Processing method of multi-layer annular plate type magnet yoke

Abstract

The invention discloses a processing method of a multilayer ring plate type magnet yoke, which comprises the following steps: processing two end ring plates and a middle ring plate, and preparing a positioning cushion block; one end annular plate is horizontally placed, the first end face of the end annular plate is punched upwards, then positioning cushion blocks are placed in the two counter bore punches correspondingly, and then the positioning cushion blocks are used for positioning so that the middle annular plates can be stacked on the end annular plate according to the designated position; lapping blocks are arranged on the periphery and are fixed; the other end annular plate is positioned by two positioning cushion blocks and stacked on the middle annular plate, and lapping blocks are arranged on the periphery and fixed; and the magnet yoke outer plane and the T-shaped groove which are connected into a whole are subjected to finish machining, and after finish machining, a tensioning screw rod penetrates into the T-shaped groove subjected to finish machining and is tightened by a hydraulic tensioner. The double-side positioning cushion blocks are adopted, and the relative position relation between the annular plates is effectively guaranteed; and meanwhile, the annular plates are connected into a whole in a spot welding and screw tensioning manner, so that the requirements of axial positioning and hoisting are met.

Description

Technical Field

[0001] The invention belongs to the technical field of rotor processing and manufacturing of a hydro-generator, and in particular relates to a processing method for a multi-layer ring plate type magnetic yoke. Background Art

[0002] The rotor yoke is an extremely critical component in the hydro-generator and an important part of the generator magnetic circuit. The inner diameter of the yoke is connected to the rotor bracket (or main shaft), and the outer diameter is connected to the magnetic pole. It is a structural component that fixes the magnetic pole. It plays an important role in the operation of the unit. The stability of its structure (meeting the normal, transitional and special operating requirements such as frequent starting, stopping, and operating condition conversion) is directly related to the safe and reliable operation of the unit. Therefore, the processing technology and quality of the yoke directly affect the operation of the entire unit.

[0003] The rotor yoke can be divided into a shrink-fit yoke and a floating yoke according to the matching form between the yoke and the rotor bracket (or spindle). According to the composition form, it can be divided into a laminated yoke, an integral solid yoke and a multi-layer ring plate yoke; the multi-layer ring plate yoke is composed of more than three layers of independent ring plates with T-slots of the same appearance. Each layer of ring plates is independent of each other and needs to be shrink-fitted with the spindle after processing, and the shape of each layer of ring plates, the size of each T-slot and the position must be consistent; the outer dimensions and inner diameter dimensions of each layer of ring plates are the same, and ventilation steel and positioning pads are provided between each layer of ring plates. One side of the positioning pad is sunk into the ring plate, which can prevent the pad from falling out during the operation of the unit and ensure the spacing between the ring plates. The inner diameter of the ring plate is an interference fit with the spindle, and the ring plate needs to be heated to complete the assembly.

[0004] The existing method for assembling the yoke ring plate is as follows:

[0005] Option 1:

[0006]

[0007] Option 2:

[0008]

[0009] Option 3:

[0010]

[0011] In the existing methods of assembling the yoke ring plate, there is a lack of circumferential positioning, so the position accuracy of each part cannot be unified. Therefore, solving the circumferential positioning of each layer of the yoke ring plate becomes the primary problem. If improvements are made based on Scheme 1 and Scheme 2, it is necessary to solve the positioning problem when multiple pieces are heat-fitted in sequence. Heat-fitting one piece at a time takes a relatively long time and has a greater impact on the temperature and dimensional changes of the workpiece after heating; if improvements are made based on Scheme 3, it is necessary to solve the problems of stacking positioning after rough processing and hoisting during overall heat-fitting. Summary of the invention

[0012] In view of the problems existing in the background technology, the present invention provides a method for processing a multi-layer ring plate type magnetic yoke, and the technical solution includes:

[0013] Step 1: Process two end ring plates and a middle ring plate and prepare positioning pads; wherein:

[0014] Processing of the middle ring plate includes: rough machining of the inner circle, outer shape and T-slot, while leaving a finishing allowance; finishing in the thickness direction according to the drawing requirements; machining of positioning countersinks;

[0015] The processing of the end ring plate includes: rough machining of the inner circle, outer shape and T-slot, leaving a finishing allowance; finishing the two end faces, and machining positioning countersinks on the first end face; the positions of the positioning countersinks correspond to the positioning pads on both sides;

[0016] Step 2, place an end ring plate horizontally, and punch the first end face of the end ring plate upwards, then place positioning pads in the two countersunk punches respectively, and then use the positioning pads to position the middle ring plate and stack it on the end ring plate at the specified position;

[0017] Set up blocks on the periphery and fix them by spot welding;

[0018] After fixing, the inner holes of the two ring plates are precisely turned according to the dimensions required by the drawing;

[0019] Step 3: Use two positioning pads to position the other end ring plate and stack it on the middle ring plate, set a stacking block on the outer periphery, and fix the stacking block by spot welding; take the inner hole of the lower middle ring plate as the reference, and finish turn the inner hole of the other end ring plate according to the size required by the drawing;

[0020] Step 4: Finish the outer plane and T-slot of the yoke that is connected as a whole. First, process the plane and T-slot without the overlap block. After finishing, insert the tensioning screw into the finished T-slot and tighten it with a hydraulic tensioner.

