US 12,442,397 B2
Overspeed safeguards in hydraulically controlled fuel boost pump
Martin Augustine Clements, Loveland, OH (US)
Assigned to Eaton Intelligent Power Limited, Dublin (IE)
Filed by Eaton Intelligent Power Limited, Dublin (IE)
Filed on May 27, 2022, as Appl. No. 17/826,498.
Claims priority of provisional application 63/193,857, filed on May 27, 2021.
Prior Publication US 2022/0381267 A1, Dec. 1, 2022
Int. Cl. F15B 15/18 (2006.01); F04D 13/04 (2006.01); F04D 13/14 (2006.01); F04D 15/00 (2006.01); F04D 15/02 (2006.01); F16H 39/14 (2006.01)
CPC F15B 15/18 (2013.01) [F04D 13/046 (2013.01); F04D 13/14 (2013.01); F04D 15/0066 (2013.01); F04D 15/0218 (2013.01); F16H 39/14 (2013.01)] 23 Claims
OG exemplary drawing
 
1. A hydraulic system comprising:
a pump including an inlet and an outlet;
a hydraulic motor for driving the pump;
a control valve including a valve body defining a spool bore, the valve body defining a fluid supply port and a fluid outlet port both in fluid communication with the spool bore, the fluid supply port being adapted to be connected to a fluid supply, and the fluid outlet port being fluidly connected to the hydraulic motor to provide fluid for driving rotation of a rotating group of the hydraulic motor, the control valve including a spool positioned within the spool bore, the spool having a first end and an opposite second end, the spool being linearly moveable within the spool bore along an axis of the spool bore to move the control valve between a first operating state and a second operating state, the spool being configured to open a non-restrictive flow path within the spool bore between the fluid supply port and the fluid outlet port when the control valve is in the first operating state, the control valve defining a restrictive flow area through which hydraulic fluid from the fluid supply port is required to pass to reach the fluid outlet port when the control valve is in the second operating state, the control valve including a piston chamber at the first end of the spool and an outlet pressure piston within the piston chamber that is acted on by an outlet pressure from the pump to move the spool along the axis of the spool bore in a first direction away from the piston chamber, the control valve including a spring at the second end of the spool to apply a bias to the spool along the axis of the spool bore in a second direction that is opposite from the first direction, the spring providing a spring force that corresponds to a normal operating pressure desired at the outlet of the pump, wherein, when the outlet pressure of the pump is at the normal operating pressure or above the normal operating pressure, the outlet pressure piston moves the spool in the first direction along the axis of the spool bore against the bias of the spring to a first position or positions corresponding to the first operating state, and wherein, when the outlet pressure of the pump is below the normal operating pressure, the spring moves the spool in the second direction along the axis of the spool bore to a second position corresponding to the second operating state, wherein the control valve is not capable of reducing fluid communication between the fluid supply port and the fluid outlet port to a flow area that is smaller than the restrictive flow area.