Rolling mill assembly operation and maintenance

Pre-installation in the roll changing room

This equipment is located in the roll changing room and is used for roll changing operations of the rolling mill. The schematic diagram of the roll changing trolley is as follows:

The roll changing device is composed of a track seat, an operating side bracket, a transmission side bracket, a frame, a roll conveying car body, a roll bracket and other components.

The operating side bracket and the transmission side bracket are fixed on two frames respectively, and the frames move on the track of the track seat one.
The roller bracket is fixed on the roller conveyor car body, and the roller conveyor car body moves on the track of the track seat two.
The frame and the roller conveyor car are driven by hydraulic cylinders and reciprocate on the track seat.
The bearing seat of the mill roll system is fixed to the operating side bracket and the transmission side bracket by bolts and nuts. The frame moves to disengage the outer ring of the bearing of the mill roll system from the roll, and the roll falls on the roller bracket.
There are two roller brackets on the roller conveyor car body, one for placing new rolls and the other for placing old rolls to increase the roll changing speed.
The roller table seat, hydraulic cylinder, frame and roller conveyor car body of the three types of mill roll changing devices are universal. The operating side bracket, the transmission side bracket and the two roller brackets are different to adapt to different specifications of rolling mills.

The specific operation process is as follows:

1. Connect the operating side bracket, transmission side bracket and roller bracket of the corresponding machine model to the frame firmly.
2. The wheel axle of the car body is an eccentric shaft. By adjusting the eccentric shaft, the car body, roller bracket and roller conveying car body are all within the tolerance range for roller changing.
3. Use the hydraulic motor on the rolling mill to adjust the rolling mill to the roller changing center distance. The roller changing center distance of the 550 rolling mill is 685mm, the roller changing center distance of the 450 rolling mill is 530mm, and the roller changing center distance of the 350 rolling mill is 395mm. Then hoist the rolling mill to the position of the roller changing device station 1 in Figure 3. The rolling mill rollers are fixed to the operating side bracket and the transmission side bracket on the two frames by bolts and nuts. The appropriate height can be adjusted by moving the eccentric pin shaft under the beam, and then tighten the screws to fix it. Remove the connecting crossbeam on the transmission side of the rolling mill, the four nuts of the guide position, and then remove the related parts of the operating side roller screws and positioning pins.
4. Retract hydraulic cylinder ① (stroke 1900mm) and hydraulic cylinder ② (stroke 1150mm) to make the frame drive the operating side bracket and the transmission side bracket to retreat, and disengage the frame and bearing seat of the rolling mill from the old roller;
5. Extend hydraulic cylinder ③ (stroke 1450mm), and transport the roller conveying bracket forward to transport the new roller from station 2 to station 1;
6. Extend hydraulic cylinder ① (stroke 1900mm) and hydraulic cylinder ② (stroke 1150mm), push the two frames and the brackets on both sides back to the position shown in the figure, and install the new roller on the bearing seat of the rolling mill, and then install the axial fixing parts of the rolling mill frame.
7. Lift away the rolling mill roll system and the old roller that have completed the roll change operation. Complete the roll change operation.

Overall assembly

The following procedures should be followed when disassembling and reassembling the rolling mill:

• First, assemble the roll gap adjustment device and the roll system separately;
• The roll, the inner ring of the four-row cylindrical roller bearing and the moving labyrinth (I) are hot-fitted as a whole;
• Check the roll journal size and verify that the interference size between it and the inner ring of the bearing is within the range of 0.06-0.09mm;
• Treat the fillet on the roll with an antiseptic;
• Install the moving labyrinth (I) on the roll;
• Heat the inner ring of the bearing to 100℃-130℃ with a heater;
• Put the inner ring of the bearing on the roll journal to ensure that there is no gap between the inner ring of the bearing, the moving labyrinth (I) and the end of the roll. When cooling, knock with a copper rod or apply axial force to make it close together until it cools to room temperature;
• Check that the clearance of the bidirectional thrust tapered roller bearing is between 0.10-0.15mm, and install it after it meets the requirements;
• Assemble the roll in the hole of the roll box , four-row cylindrical roller bearing inner ring and moving labyrinth (I);

• Assemble the single-side roll gap adjustment device;
• Install the tie rod on the support seat;
• Install the roll box on the tie rod. To ensure that the four roll boxes are parallel to each other, the roll box and the support seat are padded with equal height pads;
• Install the spherical pad, press nut and balance nut;
• Install the balance spring and adjust the balance force as required;
• Install the worm gear box of the roll gap adjustment device on the tie rod;
• Install the guide beam on the support seat;
• Install the roll boxes with worm gear boxes on both sides on the roll. If the opening degree is not appropriate, it can be adjusted with the roll gap adjustment device;
• Install the axial fastening parts of the fixed end and the floating end, and connect the two worm gear boxes of the roll gap adjustment device;
• Place the rolling mill frame on the frame locking device. The taper pin and taper key on the frame locking device match the taper sleeve and taper groove on the support seat. The installation dimension is 1100±0.08;
• During assembly, the gap between the roller box and the guide surface of the support seat is guaranteed to be 0.10-0.15mm, ensuring that the roller box and the support seat slide flexibly without obstruction during the change of the opening degree of the rolling mill frame.

Replacement hole slot

When changing the hole groove on the rolling line, first loosen the bolts between the dovetail seat and the base, rotate the screws on both sides of the guide beam to move the dovetail seat to the required position. Note that after the dovetail seat is aligned with the rolling groove position on the roller, the bolts still need to be tightened.

LMM GROUP