Technological method for machining multiple key grooves in outer circle of main shaft through milling die alignment

Abstract

The invention discloses a process method for machining multiple key grooves in the outer circle of a main shaft through alignment of a milling die and belongs to the technical field of hydro-generator manufacturing. The problems of low machining precision and long production period in the prior art are solved. According to the technical key points, alignment and error adjustment are carried out on a milling die, geometric accuracy is detected in an auxiliary mode through a laser tracker, two symmetrical key grooves in the 180-degree horizontal direction are machined through rough milling, semi-finish milling and finish milling correspondingly, a main shaft is rotated by 60 degrees anticlockwise after machining is completed, alignment is carried out again, the error is adjusted, and the rotation alignment process is repeated twice in total. The position precision and the size precision of the milling groove meet the design requirements, and the problem that main shaft outer circle multi-key-groove alignment machining cannot be achieved due to the limitation of the equipment manufacturing capacity is solved; the alignment time is saved, the machining efficiency is improved, and the production cycle is shortened; machining tasks can be completed as many as possible in one-time clamping, frequent tool changing, repositioning and other operations caused by equipment stroke limitation are avoided, and the machining process is more continuous and efficient.

Description

Technical Field

[0001] The invention relates to the technical field of hydro-generator manufacturing, in particular to a process method for machining multiple keyways on the outer circle of a main shaft by aligning a milling die. Background Art

[0002] When the main shaft of the hydro-generator is a single-shaft structure, an interference fit is used between the main shaft and the rotor support hub. For some units with high speed, small rotor diameter, and no rotor support, the torque is transmitted between the main shaft and the yoke through the key and interference fit between the main shaft and the yoke, which has the advantages of simple structure and easy adjustment of the unit axis.

[0003] However, strict machining requirements apply to the keyways on the main shaft and yoke. Dimensional deviations in the keyways directly impact the assembly quality of the main shaft and yoke, thus determining the safety and stability of the hydro-turbine generator set. To ensure proper alignment of the main shaft and yoke relative to the keyways and ensure assembly quality, the dimensions and geometric tolerances of each keyway on the main shaft must meet the requirements of the design drawings.

[0004] Therefore, the fixing method of the spindle and the method of aligning the keyway are the key. Due to the limitation of the processing capacity of the equipment, the keyway processing is prone to deviation.

[0005] However, keyway processing still has many limitations. The parts are large in size, and traditional milling requires multiple passes, resulting in a long single processing cycle; a large horizontal lathe or special machine tool is required, and the clamping process requires repeated alignment, which takes a long time; the tool wear is large in traditional processing, and precision control is difficult; the equipment cost is high, and the procurement and supporting costs are high; the requirements for operators are high; the equipment maintenance is complex and the maintenance cost is high.

[0006] Therefore, it is urgent to propose a process method for machining multiple keyways on the outer circle of the main spindle using a milling die to solve the problems of low machining accuracy and long production cycle in the existing technology. Summary of the Invention

[0007] In view of the above facts, in order to solve the problems of low machining accuracy and long production cycle in the prior art, the present invention further designs a process method for machining multiple keyways on the outer circle of the main spindle using a milling die for alignment.

[0008] To achieve the above object, the present invention adopts the following technical solutions:

[0009] A process for machining multiple keyways on the outer circle of a spindle by using a milling die alignment method, characterized in that it includes the following steps:

[0010] S1: The main shaft body, flange coupling hole and milling die are processed according to the drawing dimensions and qualified, and the keyway processing begins;

[0011] S2: Place the first V-shaped support groove and the second V-shaped support groove on the machine tool plane, place the spindle horizontally on the first V-shaped support groove and the second V-shaped support groove, and adjust the position and support height of the first V-shaped support groove and the second V-shaped support groove;

[0012] S3: Install the milling die on the flange end face of the spindle and fix it with all coupling holes. Use the product-side washers with stoppers to locate the coupling holes and bolts on the back of the flange. Align the milling die with the flange end face in the vertical direction. Align the stoppers of the milling die with the stoppers of the spindle. Use four evenly distributed inspection holes to check the alignment point position and ensure that the contact gap between the stoppers is uniform.

[0013] S4: Align the first alignment edge on the milling die so that the dial indicator value does not change by more than 0.01mm. Use a laser tracker to assist in detecting the geometric accuracy of the second and third alignment edges so that the error does not exceed ±0.01mm.

