A method for controlling the machining accuracy of the main bearing seat of a large mining mill

Abstract

This patent introduces a method for controlling the machining accuracy of the main bearing seat of a large mining mill. S1: mill the bottom surface and the mating surface of the bearing seat separately; S2: adjust the machine tool on the bearing seat and symmetrically fix the process measuring block; S3: turn the smallest inner hole of the bearing seat to find the circle, find the rotation center O passing through the mating surface, press the bearing seat and fix the position; S4: record the machining dimensions of the other bearing seat that was originally matched and make rough and fine turning of each inner hole on the bearing seat; S5: machine and measure the inner hole of the bearing shell seat. The present invention first performs pre-machining, then checks, measures and adjusts, and finally makes the rotation center of the workpiece pass through the mating surface, based on the dimensions of the other bearing seat that was originally matched, thereby ensuring that the two bearing seats are of equal height, ensuring the dimensional accuracy of the inner holes of the bearing seat and the bearing shell seat in the later processing, and ensuring that the dimensional tolerance of the distance from the lowest point of the inner hole of the bearing seat to the bottom surface meets the requirements, thereby realizing the control of dimensional accuracy when machining a single bearing seat using a vertical lathe.

Description

Technical Field

[0001] The invention relates to the technical field of mill main bearing seat processing, and in particular to a method for controlling the processing accuracy of a large-scale mining mill main bearing seat. Background Art

[0002] Mining mills generally have two main bearings installed on the base at both ends of the cylinder to support the rotation of the cylinder. Figure 1 As shown; the schematic diagram of the main bearing seat of the mining mill is shown in Figure 2 It is mainly composed of a bearing seat and a bearing shell seat welded together; the main bearing is an important component that supports the rotation of the mill cylinder, and its processing and manufacturing precision requirements are very high. It is a key factor in ensuring the normal operation of the mill.

[0003] In order to ensure that the bearing seats of the two main bearings on the same platform are of equal height and the rotation center of the working surface passes through the bearing seat joint surface, and to reduce the overall manufacturing cost, the main bearings are generally processed by combining two bearing seats during the factory manufacturing process. During the processing of the bearing seat, the dimensions must be guaranteed according to the requirements of the drawing. Figure 3 As shown, RA is the inner hole radius of the bearing seat, D2 is the minimum inner hole diameter of the bearing seat, H2 is the center height, that is, the distance from the mating surface to the bottom surface, A2 is the distance from the lowest point of the minimum inner hole of the bearing seat to the bottom surface, and E is the distance from the lowest point of the inner hole of the bearing seat to the bottom surface; before the two bearing seats of the same piece are processed in pairs by vertical lathe, they first need to be milled into the bottom surface and mating surface of the bearing seat on a milling machine to achieve the consistency of the center height H2 of the two bearing seats of the same piece, and then the mating surface connection hole is machined, and then the two bearing seats are combined into one body with the mating surface as the reference, and then the inner hole parts are fine-turned by vertical lathe, as shown Figure 4 As shown; during this period, the distance from the inner hole of the bearing seat to the bottom surfaces of the two bearing seats is detected and adjusted to be consistent, and finally the actual center position of the inner hole of the bearing shell seat is determined, that is, the rotation center passes through the joint surface, and the dimensions from the inner circle bottom of the two bearing shell seats to the bottom surface of the bearing seat are consistent, and the accuracy of the inner hole size meets the requirements of the drawing.

[0004] However, in actual use, users often encounter situations where the mill stops working due to damage to a single bearing seat, and users have to re-order a single bearing seat; when a single bearing seat as a spare part is processed on a vertical lathe, it is impossible to directly check, measure and adjust the distance from the inner hole of the bearing seat to the bottom surface of the bearing seat to ensure the actual center position of the inner hole, and it is impossible to directly ensure that the rotation center passes through the joint surface of the bearing seat. The original process method cannot be implemented, combined processing cannot be carried out, and its processing accuracy cannot be controlled according to the combined processing method. Summary of the Invention

[0005] The purpose of the present invention is to overcome the shortcomings of the existing technology and provide a method for controlling the machining accuracy of the main bearing seat of a large mining mill, which is suitable for the finishing accuracy control of a single-piece main bearing seat and provides a reliable theoretical and practical basis for single-piece machining.

