Electronically commutated hydraulic machine and operating method to reduce generation of resonance effects
AssigneeArtemis Intelligent Power Limited
InventorsNiall James Caldwell, Daniil Dumnov, Matthew Green, Stephen Laird, Jill Macpherson
Life of this patent
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Abstract
A hydraulic apparatus including an electronically commutated machine having a plurality of working chambers which are controlled on each cycle of working chamber volume to carry out active or inactive cycles of working chamber volume allows only a plurality of defined fractions of cycles to be active cycles to avoid generating frequencies of active cycles which cause low frequency resonances. The demand signal may be quantised into fractions m/n where n is an integer below a threshold selected to avoid repeating patterns of active cycles of more than a cut-off length.
Claims19
A method of operating an apparatus, the apparatus comprising
- a prime mover and a plurality of hydraulic actuators,
- a hydraulic machine having a rotatable shaft in driven engagement with the prime mover and comprising a plurality of working chambers having a volume which varies cyclically with rotation of the rotatable shaft,
- a hydraulic circuit extending between a group of one or more working chambers of the hydraulic machine and one or more of the hydraulic actuators,
- each working chamber of the hydraulic machine comprising a low-pressure valve configured to regulate a flow of hydraulic fluid between the working chamber and a low-pressure manifold and a high-pressure valve configured to regulate the flow of hydraulic fluid between the working chamber and a high-pressure manifold,
- the hydraulic machine being configured to actively control at least the low-pressure valves of the group of one or more working chambers to select a net displacement of hydraulic fluid by each working chamber on each cycle of working chamber volume, and thereby a net displacement of hydraulic fluid by the group of one or more working chambers, responsive to a demand signal,
- the method comprising controlling the valves to cause each working chamber to carry out either an active or an inactive cycle of working chamber volume during each cycle of working chamber volume,
- wherein a fraction of the working chambers of the plurality of working chambers of the hydraulic machine carry out active cycles, and the fraction is variable and is selected from of a plurality of discrete fractions.
An apparatus comprising
- a prime mover and a plurality of hydraulic actuators,
- a hydraulic machine having a rotatable shaft in driven engagement with the prime mover and comprising a plurality of working chambers having a volume which varies cyclically with rotation of the rotatable shaft,
- a hydraulic circuit extending between a group of one or more working chambers of the hydraulic machine and one or more of the hydraulic actuators,
- each working chamber of the hydraulic machine comprising a low-pressure valve configured to regulate a flow of hydraulic fluid between the working chamber and a low-pressure manifold and a high-pressure valve configured to regulate the flow of hydraulic fluid between the working chamber and a high-pressure manifold,
- the hydraulic machine comprising a controller configured to actively control at least the low-pressure valves of the group of one or more working chambers to select a net displacement of hydraulic fluid by each working chamber on each cycle of working chamber volume, and thereby a net displacement of hydraulic fluid by the group of one or more working chambers, responsive to a demand signal,
- the controller configured to control the valves to cause each working chamber to carry out either an active or an inactive cycle of working chamber volume during each cycle of working chamber volume,
- wherein the apparatus is configured such that a fraction of working chambers of the plurality of working chambers of the hydraulic machine carry out active cycles, and the fraction is variable and is selected from a plurality of discrete fractions.
Dependencies are inferred from the claim text.