Power management system for street sweeper

• US 20040045117A1
• Filed: 09/06/2002
• Published: 03/11/2004
• Est. Priority Date: 09/06/2002
• Status: Active Grant

• Current Assignee: Wayne Sweepers, LLC
• Original Assignee: Tennant Company
• Inventors: Erko, Robert J., Alowonle, Musibau O., Milun, Richard F., Block, Craig D.
• Granted Patent: US 6,959,466 B2
• Time in Patent Office: Days
• US Class Current: 15/319
• CPC Class Codes: E01H 1/042 the loading means being an endless belt or an auger
• CPC Class Codes: E01H 1/0854 Apparatus in which the mechanically dislodged dirt is partially sucked-off, e.g. dislodging- sweeping apparatus with dirt collector in brush housing or dirt container mechanical dislodging machines with independent suction nozzles E01H1/0827; combined with blowing and suction E01H1/0872

Abstract

A power management system for a surface maintenance machine, such as a street sweeper is disclosed. The system includes a variable speed engine for transporting the surface maintenance machine, a hydraulic pump powered by the engine, a vacuum fan motor powered by the hydraulic pump, an engine speed sensor coupled to the engine, an electric proportional valve coupled between the hydraulic pump and the vacuum fan motor, said valve for selectively restricting a flow rate to the vacuum fan motor, and a control unit operatively coupled to the engine speed sensor and the proportional valve, said control unit receiving engine speed information from the engine speed sensor and communicating a predetermined signal to the proportional valve to control the flow rate to the vacuum fan motor as a function of engine speed. A method of managing engine power from a single-engine street sweeper is also disclosed.

Claims

1. A street sweeper comprising:

a variable speed engine for transporting the street sweeper;

an engine speed sensor coupled to the engine for providing engine speed information;

a hydraulic pump operatively coupled to the engine;

a sweeping mechanism powered by the hydraulic pump and including a main pickup brush and a debris conveyer;

a vacuum system including a vacuum fan motor powered by the hydraulic pump, said vacuum system for creating an airflow within the street sweeper;

an electric proportional valve coupled between the hydraulic pump and the vacuum fan motor, said valve for selectively restricting a flow rate to the vacuum fan motor; and

a control unit operatively coupled to the engine speed sensor and the proportional valve, said control unit receiving the engine speed information from the engine speed sensor and communicating a predetermined signal to the proportional valve to control the flow rate to the vacuum fan motor as a function of engine speed.

2. The street sweeper of claim 1, further comprising a hydraulic conveyer motor, a hydraulic main brush motor, and a hydraulic side brush motor.

3. The street sweeper of claim 2, further comprising a set of electric proportional valves coupled between the hydraulic pump and the hydraulic conveyer motor, a hydraulic main brush motor, and a hydraulic side brush motor, each one of said set of electric proportional valves being responsive to a signal sent from the control unit to control a flow rate to an associated motor.

4. The street sweeper of claim 1 wherein the predetermined signal is a pulse-width-modulated signal.

5. The street sweeper of claim 1 wherein the predetermined signal is selected from among a group of signals including an idle speed signal, a low speed signal, and a full speed signal.

6. The street sweeper of claim 1 wherein the hydraulic pump includes at least two hydraulic pumps each operatively coupled to the engine.

7. The street sweeper of claim 1 further comprising an air filter in communication with the vacuum system, said air filter separating debris from the airflow.

8. A power management system for a street sweeper comprising:

a variable speed engine for transporting the street sweeper and for powering sweeping components of the street sweeper, said engine being operable within either an idle speed range and a full speed range;

an engine speed sensor coupled to the engine for providing engine speed information;

a hydraulic pump powered by the engine;

a vacuum fan motor powered by the hydraulic pump;

an electric proportional valve coupled between the hydraulic pump and the vacuum fan motor, said valve for selectively restricting a flow rate to the vacuum fan motor; and

a control unit operatively coupled to the engine speed sensor and the proportional valve, said control unit receiving the engine speed information from the engine speed sensor and communicating a predetermined signal to the proportional valve to control the flow rate to the vacuum fan motor as a function of engine speed.

9. The power management system of claim 8, further comprising a hydraulic conveyer motor, a hydraulic main brush motor, and a hydraulic side brush motor.

10. The power management system of claim 9, further comprising a set of electric proportional valves coupled between the hydraulic pump and the hydraulic conveyer motor, a hydraulic main brush motor, and a hydraulic side brush motor, each one of said set of electric proportional valves being responsive to a signal sent from the control unit to control a flow rate to an associated motor.

