Invisible membrane type gas meter

The invention discloses an invisible membrane type gas meter, which belongs to the technical field of gas flow measuring equipment and comprises a gas meter shell, a gas meter movement mounted in the gas meter shell and a central shaft connected with the gas meter movement, a counter is further mounted in the gas meter shell, and the central shaft is connected to the counter through a lubricating component. A limiting groove in sliding fit with the limiting block is formed in the surface of the input shaft and extends in the axial direction of the input shaft. A push plate is arranged at the tail end of the limiting groove, slidably arranged in a sliding cavity formed in the input shaft and connected to a piston through a shaft rod, a first spring is connected between the push plate and the inner wall of the sliding cavity, the piston is slidably arranged in an oil storage cavity formed in the input shaft, the oil storage cavity is filled with sponge, and the sponge is filled with lubricating oil. And an oil