[0021] The positioning pads on both sides are arranged on the same radial line.

[0022] The matching clearance between the positioning pad and the positioning countersunk hole is 0.02-0.03mm.

[0023] After step 2, if there is more than one middle ring plate 2, proceed to step A:

[0024] Step A, using two positioning pads to position the additional middle ring plate and stack it on top of the middle ring plate; setting a stacking block on the periphery and fixing the stacking block by spot welding; using the inner hole of the lower middle ring plate as a reference, precision turning the inner hole of the additional middle ring plate;

[0025] Go to step 3.

[0026] Repeat step A, and the number of times step A is repeated is equal to the number of middle ring plates minus one.

[0027] The blocks provided at the periphery are two blocks provided on different radial lines.

[0028] Step 5: After finishing the surface and T-slots of all unwelded blocks and assembling the tensioning screws, remove all blocks and finish the remaining surface and T-slots; finally, heat-seal the yoke onto the spindle as a whole.

[0029] After step 5, the tensioning screw is removed after complete cooling.

[0030] The screw diameter and material, tensile force and elongation values ​​are determined by the total weight of the yoke.

[0031] The beneficial effects of the present invention are:

[0032] 1. The original single-sided positioning pads between the ring plates are changed to double-sided positioning pads with a clearance of 0.02-0.03mm, which effectively ensures the relative position relationship between the ring plates; thus, the problem of circumferential positioning can be solved without changing the original design.

[0033] 2. Use spot welding and tightening screws to connect the ring plates as a whole to meet the axial positioning and lifting requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 The present invention is a schematic flow chart of a method for processing a multi-layer ring plate type magnetic yoke according to an embodiment of the present invention.

[0035] Figure 2 Schematic diagram of the longitudinal structure of step 1 in an embodiment of the present invention;

[0036] Figure 3 It is a schematic diagram of a top view of the structure of an embodiment of the present invention;

[0037] Figure 4 Schematic diagram of the longitudinal section structure of step 2 in an embodiment of the present invention;

[0038] Figure 5 This is a schematic diagram of the longitudinal cross-section structure of step A in an embodiment of the present invention;

[0039] Figure 6 Schematic diagram of the longitudinal structure of step 3 in an embodiment of the present invention;

[0040] Figure 7 It is a schematic diagram of the longitudinal structure of step 4 in an embodiment of the present invention;

[0041] Figure 8 It is a schematic diagram of the longitudinal cross-section structure of step 5 in an embodiment of the present invention;

[0042] Among them, 1-end ring plate, 2-middle ring plate, 3-T-slot, 4-block, 5-positioning pad, 6-screw. DETAILED DESCRIPTION

[0043] The present invention is further described in detail below in conjunction with the accompanying drawings.

[0044] like Figure 1 The embodiment of the present invention shown includes:

[0045] Step 1: Process the middle ring plate 2 and the two end ring plates 1 and prepare positioning pads; wherein:

[0046] The processing of the middle ring plate 2 includes: rough machining of the inner circle, outer shape and T-slot 3, while leaving a finishing allowance; finishing in the thickness direction according to the requirements of the drawing; CNC machining of the positioning countersunk holes according to the actual outer diameter size and position of the positioning pads 5 on both sides, with a matching clearance of 0.02-0.03mm;

[0047] The processing of the end ring plate 1 includes: rough machining of the inner circle, outer shape and T-slot, leaving a finishing allowance; finishing the left and right end faces and the positioning countersunk holes corresponding to the double-sided positioning pads on the right end face, with a matching clearance of 0.02-0.03mm, and leaving a machining allowance on the left end as the outer end; in this embodiment, the double-sided positioning pads 5 are arranged on the same radial line.

[0048] In step 1, since the present embodiment takes a five-layer yoke ring plate structure as an example, there are three middle ring plates 2 in addition to the two end ring plates, and the three middle ring plates 2 are processed at the same time.

[0049] It should be noted here that when there are multiple middle ring plates in the rotor yoke that needs to be processed, the axial dimensions of each middle ring plate are different according to the drawings, but since the shapes of all the ring plates on the radial surface are consistent, their operation methods are consistent in the installation steps of the present invention, and are thus described using the same name (middle ring plate).

[0050] like Figure 2 and Figure 3 In step 2 shown, an end ring plate is placed horizontally, and the outer end face of the end ring plate is punched down and the positioning countersunk hole is punched up, and then positioning pads are placed in the two countersunk punches respectively, and then the middle ring plate is positioned at the specified position and stacked on top of the end ring plate with the positioning pads, and finally a step block 4 is set on the outer periphery and fixed with spot welding on the outer periphery of the step block; after fixing, the inner holes of the two ring plates are precision-turned according to the size required by the drawing.

