Casting system for front end cover of wind power gear box

Abstract

A casting system for a front end cover casting of a wind power gear box comprises a pouring system and a casting cavity, and the pouring system is communicated with the casting cavity. The pouring system comprises a straight pouring gate, a transverse pouring gate, a first transition pouring gate, a foam filter, a second transition pouring gate and an inner pouring gate which are communicated with one another; the straight pouring gate is vertically communicated with one end of the transverse pouring gate, the first transition pouring gate is transversely connected to one side wall of the transverse pouring gate, the foam filter is arranged below the first transition pouring gate, and the second transition pouring gate is connected to the lower portion of the foam filter. One end of the ingate is connected below the second transition runner, and the other end of the ingate is communicated with the lower bottom surface of the casting cavity; the number of the ingates is six, the length of three ingates is larger than that of the other three ingates, and the tail ends of the six ingates are connected to different positions of the lower bottom face of the casting cavity in a scattered mode. And solidification can be effectively balanced, the defects of upper plane shrinkage concave, local shrinkage cavity or shrinkage porosity of the casting are overcome, and the yield of the casting is improved.

Description

Technical Field

[0001] The present application relates to the field of casting technology, and in particular to a casting system for a front end cover casting of a wind turbine gearbox. Background Art

[0002] As attached Figure 1-2 The figure shows a front cover casting of a wind turbine gearbox. The casting is made of QT400-18LT, with dimensions of φ1527mm×φ1072mm×63mm and a weight of 340kg. Since the casting is a disc-type product, it is easy to produce upper plane shrinkage, local shrinkage or shrinkage defects during the casting process. Figure 3-4 As shown, this type of front end cover casting product not only has a disc-shaped casting body a1', but also includes a plurality of through holes a2' of different sizes on the casting body a1'. Therefore, this type of casting requires that the entire upper surface of the casting is not allowed to have casting defects such as shrinkage cavities and shrinkage.

[0003] However, at present, for this type of front end cover casting, the corresponding pouring system cannot achieve balanced solidification of the poured molten iron (liquid iron), resulting in large differences in cooling rates at various positions of the casting, making it easy for defects such as shrinkage dents, local shrinkage holes or shrinkage porosity to appear on the upper surface of the casting, thereby reducing the yield of the casting. Utility Model Content

[0004] In view of the above-mentioned deficiencies in the prior art, the present application provides a casting system for a front end cover casting of a wind turbine gearbox, which can effectively balance solidification, solve the defects of plane shrinkage, local shrinkage cavities or shrinkage porosity on the casting, and improve the casting yield.

[0005] In order to solve the above technical problems, the technical solution adopted in the present application is: a casting system for a front end cover casting of a wind turbine gearbox, which includes a pouring system and a casting cavity, and the pouring system is interconnected with the casting cavity; the pouring system includes a straight runner, a cross runner, a first transition runner, a foam filter, a second transition runner and an ingrown runner that are interconnected; the straight runner is vertically connected to one end of the cross runner, the first transition runner is horizontally connected to one side wall of the cross runner, the foam filter is arranged below the first transition runner, the second transition runner is connected to the bottom of the foam filter, one end of the ingrown runner is connected to the bottom of the second transition runner, and the other end is connected to the lower bottom surface of the casting cavity; six ingrowns are arranged, and the length of three of them is greater than the length of the other three, and the tail ends of the six ingrowns are dispersedly connected to different positions of the lower bottom surface of the casting cavity.

[0006] By adopting the above structure, the present application feeds from the bottom of the casting cavity through six ingates, so that the molten iron (hot iron) flows more smoothly and is not easy to form turbulence in the casting cavity, thereby reducing casting defects; moreover, the six ingates simultaneously guide the molten iron into the casting cavity through six directions, and the liquid inlet is more balanced, so that the molten iron can achieve balanced solidification in the cavity, reducing casting defects; in addition, the present application sets a foam filter between the first transition runner and the second transition runner, and the molten iron can be blocked at the outlet of the foam filter and will not enter the ingates at too fast a speed, which can be beneficial to the smooth flow of the molten iron. This structure can prevent the bad molten iron containing slag, gas and debris that flows through the straight runner and the cross runner in the early stage from directly entering the ingates, which is beneficial to the floating of the molten iron slag, and is also beneficial to the molten iron entering the cavity more smoothly, reducing the generation of oxidized slag inclusions, improving the purity of the molten iron entering the casting mold, and reducing casting defects.