[0014] S5: After the alignment is qualified, use nuts, product side washers, bolts, and second washers to fix the milling die;

[0015] S6: Use a dial indicator to re-measure the first straightening edge, making sure that the dial indicator value does not change by more than 0.01mm;

[0016] S7: Fix the main shaft, the first V-shaped support groove, and the second V-shaped support groove with a first strap and a second strap;

[0017] S8: Six keyways are evenly distributed on the outer circle of the spindle body, and two symmetrical keyways in the 180° horizontal direction are processed by rough milling, semi-finishing milling, and finishing milling respectively;

[0018] S9: After the machining is completed, rotate the spindle 60° counterclockwise to align the third alignment edge so that the dial indicator value does not change by more than 0.01mm. After the alignment is qualified, perform rough milling, semi-finishing milling, and fine milling to process two symmetrical keyways in the 180° horizontal direction.

[0019] S10: After the machining is completed, rotate the spindle 60° counterclockwise to align the second alignment edge so that the dial indicator value does not change by more than 0.01mm. After the alignment is qualified, perform rough milling, semi-finishing milling, and fine milling to process two symmetrical keyways in the 180° horizontal direction.

[0020] S11: Complete all processing and inspect the finished product.

[0021] Further: In S2, the positions of the first V-shaped support groove and the second V-shaped support groove are adjusted so that they are close to the outer circle of the shaft body, the support heights of the first V-shaped support groove and the second V-shaped support groove are adjusted, and the numerical change of the upper end of the outer circle of the shaft body is checked with a dial indicator to ensure that it does not exceed 0.02 mm.

[0022] Furthermore: in said S8, the length of the keyway is 1610 mm and the width is 120 mm.

[0023] Furthermore: in said S8, the cutting depth of each rough milling is 3 mm, and the cutting width is 19 mm;

[0024] The cutting depth of each semi-finishing milling is 1.5 mm and the cutting width is 80 mm;

[0025] The cutting depth of each finishing milling is 0.3 mm.

[0026] Furthermore: when the two horizontally symmetrical keyways are rotated once, the distance from the upper end of the outer circle of the shaft body to the edge of the groove is equal to the distance from the lower end of the outer circle of the shaft body to the edge of the groove.

[0027] Furthermore: the dimension from the aligning edge on the milling die to the center of the milling die is the same as the width of the aligning edge.

[0028] Furthermore: in the above-mentioned S8-S10, when machining to the keyway root R20, a φ40 milling cutter is replaced, and machining transitions from R20 to R25, and R25 is machined to the drawing size in a programmable manner.

[0029] The beneficial effects of the present invention are:

[0030] 1. The present invention effectively reduces positioning errors, ensures that the position accuracy and dimensional accuracy of the milling groove meet the design requirements, and solves the problem of being unable to realize the alignment processing of multiple keyways on the outer circle of the spindle due to the limitation of equipment manufacturing capacity.

[0031] 2. The present invention can complete the alignment of 6 keyways by rotating the main shaft only twice, saving alignment time, improving processing efficiency and shortening production cycle.

[0032] 3. The present invention can complete as many processing tasks as possible in one clamping, avoiding frequent tool changes and repositioning operations caused by equipment travel limitations, making the processing process more continuous and efficient.

[0033] 4. The present invention can utilize existing equipment to complete the processing task, saving a lot of equipment transformation funds, and can also be extended to the processing needs of 4 keyways or 8 keyways. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 Schematic diagram of the process of the main shaft of the present invention;

[0035] Figure 2 This is a positional relationship diagram of the first aligning edge, the second aligning edge, and the third aligning edge of the present invention;

[0036] Figure 3 This is a positional relationship diagram of the six keyways of the present invention.

[0037] In the figure: 1-spindle, 2-keyway, 3-nut, 4-product side washer, 5-milling die, 6-bolt, 7-second washer, 8-first V-shaped support groove, 9-first binding strap, 10-second V-shaped support groove, 11-second binding strap, 14-first aligning edge, 15-detection hole, 16-stop contact surface, 17-second aligning edge, 18-third aligning edge. DETAILED DESCRIPTION

[0038] In order to enable those skilled in the art to better understand the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of this application.

[0039] The terms "disposed," "connected," and "fixed" should be interpreted broadly. For example, "connected" can mean a fixed connection, a removable connection, or an integral structure; it can be a mechanical connection, a direct connection, an indirect connection through an intermediary, or an internal communication between two devices, elements, or components. Those skilled in the art will understand the specific meanings of these terms in this application based on the specific circumstances.

