Counterbalance for eccentric shafts

A power tool, comprising:

• a housing;
• a motor having a motor output shaft and located within said housing, said motor being configured to rotate said motor output shaft about a first axis;
• a drive component having (i) a body attached to said motor output shaft, and (ii) an output drive pin attached to said body, said output drive pin defining a second axis which is offset from said first axis, said body being caused to rotate about said first axis in response to rotation of said motor output shaft about said first axis, and said output drive pin being caused to be eccentrically driven in response to rotation of said body about said first axis, and further said body having a hub and a counterbalance arrangement attached to said hub, said counterbalance arrangement being positioned and configured to offset forces generated by said output drive pin when eccentrically driven;
• a hub bearing structure located within said housing and including a bearing in which said hub of the drive component is received;
• a linkage coupled to said output drive pin and configured to oscillate in response to said output drive pin being eccentrically driven;
• and
• a tool mount configured to oscillate in response to oscillation of said linkage;
• wherein said counterbalance arrangement is located entirely between said bearing structure and said motor;
• wherein said hub includes a first end portion and a second end portion,
• wherein said output drive pin extends from said first end portion, and
• wherein said counterbalance arrangement includes:
• a first counterbalance structure extending radially from said second end portion of said hub, and
• a second counterbalance structure extending radially from said second end portion of said hub.