[0006] The technical solution adopted in the present invention is:

[0007] A method for controlling the machining accuracy of a main bearing seat of a large mining mill, comprising the following steps:

[0008] S1: Press the bearing seat flat on the milling machine, mill the bottom surface and the joint surface of the bearing seat respectively, and measure and record the actual size H2 from the joint surface to the bottom surface;

[0009] S2: Symmetrically fix the process measuring block; query the minimum inner hole diameter D2 of the bearing seat in the original matching processing drawing, use the reserved amount smaller than D210-12mm as the diameter, and draw a circle line on the vertical lathe worktable with the machine tool rotation center O as the center;

[0010] Adjust the bearing seat onto the machine tool, align the smallest inner hole of the bearing seat with the lofted circle line, leaving an even gap of 1-2mm, then use the table to align the bottom vertical workbench according to the processed bottom surface of the bearing seat. After passing the inspection, place a counterweight box at a 180° position opposite the bearing seat on the vertical lathe workbench according to the size and position of the inner hole of the bearing seat, and set a process measuring block on the counterweight box. The process measuring block should be flush with the inner hole of the bearing seat. The distance from the process measuring block to the machine tool rotation center O is S1 = D2 / 2-10mm, and the distance from the counterweight box to the machine tool rotation center O is S2 = D2 / 2+20mm;

[0011] S3: Adjust the single-piece bearing seat; turn the smallest inner hole of the bearing seat to find the circle, with a cutting amount of 1-2mm, until the circle is visible, and the roughness requirement is Ra6.3; after the trial cutting, check and measure the measured value A1 of the distance from the lowest point of the inner hole of the bearing seat to the bottom surface and the measured value D1 of the diameter of the circle.

[0012] According to the measured dimensional relationship, the actual distance H1 from the machine tool rotation center O to the bottom surface can be obtained:

[0013] H1=A1+D1 / 2

[0014] According to the theoretical dimensional relationship required by the bearing seat drawing, the distance H2 from the joint surface to the bottom surface is:

[0015] H2=A2+D2 / 2

[0016] When the difference between H1 and H2 is ≤0.02mm, it can be considered that the machine tool rotation center O passes through the joint surface and can meet the processing requirements;

[0017] If the difference between H1 and H2 is not ≤ 0.02mm, adjust the workpiece according to the measured values ​​A1 and D1 of this trial cutting, loosen the pressure plate, and readjust the clamping position of the bearing seat. Continue trial cutting and re-measure A1, D1, and H1. The cutting amount of each trial cutting is 1-2mm. Through continuous trial cutting, inspection, and adjustment, the machine tool rotation center O can finally pass through the bearing seat joint surface. After the machine tool rotation center O passes through the joint surface, press the bearing seat and fix the position.

[0018] S4: Keep the bearing seat fixed, and re-turn the smallest inner hole of the bearing seat to find a true circle with a diameter of D3. It is sufficient to see the circle, and the roughness requirement is Ra6.3; query the machining dimension records of each inner hole of the bearing seat in the other bearing seat in the original matching machining drawing, and rough and fine turn each inner hole on the bearing seat according to the recorded values;

[0019] S5: Query the bearing shell inner hole size D4 of the other bearing seat in the original matching processing drawing and the processing dimension record value of the distance from the lowest point of the inner hole to the bottom surface, adjust the position and height of the process measuring block to be flush with the height position of the bearing shell inner hole, and after meeting the requirements for measuring the bearing shell inner hole size, process and measure the bearing shell inner hole.

[0020] Due to the adoption of the above technical solution, the present invention has the following advantages:

[0021] The method for controlling the machining accuracy of the main bearing seat of a mining mill of the present invention first performs pre-machining, then checks, measures, and adjusts, and finally makes the rotation center of the workpiece pass through the joint surface. The size of the other bearing seat originally matched is used as a basis, thereby ensuring that the two bearing seats are of equal height, ensuring the dimensional accuracy of the inner holes of the bearing seat and the bearing shell seat in the later processing, and ensuring that the dimensional tolerance of the distance from the lowest point of the inner hole of the bearing seat to the bottom surface meets the requirements, thereby realizing the control of the dimensional accuracy when using a vertical lathe to process a single bearing seat. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the bearing seat support of a mining mill of the present invention.

[0023] Figure 2 It is a schematic diagram of a bearing seat of the present invention.

[0024] Figure 3 It is a schematic diagram of the bearing seat dimensions of the present invention.

[0025] Figure 4 It is a schematic diagram of processing paired bearing seats of the present invention.

