Cam actuated gas admission valve with electro-hydraulic trim control

A gas admission valve assembly, comprising:

• an actuation cylinder,
• a hydraulic piston to be actuated by a cam and disposed in the actuation cylinder,
• a check valve to supply a hydraulic fluid to a first portion of the actuation cylinder,
• an electronic controlled valve to remove the hydraulic fluid from the first portion of the actuation cylinder,
• a fuel supply to supply a fuel to a second portion of the actuation cylinder,
• an admission valve to remove the fuel from the second portion of the actuation cylinder,
• an engine control module to control the electronic controlled valve to alter a hydraulic pressure in the first portion of the actuation cylinder and to control whether the admission valve is opened by rotation of the cam.

A method, comprising:

• receiving, by an engine control module and from a pressure sensor, information identifying a cylinder pressure of a combustion cylinder in a natural gas engine;
• determining, by the engine control module, a deviation of the cylinder pressure from a pre-configured cylinder pressure for the combustion cylinder;
• determining, by the engine control module, a control signal based on the deviation of the cylinder pressure from the pre-configured cylinder pressure;
• and
• transmitting, by the engine control module, the control signal to actuate an electronic controlled valve of a gas admission valve assembly to alter a rate of natural gas injection via an admission valve of the gas admission valve assembly.