Split type longitudinal tree type tenon tooth blade root diamond roller and design method thereof

Abstract

The invention discloses a split type longitudinal tree type tenon tooth blade root diamond roller which is simple in structure, capable of achieving multi-size blade root tooth profile machining, small in limitation and low in consumption cost when large machining sizes are changed. The diamond roller comprises an end face diamond roller body, an axial gasket and a blade root molded line diamond roller body, the thickness of a blade root is sequentially increased from front to back, the axial gasket is arranged between the end face diamond roller body and the blade root molded line diamond roller body and is annular, and the blade root molded line diamond roller body is sequentially sleeved with the axial gasket and the end face diamond roller body. The end face diamond roller, the axial gasket and the blade root molded line diamond roller are kept concentric on the same horizontal plane. Therefore, the invention further provides a design method of the split type longitudinal tree type tenon tooth blade root diamond roller, the blade root type diamond roller is designed according to a blade root median graph made by a blade root graph and a blade root tolerance graph, and the working face and the non-working face of the blade root diamond roller are correspondingly offset according to blade root tolerance. The working face and the non-working face are subjected to transition treatment.

Description

Technical Field

[0001] The invention relates to the technical field of steam turbine blade processing, and in particular to a split longitudinal tree-shaped tenon-tooth blade root diamond roller and a design method thereof. Background Art

[0002] Steam turbine blades are important components of steam turbines. They are directly involved in the process of converting the energy of high-temperature and high-pressure gas generated by the combustion of fuel and air into mechanical energy. In order to increase the versatility of products and reduce the cost of replacement and maintenance, most OEMs have made the longitudinal tree-shaped blade root profiles of many steam turbine blades exactly the same, only changing the size of the intermediate body, the width of the two sides of the blade root or the arc of the blade root tooth profile. The longitudinal tree-shaped blade roots of existing steam turbine blades are processed by longitudinal tree-shaped blade root forming diamond rollers. Although the diamond roller can ensure the size of the blade root tooth profile, one type of diamond roller can only process one size of blade root tooth profile, which has great limitations. When the size of the blade root tooth profile changes significantly, the diamond roller needs to be remade as a whole, which consumes too high costs for the enterprise. Summary of the invention

[0003] In view of the defects of the existing longitudinal tree type blade root forming diamond roller, which has a single processing size, great limitations, and high costs when facing larger processing size changes, the present invention provides a split longitudinal tree type tenon tooth blade root diamond roller, which has a simple structure, can realize multi-size blade root tooth processing, has few limitations, and has low costs when facing larger processing size changes. To this end, the present invention also provides a design method for the split longitudinal tree type tenon tooth blade root diamond roller.

[0004] The present invention provides the following technical solutions: It includes an end face diamond roller, an axial gasket and a blade root profile diamond roller, and is characterized in that: the diameter of the blade root profile diamond roller gradually increases from front to back, the blade root of the blade root profile diamond roller is arranged in a stepped manner, the thickness of the blade root increases from front to back, an axial gasket is arranged between the end face diamond roller and the blade root profile diamond roller, the axial gasket is set in a ring shape, the axial gasket and the end face diamond roller are sequentially mounted on the blade root profile diamond roller, and the end face diamond roller, the axial gasket and the blade root profile diamond roller remain concentric in the same horizontal plane.

[0005] It is further characterized by: The end face diamond roller, the axial gasket and the blade root profile diamond roller are all provided with bearing holes, and the bearing holes are circumferentially provided with limit screw holes. The end face diamond roller, the axial gasket and the blade root profile diamond roller are fixedly connected by screws.

