Metering pump and drive device thereof

A metering pump, comprising

• a pump sleeve comprising a liquid-inlet hole and a liquid-outlet hole;
• a pump body comprising a cavity and a diversion outlet;
• a plunger;
• and
• a drive device, comprising
• a housing;
• a rod;
• a limiting device;
• a sliding block;
• a rotating block;
• a pair of springs;
• a pair of first grooves;
• and
• a second groove;
• wherein
• said pump body is movably disposed in said pump sleeve;
• said plunger is disposed in said cavity of said pump body;
• said diversion outlet is disposed on a side wall of said pump body and connected to said cavity;
• said liquid-inlet hole and said liquid-outlet hole are opposite to said diversion outlet;
• said diversion outlet is alternatively aligned with said liquid-inlet hole and said liquid-outlet hole;
• said housing is fixedly connected to said pump sleeve;
• said rod is fixed to said pump body;
• said limiting device operates to limit travel distance of said pump body;
• said sliding block is movably disposed in said housing;
• said plunger is fixedly connected to said sliding block;
• said rod passes through said sliding block;
• an axis is disposed on said sliding block;
• said rotating block is disposed on said axis;
• said springs are disposed on both sides of said rotating block;
• the top of said spring is contacted with one side of said rotating block;
• said first grooves are disposed on one side of said rod opposite to said housing;
• said second groove is disposed on inner side of said housing opposite to said first groove;
• a middle part of said second groove is lower than other parts thereof;
• one end of said rotating block slides in said second groove;
• and
• the other end of said rotating block slides in and between said first grooves.