A bearing block with small diameter curved oil pipe, a mold and a molding method

Abstract

The application discloses a bearing seat with a small-diameter curved oil pipe, a die and a forming method. The bearing seat is internally provided with an oil pipe which is communicated between the inside and outside of the bearing seat and is a seamless steel pipe. The application has the advantages that the seamless steel pipe with the same material as the bearing seat is introduced as the oil pipe channel, the pipe wall is completely fused with high-temperature molten steel during high-temperature molten steel pouring, and the curved oil pipe is realized to be cast formed. The problems that the sand sticking after the small-diameter curved oil pipe is cast formed is difficult to clean, the machining after the oil pipe is cast formed is difficult and the machining cost is too high and the like are effectively solved.

Description

Technical Field

[0001] This application relates to the field of bearing housing oil pipe technology, and in particular to a bearing housing with a small-diameter curved oil pipe, a mold, and a forming method. Background Technology

[0002] The bearing is mounted inside the bearing housing, which provides effective support for the bearing. During operation, the bearing experiences significant internal friction. To prevent damage to the contacting working surfaces, lubricating oil is typically used for lubrication, effectively avoiding dry friction. To ensure bearing lubrication, oil lines are usually installed inside the bearing housing to connect the external oil bath environment to the bearing. In existing technologies, bearing housings are usually cast, which offers high molding efficiency. However, the small diameter of the oil lines or oil holes inside the bearing housing makes casting difficult and prone to defects.

[0003] For example, Chinese patent document CN 202020510873.8, authorized and announced on December 8, 2020, discloses a bearing lubrication structure based on a submersible axial flow pump. The structure includes a housing, a suction chamber, and a guide vane. A bearing chamber is located in the middle of the housing, and a stationary shaft is located within the bearing chamber. Both ends of the stationary shaft extend to the outside of the bearing chamber. Several bearings are movably connected to both sides of the middle of the stationary shaft. These bearings are used to rotate the impeller of the electric pump. The guide vane and suction chamber are fixedly placed on the left and right sides of the housing, respectively. This invention, by adding circular ribs to the suction chamber and guide vane, and utilizing the axial, radial, radial, and axial oil injection holes at both ends of the stationary shaft, connects the oil injection pipe and the oil outlet pipe to the bearing chamber inside the bearing housing, forming an integrated oil lubrication pipeline. This solves the problem that axial flow pumps with a diameter greater than 1.6m, power greater than 710kW, and speed less than 300r / min cannot achieve oil lubrication because oil injection holes cannot be directly cast on their bearing housings. The application achieves oil flow and lubrication by splicing together multiple oil injection holes and lard pipes, which presents a problem of difficulty in assembling the various oil pipes.

[0004] The challenge in designing existing bearing housing oil pipes lies in the need for a small-diameter, curved structure. This ensures sufficient oil volume while preventing a turbine effect caused by liquid rising during oil suction. The oil pipes inside the bearing housing are characterized by their small diameter, typically below φ50, and a certain bending radius of 90 degrees. Due to the unique location and structure of these pipes, if a core molding method is used, the thin sand layer of the sand core (with a diameter below φ50) is likely to be eroded and damaged during subsequent high-temperature molten steel pouring, in addition to the space occupied by the core. Even if the sand and clay remain intact, they will completely adhere to the high-temperature molten steel, making subsequent cleaning extremely difficult. If this curved oil pipe is completely cast, this structure cannot be machined on ordinary machine tools, and machining it on CNC machine tools would be extremely costly. Summary of the Invention

[0005] In view of the above-mentioned deficiencies in the prior art, the present invention provides a bearing housing with a small-diameter curved oil pipe, a mold and a forming method, so as to realize the reliable setting of the small-diameter curved oil pipe in the bearing housing, and the bearing housing and the curved oil pipe are cast together, resulting in high forming quality.

[0006] To achieve the above-mentioned objectives, the present invention adopts the following technical solution.

[0007] A bearing housing with a small-diameter curved oil pipe is characterized in that the bearing housing contains an oil pipe connecting the inside and outside of the bearing housing, and the oil pipe is a seamless steel pipe. By introducing a seamless steel pipe of the same material as the bearing housing as the oil transport channel, its wall completely fuses with the high-temperature molten steel during the high-temperature casting process, achieving the casting and forming of the curved oil pipe. This effectively solves the problems of difficult sand removal after casting of small-diameter curved oil pipes, and the difficulties and high costs of machining the cast oil pipe.

