Lifting mechanism for tray

The utility model discloses a lifting mechanism for a tray. The lifting mechanism comprises a mechanism frame, a bearing lifting frame, a lifting driver, a movable wheel, a fixed wheel, a first shaft, a second shaft and a traction piece, wherein the bearing lifting frame is used for bearing the tray; the lifting driver is used for driving the bearing lifting frame and the tray to lift together; the lifting driver is assembled on the mechanism frame, and the output end of the lifting driver does linear telescopic motion; the first shaft is located below the lifting driver and further connected with the output end of the lifting driver in an assembled mode. The first shaft is rotatably sleeved with the driving wheel, the second shaft is located above the first shaft in parallel, and the second shaft is further rotatably assembled on the mechanism frame; the fixed wheel sleeves the second shaft, the head end of the traction piece is fixedly connected with the mechanism frame, and the position, away from the head