[0007] Furthermore, the sprue and inner pouring channel are refractory ceramic tubes. This arrangement can reduce the sand erosion defects on the pouring channel during the molten iron pouring process.

[0008] Furthermore, the straight runner includes a first vertical portion, a second transverse portion and a third vertical portion which are connected in sequence, the tail end of the third vertical portion is vertically connected to the cross runner, and the extension lengths of the first vertical portion and the third vertical portion are smaller than the extension length of the second transverse portion. With this structure, the molten iron in the straight runner can be bent multiple times, thereby reducing its flow velocity, reducing turbulence, and reducing the impact on the casting cavity.

[0009] Furthermore, a small safety riser is provided on the upper surface of the casting cavity; with the above structure, the safety riser can realize the replenishment of molten iron, and the flat vent can effectively discharge the gas in the molten iron, so the above structure forms a balanced solidification state, combined with the structure of six inner runners, solves the casting defects of plane shrinkage, local shrinkage cavity defects and casting cracking on the casting.

[0010] Furthermore, among the six ingates, three long ingates are of equal length, three short ingates are of equal length, and the long ingates and the short ingates are alternately connected circumferentially along the bottom surface of the casting cavity; adopting this structure, more balanced feeding to all directions of the casting cavity can be achieved, so that the solidification of the molten iron is also more balanced.

[0011] Furthermore, the first transition runner, foam filter and second transition runner are stacked up and down and located at the center of the casting cavity; with this structure, impurities such as gas and slag inclusions in the molten iron can fully float up to avoid entering the cavity, and the central setting can ensure that the molten iron enters the cavity evenly, and the flow is more balanced and stable.

[0012] Furthermore, the bottom surface of the casting cavity is higher than the upper surface of the foam filter; with this structure, the flow rate of the molten iron can be reduced when passing through the foam filter, so that impurities in the molten iron can float up fully, reducing the impurities entering the casting cavity and improving the casting quality of the casting.

[0013] Furthermore, the total cross-sectional area ratio of the main pouring units of the sprue, runner and entgate is: ΣA sprue: ΣA runner: ΣA entgate = 1: 1.20~1.30: 1.0~1.05; using the above ratio, the minimum cross-sectional area is set on the sprue, which can enable the pouring system to achieve the characteristics of "low flow rate, smooth and clean filling".

[0014] Furthermore, a disc-shaped indirect chiller is arranged in the molding sand at the upper part of the casting cavity, and a distance is arranged between the disc-shaped indirect chiller and the upper plane of the casting cavity; a plurality of riser notches for accommodating small safety risers are arranged in the circumferential direction of the outer edge of the disc-shaped indirect chiller, and a plurality of through holes are arranged in the thickness direction of the disc-shaped indirect chiller; the adoption of this structure eliminates the oxidized slag inclusions caused by poor direct chiller; it can also accelerate the effective cooling and rapid cooling of the casting iron liquid at this location to achieve the purpose of balanced cooling; and this integrated disc-shaped indirect chiller is easier to position in the casting positioning process, the process is easy to operate, and the positioning is accurate and not prone to deviation; and the arrangement of the through holes can fill the molding sand during the molding sand casting process, thereby improving the connection firmness between the indirect chiller and the molding sand forming the casting cavity.

[0015] Furthermore, the distance between the disc-shaped indirect chiller and the upper surface of the casting cavity is 25 mm to 45 mm; this distance setting allows the indirect chiller to achieve a more balanced cooling effect on the casting.

