Pneumatic reciprocating saw

A pneumatic reciprocating saw, comprising:

• a housing, formed with a first assembly space, a second assembly space orthogonal to the first assembly space, a first assembly hole communicating with the first assembly space and a saw assembly opening communicating with the second assembly space;
• a pneumatic motor, assembled with the housing through the first assembly hole, the pneumatic motor being provided with an output shaft;
• a saw, extending into the second assembly space through the saw assembly opening;
• and
• a transmission assembly, the transmission assembly being provided with a driving bevel gear arranged on the output shaft and extending into the first assembly space, a transmission bevel gear being arranged in the first assembly space and engaged with the driving bevel gear, a driven rod being arranged on the transmission bevel gear, a pushing block being arranged on the driven rod and positioned in the second assembly space and being eccentrically arranged from an axis of the driven rod, a transmission rod being arranged in the second assembly space and assembled with the saw, and a thermal insulator being sleeved on a tail end of the transmission rod which is not connected with the saw and contacting the housing without being shifting along with the transmission rod, the transmission rod being provided with a groove for placing the pushing block, when the transmission rod is driven to reciprocate in a linear track, the tail end of the transmission rod which is not connected with the saw being limited by the thermal insulator and being able to only move in the linear track, and the pushing block sliding in the groove.