Machining method for annular thrust bearing of supercharger

Abstract

The invention discloses a machining method for an annular thrust bearing of a supercharger. The machining precision of the thrust bearing is higher. Comprising the following procedures: 10, roughly turning the outer circle and the end surface of the large end; 20, ultrasonic flaw detection; 30, roughly turning the outer circle and the end face of the small end and the large end of the inner hole; 40, the roughly turned outer circle of the large end serves as a positioning outer circle, the end face of the large end serves as a flat end face, the outer circle of the small end and the large end of the inner hole are subjected to semi-finish turning, a large end back annular groove is machined, and two steps are reserved in the large end of the inner hole; 50, the end face of the large end, the stepped hole and the outer circle of the part adjacent to the large end are subjected to semi-finish turning; 60, two steps in the inner hole and the end face of the inner hole are ground; 70, clamping is conducted, and the part machined in the 60 step is polished and deburred; 80, finish turning is conducted on external threads in the middle of the large end and an outer circle of the part adjacent to the large end face; 90, the end face of the large end is subjected to finish turning; 100, finish turning of the small end of the inner hole; 110 working procedure: clamping; 120, annealing is conducted; 130, inspection, wherein ultrasonic flaw detection is conducted.

Description

Technical Field

[0001] The invention relates to the technical field of ship turbochargers, and in particular to a method for processing a turbocharger annular thrust bearing. Background Art

[0002] VTC304 annular thrust bearing parts are the core parts of the supercharger bearing sleeve. Its main function is to cooperate with the bladed shaft and the compressor impeller to effectively convert the airflow with large kinetic energy from the impeller into pressure energy. Its quality directly affects the working efficiency of the whole machine and even affects the normal operation of the supercharger. At present, the annular thrust bearings used in the matching are all purchased as finished products. In order to realize the independent processing of the company's key parts and controllable manufacturing cycle, it is necessary to conduct independent processing and trial production of this part.

[0003] The inner holes of each gear of the annular thrust bearing are interference fit with the outer circle of the bladed shaft, and its large end face (alloy TOKAT50 end face) is tightly matched with the end face of the sliding bearing. A good fit must be ensured to ensure the precise operation of the supercharger. Therefore, the dimensional accuracy and form and position tolerance requirements of the inner holes and large end faces of each gear of the annular thrust bearing are relatively high, especially the flatness and parallelism of the large end face. Therefore, it is particularly important to ensure the accuracy and quality of the annular thrust bearing by using existing machine tools and tooling during the processing. Summary of the invention

[0004] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a method for machining a supercharger annular thrust bearing, so that the machining accuracy of the thrust bearing is higher.

[0005] The object of the present invention is achieved in that:

[0006] A method for processing a supercharger annular thrust bearing, the processing method comprising the following steps:

[0007] 10th process: rough turning the outer circle and end face of the big end;

[0008] 20 process: ultrasonic flaw detection;

[0009] 30th process: rough turning the outer circle and end face of the small end, and the large end of the inner hole;

[0010] Process 40: Use the outer circle of the large end after rough turning as the positioning outer circle, the end face of the large end as the flat end face, semi-finish turning the outer circle of the small end and the large end of the inner hole, and process the annular groove on the back of the large end, leaving two steps in the large end of the inner hole;

[0011] Process 50: semi-finishing turning of the end face of the big end, the stepped hole, and the outer circle of the part adjacent to the big end;

[0012] Step 60: Grinding the two steps in the inner hole and the end face of the inner hole;

[0013] Process 70: Pliers, polishing and deburring the parts processed in process 60;

[0014] Process 80: Finish turning the external thread in the middle of the big end and the outer circle of the part adjacent to the big end face;

[0015] 90 process: fine turning of the large end face;

[0016] 100 process: fine turning of the small end of the inner hole;

[0017] 110 process: clamp;

[0018] 120 process: annealing;

[0019] 130 Inspection: Ultrasonic flaw detection.

[0020] Preferably, in step 80, a three-needle method is used to detect the large-end external thread.