[0016] Furthermore, the distance between the small safety riser arranged in the riser notch and the indirect chiller is 25mm to 45mm; with this structure, there is no need for the riser to directly contact the indirect chiller, and molding sand is filled between the two to protect their respective functions and facilitate separation of the two after pouring is completed.

[0017] Furthermore, there are five riser notches, which are evenly arranged along the circumference of the outer edge of the chiller body; with this structure, the disc-shaped indirect chiller can be positioned more accurately according to the position of the riser in the casting system.

[0018] Furthermore, the size of the through hole is φ40mm~60mm; the through hole of this size can fix the sand layer between the indirect chiller and the mold more tightly to the indirect chiller through the molding sand in the through hole, solving the problem that the sand layer between the indirect chiller and the mold is easily detached. On the one hand, the indirect chiller is more firmly fixed in the casting mold, and on the other hand, it is convenient to exhaust the indirect chiller and the sand layer between the indirect chiller and the mold. The hot gas in the sand layer between the indirect chiller and the mold is discharged through the through hole, thereby improving the cooling effect.

[0019] Furthermore, there are five through holes, and the five through holes and the five riser notches are alternately arranged; adopting this structure can further stabilize the positioning accuracy between the indirect chiller, the molding sand and the mold, and improve the positioning effect of the chiller. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A schematic structural diagram of a first view of an example of a front end cover casting of a wind turbine gearbox in the present application.

[0021] Figure 2 A schematic structural diagram of the second view of an example of a front end cover casting of a wind turbine gearbox in the present application.

[0022] Figure 3 A structural schematic diagram of the first view of another example of a front end cover casting of a wind turbine gearbox in the present application.

[0023] Figure 4 A structural schematic diagram of the second view of another example of a front end cover casting of a wind turbine gearbox in the present application.

[0024] As shown in the attached drawings: a1'. Casting body, a2'. Through hole.

[0025] Figure 5 The structural diagram of the first view of the pouring system of this application.

[0026] Figure 6 The structural diagram of the second view of the pouring system of this application.

[0027] Figure 7 A schematic diagram of the structure of the pouring system of this application from bottom view.

[0028] Figure 8 A schematic diagram of the structure of the pouring system of this application from a top view.

[0029] Fig. 9 A schematic structural diagram of the first view of the casting system of the present application.

[0030] Fig.10 A schematic structural diagram of the second view of the casting system of the present application.

[0031] Fig.11This application shows a schematic diagram of the structure of the pouring system front view.

[0032] As shown in the accompanying drawings: a. pouring system, a1. casting cavity, 1. straight runner, 101. first vertical part, 102. second transverse part, 103. third vertical part, 2. horizontal runner, 3. first transition runner, 4. foam filter, 5. second transition runner, 6. inner runner, 7. small safety riser, 8. indirect chiller, 801. riser notch, 802. through hole. DETAILED DESCRIPTION

[0033] The following will combine the embodiments and drawings to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only preferred embodiments, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention;

[0034] It should also be noted that when a component is referred to as being "fixed to" another component, it may be directly on the other component or there may also be another intermediate component, fixed through the intermediate component. When a component is considered to be "connected" to another component, it may be directly connected to the other component or there may be another intermediate component at the same time. When a component is considered to be "set on" another component, it may be directly set on the other component or there may be another intermediate component at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by technicians in the technical field of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0035] The casting cavity of the present application can be the structure of the casting cavity for pouring, or the final casting structure, because the casting is obtained by first forming a cavity consistent with the casting structure, pouring molten iron in the cavity and cooling it. Therefore, the casting cavity (body) of the present application can refer to the same structure as the casting, and the structural relationship between each structure and the casting cavity body can also be seen as the structural relationship between the casting; the mold involved in the present application is a mold for forming the casting cavity, so the specifications and dimensions of the mold are also consistent with the casting.