[0051] After step 2, if there is more than one middle ring plate 2, proceed to step Figure 4In step A, two positioning pads are used to position the additional middle ring plate 2 and stack it on the middle ring plate 2; a stacking block is arranged on the periphery and fixed on the periphery of the stacking block by spot welding; the inner hole of the middle ring plate 2 below is used as a reference, and the inner hole of the middle ring plate 2 is precision-turned according to the size required by the drawing;

[0052] The number of operations of step A depends on the number of additional middle ring plates 2. Since there are two additional middle ring plates 2 in this embodiment (three middle ring plates 2 in total), step A is performed twice. Figure 5 Then proceed to step 3.

[0053] like Figure 6 In step 3 shown, the other end ring plate is positioned with two positioning pads and stacked on the middle ring plate 2, a step block is set on the outer periphery, and fixed with spot welding on the outer periphery of the step block; with the inner hole of the lower middle ring plate 2 as the reference, the inner hole of the other end ring plate is precision-turned according to the size required by the drawing.

[0054] In this embodiment, the blocks 4 are arranged on the outer circumference, and two blocks 4 are arranged on different radial lines.

[0055] like Figure 7 Step 4 shown is to fine-machine the outer plane and T-slot of the yoke connected as a whole. First, machine the plane and T-slot without the overlap block. After fine-machining, insert the tensioning screw 6 into the finely machined T-slot and tighten it with a hydraulic tensioner. Determine the screw diameter and material, tensile force and elongation value according to the total weight of the yoke.

[0056] Step 5: After finishing the surface and T-slots of all unwelded blocks and assembling the tensioning screws, remove all blocks and finish the remaining surface and T-slots; finally, heat-seal the yoke onto the spindle as a whole.

[0057] like Figure 8 As shown, remove the tensioning screw after it has completely cooled.

Claims

1. A method for processing a multi-layer ring plate type magnetic yoke, characterized in that: include: Step 1: Process two end ring plates and a middle ring plate and prepare positioning pads; wherein: Processing of the middle ring plate includes: rough machining of the inner circle, outer shape and T-slot, while leaving a finishing allowance; finishing in the thickness direction according to the drawing requirements; machining of positioning countersinks; The processing of the end ring plate includes: rough machining of the inner circle, outer shape and T-slot, leaving a finishing allowance; finishing the two end faces, and machining positioning countersinks on the first end face; the positions of the positioning countersinks correspond to the positioning pads on both sides; Step 2, place an end ring plate horizontally, and punch the first end face of the end ring plate upwards, then place positioning pads in the two countersunk punches respectively, and then use the positioning pads to position the middle ring plate and stack it on the end ring plate at the specified position; Set up blocks on the periphery and fix them by spot welding; After fixing, the inner holes of the two ring plates are precisely turned according to the dimensions required by the drawing; Step 3: Use two positioning pads to position the other end ring plate and stack it on the middle ring plate, set a stacking block on the outer periphery, and fix the stacking block by spot welding; take the inner hole of the lower middle ring plate as the reference, and finish turn the inner hole of the other end ring plate according to the size required by the drawing; Step 4: Finish the outer plane and T-slot of the yoke that is connected as a whole. First, process the plane and T-slot without the overlap block. After finishing, insert the tensioning screw into the finished T-slot and tighten it with a hydraulic tensioner.

2. A method for processing a multi-layer ring plate type magnetic yoke according to claim 1, characterized in that: The positioning pads on both sides are arranged on the same radial line.

3. A method for processing a multi-layer ring plate type magnetic yoke according to claim 1 or 2, characterized in that: The matching clearance between the positioning pad and the positioning countersunk hole is 0.02-0.03mm.

4. The method for processing a multi-layer ring plate type magnetic yoke according to claim 1, characterized in that: After step 2, if there is more than one middle ring plate 2, proceed to step A: Step A, using two positioning pads to position the additional middle ring plate and stack it on top of the middle ring plate; setting a stacking block on the periphery and fixing the stacking block by spot welding; using the inner hole of the lower middle ring plate as a reference, precision turning the inner hole of the additional middle ring plate; Go to step 3.

5. A method for processing a multi-layer ring plate type magnetic yoke according to claim 4, characterized in that: Repeat step A, and the number of times step A is repeated is equal to the number of middle ring plates minus one.

6. A method for processing a multi-layer ring plate type magnetic yoke according to claim 1, 4 or 5, characterized in that: The blocks provided at the periphery are two blocks provided on different radial lines.

7. The method for processing a multi-layer ring plate type magnetic yoke according to claim 1, characterized in that: Step 5: After finishing the surface and T-slots of all unwelded blocks and assembling the tensioning screws, remove all blocks and finish the remaining surface and T-slots; finally, heat-seal the yoke onto the spindle as a whole.

8. A method for processing a multi-layer ring plate type magnetic yoke according to claim 7, characterized in that: After step 5, the tensioning screw is removed after complete cooling.

9. A method for processing a multi-layer ring plate type magnetic yoke according to claim 1, 7 or 8, characterized in that: The screw diameter and material, tensile force and elongation values ​​are determined by the total weight of the yoke.

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