Power tool with impulse assembly including a valve

A power tool comprising:

• a housing;
• a motor positioned within the housing;
• an impulse assembly coupled to the motor to receive torque therefrom, the impulse assembly including
• a cylinder at least partially forming a chamber containing a hydraulic fluid,
• an anvil positioned at least partially within the chamber, and
• a hammer positioned at least partially within the chamber and engageable with the anvil for transferring rotational impacts to the anvil, the hammer including a first through hole configured to at least partially receive the anvil when the hammer engages the anvil;
• and
• a biasing member biasing the hammer towards the anvil;
• wherein an annular opening is defined between the anvil and the first through hole, and
• wherein an area of the annular opening varies as the hammer translates away from the anvil.

A power tool comprising:

• a housing;
• a motor positioned within the housing;
• an impulse assembly coupled to the motor to receive torque therefrom, the impulse assembly including
• a chamber containing a hydraulic fluid,
• an anvil positioned at least partially within the chamber,
• a camshaft driven by the motor, and
• a hammer configured to reciprocate within the chamber in response to rotation of the camshaft, the hammer including a first through hole receiving the camshaft and
• a second through hole;
• and
• a one-way valve configured to control flow of the hydraulic fluid through the second through hole.