[0036] As attached Figure 5-11As shown, it is a casting system of the front end cover casting of the wind turbine gearbox described in the present application, the system includes a pouring system a and a casting cavity a1, the pouring system a is interconnected with the casting cavity a1; the pouring system a includes a straight runner 1, a cross runner 2, a first transition runner 3, a foam filter 4 (the foam filter sold by the manufacturer: Jinan Shengquan Group Co., Ltd. can be used), a second transition runner 5 and an inner runner 6 that are interconnected; the straight runner 1 is vertically connected to one end of the cross runner 2, the first transition runner 3 is horizontally connected to a side wall of the cross runner 2, the foam filter 4 is arranged below the first transition runner 3, and the second transition runner 5 is connected below the foam filter 4, One end of the ingrowth channel 6 is connected to the bottom of the second transition runner 5, and the other end is connected to the lower bottom surface of the casting cavity a1; there are six ingrowth channels 6, and the lengths of three of them are greater than those of the other three, and the tail ends of the six ingrowth channels are dispersedly connected to different positions of the lower bottom surface of the casting cavity a1; specifically, the cross-section of the straight runner is circular, the cross-casting surface of the cross-runner is trapezoidal with a narrow upper part and a wide lower part, the cross-sections of the first transition runner and the second transition runner are also trapezoidal, and one side of the large bottom surface of the two is close to and connected to the foam filter; the outer peripheral edge of the foam filter protrudes from the outer edge of the bottom surface connected to it by the two transition runners, so that the foam can be filtered in the molding sand and supported by the molding sand to maintain the stability of the position.

[0037] By adopting the above structure, the present application feeds from the bottom of the casting cavity through six ingates, so that the molten iron (hot iron) flows more smoothly and is not easy to form turbulence in the casting cavity, thereby reducing casting defects; moreover, the six ingates simultaneously guide the molten iron into the casting cavity through six directions, and the liquid inlet is more balanced, so that the molten iron can achieve balanced solidification in the cavity, reducing casting defects; in addition, the present application sets a foam filter between the first transition runner and the second transition runner, and the molten iron can be blocked at the outlet of the foam filter and will not enter the ingates at too fast a speed, which can be beneficial to the smooth flow of the molten iron. This structure can prevent the bad molten iron containing slag, gas and debris that flows through the straight runner and the cross runner in the early stage from directly entering the ingates, which is beneficial to the floating of the molten iron slag, and is also beneficial to the molten iron entering the cavity more smoothly, reducing the generation of oxidized slag inclusions, improving the purity of the molten iron entering the casting mold, and reducing casting defects.

[0038] As an example, the straight runner and inner runner described in this application are refractory ceramic tubes (tubes made of high-temperature resistant and refractory ceramic materials commonly used in the casting field can be suitable for this application). This setting can reduce the sand erosion defects of the runner during the molten iron casting process.

[0039] As attached Figure 5-6As shown in Figures 9-10, the straight runner 1 described in the present application includes a first vertical portion 101, a second horizontal portion 102 and a third vertical portion 103 which are connected in sequence, the tail end of the third vertical portion 103 is vertically connected to the cross runner 2, and the extension lengths of the first vertical portion 101 and the third vertical portion 103 are smaller than the extension length of the second horizontal portion 102. With this structure, the path through which the molten iron in the straight runner flows can be bent multiple times, thereby reducing its flow velocity, reducing turbulence, and reducing the impact on the casting cavity.

[0040] As attached Figure 5-6 As shown, a small safety riser 7 is provided on the upper surface of the casting cavity a1 described in the present application; specifically, 5 small safety risers are provided, which are evenly distributed along the circumference of the casting cavity and connected with the casting cavity; with the above structure, the safety riser can realize the replenishment of molten iron, and the flat vent can effectively discharge the gas in the molten iron, so the above structure forms a state of balanced solidification, and combined with the structure of six inner runners, the casting defects of plane shrinkage, local shrinkage cavity defects and casting cracking on the casting are solved.