[0008] A mold for a bearing housing with a small-diameter curved oil tube is characterized by comprising a first core box and a second core box with their parting surfaces perpendicularly arranged. The curved oil tube within the bearing housing has a first connecting section and a second connecting section extending outwards at both ends. The first core box has a first positioning groove for connecting the first connecting section, and the second core box has a second positioning groove for connecting the second connecting section. By separately setting the first and second positioning grooves on the first and second core boxes, the pre-positioning of the curved oil tube before the bearing housing is cast is achieved. During the casting of the bearing housing, the curved oil tube is simultaneously welded integrally to the bearing housing, improving the forming efficiency of the curved oil tube within the bearing housing and ensuring the accuracy of the formed curved oil tube.

[0009] Preferably, the second positioning groove is a U-shaped groove, and its width is designed to match the outer diameter of the curved oil pipe. When the seamless steel pipe is installed into the first and second core boxes, the second positioning groove provides guidance for the installation of the seamless steel pipe, facilitating its installation relative to the first and second core boxes.

[0010] As a preferred option, seamless steel pipes are used for the curved oil tubing. The seamless steel pipes themselves are formed and inspected and are free of defects. The inner wall of the curved oil tubing remains solid and unchanged in shape during the casting process of the bearing housing. Therefore, during the casting of the curved oil tubing and the bearing housing, the inner wall of the curved oil tubing ensures a reliable oil tubing passage.

[0011] Preferably, the seamless steel pipe is made of the same material as the bearing housing to ensure the integrity of the joint between the seamless steel pipe and the bearing housing.

[0012] A bearing housing forming method based on the above-mentioned mold for bearing housings with small-diameter curved oil pipes, characterized by comprising the following steps:

[0013] A. Prepare seamless steel pipes. The length of the seamless steel pipes should be greater than that of the bent oil pipe assembly. The inner diameter of the seamless steel pipes should match the inner diameter of the required bent oil pipes. The seamless steel pipes should be bent into the required shape by hot bending.

[0014] B. Mold forming and assembly; A first positioning groove is made in the first core box. The first positioning groove is cylindrical and its diameter matches the outer diameter of the seamless steel pipe. A second positioning groove is made in the second core box. The lower end of the second positioning groove is open. The groove depth of the second positioning groove corresponds to the length of the second connecting section of the seamless steel pipe. The groove width of the second positioning groove corresponds to the diameter of the seamless steel pipe. The length of the second positioning groove corresponds to the groove depth of the first positioning groove.

[0015] C. Seamless steel pipe and mold assembly: First, assemble the No. 1 core box and the No. 2 core box. The position of the oil pipe has been pre-positioned in the No. 1 core box. The first connecting section of the seamless steel pipe is matched with the No. 1 positioning groove, and the second connecting section is matched with the No. 2 positioning groove. The seamless steel pipe moves along the No. 2 positioning groove to the bottom of the No. 1 positioning groove until the No. 1 connecting section and the No. 1 positioning groove are fully matched.

[0016] D. Fill the No. 2 positioning groove with sand and mud; seal the part of the No. 2 positioning groove corresponding to the outer side of the No. 2 connecting section, fill it completely with sand and mud and scrape it flat to ensure the flatness of the outer end face of the bearing seat.

[0017] E. Proceed with casting, unpacking, sand removal, and heat treatment in sequence;

[0018] F. Remove the first and second connecting sections by machining or flame cutting.

[0019] Preferably, in step A, the seamless steel pipe is ground to remove the surface oxide scale before step C.

[0020] Preferably, in step A, the wall thickness of the seamless steel pipe is obtained using the calculation method for internal chills.

[0021] The introduction of seamless steel pipes presents two challenges: First, the presence of a wall thickness in the seamless steel pipe is essentially equivalent to placing an internal chill during the casting process; second, given the large bending angle and small bending radius of the oil pipe, how can a perfectly straight seamless steel pipe be bent into shape? To address the wall thickness issue, the calculation method for internal chills is referenced to determine the theoretical value of the seamless steel pipe wall thickness. This ensures that the seamless steel pipe is completely fused with the casting without causing casting defects such as shrinkage cavities or porosity due to melting. Regarding the bending forming issue, after determining the bending radius, the required bending dimensions can be manufactured using hot bending technology. Therefore, by combining these two technologies, the practical production challenge of casting small-diameter bent oil pipes can be solved.

