A processing method for the floating ring of the main bearing of a roadheader

Abstract

The present invention provides a processing method for the floating ring of a roadheader main bearing, belonging to the technical field of roadheader main bearing processing; it includes: rough turning the floating ring forging; heat treating the floating ring after rough turning; performing the first finish turning on the floating ring after low-temperature tempering treatment; performing vibration aging treatment on the floating ring; performing the second finish turning; after the floating ring is finished with finish turning, correcting the elliptical deformation of the floating ring by means of thermal correction; performing finish grinding on the floating ring after the second finish turning to complete the processing of the floating ring. The main inventive point of the present invention lies in that during the heat treatment process, the quenching coupling gap and quenching parameters are strictly controlled to balance the quenching internal stress on both end faces of the floating ring; during the machining process, it is proposed to release the machining internal stress of the floating ring by means of vibration aging, effectively reducing the deformation during the machining process; aiming at the problem of radial elliptical deformation of the floating ring, a correction method of applying thermal stress is proposed for control.

Description

Technical Field

[0001] The invention belongs to the technical field of the processing of the main bearing of a roadheader, and relates to a processing method for a floating ring of the main bearing of a roadheader. Background Art

[0002] The main bearing of a roadheader is a core component of the roadheader, mainly composed of an inner / outer ring, a floating ring, and a gear ring. The floating ring is the most important component in the main bearing, and the two end faces need to be quenched. The depth of the hardened layer is required to be more than 7 mm, and the hardness is required to be more than 58 HRC, so the processing and manufacturing are difficult. The processing of the floating ring needs to go through processes such as rough turning, quenching, finish turning, and grinding. The larger the diameter, the more difficult it is to control the accuracy, and the greater the processing and manufacturing difficulty. The main problems in the processing and manufacturing process of the floating ring are the large warping deformation of the end face after quenching, the large elliptical deformation in the radial direction, and the large warping deformation caused by the stress release during the processing. Excessive warping deformation after quenching will make it difficult to guarantee the flatness accuracy and the uniformity of the depth of the hardened layer on the plane. After ensuring the flatness accuracy, the depth of the hardened layer may not meet the requirements. If the depth of the hardened layer is increased, the risks of quenching deformation and quenching cracking will also increase correspondingly, and the processing difficulty will be greater. The large elliptical deformation after quenching will result in no machining allowance for the inner and outer diameters and difficult assembly. The large warping deformation caused by the stress release during the processing will make it impossible to guarantee the flatness accuracy, the workpiece thickness, and the depth of the hardened layer, resulting in the scrapping of the workpiece. Summary of the Invention

[0003] In order to effectively release the quenching internal stress of the floating ring of the main bearing of a roadheader and control the processing accuracy, the invention provides a method for controlling the processing deformation of the floating ring of the main bearing of a roadheader.

[0004] The invention provides a processing method for a floating ring of the main bearing of a roadheader, comprising the following steps:

[0005] Step 1: Rough turn the floating ring forging;

[0006] Step 2: Heat-treat the floating ring after rough turning; the specific process is as follows:

[0007] S2.1: Place the floating ring after rough turning between a first quenching inductor and a second quenching inductor that are arranged at intervals in the vertical direction, and set a gap a between the first quenching inductor and the upper end face of the floating ring and between the second quenching inductor and the lower end face of the floating ring;

[0008] S2.2: Heat the first quenching inductor and the second quenching inductor respectively, and control the heating temperature to 800°C - 900°C to perform surface quenching treatment on the floating ring after rough turning;

[0009] S2.3: Perform low-temperature tempering treatment on the floating ring after quenching treatment within 4 hours after the quenching is completed;

[0010] Step 3: Perform the first precision turning on the floating ring after low-temperature tempering treatment to remove 0.5 mm of allowance from both the upper and lower end faces of the floating ring, and control the machining allowance for the inner and outer diameters of the floating ring within 1 mm.

[0011] Step 4: Evenly pad elastic materials between the floating ring after the first precision turning and the high-support of the machine tool used for precision turning the floating ring, and perform vibration aging treatment on the floating ring.

[0012] Step 5: Perform the second precision turning on the floating ring after vibration aging treatment.

[0013] Step 6: After the floating ring is completed with precision turning, correct the elliptical deformation of the floating ring by means of thermal correction.

[0014] Step 7: Perform precision grinding on the floating ring after the second precision turning to complete the processing of the floating ring.

[0015] Furthermore, after rough turning the floating ring forging, control the dimensional tolerance of the rough turning thickness of the floating ring within 0.3 mm.