[0041] As attached Figure 7-11 As shown, among the six ingates 6 described in the present application, three long ingates 6 are of equal length, three short ingates 6 are of equal length, and the long ingates 6 and the short ingates 6 are alternately connected along the circumferential direction of the bottom surface of the casting cavity a1; that is, a long one is adjacent to a short one; with this structure, a more balanced feeding to all directions of the casting cavity can be achieved, so that the solidification of the molten iron is also more balanced.

[0042] As attached Figure 7-11 As shown, the first transition runner 3, foam filter 4 and second transition runner 5 described in the present application are stacked up and down and located at the center of the casting cavity a1; with this structure, impurities such as gas and slag inclusions in the molten iron can fully float up to avoid entering the cavity, and the central setting can ensure that the molten iron enters the cavity evenly, and the flow is more balanced and stable.

[0043] As attached Fig.11 As shown, the lower bottom surface of the casting cavity a1 described in the present application is higher than the upper surface of the foam filter 4; with this structure, the flow velocity of the molten iron can be reduced when passing through the foam filter, so that the impurities in the molten iron can float up fully, reducing the impurities entering the casting cavity and improving the casting quality of the casting.

[0044] As an example, the total cross-sectional area ratio of the main pouring units of the sprue 1, runner 2 and ingode 6 described in the present application is: ΣA sprue: ΣA runner: ΣA ingode = 1: 1.20~1.30: 1.0~1.05; using the above ratio, the minimum cross-sectional area is set on the sprue, which can enable the pouring system to achieve the characteristics of "low flow rate, smooth and clean filling".

[0045] As attached Figure 9-11 As shown, a disc-shaped indirect chiller 8 is arranged in the molding sand at the upper part of the casting cavity a1 described in the present application (the entire casting system is cast in the molding sand, and the casting cavity is formed in the molding sand, so the upper part of the casting cavity which is the same as the casting is the molding sand layer) (the indirect chiller is arranged concentrically with the casting cavity, and its inner diameter is larger than the inner diameter of the cavity, and its outer diameter is smaller than the outer diameter of the cavity, that is, the radial extension width is smaller than the radial extension width of the cavity), and a spacing is arranged between the disc-shaped indirect chiller 8 and the upper plane of the casting cavity a1; a plurality of safety small risk protection devices are arranged circumferentially on the outer edge of the disc-shaped indirect chiller 8 The riser notch 801 accommodated in the opening 7, the disc-shaped indirect chiller 8 is provided with a plurality of through holes 802 in the thickness direction; this structure can eliminate the oxidized slag inclusions caused by poor direct chiller; it can also accelerate the effective cooling and rapid cooling of the molten iron in the casting to achieve the purpose of balanced cooling; and this one-piece disc-shaped indirect chiller is easier to position in the casting mold positioning process, the process is easy to operate, and the positioning is accurate and not prone to deviation; and the through holes can be filled with molding sand during the sand casting process, thereby improving the connection firmness of the sand layer between the chiller and the mold forming the casting cavity.

[0046] As an example, the distance between the indirect chiller 8 described in the present application and the upper surface of the casting cavity a1 is 25 mm to 45 mm; this distance setting can enable the indirect chiller to achieve a more balanced cooling effect on the casting.

[0047] As an example, the distance between the small safety riser 7 and the indirect chiller 8 set in the riser gap 801 described in the present application is 25mm to 45mm; with this structure, there is no need to directly contact the riser with the indirect chiller, and molding sand is filled between the two to protect their respective functions and facilitate the separation of the two after pouring is completed.

[0048] As attached Fig. 9 As shown, the riser notches 801 described in the present application are provided with five, which are evenly arranged circumferentially along the outer edge of the chiller body; with this structure, the disc-shaped indirect chiller can be positioned more accurately according to the position of the riser in the casting system.