[0021] Preferably, the thrust bearing comprises an annular thrust bearing body, the material of the annular thrust bearing body is 42CrMoA, and the large end of the thrust bearing body is sintered with TOKAT50 material.

[0022] Preferably, in process 60, a first tool is used for clamping, and the first tool includes a first base. A first positioning hole is provided in the middle of the first base, and the first positioning hole is used for the large end of the thrust bearing to be embedded and positioned. The first base is equipped with a first bolt, and a first L-shaped pressure plate is sleeved on the first bolt. The vertical section of the first L-shaped pressure plate is supported on the first base, and the flat section end of the first L-shaped pressure plate is pressed on the step surface on the back of the large end of the thrust bearing for positioning.

[0023] Preferably, in process 80, a second tool is used for clamping, and the second tool includes a second base, a positioning ring, a pressure ring, and a centering bolt. A second positioning hole is provided in the middle of the second base, and the lower end of the positioning ring is embedded in the second positioning hole for positioning. The upper end of the positioning ring is used to fit and position with the step surface on the back of the large end of the thrust bearing, and the pressure ring is used to press on the large end surface of the thrust bearing for positioning. The nut of the centering bolt cooperates with the pressure ring to limit the position, and the screw of the centering bolt passes through the pressure ring, the positioning ring and the second base and is threadedly connected. The second base is equipped with a second bolt, and the second bolt is sleeved with a second L-shaped pressure plate. The vertical section of the second L-shaped pressure plate is supported on the second base, and the flat section end of the second L-shaped pressure plate is pressed on the step surface of the large end of the thrust bearing for positioning.

[0024] How to use: First put on the second L-shaped pressure plate, and do not assemble the pressure ring yet. Then use a dial indicator to measure the runout of the large end face of the part to ensure that the part has been assembled in place and the tooling has not loosened during the assembly process. Then put the pressure ring on the large end face of the part and press it tightly. After the pressure ring is tightened, remove the second L-shaped pressure plate and process the thread on the outer circle.

[0025] Preferably, in process 90, a third tooling is used for clamping, and the third tooling includes a third base and a cylindrical pressure plate. The third base is in a convex shape, and a third positioning hole is provided in the middle of the top surface of the third base. The outer cylindrical surface and the inner hole of the pressure plate are both stepped, and the third positioning hole is used for the small end of the pressure plate to be embedded and positioned. The small end of the third base is used to be sleeved with the inner hole of the thrust bearing, and the edge portion of the top surface of the third base is used to fit and position with the inner hole end surface of the thrust bearing. The large end step surface of the pressure plate is used to fit and position with the large end step surface of the thrust bearing. The large end of the pressure plate is immersed in the large end step surface of the thrust bearing, and an axial positioning screw is provided in the pressure plate. The nut of the axial positioning screw cooperates with the inner hole end surface of the pressure plate to limit the position, and the screw of the axial positioning screw cooperates with the thread of the third base.

[0026] Preferably, a through hole is provided in the large end surface of the pressure plate along the axial direction, the through hole corresponds to the top surface of the third base and is offset from the thrust bearing, and the through hole can be used to insert a probe of a micrometer depth micrometer to directly detect the corresponding size.

[0027] Preferably, it also includes a detection base, which is in the shape of a stepped cylinder. The parallelism of the two end faces of the detection base is within 0.002. The small end of the detection base is used for positioning with the inner hole of the thrust bearing, and the large end of the detection base is used for placing on the detection platform. The parallelism of the large end face of the thrust bearing and the small end face of the detection base is detected by a micrometer.

[0028] Due to the adoption of the above technical solution, the present invention has the following beneficial effects:

[0029] (1) In the 40th step of the process, the datum A is processed in advance, and the runout between the positioning outer circle and the flat end face and the datum A is ensured to be no greater than 0.01; in the 50th step, the outer circle is aligned again to ensure that the runout between the datum A and the large end positioning outer circle and the end face is no greater than 0.02, and the processing datum originally for the inner hole is transferred to the outer circle to facilitate subsequent processing and tooling positioning.

