US Patent 12129843 Breather valve

A positive displacement pump includes a housing surrounding a drive chamber and a diaphragm compartment. A drive element is inside the drive chamber. A diaphragm is inside the diaphragm compartment and divides the diaphragm compartment into a fluid chamber and a cavity. A shaft connects the drive element and the diaphragm. A breather valve is fluidically connected to the cavity and is configured to allow air to exit the cavity. The cavity is fluidically disconnected from the drive chamber.