Method for replacing crankshaft of hot rolling SSP width setting machine

Abstract

This invention discloses a method for replacing the crankshaft of a hot-rolling SSP (Special Spatial Propulsion) mill. The method first involves dismantling the inner block frame by loosening the connecting pins between the balance cylinders, removing the bellows and slide rails within the inner block frame, and then laterally lifting the inner block frame away. Next, the outer block frame is dismantled by using a hand-operated hoist to hold the crank, disassembling the crank hook, loosening the connecting pins between the balance cylinders, removing the worm gear drive universal joint, and then using a crane to lift the outer block frame out of the mill frame window. Finally, the crankshaft is dismantled by removing the crank mechanism, removing the crankshaft's connecting bolts, fixing the crank bearing seat with a V-shaped bracket, installing the support legs and adjusting the support bolts to hold the crankshaft in place, dismantling the half-half fixing bracket that secures the crankshaft bearing seat, removing the operating side beam support, and then lifting the crankshaft out using a crane. After cleaning the mill stand, the crankshaft, outer block frame, and inner block frame are reinstalled sequentially. This method improves operational efficiency, reduces operation time, saves operating costs, and ensures normal maintenance and production operation of the hot-rolling production line.

Description

Technical Field

[0001] This invention relates to the field of equipment maintenance technology, and in particular to a method for replacing the crankshaft of a hot-rolled SSP width-fixing mill. Background Technology

[0002] With the rapid development of continuous casting and rolling technology, the SSP (Short Scale Spinning Mill) has gradually replaced heavy vertical rolling mills and is widely used in hot rolling production lines due to its advantages such as high production efficiency and a large width reduction adjustment range. The SSP is a key piece of equipment on the hot rolling production line, and its core components consist of an inner frame, an outer frame, and a crankshaft assembly. Based on design and on-site maintenance experience, these three key components need to be taken offline for repair after 5-6 years of use. The repair process requires replacing the SSP crankshaft, but there is currently no guideline for this replacement. The crankshaft (weighing approximately 46 tons) is horizontally fixed to the mill stand, with two 5-ton bearing half-halls hidden under the upper crossbeam. During equipment installation, in order to install the bearing half-halls using a crane, maintenance workers used a 15-ton hoist to secure the crankshaft. During this process, the hoist chain slipped, causing the crankshaft to fall and potentially cause a serious accident. Therefore, how to quickly, efficiently and safely replace the crankshaft assembly has become a challenge in maintenance, seriously affecting the normal maintenance of equipment and the production operation of the hot rolling production line. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a method for replacing the crankshaft of a hot rolling SSP fixed width mill. This method effectively reduces the difficulty and safety risks of crankshaft replacement operations, improves operational efficiency, reduces operation time, saves operating costs, and ensures the normal maintenance and production operation of the hot rolling production line.

[0004] To solve the above-mentioned technical problems, the present invention provides a method for replacing the crankshaft of a hot-rolled SSP width-fixing mill, comprising the following steps:

[0005] Step 1: Remove the inner block frame. Install a transition liner on the top of the inner block frame. Remove the oil and water pipes connected inside the inner block frame. Loosen the connecting pins between the balance cylinders inside the inner block frame. Remove the bellows and slide rails inside the inner block frame. Move the inner block frame horizontally and lift it away.

[0006] Step 2: Remove the outer frame. Install the transition liner on the top of the outer frame. Use a hand chain hoist to hold the crank and remove the crank hook. Remove the oil and water pipes connected inside the outer frame. Loosen the connecting pins between the balance cylinders inside the outer frame. Remove the worm gear drive universal joint of the width adjustment mechanism. Use a hand chain hoist to move the outer frame and pass it through the center side. Use a crane to lift the outer frame out of the window of the width fixing machine frame.

[0007] Step 3: Construct a maintenance platform, V-shaped bracket, and crankshaft legs made of steel plates with railings and stairs;

[0008] Step 4: Crankshaft removal. Hoist the maintenance platform to the crankshaft assembly location and install a guardrail. Remove the crank mechanism of the crankshaft assembly and the oil and water pipes that affect the crankshaft hoisting. Remove the crankshaft connecting bolts. Hoist the V-shaped bracket into place and fix it to the crank bearing housing. Install the stool legs and adjust the support bolts to hold the crankshaft in place. Remove the half-half fixing bracket that fixes the crankshaft bearing housing. Remove the main beam support on the operating side of the width-fixing machine. Use a crane to hoist the crankshaft out.

