Pneumatic device

A pneumatic device, comprising:

• an outer ring, having at least two driving recesses on an inner ring surface of the outer ring in a circumferential direction;
• a core body, being coaxially arranged in the outer ring and being capable of rotating relative to the outer ring, where an outer ring surface of the core body is provided with at least one nozzle and at least one exhaust port, and the core body is further provided with at least one secondary stroke flow channel between the at least one nozzle and the at least one exhaust port, wherein each secondary stroke flow channel is delimited by radially inner and outer boundaries, a portion of which are radially spaced from the outer ring surface of the core body, and includes a return channel and a stroke channel communicated with the return channel,
• at least one intake passage communicating with the at least one nozzle, and
• at least one exhaust passage communicating with the at least one exhaust port;
• wherein the at least one intake passage terminates at the at least one nozzle on the outer ring surface of the core body, and
• wherein, for a rotational position of the core body relative to the outer ring:
• the at least one nozzle communicates with a driving recess of the at least two driving recesses of the outer ring, and
• each secondary stroke flow channel communicates with two driving recesses of the at least two driving recesses, i.e., front and rear driving recesses, of the outer ring and forms a N-stage flow channel along the circumferential direction of the core body, where N is a natural number greater than or equal to 2,
• the return channel of a N-stage secondary stroke flow channel of the at least one secondary stroke flow channel communicates with a N-stage driving recess of the at least two driving recesses, and the stroke channel of the N-stage secondary stroke flow channel communicates with another N-stage driving recess of the at least two driving recesses;
• wherein the N-stage flow channels are arranged in series to form a multi-stage stroke structure with decreasing energy of gas flowing therethrough;
• wherein a running direction of the at least one intake passage is a logarithmic spiral line extending from a middle to an outside of the core body, and a running direction of each stroke channel is a portion of a logarithmic spiral line extending from the middle to the outside of the core body,
• wherein, in operation, the gas enters from the at least one intake passage and flows through the multi-stage stroke structure to generate a pushing force that causes the outer ring to rotate and do work, so as to achieve a power output, and finally, the gas is discharged from the at least one exhaust passage through the at least one exhaust port of the core body.