[0022] The present invention has the following beneficial effects: it introduces a seamless steel pipe of the same material as the bearing housing as the channel for oil transportation. During the high-temperature molten steel pouring process, its pipe wall is completely fused with the high-temperature molten steel, realizing the casting and forming of the curved oil pipe; it effectively solves the problems of sand sticking to small-diameter curved oil pipes after casting and forming, which are difficult to clean; and the difficulties and high processing costs of the oil pipes after casting. Attached Figure Description

[0023] Figure 1 This is a partial schematic diagram of the bearing housing of the present invention.

[0024] Figure 2 This is a simplified diagram of a partial casting structure of the bearing housing used in this invention.

[0025] Figure 3 This is a partial structural diagram of the No. 2 core box in this invention, facing upwards.

[0026] In the figure: bearing housing 1, corresponding bearing working surface 101, bearing housing outer end face 102, bent oil pipe 11, first connecting section 111, second connecting section 112, core box 1, core box 2, positioning groove 2 301. Detailed Implementation

[0027] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0028] Example 1,

[0029] like Figure 1 As shown, a bearing housing with a small-diameter curved oil pipe is disclosed. The bearing housing 1 contains a curved oil pipe 11 connecting the inside and outside of the bearing housing 1. The curved oil pipe 11 is made of seamless steel. The curved oil pipe 11 is bent, with a semi-circular middle section and straight ends. Figure 1 This is a partial sectional view of the interior of the bearing housing 1. The upper side is the working surface 101 corresponding to the bearing, and the right side is the outer end face 102 of the bearing housing. A seamless steel pipe of the same material as the bearing housing 1 is introduced as the oil pipeline channel. During the high-temperature molten steel pouring process, its pipe wall is completely fused with the high-temperature molten steel, realizing the casting of the curved oil pipe 11. This effectively solves the problems of difficult sand removal after casting of small-diameter curved oil pipes and the difficulties and high processing costs of processing the cast oil pipe.

[0030] Example 2,

[0031] like Figure 2 and Figure 3As shown, a mold for a bearing housing with a small-diameter curved oil pipe includes a first core box 2 and a second core box 3 with their parting surfaces vertically arranged. The first core box 2 and the second core box 3 can be used in existing bearing housing casting molds. The curved oil pipe 11 inside the bearing housing 1 has a first connecting section 111 and a second connecting section 112 extending outwards at both ends, respectively. The curved oil pipe 11 is made of seamless steel pipe. The first core box 2 has a first positioning groove for connecting the first connecting section 111, and the second core box 3 has a second positioning groove 301 for connecting the second connecting section 112. The second positioning groove 301 is a U-shaped groove, and its width is matched to the outer diameter of the curved oil pipe. The first connecting section 111 and the second connecting section 112 are cylindrical tube structures. The seamless steel pipe is made of the same material as the bearing housing. By setting the No. 1 positioning groove and the No. 2 positioning groove 301 on the No. 1 core box 2 and the No. 2 core box 3 respectively, the pre-positioning of the curved oil pipe before the bearing seat is cast is realized. During the casting of the bearing seat, the curved oil pipe and the bearing seat are welded together, which improves the forming efficiency of the curved oil pipe in the bearing seat and ensures the accuracy of the curved oil pipe after forming.

[0032] Example 3,

[0033] A bearing housing forming method based on the above-mentioned mold for bearing housing with small-diameter curved oil pipe includes the following steps:

[0034] A. Prepare seamless steel pipes. The inner diameter of the seamless steel pipes should match the inner diameter of the required bent oil pipe. The seamless steel pipes are then hot-bent into the desired shape. Before step C, the oxide scale on the surface of the seamless steel pipes is removed by grinding. The wall thickness of the seamless steel pipes is calculated using the internal chill method to determine the theoretical value of the wall thickness, ensuring that the seamless steel pipes are completely fused with the casting without causing casting defects such as shrinkage cavities or porosity due to melting. The length of the seamless steel pipe is greater than that of the bent oil pipe assembly. The specific length of the seamless steel pipe is the bent oil pipe plus the length of the first and second connecting sections.