[0030] (2) In order to avoid the problems of clamping deformation and cumbersome processing operations, while ensuring its processing accuracy and quality and improving processing efficiency, three toolings were designed for the 60, 80, and 90 processes respectively.

[0031] (3) The three-needle method was used to detect the external thread. By borrowing a suitable measuring needle in the factory, the detection data of the M98×2 external thread and the measuring needle were calculated, and the M98×2 external thread was processed in cooperation with the operator.

[0032] (4) The process solves the processing and inspection problems of the 90 process from four aspects: 1. Select the CNC lathe QT250L with high processing accuracy. This equipment is stable and has high precision. Then select the alloy blade with high hardness and sharp blade, so that the flatness of the processed part reaches 0.002 and the roughness reaches Ra0.23, which is far lower than the flatness of 0.005 and Ra0.8 required by the drawing, laying the foundation for ensuring the parallelism of 0.005. 2. Design a special tooling, install the tooling base on the equipment, polish the fitting surface after alignment, and then align it with the reference C of the 90 process of the part, and process the TOKAT50 end face of the alloy of the part after pressing it with a pressure plate. This processing can better ensure the parallelism of the part reference C and the processing surface. The final parallelism reaches about 0.004, meeting the 0.005 requirement of the drawing. At the same time, the tooling is conducive to batch processing, without repeated alignment, and reduces the clamping cycle of the part. 3. A φ4 through hole is designed on the large end surface of the pressure plate, into which the probe of the micrometer depth micrometer can be placed, so that the size can be directly detected without removing the parts from the tooling. If the dimension is not in place, the end face can be directly re-processed through program compensation to ensure processing accuracy and avoid errors caused by repeated clamping. 4. Design a detection base with a detection parallelism of 0.005. In order to avoid the parallelism of the detection base itself having too much influence on the detection results of the parts, the parallelism of both ends of the detection base needs to be controlled within 0.002. In the actual site, through surface grinding → grinding → detection → surface grinding → grinding → detection, repeated processing and detection in this way, finally the parallelism of the two end faces of the tooling is controlled at about 0.001 to ensure its optimal detection accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is the assembly drawing;

[0034] Figure 2 It is a partial assembly drawing;

[0035] Figure 3 This is the machining diagram of the annular thrust bearing;

[0036] Figure 4 This is the rough drawing of the annular thrust bearing;

[0037] Figure 5 It is a schematic diagram of process 40;

[0038] Figure 6 It is a schematic diagram of the process 50;

[0039] Figure 7 It is a schematic diagram of process 60;

[0040] In the figure, 1 is the first base, 3 is the first bolt, 4 is the washer, and 5 is the first L-shaped pressure plate.

[0041] Figure 8 It is a schematic diagram of process 90;

[0042] Fig. 9 This is a schematic diagram of the tooling for process 60;

[0043] Fig.10 This is the schematic diagram of the tooling for process 80;

[0044] In the figure, 1 is a positioning ring, 2 is a pressure ring, 3 and 5 are washers, 4 is a centering bolt, 6 is a second bolt, 7 is a second L-shaped pressure plate, 8 is a second base, and 9 is a fixing bolt of the positioning ring (the positioning ring is replaced according to different thrust bearings).

[0045] Fig.11 This is the schematic diagram of the 90-process tooling;

[0046] In the figure, 1 is the third base, 2 is the axial positioning screw, and 3 is the pressure plate.

[0047] Fig.12 It is the tooling press plate for 90 processes;

[0048] Fig.13 Test tooling for 90 processes;

[0049] Fig.14 10 is a schematic diagram of the process;

[0050] Fig.15 It is a schematic diagram of process 30;

[0051] Fig.16 It is a schematic diagram of process 80;

[0052] Fig.17 It is a schematic diagram of 100 processes;

[0053] Fig.18 This is a schematic diagram of the micrometer detection.