[0040] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0041] Preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0042] Embodiment: A process for machining multiple keyways on the outer circle of a main spindle by using a milling die alignment method of this embodiment includes the following steps:

[0043] S1: The shaft body, flange coupling hole and milling die 5 of the main shaft 1 are processed and qualified according to the drawing dimensions, and the keyway 2 processing begins;

[0044] S2: Place the first V-shaped support groove 8 and the second V-shaped support groove 10 on the machine tool plane, place the spindle 1 horizontally on the first V-shaped support groove 8 and the second V-shaped support groove 10, and adjust the position and support height of the first V-shaped support groove 8 and the second V-shaped support groove 10;

[0045] S3: Install the milling die 5 on the flange end face of the main shaft 1 and fix it with all coupling holes. Use the product-side gasket 4 with a stopper to locate the coupling holes and bolts on the back of the flange. Align the milling die 5 with the vertical positive position of the flange end face. Align the stopper of the milling die 5 with the stopper of the main shaft 1. Use four evenly distributed detection holes 15 to check the alignment point position and ensure that the gap between the stopper contact surface 16 is uniform.

[0046] S4: Align the first aligning edge 14 on the milling die 5 so that the dial indicator value does not vary by more than 0.01 mm, and use a laser tracker to assist in detecting the geometric accuracy of the second aligning edge 17 and the third aligning edge 18 so that the error does not exceed ±0.01 mm;

[0047] S5: After the alignment is qualified, fix the milling die 5 with the nut 3, the product side washer 4, the bolt 6, and the second washer 7;

[0048] S6: Use a dial indicator to re-measure the first aligning edge 14, so that the change in the dial indicator value does not exceed 0.01mm;

[0049] S7: Use the first binding strap 9 and the second binding strap 11 to fix the spindle 1, the first V-shaped support groove 8, and the second V-shaped support groove 10 to prevent the spindle 1 from moving during the machining process;

[0050] S8: Six keyways 2 are evenly distributed on the outer circle of the spindle 1, and two symmetrical keyways 2 in the 180° horizontal direction are processed by rough milling, semi-finishing milling, and fine milling respectively;

[0051] S9: After the machining is completed, the spindle 1 is rotated 60° counterclockwise to align the third alignment edge 18 so that the dial indicator value does not change by more than 0.01mm. After the alignment is qualified, two symmetrical keyways 2 in the horizontal direction of 180° are processed by rough milling, semi-finishing milling, and fine milling respectively;

[0052] S10: After the machining is completed, the spindle 1 is rotated 60° counterclockwise to align the second alignment edge 17 so that the dial indicator value does not change by more than 0.01mm. After the alignment is qualified, two symmetrical keyways 2 in the horizontal direction of 180° are processed by rough milling, semi-finishing milling, and fine milling respectively;

[0053] S11: Complete all processing and inspect the finished product.

[0054] More specifically: In S2, the positions of the first V-shaped support groove 8 and the second V-shaped support groove 10 are adjusted so that they are close to the outer circle of the shaft body, the support heights of the first V-shaped support groove 8 and the second V-shaped support groove 10 are adjusted, and the numerical change of the upper end of the outer circle of the shaft body is checked with a dial indicator to ensure that it does not exceed 0.02 mm.

[0055] More specifically: in S8, the length of the keyway 2 is 1610 mm and the width is 120 mm.

[0056] More specifically: in said S8, the cutting depth of each rough milling is 3 mm, and the cutting width is 19 mm;

[0057] The cutting depth of each semi-finishing milling is 1.5 mm and the cutting width is 80 mm;

[0058] The cutting depth of each finishing milling is 0.3 mm.

[0059] More specifically: when the two horizontally symmetrical keyways 2 are rotated once, the distance from the upper end of the shaft outer circle to the edge of the groove is equal to the distance from the lower end of the shaft outer circle to the edge of the groove.

[0060] More specifically, the dimension from the alignment edge on the milling die 5 to the center of the milling die 5 is the same as the width of the alignment edge, which is beneficial to reducing the deviation when machining the keyway 2.

[0061] More specifically: in the above S8-S10, when machining to the root R20 of the keyway 2, the φ40 milling cutter is replaced, and the machining transitions from R20 to R25. The R25 is programmed to the drawing size, which is beneficial to ensure the root R20 and R25 sizes, ensure the transition needs when machining the keyway 2 to the root, and reduce the tool connection.

[0062] Finally, it should be noted that the above 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 with reference to the aforementioned embodiments, the technical solutions described in the aforementioned embodiments can still be modified, or some or all of the technical features therein can be replaced by equivalents. As long as there is no structural conflict, the various features in the specific implementation methods disclosed in this application can be combined with each other in any way, and the essence of the corresponding technical solutions will not deviate from the scope of the technical solutions of the present invention.