[0026] Figure 5 This is a schematic diagram of a single-piece bearing seat of the present invention with process measurement blocks symmetrically placed on a vertical lathe.

[0027] Figure 6It is a schematic diagram of the adjustment of the vertical lathe processing of a single-piece bearing seat of the present invention.

[0028] Figure 7 It is a schematic diagram of the single-piece bearing seat adjustment process measuring block of the present invention.

[0029] In the figure: 1-bearing seat, 2-bearing seat, 21-bearing seat bottom surface, 22-bearing seat mating surface, 3-vertical lathe workbench, 4-counterweight box, 5-process measuring block, 6-mill cylinder, 7-free end main bearing, 8-fixed end main bearing. DETAILED DESCRIPTION

[0030] The present invention will be further explained below with reference to the accompanying drawings and embodiments, which should not be used to limit the scope of protection of the present invention. The purpose of disclosing the present invention is to protect all technical improvements within the scope of the present invention.

[0031] Take the processing project of a single-piece bearing seat of a semi-autogenous grinding mill spare part with a cylinder diameter of 9.15m on a vertical lathe as an example. The single-piece bearing seat of the spare part is processed to be 4500mm long, 1030mm wide, 1950mm high, and weighs about 7t.

[0032] Combined with attachment Figure 1-7 The method for controlling the machining accuracy of the main bearing seat of a large mining mill is shown in the figure. The specific steps are as follows:

[0033] S1: Press the bearing seat flat on the milling machine and mill the bearing seat bottom surface 21 and the joint surface 22 respectively. Measure and record the actual dimension H2 of the joint surface 22 to the bottom surface 21, which is 1950mm.

[0034] S2: Symmetrically fix the process measuring block; query the original matching processing drawing for the minimum inner hole diameter of the bearing seat, D2 = 2900 mm. With a reserve of 10 mm less than D2 as the diameter, draw a circular line on the vertical lathe worktable 3 with the machine tool rotation center O as the center; leave an 8 mm machining allowance for the minimum inner hole of the bearing seat workpiece;

[0035] Adjust the bearing seat on the machine tool, align the minimum inner hole of the bearing seat 2 with the lofted circle line, leave a uniform gap of 2mm, and then use the table to align the bottom surface of the vertical workbench 3 according to the processed bottom surface 21 of the bearing seat. The tolerance is less than 0.05mm. After passing the inspection, place the counterweight box 4 at the 180° position opposite the bearing seat on the vertical lathe workbench according to the size and position of the inner hole of the bearing seat, and fix the process measuring block 5 on the counterweight box 4. The process measuring block 5 is made of Q235A and has a specification of 250mm×100mm×50mm. The process measuring block 5 is flush with the inner hole of the bearing seat 2 at the same height. The distance S1 from the process measuring block 5 to the machine tool rotation center O is D2 / 2-10mm=1440 mm, and the distance S2 from the counterweight box 4 to the machine tool rotation center O is D2 / 2+20mm=1470 mm.

[0036] S3: Adjust the single-piece bearing seat; turn the smallest inner hole of the bearing seat 2 to find the circle, with a cutting amount of 1-2mm, until the circle is visible, and the roughness requirement is Ra6.3; after the trial cutting, check and measure the distance from the lowest point of the inner hole of the bearing seat 2 to the bottom surface. The measured value A1 is 503.54mm, and the measured value of the diameter of the circle is D1 = 2893mm.

[0037] According to the measured dimensional relationship, the actual distance between the machine tool rotation center O and the bottom surface is H1=A1+D1 / 2=1950.04:

[0038] The distance A2 from the lowest point of the minimum inner hole of the bearing seat 2 to the bottom surface in the original matching processing drawing is 500mm. According to the theoretical size relationship required by the bearing seat 2 drawing, the distance H2 from the mating surface to the bottom surface is H2=A2+D2 / 2=1950mm; the difference between H1 and H2 is not ≤0.02mm; loosen the pressure plate, and readjust the clamping position of the bearing seat 2, continue to test cut, re-measure A1, D1, H1, and the cutting amount of each test cut is 1-2mm. After three test cuts, inspections, and adjustments, the diameter D1 of the inner hole of the bearing seat 2 is 2897mm, and the distance A1 from the lowest point of the inner hole of the bearing seat 2 to the bottom surface is 501.51mm. The difference between H1 and H2 is 0.01, and the difference is ≤0.02mm. The rotation center O of the machine tool and the mating surface 22 of the bearing seat meet the coincidence requirements; press the bearing seat and fix the position;

[0039] S4: Keep the bearing seat 2 fixed, and re-turn the smallest inner hole of the bearing seat 2 to find a true circle. The diameter D3 is 2898mm, and it is sufficient to see the circle. The roughness requirement is Ra6.3. Query the machining dimension records of each inner hole of the bearing seat 2 in the other bearing seat in the original matching machining drawing. Rough and fine turn each inner hole of the bearing seat 2 according to the recorded values.