[0054] The bold part is the processed surface. DETAILED DESCRIPTION

[0055] Description of parts and assembly relationships

[0056] (1) The supercharger is composed of a main shaft, a pressure end bearing, a bearing shell and other components. The annular thrust bearing to be introduced in this patent is the core component of the supercharger and one of the key parts. The assembly relationship of the supercharger parts is as follows: Figure 1 , 2 As shown, the processing diagram of the annular thrust bearing is shown in Figure 3 .

[0057] (2) The large end face of the annular thrust bearing is an alloy TOKAT50 end face, which is currently combined with the body by melting and sintering (see Figure 4, where 1 refers to the annular thrust bearing body, the material is 42CrMoA, and 2 refers to the TOKAT50 end face, the thickness is 2.5).

[0058] Process route determination and trial production process

[0059] After analysis and sorting, a process plan was formulated. In order to verify the feasibility of the plan, a small batch trial production experiment was carried out. The final processing route is as follows: Through the analysis of the drawings and the discussion of key difficulties, the following process route is formed, leading out the blank of TOKAT50 that has been poured → 10 rough turning → 20 flaw detection → 30 semi-finishing turning → 40 finishing turning → 50 semi-finishing turning → 60 grinding → 70 polishing → 80 finishing turning → 90 finishing turning (key process) → 100 finishing turning → 110 clamping → 120 heat treatment → 130 inspection → 140 clamping. (For the specific content of the processing technology, please refer to the process data)

[0060] First, take out the sintered TOKAT50 alloy blank, and the specific processing process is as follows:

[0061] →10th process: Rough turning of the outer circle and end surface;

[0062] →20th process: Ultrasonic flaw detection to detect internal defects, inclusions and pores;

[0063] →30 process: Rough turning of the outer circle and end face of the small end;

[0064] →40 process: semi-finishing the outer circle and inner hole of the small end, ensuring the runout of 0.01, for positioning and alignment of subsequent processing (see Figure 5 );

[0065] →50 process: Lathe semi-finishing step hole and positioning circle for subsequent processing positioning and alignment (see Figure 6 );

[0066] →60 process: fine grinding of holes ф49.8+0.003-0.013, ф50+0.003-0.013 and inner hole end faces, ensuring runout 0.01 and verticality 0.01 (see Figure 7 );

[0067] →70 process: pliers, polish and deburr the holes in 60 process;

[0068] →80 process: finishing turning M98X2 thread and ф95 outer circle;

[0069] →90 process: Fine turning of TOKAT50 alloy end face, ensuring roughness Ra0.8, parallelism 0.005 and flatness 0.005, (see Figure 8 );

[0070] →100 process: finishing inner hole;

[0071] →110 process: deburring;

[0072] →120 process: annealing treatment;

[0073] →130 Inspection: Ultrasonic flaw detection to detect internal defects, inclusions and pores;

[0074] There are 13 processes in total.

[0075] Processing difficulties:

[0076] Through follow-up research on on-site trial processing, it was found that the processing difficulties of VTC304 annular thrust bearings are mainly in the following aspects:

[0077] (1) The inner hole size requirements of the VTC304 annular thrust bearing 60 process are high, and it is also the processing reference. In addition, the outer circle and end face of each gear of the part are related to this reference, which cannot be guaranteed in one process, making the processing difficult.

[0078] (2) In the finishing process of processes 60, 80, and 90, since the large end of the part has an annular groove and an external thread, if three-jaw clamping is used, problems such as clamping deformation, large alignment error, error accumulation, and cumbersome operation may occur.

[0079] (3) In the process of machining the M98×2 external thread on the large outer circle of the annular thrust bearing in step 80, since this machining test is the first machining and there is a lack of thread ring gauges that can directly detect it, it is necessary to provide another method that can stably detect it.

[0080] (4) 90 process precision turning TOKAT50 alloy end face, the end face must not only ensure the roughness Ra0.8 and flatness 0.005, but also ensure the parallelism with the reference C 0.005. Since it cannot be processed in the same process as the reference C, the processing difficulty is very large. The parallelism 0.005 detection method is also particularly important.

