Patent ID: 7946354

Claim:
A pneumatic power tool, comprising: a housing; a motor; an output shaft and a gearing connecting the motor to the output shaft; a pressure air inlet passage and an air outlet passage arranged in the housing which communicate air to and from, respectively, the motor; and a cooling chamber provided between the motor and the partition wall, said cooling chamber being sealed off relative to the gearing chamber and communicating with the atmosphere via an auxiliary outlet passage; wherein the gearing is located in a gearing chamber partly defined by a partition wall in the housing, said partition wall providing a heat transferring surface which is exposed to the cooling chamber and cold exhaust air passing through said cooling chamber, thereby transferring heat from the gearing chamber; wherein said heat transferring surface comprises walls of at least one groove formed in the housing for increasing the heat transferring efficiency; and wherein a tubular section formed by a circular groove in the housing forms part of the walls of the heat transferring surface exposed to the cooling chamber.