Pump Assembly and Proportioning Machine

A pump assembly, comprising:

• a driving mechanism, comprising a driving motor;
• a first pump body, configured to extract a first solution;
• a second pump body, configured to extract a second solution;
• and
• a third pump body, configured to extract a diluent, the first pump body and the second pump body are in transmission connection, the second pump body and the third pump body are both in driving connection with the driving motor, when the driving motor rotates along a first direction, a rotating shaft of the third pump body does not rotate, the driving motor drives a rotating shaft of the second pump body to rotate, the rotating shaft of the second pump body drives a rotating shaft of the first pump body to rotate, when the driving motor rotates along a second direction, the rotating shafts of the first pump body and the second pump body do not rotate, the driving motor drives the rotating shaft of the third pump body to rotate, and the first direction and the second direction are opposite.