[0006] A design method for a split longitudinal tree-type tenon blade root diamond roller, characterized in that: the blade root diamond roller is designed according to a blade root median diagram made from a blade root diagram and a blade root tolerance diagram, the working surface and non-working surface of the blade root diamond roller are offset accordingly according to the blade root tolerance, the working surface and the non-working surface are transitionally processed, the mean difference contour of the tooth profile straight surface and the mean difference contour at the arc R where the tooth profile is connected are artificially tangently transitioned, a tangent is made along the arc R to intersect the straight surface, the angle G between the tangent and the straight surface is 3°~10°, the inner hole diameter size tolerance of the blade root profile diamond roller is designed to be 0~+0.025mm, the blade root profile diamond roller and the end face diamond roller adopt the basic hole system matching size, the axial gasket size base is 2mm, and is set according to the straight surface tolerance of the blade root intermediate body.

[0007] It is further characterized by: The end face diamond roller is designed according to the cooperation of the blade root intermediate body and the blade root profile diamond roller. According to the blade root profile, it can be concluded that the effective width of the blade root profile diamond roller is P, the inner hole radius of the blade root profile diamond roller is d, the minimum thickness of the blade root profile diamond roller is H, and the inner cavity diameter E of the end face diamond roller is the maximum size Q + 0.04mm of the blade root profile diamond roller, where Q=2(d+H+P). The thickness F of the end face diamond roller must be greater than the actual effective length of the blade root intermediate body and does not interfere with the inner arc of the blade root profile.

[0008] In the above technical solution, the technical effects and advantages provided by the present invention are: The axial gasket and the end face diamond roller are sequentially mounted on the blade root profile diamond roller, which is easy to disassemble and replace. For the processing of the longitudinal tree-shaped blade roots of steam turbines with the same blade root profile and different intermediate body thickness, it is only necessary to replace the end face diamond roller or produce the end face diamond roller of a new size. It is not necessary to redesign the entire set of diamond rollers to adapt to the new modified products as in the traditional process, and the modification consumption cost is reduced; The design of the diamond roller on the blade root profile will not produce steps on the ground blade root tooth shape, making the appearance more smooth; BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is a schematic diagram of the overall structure of the product of the present invention; Figure 2 It is a schematic diagram of the overall structure of the present invention; Figure 3 is the blade root median diagram of the present invention; Figure 4 It is a transition processing schematic diagram of the present invention; Figure 5 It is a side view of the blade root profile diamond roller of the present invention; Figure 6 It is a schematic diagram of the structure of the end face diamond roller of the present invention.

[0010] Description of reference numerals: 1. End face diamond roller; 2. Blade root profile diamond roller; 3. Axial gasket; 4. Profile tolerance zone; 5. Straight face tolerance zone; 6. Median line; 7. Blade root intermediate. DETAILED DESCRIPTION

[0011] The present invention provides Figure 2 The present invention shows a split type longitudinal tree type tenon tooth blade root diamond roller, which comprises an end face diamond roller 1, an axial gasket 3 and a blade root profile diamond roller 2. The diameter of the blade root profile diamond roller 2 gradually increases from front to back. The blade root of the blade root profile diamond roller 2 is arranged in a stepped manner. The thickness of the blade root increases from front to back. An axial gasket 3 is arranged between the end face diamond roller 1 and the blade root profile diamond roller 2. The axial gasket 3 is set in a ring shape. The axial gasket 3 and the end face diamond roller 1 are sequentially mounted on the blade root profile diamond roller 2. The end face diamond roller 1, the axial gasket 3 and the blade root profile diamond roller 2 are kept concentric on the same horizontal plane. The end face diamond roller 1, the axial gasket 3 and the blade root profile diamond roller 2 are all provided with bearing holes, and the bearing holes are circumferentially provided with limit screw holes. The end face diamond roller 1, the axial gasket 3 and the blade root profile diamond roller 2 are fixedly connected by screws.