[0009] Step 5: Clean the rolling mill stand, and reinstall the crankshaft, outer block frame, and inner block frame in sequence;

[0010] Step 6: Measure and adjust the crankshaft synchronization position, arc plate, and sector tooth clearance.

[0011] Furthermore, during crankshaft reinstallation, clean the contact surfaces of the crankshaft bearing housing and the half-half retainer to ensure there are no burrs. After installation, a 0.02mm feeler gauge should not be able to be inserted into the contact surfaces. The bolt tightening torque of the crank mechanism is 6654 NM, and the heating rotation angle is 95°. The bolt tightening torque of the crankshaft bearing housing is 13111 NM, and the heating rotation angle is 122°.

[0012] Furthermore, the clearance adjustment range of the sector teeth is 0.355 to 0.888 mm, and the crankshaft eccentricity synchronization error is ≤2°.

[0013] Furthermore, the gap between the sector teeth is adjusted to 0.622 mm.

[0014] Because the crankshaft replacement method for the hot-rolled SSP width-fixing mill of this invention adopts the above-mentioned technical solution, namely, this method first removes the inner block frame, installs the transition liner, removes the oil pipes and water pipes, loosens the connecting pins between the balance cylinders, removes the bellows and slide rails inside the inner block frame, and then moves and lifts the inner block frame laterally; then, the outer block frame is removed, the transition liner is installed, the crank is held in place by a hand-operated hoist, the crank hook is disassembled, the oil pipes and water pipes are removed, the connecting pins between the balance cylinders are loosened, the worm gear drive universal joint is removed, and the outer block frame is moved... After the operation, the outer frame is lifted out of the frame window using a crane. The crankshaft is removed, along with the crank mechanism, oil pipes, and water pipes. The crankshaft's connecting bolts are disassembled, and the crank bearing housing is fixed using a V-bracket. The support legs are installed, and the support bolts are adjusted to hold the crankshaft in place. The half-half fixing bracket that secures the crankshaft bearing housing is disassembled, and the operating side beam support is removed. The crankshaft is then lifted out using a crane. After cleaning the mill stand, the crankshaft, outer frame, and inner frame are reassembled in sequence. The crankshaft synchronization position, arc plate, and sector tooth clearance are measured and adjusted. This method effectively reduces the difficulty and safety risks of crankshaft replacement operations, improves operational efficiency, reduces operation time, saves operating costs, and ensures the normal maintenance and production operation of the hot rolling production line. Attached Figure Description

[0015] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments:

[0016] Figure 1 This is a schematic diagram of the arrangement of the inner block frame, outer block frame, and crankshaft in a hot-rolled SSP width-fixing mill. Detailed Implementation

[0017] Implementation, for example Figure 1 As shown, the crankshaft replacement method for the hot-rolled SSP width-fixing mill of the present invention includes the following steps:

[0018] Step 1: Remove the inner block frame 1. Install a transition liner on the top of the inner block frame 1. Remove the oil pipes and water pipes connected inside the inner block frame 1. Loosen the connecting pins between the balance cylinders inside the inner block frame 1. Remove the bellows and slide rails inside the inner block frame 1. Move the inner block frame 1 horizontally and lift it away.

[0019] Step 2: Remove the outer frame 2. Install the transition liner on the top of the outer frame 2. Use a hand chain hoist to hold the crank and remove the crank hook. Remove the oil pipe and water pipe connected inside the outer frame 2. Loosen the connecting pin between the balance cylinders inside the outer frame 2. Remove the worm gear drive universal joint of the width adjustment mechanism. Use a hand chain hoist to move the outer frame 2 and pass it through the center side. Use a crane to lift the outer frame 2 out of the window of the width fixing machine frame 4.

[0020] Step 3: Construct a maintenance platform, V-shaped bracket, and crankshaft legs made of steel plates with railings and stairs;

[0021] Step 4: Crankshaft 3 removal. Hoist the maintenance platform to the crankshaft 3 assembly position and install a guardrail. Remove the crank mechanism of the crankshaft 3 assembly and the oil and water pipes that affect the hoisting of crankshaft 3. Remove the connecting bolts of crankshaft 3. Hoist the V-shaped bracket into place and fix it to the crank bearing seat. Install the stool legs and adjust the support bolts to hold crankshaft 3 in place. Remove the half-half fixing bracket that fixes the crankshaft 3 bearing seat. Remove the main beam support on the operating side of the fixed width machine. Use a crane to hoist crankshaft 3 out.

