The spindle drive modes of CNC milling machine are belt drive and gear shift drive in two ways. Now let's look at these two ways separately.
In the case of the spindle motor with a special three-phase AC asynchronous motor and a variable frequency speed control, since the spindle motor has a wide range of constant torque and constant power speed range, the spindle motor can be connected to the milling machine spindle through the drive belt. Spindle motor control to achieve the spindle speed and steering control, simplifying the spindle drive mechanism. The belt drive is used for spindle milling of CNC mill machines and medium and small machining centers.
2.Gear shift drive
In the case of spindle motor with ordinary three-phase AC asynchronous motor and frequency control, in order to obtain the spindle low speed and increase the constant power speed range, some CNC milling machine spindle gear shift.
Gear shift mechanism with hydraulic fork and electromagnetic clutch in two forms, as shown in the figure, the gear shift using hydraulic cylinder and fork for high and low two switch. When the high-speed gear, the solenoid valve action, the hydraulic cylinder piston out, through the fork to slip gear shift, Z1 and Z2 meshing, Z3 and Z4 off, high-speed detection device in place SQ1 signal, drive path: spindle motor → drive belt d1 / d2 → I axis → Z1 / Z2 → spindle. In the low gear, the solenoid valve moves, the hydraulic cylinder piston retracts, moves the slip gear by the fork, Z3 and Z4 are engaged, Z1 and Z2 are disengaged, the low gear detection switch SQ2 sends the signal, the transmission path: the spindle motor → drive belt d1 / d2 → I axis → Z3 / Z4 → spindle.
Gear shift has manual and automatic (M command) two kinds of operation. Electromagnetic reversing valve movement and the shift position detection are controlled by the PLC of the CNC system.
The above is about the two kinds of spindle transmission of CNC milling machine, welcome you continue to pay attention.