System and method of operating a hydrovac to adjust suction

Abstract

A hydrovac is provided having an engine mounted on the frame, a transmission connected to the engine with a power take-off, a hydraulic fluid pump connected to the power take-off, steering wheels operative to steer the hydrovac, ground wheels operative to be driven by the engine through the transmission, a debris tank, a vacuum hose fluidly connected to the debris tank, a boom pivotally carrying the vacuum hose, a blower operatively connected to the debris tank to create a vacuum in the debris tank, and a hydraulic motor connected to the blower, the hydraulic motor connected to the hydraulic pump. A controller can be provided, operative to vary a speed of the engine between a first RPM and a second RPM, whereby operating the engine at the first RPM drives the hydraulic pump faster than operating the engine at the second RPM.

1 . A hydrovac comprising:
 a frame;   a cab mounted near a front end of the frame;   an engine mounted on the frame;   a transmission connected to the engine, the transmission having at least one power take-off;   at least one hydraulic fluid pump connected to the at least one power take-off;   steering wheels operative to steer the hydrovac;   ground wheels connected to the frame and operative to be driven by the engine through the transmission;   a debris tank mounted on the frame behind the cab;   a vacuum hose fluidly connected to the debris tank;   a boom pivotally mounted at a first end and carrying the vacuum hose;   a blower operatively connected to the debris tank and operative to create a vacuum in the debris tank;   a hydraulic motor connected to the blower to drive the blower, the hydraulic motor connected to the at least one hydraulic pump; and   a controller, the controller operative to vary a speed of the engine between a first revolutions per minute (RPM) and a second RPM, the second RPM higher than the first RPM,   whereby operating the engine at the first RPM drives the at least one hydraulic pump faster than operating the engine at the second RPM.   
     
     
         2 . The hydrovac of  claim 1  wherein the controller is operative to vary a speed of the engine between the first RPM, the second RPM and a third RPM, the third RPM higher than the second RPM. 
     
     
         3 . The hydrovac of  claim 1  wherein the controller is operative to vary the speed of the engine in response to a signal from a remote control. 
     
     
         4 . The hydrovac of  claim 3  wherein the controller is operative to vary a speed of the engine between the first RPM, the second RPM and a third RPM, the third RPM higher than the second RPM. 
     
     
         5 . The hydrovac of  claim 4  wherein the remote has a button and the first RPM, the second RPM and the third RPM are selected by pressing the button and cycling through the set engine speeds. 
     
     
         6 . They hydrovac of  claim 3  wherein the remote control is a wireless remote control. 
     
     
         7 . The hydrovac of  claim 1  wherein the transmission comprises: a first power take-off connected to a first hydraulic; and a second power take-off connected to a second hydraulic pump, and wherein the first hydraulic pump and the second hydraulic pump are connected to the hydraulic motor. 
     
     
         8 . A controller for controlling the operation of hydrovac comprising: an engine; a transmission connected to the engine, the transmission having at least one power take-off; at least one hydraulic fluid pump connected to the at least one power take-off; a debris tank; a blower operatively connected to the debris tank and operative to create a vacuum in the debris tank; and, a hydraulic motor connected to the blower to drive the blower, the hydraulic motor connected to the at least one hydraulic pump, the controller comprising:
 at least one processing unit;   an output interface operatively connected to the engine; and   at least one memory containing program instructions, the at least one processing unit, responsive to the program instructions, operative to:
 send signals to the engine to vary a speed of the engine between a first revolutions per minute (RPM) and a second RPM, the second RPM higher than the first RPM. 
   
     
     
         9 . The controller of  claim 8  wherein the controller is operative to sends signals to the engine to vary a speed of the engine between the first RPM, the second RPM and a third RPM, the third RPM higher than the second RPM. 
     
     
         10 . The controller of  claim 8  wherein the controller is operative to vary the speed of the engine in response to a signal form a remote control. 
     
     
         11 . The controller of  claim 10  wherein the controller is operative to vary a speed of the engine between the first RPM, the second RPM and a third RPM, the third RPM higher than the second RPM. 
     
     
         12 . The controller of  claim 8  further comprising a wireless operative to receive signals from a wireless remote control, the controller operative to, in response to receiving signals form the wireless remote control, send signal so the engine to vary the speed of the between a first RPM and a second RPM, the second RPM higher than the first RPM.