[0049] As an example, the size of the through hole 802 described in the present application is φ40mm~60mm; the through hole of this size, through the molding sand in the through hole, fixes the sand layer between the indirect chiller and the mold more tightly to the indirect chiller, solving the problem that the sand layer between the indirect chiller and the mold is easily detached. On the one hand, the indirect chiller is more firmly fixed in the casting mold, and on the other hand, it is convenient to exhaust the indirect chiller and the sand layer between the indirect chiller and the mold. The hot gas in the sand layer between the indirect chiller and the mold is discharged through the through hole, thereby improving the cooling effect.

[0050] As attached Fig. 9 As shown, as an example, the through holes 802 described in the present application are provided with five, and the five through holes 802 and the five riser notches 801 are alternately arranged with each other; adopting this structure, the positioning accuracy between the indirect chiller and the molding sand and the mold can be further stabilized, and the positioning effect of the chiller can be improved.

[0051] The casting system of the present application can maintain a balanced solidification state of disc-type products, solve the defects of plane shrinkage, local shrinkage holes or shrinkage porosity on the castings, and improve the casting yield rate.

Claims

1. A casting system for a front end cover of a wind turbine gearbox, characterized in that: It includes a pouring system and a casting cavity, wherein the pouring system is interconnected with the casting cavity; the pouring system includes a straight runner, a cross runner, a first transition runner, a foam filter, a second transition runner and an ingrown runner which are interconnected; the straight runner is vertically connected to one end of the cross runner, the first transition runner is horizontally connected to a side wall of the cross runner, the foam filter is arranged below the first transition runner, the second transition runner is connected to the bottom of the foam filter, one end of the ingrown runner is connected to the bottom of the second transition runner, and the other end is connected to the lower bottom surface of the casting cavity; the ingrown runner is provided with six , and the lengths of three of them are greater than those of the other three, the tail ends of the six ingates are dispersedly connected to different positions of the lower bottom surface of the casting cavity; a small safety riser is arranged on the upper surface of the casting cavity; the sprue and the ingate are refractory ceramic tubes; the three long ingates among the six ingates are of equal length, the three short ingates are of equal length, and the long ingates and the short ingates are alternately connected along the circumferential direction of the bottom surface of the casting cavity; the first transition runner, the foam filter and the second transition runner are arranged in an upper and lower stack and are located at the center of the casting cavity; the lower bottom surface of the casting cavity is higher than the upper surface of the foam filter.

2. The casting system for the front end cover of a wind turbine gearbox according to claim 1, characterized in that: The straight runner includes a first vertical portion, a second horizontal portion and a third vertical portion connected in sequence, the tail end of the third vertical portion is vertically connected to the horizontal runner, and the extension lengths of the first vertical portion and the third vertical portion are smaller than the extension length of the second horizontal portion.

3. The casting system for the front cover of a wind turbine gearbox according to claim 1, characterized in that: The total cross-sectional area ratio of the main pouring units of the sprue, runner and ingode is: ΣA sprue: ΣA runner: ΣA ingode = 1: 1.20-1.30: 1.0-1.

05.

4. The casting system for the front end cover of a wind turbine gearbox according to claim 1, characterized in that: A disc-shaped indirect chill is arranged in the molding sand at the upper part of the casting cavity, and a distance is arranged between the disc-shaped indirect chill and the upper plane of the casting cavity; a plurality of riser notches for accommodating small safety risers are arranged in the circumferential direction of the outer edge of the disc-shaped indirect chill, and a plurality of through holes are arranged in the thickness direction of the disc-shaped indirect chill.

5. The casting system for the front end cover of a wind turbine gearbox according to claim 4, characterized in that: The distance between the disc-shaped indirect chiller and the upper surface of the casting cavity is 25 mm to 45 mm.

6. The casting system for the front end cover of a wind turbine gearbox according to claim 4, characterized in that: The distance between the small safety riser arranged in the riser notch and the indirect chiller is 25mm-45mm; the size of the through hole is φ40mm-60mm.

7. The casting system for the front end cover of a wind turbine gearbox according to claim 4, characterized in that: There are five riser notches, which are evenly arranged along the outer edge of the cold iron body; there are five through holes, and the five through holes and the five riser notches are alternately arranged.

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