A slush pump comprises a machine body and a linkage-free reciprocating and rotation motion conversion mechanism and a cylinder sleeve which are arranged in the machine body. The machine body is a combined machine body which comprises a crank case, runway seats and guide rails. The runway seats are arranged on the crank case detachably, and the guide rails are arranged on the runway seats. The guide rails of the runway seats on the opposite side walls of the combined machine body are aligned. Two ends of a crank shaft of the linkage-free reciprocating and rotation motion conversion mechanism are arranged at an upper main bearing hole and a lower main bearing hole respectively. Motion directions of two reciprocating motion parts are perpendicular to each other, and guide portions of the reciprocating motion parts are arranged in the crank case and matched with the corresponding guide rails. Working portions are arranged on the outside of the crank case, and connection portions are formed by piston rods on the runway seats, which stretch out through holes and connect the guide portions and the connection portions together. The machine body of the slush pump is convenient to machine and low in manufacture cost. Meanwhile, the invention further relates to the crank case, the combined machine body and equipment using the combined machine body.