11. The power management system of claim 8 wherein the predetermined signal is a pulse-width-modulated signal.

12. The power management system of claim 8 wherein the predetermined signal is selected from among a group of signals including a predetermined idle speed signal and a full speed signal.

13. The power management system of claim 8 wherein the hydraulic pump includes at least two hydraulic pumps each operatively coupled to the engine.

14. The power management system of claim 8 further comprising an air filter in communication with the vacuum system, said air filter separating debris from an airflow.

15. A street sweeper comprising:

a vehicle;

an engine for transporting the vehicle and for powering a sweeping mechanism and a vacuum system;

an engine speed sensor coupled to the engine for providing engine speed information;

a hydraulic pump operatively coupled to the engine;

a hydraulic vacuum fan motor powered by the hydraulic pump;

a main cylindrical pickup broom coupled to the vehicle;

a debris conveyer for transporting debris from the pickup broom to a debris collection hopper;

a gutter broom operatively coupled to the vehicle;

an electric proportional valve coupled between the hydraulic pump and the vacuum fan motor, said valve for selectively restricting a flow rate to the vacuum fan motor; and

a control unit operatively coupled to the engine speed sensor and the proportional valve, said control unit receiving the engine speed information from the engine speed sensor and communicating a predetermined signal to the proportional valve to control the flow rate to the vacuum fan motor as a function of engine speed.

16. The street sweeper of claim 15, further comprising a hydraulic conveyer motor, a hydraulic main brush motor, and a hydraulic side brush motor.

17. The street sweeper of claim 16, further comprising a set of electric proportional valves coupled between the hydraulic pump and the hydraulic conveyer motor, a hydraulic main brush motor, and a hydraulic side brush motor, each one of said set of electric proportional valves being responsive to a signal sent from the control unit to control a flow rate to an associated motor.

18. The street sweeper of claim 15 wherein the predetermined signal is a pulse-width-modulated signal.

19. The street sweeper of claim 15 wherein the predetermined signal is selected from among a group of signals including an idle speed signal, a low speed signal, and a full speed signal.

20. A method of managing engine power from a single-engine street sweeper, said street sweeper including a variable speed engine for transporting the street sweeper, a sweeping mechanism powered by the engine and including a main pickup brush and a debris conveyer, a vacuum system including a hydraulic vacuum fan motor, an air filter in communication with the vacuum system for collecting debris, an engine speed sensor coupled to the engine for providing engine speed information, a hydraulic pump coupled to the engine, an electric proportional valve coupled between the hydraulic pump and the vacuum fan motor, said valve for selectively restricting a flow rate to the vacuum fan motor, and a control unit operatively coupled to the engine speed sensor and the proportional valve, said control unit receiving the engine speed information from the engine speed sensor and communicating a predetermined signal to the proportional valve to control the flow rate to the vacuum fan motor as a function of engine speed, said method comprising the steps of:

(a) operating the engine at a first selected engine speed;

(b) communicating engine speed information from the engine speed sensor to the control unit;

(c) selecting a proportional valve setting from among a group of predetermined valve settings;

(d) communicating a signal from the control unit to the proportional valve, said signal associated with the proportional valve setting selected in step (c);

(e) adjusting the proportional valve in response to the signal communicated in step (d); and

(f) repeating steps (a) through (e) with the engine operating at a second engine speed.

21. The method of managing engine power of claim 20 from a single-engine street sweeper wherein the group of predetermined valve settings includes at least an idle speed setting and a full speed setting.

22. The method of managing engine power of claim 20 from a single-engine street sweeper wherein the signal communicated from the control unit to the proportional valve is a pulse-width-modulated signal.

23. A power management system for a surface maintenance machine, said system comprising:

a variable speed engine for transporting the surface maintenance machine, said engine operating within one of an idle speed range, an intermediate speed range, and a full speed range;

a hydraulic pump powered by the engine;

a vacuum system including a hydraulic vacuum fan motor powered by the hydraulic pump;

an engine speed sensor coupled to the engine for providing engine speed information;

an electric proportional valve coupled between the hydraulic pump and the vacuum fan motor, said valve for selectively restricting a flow rate to the vacuum fan motor; and

a control unit operatively coupled to the engine speed sensor and the proportional valve, said control unit receiving the engine speed information from the engine speed sensor and communicating a predetermined signal to the proportional valve to control the flow rate to the vacuum fan motor as a function of engine speed.

24. A power management system of claim 23 wherein the predetermined signal is selected from among a group of signals including at least an idle speed signal and a full speed signal.

25. A power management system of claim 24 wherein the group of signals includes an intermediate speed signal.

26. A power management system of claim 24 wherein the hydraulic pump includes at least two hydraulic pumps each operatively coupled to the engine.