[0016] Furthermore, the setting method of the gap a is as follows:

[0017] Let the thickness of the floating ring after rough turning be h, and the opening width of the quenching inductor be d, then a = (d - h) / 2.

[0018] Furthermore, after quenching the upper and lower end faces of the floating ring after rough turning, control the radial warpage deformation of the floating ring after quenching within 0.5 mm and control the whole-circle runout error of the floating ring after quenching within 0.3 mm.

[0019] Furthermore, when performing low-temperature tempering treatment on the floating ring after quenching treatment, control the tempering temperature at 150°C - 180°C, the tempering time at 5 hours - 6 hours, and the heating rate at 20°C / hour - 25°C / hour.

[0020] Furthermore, when performing vibration aging treatment on the floating ring after the first precision turning, its parameter settings are as follows: the vibration frequency uses the resonance frequency, and the vibration time is set at 15 min - 20 min.

[0021] Furthermore, after performing the second precision turning on the floating ring after vibration aging treatment, control the deformation amount of the floating ring within 0.2 mm.

[0022] Furthermore, the correction process parameters are: heating temperature 250°C - 350°C, heating time 3 - 6 s, coupling gap 2 - 3 mm, no cooling.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] (1) Combining the previous data and experience summary, the present invention proposes a processing method for the floating ring of the main bearing of a roadheader. The main inventive point lies in strictly controlling the quenching coupling gap and quenching parameters during the heat treatment process to balance the quenching internal stress on both end faces of the floating ring; during the machining process, it is proposed to use vibration aging to release the machining internal stress of the floating ring, effectively reducing the deformation during the machining process; aiming at the problem of radial elliptical deformation of the floating ring, a correction method of applying thermal stress is proposed for control.

[0025] (2) By strictly controlling the thickness dimension tolerance of the floating ring forging during rough turning, the present invention can effectively ensure the gap between the floating ring and the quenching induction device, thereby balancing the internal stress on both end faces during quenching, effectively adjusting the hardness and strength of the floating ring, and improving the deformation of the floating ring after quenching.

[0026] (3) In order to eliminate the influence of the release of internal stress during the machining process on the size and precision of the floating ring, mechanical aging stress relief is used during the machining process to release the internal stress inside the floating ring, thereby achieving the purpose of controlling the dimensional and precision stability of the workpiece.

[0027] (4) In order to eliminate the ellipse during the machining process, after the workpiece is finish-turned, a thermal correction method is used to correct the elliptical deformation of the workpiece. A special correction inductor is used on the quenching machine tool to heat the corresponding position of the inner diameter, applying thermal stress to the workpiece to achieve the purpose of correcting the elliptical deformation of the workpiece.

[0028] In addition to the purposes, features and advantages described above, the present invention has other purposes, features and advantages. The present invention will be further described in detail below with reference to the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The drawings constituting a part of this application are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0030] Figure 1 is a schematic diagram after the quenching induction device and the floating ring are connected to each other in the embodiment of the present invention.

[0031] Wherein:

[0032] 1. First quenching inductor, 2. Floating ring, 3. Second quenching inductor. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0033] To make the above objects, features, and advantages of the present invention more clearly understandable, the following provides a detailed description of the specific embodiments of the present invention in conjunction with the accompanying drawings. It should be noted that the drawings of the present invention are all in simplified forms and use non-precise scales, only for conveniently and clearly assisting in the description of the embodiments of the present invention; the several mentioned in the present invention are not limited to the specific quantities in the drawing examples; the orientation or positional relationships indicated by 'front','middle', 'back', 'left', 'right', 'up', 'down', 'top', 'bottom','middle', etc. in the present invention are all based on the orientation or positional relationships shown in the drawings of the present invention, and do not indicate or imply that the devices or components referred to must have a specific orientation, nor can it be understood as a limitation to the present invention. Embodiment

[0034] A processing method for the floating ring of the main bearing of a roadheader provided by the present invention includes the following steps:

[0035] Step 1: Rough-turn the floating ring forging, and control the dimensional tolerance of the rough-turned thickness of the floating ring within 0.3 mm;

[0036] Step 2: Heat-treat the floating ring after rough turning; the specific process is as follows:

[0037] S2.1: Set the floating ring after rough turning and the quenching induction device in a clearance fit relative to each other; specifically, as shown in Figure 1 shown, a first quenching inductor 1 and a second quenching inductor 3 are respectively arranged at the upper end and the lower end of the floating ring after rough turning, and a clearance a is provided between the first quenching inductor 1 and the upper end face of the floating ring 2 and between the second quenching inductor 3 and the lower end face of the floating ring 2;