[0081] After analyzing and solving the above processing difficulties, a reliable and stable manufacturing method for annular thrust bearings was found. The specific contents are as follows (the following serial numbers correspond to the above processing difficulties):

[0082] (1) In the 40th step of the process, the datum A is processed in advance, and the runout between the positioning outer circle and the flat end face and the datum A is ensured to be no greater than 0.01; in the 50th step, the outer circle is aligned again to ensure that the runout between the datum A and the large end positioning outer circle and the end face is no greater than 0.02, and the processing datum originally for the inner hole is transferred to the outer circle to facilitate subsequent processing and tooling positioning.

[0083] (2) In order to avoid the problem of clamping deformation and cumbersome processing operation, and to ensure the processing accuracy and quality and improve the processing efficiency, three toolings were designed for the 60, 80, and 90 processes, respectively. Fig. 9 , Fig.10 , Fig.11 .

[0084] (3) The three-needle method was used to detect the external thread. By borrowing a suitable measuring needle in the factory, the detection data of the M98×2 external thread and the measuring needle were calculated, and the M98×2 external thread was processed in cooperation with the operator.

[0085] (4) The process solves the processing and testing problems of 90 processes from four aspects:

[0086] 1. Select the CNC lathe QT250L with high processing precision. This equipment is stable and has high precision. Then select the alloy blade with high hardness and sharp blade to make the flatness of the machined part reach 0.002 and the roughness reach Ra0.23, which is much lower than the flatness of 0.005 and Ra0.8 required by the drawing, laying the foundation for ensuring the parallelism of 0.005.

[0087] 2. Design special tooling (see Fig.11 ), install the tooling base on the equipment, align it and polish the fitting surface, then align it with the reference C of the part 90 process, and pass the pressing plate (see Fig.12 ) After clamping, the TOKAT50 end face of the part alloy is processed. This processing can better ensure the parallelism between the part reference C and the processing surface. The final parallelism reaches about 0.004, meeting the requirement of 0.005 in the drawing. At the same time, this tooling is conducive to batch processing, without repeated alignment, and reduces the clamping cycle of the parts.

[0088] 3. On the pressing plate (see Fig.12 ) A φ4 through hole is designed on the large end surface, into which the probe of the micrometer depth micrometer can be placed, so that the size can be directly detected without removing the part from the tooling If the dimension is not achieved, the end face can be directly re-processed through program compensation to ensure processing accuracy and avoid errors caused by repeated clamping.

[0089] 4. Design a test base with a parallelism of 0.005 (see Fig.13 ), in order to avoid the parallelism of the detection base itself interfering with the detection results of the parts, the parallelism of the two ends of the detection base needs to be controlled within 0.002.

[0090] Test instructions: Assemble the part and the test base as shown below, then place it on the test platform, and use a micrometer to test the parallelism of the large end face of the part with reference C to 0.005. The parallelism of the two end faces of the test base itself must be controlled within 0.002 (preferably 0.001) to avoid excessive influence of the parallelism of the test base itself on the test results of the part, which can be reduced but not avoided.

[0091] In the actual site, the process of surface grinding → grinding → testing → surface grinding → grinding → testing is repeated, and finally the parallelism of the two end surfaces of the tooling is controlled at about 0.001 to ensure its optimal detection accuracy.

[0092] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made in form and details without departing from the scope defined by the claims of the present invention.