[0022] Step 5: Clean the rolling mill stand, and reinstall crankshaft 3, outer block frame 2 and inner block frame 1 in sequence;

[0023] Step 6: Measure and adjust the synchronous position of crankshaft 3, the arc plate, and the clearance of the sector teeth.

[0024] Preferably, when reinstalling crankshaft 3, the contact surfaces of the crankshaft bearing housing and the half-half retainer are cleaned to ensure there are no burrs on the contact surfaces. After installation, a 0.02mm feeler gauge cannot be inserted into the contact surfaces. The bolt tightening torque of the crank mechanism is 6654 NM, and the heating rotation angle is 95°. The bolt tightening torque of the crankshaft bearing housing is 13111 NM, and the heating rotation angle is 122°.

[0025] Preferably, the sector tooth clearance adjustment range is 0.355 to 0.888 mm, and the crankshaft eccentricity synchronization error is ≤2°.

[0026] Preferably, the gap between the sector teeth is adjusted to 0.622 mm.

[0027] There is only one fixed width mill installed in China, located in Baosteel's 1880 hot rolling mill. Therefore, there is no technology for disassembling and assembling the crankshaft to learn from. This method starts with the comprehensive overall maintenance of the equipment, realizing an efficient and safe equipment maintenance approach. It can effectively solve the problem of crankshaft replacement for the fixed width mill and is an innovation in the on-site maintenance method of this equipment.

[0028] This method enables efficient disassembly and assembly of the crankshaft of the hot-rolling SSP width-fixing mill, reducing the difficulty and safety risks of crankshaft replacement operations, improving operational efficiency and reducing operation time, indirectly reducing operating costs, and helping to improve the overall work efficiency and safety of operators, thus ensuring the normal maintenance and reliable operation of the hot-rolling production line.

Claims

1. A method for replacing the crankshaft of a hot-rolled SSP width-fixing mill, characterized in that... This method includes the following steps: Step 1: Remove the inner block frame. Install a transition liner on the top of the inner block frame. Remove the oil and water pipes connected inside the inner block frame. Loosen the connecting pins between the balance cylinders inside the inner block frame. Remove the bellows and slide rails inside the inner block frame. Move the inner block frame horizontally and lift it away. Step 2: Remove the outer frame. Install the transition liner on the top of the outer frame. Use a hand chain hoist to hold the crank and remove the crank hook. Remove the oil and water pipes connected inside the outer frame. Loosen the connecting pins between the balance cylinders inside the outer frame. Remove the worm gear drive universal joint of the width adjustment mechanism. Use a hand chain hoist to move the outer frame and pass it through the center side. Use a crane to lift the outer frame out of the window of the width fixing machine frame. Step 3: Construct a maintenance platform, V-shaped bracket, and crankshaft legs made of steel plates with railings and stairs; Step 4: Crankshaft removal. Hoist the maintenance platform to the crankshaft assembly location and install a guardrail. Remove the crank mechanism of the crankshaft assembly and the oil and water pipes that affect the crankshaft hoisting. Remove the crankshaft connecting bolts. Hoist the V-shaped bracket into place and fix it to the crank bearing housing. Install the stool legs and adjust the support bolts to hold the crankshaft in place. Remove the half-half fixing bracket that fixes the crankshaft bearing housing. Remove the main beam support on the operating side of the width-fixing machine. Use a crane to hoist the crankshaft out. Step 5: Clean the rolling mill stand, and reinstall the crankshaft, outer block frame, and inner block frame in sequence; Step 6: Measure and adjust the crankshaft synchronization position, arc plate, and sector tooth clearance.

2. The crankshaft replacement method for a hot-rolled SSP width-fixing mill according to claim 1, characterized in that: When reinstalling the crankshaft, clean the contact surfaces of the crankshaft bearing housing and the half-half retainer to ensure there are no burrs. After installation, a 0.02mm feeler gauge should not be able to be inserted into the contact surfaces. The bolt tightening torque of the crank mechanism is 6654 NM, and the heating rotation angle is 95°. The bolt tightening torque of the crankshaft bearing housing is 13111 NM, and the heating rotation angle is 122°.

3. The crankshaft replacement method for a hot-rolled SSP width-fixing mill according to claim 1, characterized in that: The clearance adjustment range of the sector teeth is 0.355 to 0.888 mm, and the crankshaft eccentricity synchronization error is ≤2°.

4. The crankshaft replacement method for a hot-rolled SSP width-fixing mill according to claim 3, characterized in that: The gap between the sector teeth is adjusted to 0.622 mm.

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