[0038] S2.2: Heat the first quenching inductor and the second quenching inductor respectively, and control the heating temperature at 800°C - 900°C to perform surface quenching treatment on the floating ring after rough turning, and ensure that the hardened layer depth and internal stress of the upper end face and the lower end face of the floating ring after quenching treatment are consistent, so as to balance the internal stress of the floating ring after quenching treatment;

[0039] S2.3: Within 4 hours after the quenching is completed, perform low-temperature tempering treatment on the floating ring after quenching treatment to relieve the internal stress generated by quenching, adjust the hardness and strength of the floating ring, and improve the machining performance of the floating ring;

[0040] Step 3: Perform the first finish turning treatment on the floating ring after low-temperature tempering treatment to remove 0.5 mm of allowance from both the upper end face and the lower end face of the floating ring, and control the machining allowance of the inner diameter and the outer diameter of the floating ring within 1 mm;

[0041] Step 4: Elastic materials (such as rubber, wooden pads, rigid springs, etc.) are evenly padded between the floating ring after the first precision turning and the high - support of the machine tool used for precision turning the floating ring, and the floating ring is subjected to vibration aging treatment;

[0042] Step 5: The floating ring after vibration aging treatment is subjected to a second precision turning to remove a margin of 0.2 mm - 0.5 mm from the upper end face, lower end face, inner diameter, and outer diameter of the floating ring, so as to achieve uniform removal of the machining allowance on the upper end face and lower end face of the floating ring, gradually release the quenching internal stress of the floating ring, and control the deformation of the floating ring within 0.2 mm;

[0043] Step 6: After the floating ring is completed with precision turning, the elliptical deformation of the floating ring is corrected by means of thermal correction. On the quenching machine tool, a special correction inductor is used to heat the corresponding position of the inner diameter, applying thermal stress to the floating ring to achieve the purpose of correcting the elliptical deformation of the floating ring; the correction process parameters are: heating temperature about 300 °C, heating time 3 - 6 s, coupling gap 2 - 3 mm, without cooling.

[0044] Step 7: The floating ring after the second precision turning is subjected to precision grinding to remove a margin of 0.1 - 0.3 mm from the upper end face, lower end face, inner diameter, and outer diameter of the floating ring, so as to achieve uniform removal of the machining allowance on the upper end face and lower end face of the floating ring, gradually release the quenching internal stress of the floating ring, and control the geometric tolerance of the floating ring within its design requirements, thus completing the machining of the floating ring.

[0045] Further, the setting rule of the gap a between the first quenching inductor and the upper end face of the floating ring and between the second quenching inductor and the lower end face of the floating ring is as follows:

[0046] Let the thickness of the floating ring after rough turning be h, and the opening width of the quenching inductor be d, then a = (d - h) / 2.

[0047] Further, the gap a between the first quenching inductor and the upper end face of the floating ring and between the second quenching inductor and the lower end face of the floating ring can also be specifically set to 1 - 1.5 mm. Through experiments, when the coupling gap < 1 mm, due to the deformation of the workpiece and the inductor during the machining process, there is a risk of short - circuit caused by the inductor contacting the workpiece; when the coupling gap > 1.5 mm, it is not conducive to the heating of the raceway, and there is a certain impact on the quenching hardness and hardened layer depth of the workpiece. Therefore, the coupling gap is controlled to 1 - 1.5 mm.

[0048] Further, after the quenching treatment of the upper end face and lower end face of the floating ring after rough turning, the radial warping deformation between the outer surface and the internal structure of the quenched floating ring is controlled within 0.5 mm, and the full - circle run - out error of the quenched floating ring is controlled within 0.3 mm.

[0049] Further, when performing low-temperature tempering on the floating ring after quenching treatment, the tempering temperature is controlled at 150°C - 180°C, the tempering time is controlled at 5 hours - 6 hours, and the heating rate is controlled at 20°C / hour - 25°C / hour. Preferably, a tempering furnace is used to perform low-temperature tempering on the floating ring after quenching treatment.

[0050] Further, when performing vibration aging treatment on the floating ring after the first precision turning, the parameter settings are as follows: the vibration frequency adopts the resonance frequency (determined according to the detection of the vibration aging instrument for workpieces of different sizes), the vibration time is 15 min - 20 min, and the dynamic stress is determined according to the detection of the vibration aging instrument.