Claims

1. A method for processing a supercharger annular thrust bearing, characterized in that: The processing method includes the following steps: 10th process: rough turning the outer circle and end face of the big end; 20 process: ultrasonic flaw detection; 30th process: rough turning the outer circle and end face of the small end, and the large end of the inner hole; Process 40: Use the outer circle of the large end after rough turning as the positioning outer circle, the end face of the large end as the flat end face, semi-finish turning the outer circle of the small end and the large end of the inner hole, and process the annular groove on the back of the large end, leaving two steps in the large end of the inner hole; Process 50: semi-finishing turning of the end face of the big end, the stepped hole, and the outer circle of the part adjacent to the big end; Step 60: Grinding the two steps in the inner hole and the end face of the inner hole; Process 70: Pliers, polishing and deburring the parts processed in process 60; Process 80: Finish turning the external thread in the middle of the big end and the outer circle of the part adjacent to the big end face; 90 process: fine turning of the large end face; 100 process: fine turning of the small end of the inner hole; 110 process: clamp; 120 process: annealing; 130 Inspection: Ultrasonic flaw detection.

2. The method for processing a supercharger annular thrust bearing according to claim 1, characterized in that: In process 80, the three-needle method is used to detect the large-end external thread.

3. The method for processing a supercharger annular thrust bearing according to claim 1, characterized in that: The thrust bearing comprises an annular thrust bearing body, the material of the annular thrust bearing body is 42CrMoA, and the large end of the thrust bearing body is sintered with TOKAT50 material.

4. The method for processing a supercharger annular thrust bearing according to claim 1, characterized in that: In process 60, a first tool is used for clamping, and the first tool includes a first base. A first positioning hole is provided in the middle of the first base, and the first positioning hole is used for the large end of the thrust bearing to be embedded and positioned. The first base is equipped with a first bolt, and a first L-shaped pressure plate is sleeved on the first bolt. The vertical section of the first L-shaped pressure plate is supported on the first base, and the flat section end of the first L-shaped pressure plate is pressed on the step surface on the back of the large end of the thrust bearing for positioning.

5. The method for processing a supercharger annular thrust bearing according to claim 1, characterized in that: In process 80, a second tool is used for clamping. The second tool includes a second base, a positioning ring, a pressure ring, and a centering bolt. A second positioning hole is provided in the middle of the second base. The second positioning hole is used for the lower end of the positioning ring to be embedded and positioned. The upper end of the positioning ring is used to fit and position with the step surface on the back of the large end of the thrust bearing. The pressure ring is used to press on the large end face of the thrust bearing for positioning. The nut of the centering bolt cooperates with the pressure ring to limit the position. The screw of the centering bolt passes through the pressure ring, the positioning ring, and is threadedly connected to the second base.

6. The method for processing a supercharger annular thrust bearing according to claim 1, characterized in that: In process 90, a third tooling is used for clamping. The third tooling includes a third base and a cylindrical pressure plate. The third base is in a convex shape. A third positioning hole is provided in the middle of the top surface of the third base. The outer cylindrical surface and the inner hole of the pressure plate are both stepped. The third positioning hole is used for the small end of the pressure plate to be embedded and positioned. The small end of the third base is used to be sleeved with the inner hole of the thrust bearing. The edge portion of the top surface of the third base is used to fit and position with the inner hole end surface of the thrust bearing. The large end step surface of the pressure plate is used to fit and position with the large end step surface of the thrust bearing. The large end of the pressure plate is immersed in the large end step surface of the thrust bearing. An axial positioning screw is provided in the pressure plate. The nut of the axial positioning screw cooperates with the inner hole end surface of the pressure plate to limit the position, and the screw of the axial positioning screw cooperates with the thread of the third base.

7. A method for processing a supercharger annular thrust bearing according to claim 6, characterized in that: A through hole is axially arranged on the large end face of the pressure plate, the through hole corresponds to the top face of the third base and is offset from the thrust bearing, and the probe of a micrometer depth micrometer can be placed in the through hole to directly detect the corresponding size.

8. The method for processing a supercharger annular thrust bearing according to claim 6, characterized in that: It also includes a detection base, which is in the shape of a stepped cylinder. The parallelism of the two end faces of the detection base is within 0.

002. The small end of the detection base is used for positioning with the inner hole of the thrust bearing, and the large end of the detection base is used for being placed on the detection platform. The parallelism of the large end face of the thrust bearing and the small end face of the detection base is detected by a micrometer.

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