[0063] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A process for machining multiple keyways on the outer circle of a spindle using a milling die alignment method, characterized in that: The following steps are involved: S1: The shaft body, flange coupling hole and milling die (5) of the main shaft (1) are processed according to the drawing dimensions and qualified, and the keyway (2) processing begins; S2: placing a first V-shaped support groove (8) and a second V-shaped support groove (10) on the machine tool plane, placing the spindle (1) horizontally on the first V-shaped support groove (8) and the second V-shaped support groove (10), and adjusting the position and support height of the first V-shaped support groove (8) and the second V-shaped support groove (10); S3: Install the milling die (5) on the flange end face of the main shaft (1) and fix it with all the coupling holes. The coupling holes on the back of the flange and the bolts are positioned with the product side gasket (4) with the stopper. The milling die (5) is aligned with the vertical positive direction of the flange end face. The stopper of the milling die (5) is aligned with the stopper of the main shaft (1). The gap between the stopper contact surface (16) is uniform by detecting the alignment position through 4 evenly distributed detection holes (15). S4: Align the first alignment edge (14) on the milling die (5) so that the change in the dial indicator value does not exceed 0.01 mm, and use a laser tracker to assist in detecting the geometric accuracy of the second alignment edge (17) and the third alignment edge (18) so that the error does not exceed ±0.01 mm; S5: After the alignment is qualified, the milling die (5) is fixed with a nut (3), a product side washer (4), a bolt (6), and a second washer (7); S6: Use a dial indicator to re-measure the first aligning edge (14), so that the change in the dial indicator value does not exceed 0.01 mm; S7: Fix the main shaft (1), the first V-shaped support groove (8), and the second V-shaped support groove (10) with a first binding strap (9) and a second binding strap (11); S8: Six keyways (2) are evenly distributed on the outer circle of the spindle (1), and two symmetrical keyways (2) in the horizontal direction of 180° are processed by rough milling, semi-finishing milling and finishing milling respectively; S9: After the machining is completed, the spindle (1) is rotated 60° counterclockwise to align the third alignment edge (18) so that the dial indicator value does not change by more than 0.01 mm. After the alignment is qualified, two symmetrical keyways (2) are processed in the horizontal direction of 180° by rough milling, semi-finishing milling, and finishing milling respectively. S10: After the machining is completed, the spindle (1) is rotated 60° counterclockwise to align the second alignment edge (17) so that the dial indicator value does not change by more than 0.01 mm. After the alignment is qualified, two symmetrical keyways (2) are processed in the horizontal direction of 180° by rough milling, semi-finishing milling, and finishing milling respectively. S11: Complete all processing and inspect the finished product.

2. The process for machining multiple keyways on the outer circle of a main spindle by using a milling die alignment method according to claim 1, characterized in that: In the above-mentioned S2, the positions of the first V-shaped support groove (8) and the second V-shaped support groove (10) are adjusted so as to be close to the outer circle of the shaft body, the support heights of the first V-shaped support groove (8) and the second V-shaped support groove (10) are adjusted, and the numerical change of the upper end of the outer circle of the shaft body is checked with a dial indicator so as not to exceed 0.02 mm.

3. The process for machining multiple keyways on the outer circle of a main spindle by using a milling die alignment method according to claim 1, characterized in that: In the S8, the keyway (2) has a length of 1610 mm and a width of 120 mm.

4. The process for machining multiple keyways on the outer circle of a main spindle by using a milling die alignment method according to claim 1, characterized in that: In S8, the cutting depth of each rough milling is 3 mm and the cutting width is 19 mm; The cutting depth of each semi-finishing milling is 1.5 mm and the cutting width is 80 mm; The cutting depth of each finishing milling is 0.3 mm.

5. The process for machining multiple keyways on the outer circle of a main spindle by using a milling die alignment method according to claim 1, characterized in that: When the two horizontally symmetrical keyways (2) are machined by one rotation, the distance from the upper end of the shaft outer circle to the edge of the groove is equal to the distance from the lower end of the shaft outer circle to the edge of the groove.

6. The process for machining multiple keyways on the outer circle of a main spindle by using a milling die alignment method according to claim 1, characterized in that: The dimension from the alignment edge on the milling die (5) to the center of the milling die (5) is the same as the width dimension of the alignment edge.

7. The process for machining multiple keyways on the outer circle of a main spindle by using a milling die alignment method according to claim 1, characterized in that: In the above-mentioned S8-S10, when the keyway (2) root R20 is machined, a φ40 milling cutter is replaced, and the machining transitions from R20 to R25, and R25 is machined to the drawing size in a programmable manner.

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