Impact tool

An impact power tool comprising:

• a main housing;
• a motor;
• a transmission housing coupled to the main housing, the transmission housing including a bearing pocket open to a front of the transmission housing and defined at least partially by a radially inward-extending flange;
• an output shaft to which a tool bit is attachable for performing work on a workpiece;
• an impact mechanism disposed between the motor and the output shaft for converting a continuous torque output from the motor to discrete rotational impacts upon the output shaft, the impact mechanism including a cylinder concentrically disposed about the output shaft which receives torque from the motor;
• a bearing positioned within the bearing pocket adjacent and in abutting relationship with the radially inward-extending flange for rotatably supporting the output shaft in the transmission housing;
• and
• a radially outward-extending flange on the output shaft that radially overlaps at least a portion of the bearing on an opposite side of the bearing as the radially inward-extending flange;
• wherein a line of action of an axial reaction force applied to the output shaft is directed to the transmission housing via the radially outwardly-extending flange, the bearing, and the radially inward-extending flange, and
• wherein the cylinder imparts repeated rotational impacts upon the output shaft, and
• wherein a nominal axial clearance between a rear end of the output shaft and the cylinder is maintained in response to the application of the axial reaction force on the output shaft.

An impact power tool comprising:

• a motor;
• an output shaft to which a tool bit is attachable for performing work on a workpiece;
• and
• an impact mechanism disposed between the motor and the output shaft for converting a continuous torque output from the motor to discrete rotational impacts upon the output shaft, the impact mechanism including
• a cylinder assembly concentrically disposed about the output shaft,
• a cavity defined within the cylinder assembly containing a hydraulic fluid, and
• a collapsible bladder having a first closed end, a second closed end opposite the first closed end, and an interior volume defined between the first and second closed ends and filled with a gas, the bladder being maintained in a shape coinciding with that of the cavity by fitment within the cavity, with the first and second closed ends being disconnected from each other;
• wherein each of the first and second closed ends is seamless.