[0012] A split longitudinal tree-shaped tenon blade root diamond roller design method: The blade root profile diamond roller 2 is based on the blade root diagram and the blade root tolerance diagram to make the blade root median diagram (see Figure 3 ) design, the working surface and non-working surface of the blade root profile diamond roller 2 are offset accordingly according to the blade root tolerance, and the working surface and non-working surface are treated as a transition, see Figure 4 The transition at the top of the blade root requires a smooth transition, and the center difference contour of the tooth profile straight surface and the center difference contour of the arc R where the tooth profile connects need to be artificially tangent transition. In the median diagram, a tangent is drawn along the arc R to intersect the straight surface, and the angle G between the tangent and the straight surface is 3°~10°. The dimension tolerance of the inner hole diameter of the blade root profile diamond roller 2 is designed to be 0~+0.025mm, and the matching dimensions of the blade root profile diamond roller 2 and the end face diamond roller 1 adopt the basic hole system. The base size of the axial gasket 3 is 2mm, which is set according to the tolerance of the lower straight surface of the blade root intermediate body.

[0013] See Figure 5 The end face diamond roller 1 is designed according to the blade root intermediate body and the blade root profile diamond roller 2. According to the blade root profile, the effective width of the blade root profile diamond roller 2 is P, the inner hole radius of the blade root profile diamond roller 2 is d, the minimum thickness of the blade root profile diamond roller 2 is H, and the inner cavity diameter E of the end face diamond roller 1 is the maximum size Q of the blade root profile diamond roller + 0.04mm, where Q=2(d+H+P), see Figure 6The thickness F of the end face diamond roller 1 must be larger than the effective length of the actual blade root intermediate body and must not interfere with the inner arc of the blade root profile.

Claims

1. A split longitudinal tree-shaped tenon blade root diamond roller, comprising an end face diamond roller, an axial gasket and a blade root profile diamond roller, characterized in that: The diameter of the blade root profile diamond roller gradually increases from front to back, the blade root of the blade root profile diamond roller is arranged in a stepped manner, and the thickness of the blade root increases from front to back. An axial gasket is provided between the end face diamond roller and the blade root profile diamond roller, and the axial gasket is set in a ring shape. The axial gasket and the end face diamond roller are sequentially mounted on the blade root profile diamond roller, and the end face diamond roller, the axial gasket and the blade root profile diamond roller remain concentric in the same horizontal plane.

2. A split type longitudinal tree type tenon blade root diamond roller according to claim 1, characterized in that: The end face diamond roller, the axial gasket and the blade root profile diamond roller are all provided with bearing holes, and the bearing holes are circumferentially provided with limit screw holes. The end face diamond roller, the axial gasket and the blade root profile diamond roller are fixedly connected by screws.

3. A split longitudinal tree-type tenon blade root diamond roller design method, characterized in that: The blade root type diamond roller is designed according to the blade root median diagram made from the blade root diagram and the blade root tolerance diagram. The working surface and non-working surface of the blade root diamond roller are offset accordingly according to the blade root tolerance. The working surface and the non-working surface are transitionally processed. The median difference contour of the tooth profile straight surface and the median difference contour at the arc R where the tooth profile is connected are artificially tangent to each other. A tangent is made along the arc R to intersect the straight surface, and the angle G between the tangent and the straight surface is 3°~10°. The dimension tolerance of the inner hole diameter of the blade root profile diamond roller is designed to be 0~+0.025mm. The blade root profile diamond roller and the end face diamond roller adopt the basic hole system matching size. The base size of the axial gasket is 2mm, which is set according to the tolerance of the straight surface under the blade root intermediate.

4. A split type longitudinal tree type tenon blade root diamond roller design method according to claim 3, characterized in that: The end face diamond roller is designed according to the cooperation of the blade root intermediate body and the blade root profile diamond roller. According to the blade root profile, it can be concluded that the effective width of the blade root profile diamond roller is P, the inner hole radius of the blade root profile diamond roller is d, the minimum thickness of the blade root profile diamond roller is H, and the inner cavity diameter E of the end face diamond roller is the maximum size Q+0.04mm of the blade root profile diamond roller, where Q=2(d+H+P). The thickness F of the end face diamond roller must be greater than the actual effective length of the blade root intermediate body and does not interfere with the inner arc of the blade root profile.

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