[0040] S5: Query the inner hole size D4 of the bearing seat 1 of the other bearing seat in the original matching processing drawing and the processing size record value of the distance from the lowest point of the inner hole to the bottom surface, adjust the position and height of the process measuring block 5 to be flush with the equal height position of the inner hole of the bearing seat 1, and after meeting the requirements for measuring the inner hole size of the bearing seat 1, process and measure the inner hole of the bearing seat 1; realize the control of dimensional accuracy when using vertical lathe to process a single bearing seat.

[0041] The parts not described in detail in this invention are prior art.

[0042] The embodiments selected herein for the purpose of disclosing the invention are presently considered suitable, but it should be understood that the invention is intended to include all variations and modifications of the embodiments that fall within the scope of the concept and invention.

Claims

1. A method for controlling the machining accuracy of a main bearing seat of a large mining mill, characterized by: The specific steps are: S1: Press the bearing seat flat on the milling machine, mill the bottom surface and the joint surface of the bearing seat respectively, and measure and record the actual size H2 from the joint surface to the bottom surface; S2: Symmetrically fix the process measuring block; query the minimum inner hole diameter D2 of the bearing seat in the original matching processing drawing, use the reserved amount smaller than D210-12mm as the diameter, and draw a circle line on the vertical lathe work table with the machine tool rotation center O as the center; Adjust the bearing seat onto the machine tool, align the smallest inner hole of the bearing seat with the lofted circle line, leaving a uniform gap of 1-2mm, and then use the table to align the bottom vertical workbench according to the processed bottom surface of the bearing seat. After passing the inspection, place the counterweight box at a 180° position opposite the bearing seat on the vertical lathe workbench according to the size and position of the inner hole of the bearing seat, and set the process measuring block on the counterweight box. The process measuring block should be flush with the inner hole of the bearing seat at the same height. The distance from the process measuring block to the center of rotation of the machine tool is S1 = D2 / 2-10mm, and the distance from the counterweight box to the center of rotation of the machine tool is S2 = D2 / 2+20mm; S3: Adjust the single-piece bearing seat; turn the smallest inner hole of the bearing seat to find the circle, with a cutting amount of 1-2mm. After the trial cutting, check and measure the measured value A1 of the distance from the lowest point of the inner hole of the bearing seat to the bottom surface and the measured value D1 of the diameter of the circle. According to the measured dimensional relationship, the actual distance H1 from the machine tool rotation center O to the bottom surface can be obtained: H1=A1+D1 / 2 According to the theoretical dimensional relationship required by the bearing seat drawing, the distance H2 from the joint surface to the bottom surface is: H2=A2+D2 / 2 When the difference between H1 and H2 is ≤0.02mm, it can be considered that the machine tool rotation center O passes through the joint surface and can meet the processing requirements; If the difference between H1 and H2 is not ≤ 0.02mm, adjust the workpiece according to the measured values ​​A1 and D1 of this trial cutting, loosen the pressure plate, and readjust the clamping position of the bearing seat. Continue trial cutting and re-measure A1, D1, and H1. The cutting amount of each trial cutting is 1-2mm. Through continuous trial cutting, inspection, and adjustment, the machine tool rotation center O can finally pass through the bearing seat joint surface. After the machine tool rotation center O passes through the joint surface, press the bearing seat and fix the position. S4: Keep the bearing seat fixed and re-turn the smallest inner hole of the bearing seat to find a perfect circle with a diameter of D3; query the machining dimension records of each inner hole of the bearing seat in the other bearing seat in the original matching machining drawing, and rough and fine turn each inner hole of the bearing seat according to the recorded values; S5: Query the bearing shell inner hole size D4 of the other bearing seat in the original matching processing drawing and the processing dimension record value of the distance from the lowest point of the inner hole to the bottom surface, adjust the position and height of the process measuring block to be flush with the height position of the bearing shell inner hole, and after meeting the requirements for measuring the bearing shell inner hole size, process and measure the bearing shell inner hole.

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