[0051] Experimental example:

[0052] Table 1: Deformation conditions of the floating ring under different quenching conditions

[0053]

[0054] As shown in Table 1, the double-end face quenching method with strict control of the quenching inductor gap has a good effect on controlling the whole-circle runout and warping deformation of the workpiece.

[0055] Table 2: Residual stress conditions on the workpiece surface under different tempering process conditions

[0056]

[0057] In Table 2, the unit of residual stress is MPa, and the minus sign indicates that the surface residual stress is compressive stress. When the temperature is relatively low and the tempering time is relatively short, the elimination of the surface residual stress of the workpiece is not obvious; when the temperature is relatively high and the tempering time is relatively long, the elimination effect of the surface residual stress of the workpiece is better, but a relatively high temperature and a long time will have a certain impact on the hardness of the workpiece, and the processing cost is relatively high. Therefore, the tempering temperature of the workpiece is set at 150°C - 180°C, and the tempering time is controlled at 5 - 6 h to eliminate the residual stress of the workpiece and control the deformation of the workpiece while ensuring the hardness of the workpiece.

[0058] Table 3: Workpiece deformation control conditions under different vibration conditions

[0059]

[0060] As shown in Table 3, after adding vibration aging, the surface stress of the workpiece decreases, the deformation amount during the workpiece processing is relatively small, and it has a good effect on deformation control.

[0061] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A processing method for the floating ring of the main bearing of a roadheader, characterized in that, It includes the following steps: Step 1: Rough turning the floating ring forging; Step 2: Heat-treating the floating ring after rough turning; the specific process is as follows: S2.1: Place the floating ring after rough turning between a first quenching inductor and a second quenching inductor that are spaced apart vertically, and set a gap a between the first quenching inductor and the upper end face of the floating ring and between the second quenching inductor and the lower end face of the floating ring. The gap a is set to 1 - 1.5 mm; S2.2: Heat the first quenching inductor and the second quenching inductor respectively, and control the heating temperature to 800°C - 900°C to perform quenching treatment on the surface of the floating ring after rough turning; after quenching the upper end face and the lower end face of the floating ring after rough turning, control the radial warpage deformation of the floating ring after quenching within 0.5 mm and control the total runout error of the floating ring after quenching within 0.3 mm; S2.3: Within 4 hours after quenching is completed, perform low-temperature tempering treatment on the floating ring after quenching; when performing low-temperature tempering treatment on the floating ring after quenching, control the tempering temperature to 150°C - 180°C, the tempering time to 5 - 6 hours, and the heating rate to 20°C / hour - 25°C / hour; Step 3: Perform the first finish turning on the floating ring after low-temperature tempering treatment to remove 0.5 mm of allowance from both the upper end face and the lower end face of the floating ring, and control the machining allowance for the inner diameter and outer diameter of the floating ring within 1 mm; Step 4: Evenly pad elastic materials between the floating ring after the first finish turning and the equal-height support of the machine tool for finish turning the floating ring, and perform vibration aging treatment on the floating ring; Step 5: Perform the second finish turning on the floating ring after vibration aging treatment; Step 6: After the floating ring is finish turned, correct the elliptical deformation of the floating ring by means of thermal correction; Step 7: Perform fine grinding on the floating ring after the second finish turning to complete the machining of the floating ring.

2. The processing method of the floating ring of the main bearing of the roadheader according to claim 1, characterized in that After rough turning the floating ring forging, control the dimensional tolerance of the rough turning thickness of the floating ring within 0.3 mm.

3. The processing method of the floating ring of the main bearing of the roadheader according to claim 1 or 2, characterized in that, The setting method of the gap a is as follows: Let the thickness of the floating ring after rough turning be h, and the opening width of the quenching inductor be d, then a = (d - h) / 2.

4. The processing method of the floating ring of the main bearing of the roadheader according to claim 1, characterized in that, When performing vibration aging treatment on the floating ring after the first finish turning, its parameter settings are: the vibration frequency adopts the resonance frequency, and the vibration time is set to 15 min - 20 min.

5. The processing method of the floating ring of the main bearing of the roadheader according to claim 4, characterized in that, After performing the second finish turning on the floating ring after vibration aging treatment, control the deformation amount of the floating ring within 0.2 mm.

6. The processing method of the floating ring of the main bearing of a roadheader according to claim 5, wherein, The correction process parameters are: heating temperature 250°C - 350°C, heating time 3 - 6 s, coupling gap 2 - 3 mm, without cooling.

Images