or working implement, a traction drive, and at least one cooling fan, all of which comprise loads on the prime mover, wherein the at least one cooling fan cools at least one fluid;
(b) a power management controller on the frame, wherein the controller further stores data representing variable fan speeds for use in cooling the at least one fluid in normal and above normal temperature ranges thereof and for use when prime mover load within a first range above a predetermined value is present, wherein the controller uses a normal temperature fan speed required for cooling the at least one fluid in the normal temperature range unless the prime mover load fan speed is lower in which case the lower prime mover load fan speed is used for as long as the lower prime mover load fan speed remains less than the normal temperature fan speed and/or less than an above normal temperature fan speed required for cooling the at least one fluid in the above normal temperature range; and
(c) wherein the controller further stores data representing variable operational speeds of the traction drive for use when the prime mover load is within a second range above the predetermined value, and wherein a start point of the first range is closer to the predetermined value than is a start point of the second range such that the controller when use of the prime mover fan speed is permitted in accordance with limitation (b) hereof automatically reduces the prime mover load fan speed from a higher value to a lower value before the controller begins any automatic reduction of the operational speed of the traction drive.

2. The unit of claim 1 , wherein engine droop comprising an instantaneous engine speed below a target speed is used to indicate when the prime mover load is above the predetermined value.

3. The unit of claim 1 , wherein the at least one cooling fan comprises a single cooling fan for cooling at least first and second fluids, and wherein the normal temperature fan speed is whichever fan speed is highest from a group of fan speeds comprising:
(a) a first fan speed for cooling the first fluid in the normal temperature range; and
(b) a second fan speed for cooling the second fluid in the normal temperature range; and wherein the above normal temperature fan speed is whichever fan speed is highest from a group of fan speeds comprising:
(c) a first fan speed for cooling the first fluid in the above normal temperature range; and
(d) a second fan speed for cooling the second fluid in the above normal temperature range.

4. The unit of claim 3 , wherein the first fluid is engine coolant fluid and the second fluid is hydraulic oil.

5. The unit of claim 1 , wherein the at least one cooling fan comprises at least first and second cooling fans with each cooling fan separately cooling at least first and second fluids, and wherein the fan speed determination of limitation (b) of claim 1 is done separately for each of the first and second cooling fans in accordance with temperatures in the first and second fluids.

6. The unit of claim 5 , wherein the first fluid is engine coolant fluid and the second fluid is hydraulic oil.

7. The unit of claim 5 , further including a fan reduction prioritization scheme for determining fan speed reductions in the first and second cooling fans when permitted when prime mover load above a predetermined value is present.

8. The unit of claim 1 , wherein the first and second ranges do not overlap such that the higher value of the prime mover load fan speed is a maximum value thereof and the lower value of the prime mover load fan speed is a minimum value thereof.

9. The unit of claim 8 , wherein the maximum value is 100% prime mover load fan speed and the minimum value is 0% prime mover load fan speed.

Assignees

• The Toro Co

Inventors

• Frick Alexander S
• Arendt Peter M
• Gamble Jesse R

Classifications

• A01D34/80 Primary

  fluid · CPC title

• A01D69/005

  Non electric hybrid systems, e.g. comprising mechanical and/or hydraulic and/or pneumatic drives · CPC title

• F01P2005/025

  using two or more air pumps · CPC title

• F01P7/12 Primary

  by thermostatic control · CPC title

• F01P11/08

  Arrangements of lubricant coolers (in lubrication apparatus F01M) · CPC title