Extreme pressure ( ep ) additive ? chemical compound imparting extreme pressure characteristics to a lubricant with the objecfive of reducing wear under conditions where rubbing or sliding accompanies high contact pressures ， as in heavily loaded gears ， particulars of the hypoid type 极压( ep )添加剂在伴随着高接触压力的摩擦和滑动的情况下(如：在重载齿轮，特别是准双曲面型齿轮中) ，能够赋予润滑油抗极压性能，以达到减轻磨损目的的化合物。