[0035] B. Mold Forming and Assembly; A first positioning groove is created in the first core box 2. The first positioning groove is cylindrical, and its diameter matches the outer diameter of the seamless steel pipe. A second positioning groove 301 is created in the second core box 3. The lower end of the second positioning groove 301 is open. The depth of the second positioning groove 301 corresponds to the length of the second connecting section of the seamless steel pipe, the width of the second positioning groove 301 corresponds to the diameter of the seamless steel pipe, and the length of the second positioning groove 301 corresponds to the depth of the first positioning groove. During mold making, first... Position the corresponding bent oil pipe 11 in the first core box 2 to determine the first positioning groove, which facilitates the matching of the first positioning groove and the first connecting section. When making the second core box 3, first position the bent oil pipe on one side of the outer end face of the corresponding bearing seat, and reserve the second positioning groove 301 in the corresponding position. The upper end of the second positioning groove is a semi-cylindrical surface. The second positioning groove 301 has a vertical groove wall tangent to the semi-cylindrical surface on the lower side of the semi-cylindrical surface, so that the second positioning groove is a U-shaped groove with the opening facing downward.

[0036] C. Seamless steel pipe and mold assembly: First, assemble the No. 1 core box and the No. 2 core box. The position of the oil pipe has been pre-positioned in the No. 1 core box. The first connecting section of the seamless steel pipe mates with the No. 1 positioning groove, and the second connecting section mates with the No. 2 positioning groove. The seamless steel pipe moves along the No. 2 positioning groove to the bottom of the No. 1 positioning groove until the No. 1 connecting section and the No. 1 positioning groove are fully engaged. At this time, the upper side wall of the No. 2 connecting section is in contact with the mold.

[0037] D. Fill the No. 2 positioning groove with sand and mud; seal the part of the No. 2 positioning groove corresponding to the outer side of the No. 2 connecting section, that is, the lower part of the No. 2 positioning groove, and fill it completely with sand and mud and scrape it flat to ensure the flatness of the outer end face of the bearing seat.

[0038] E. Proceed with casting, unpacking, sand removal, and heat treatment in sequence;

[0039] F. Remove the first and second connecting sections by machining or flame cutting.

[0040] The introduction of seamless steel pipes presents two challenges: First, the presence of a wall thickness in the seamless steel pipe is essentially equivalent to placing an internal chill during the casting process; second, given the large bending angle and small bending radius of the oil pipe, how can a perfectly straight seamless steel pipe be bent into shape? To address the wall thickness issue, the calculation method for internal chills is referenced to determine the theoretical value of the seamless steel pipe wall thickness. This ensures that the seamless steel pipe is completely fused with the casting without causing casting defects such as shrinkage cavities or porosity due to melting. Regarding the bending forming issue, after determining the bending radius, hot bending technology can be used to manufacture the required bend size. By combining these two technologies, the practical production challenge of casting small-diameter bent oil pipes can be solved.

Claims

1. A method for forming a bearing housing with a small-diameter curved oil pipe, characterized in that, The bearing housing is equipped with an oil pipe connecting the inside and outside of the bearing housing; the oil pipe is a seamless steel pipe; the mold used includes a first core box and a second core box with the parting surface vertically arranged; the process includes the following steps: A. Prepare seamless steel pipes. The material of the seamless steel pipes is the same as that of the bearing housing. The length of the seamless steel pipes is greater than that of the bent oil pipe assembly. The inner diameter of the seamless steel pipes matches the inner diameter of the required bent oil pipes. The seamless steel pipes are bent into the required shape by hot bending. B. Mold forming and assembly; A first positioning groove is made in the first core box. The first positioning groove is cylindrical and its diameter matches the outer diameter of the seamless steel pipe. A second positioning groove is made in the second core box. The lower end of the second positioning groove is open. The groove depth of the second positioning groove corresponds to the length of the second connecting section of the seamless steel pipe. The groove width of the second positioning groove corresponds to the diameter of the seamless steel pipe. The length of the second positioning groove corresponds to the groove depth of the first positioning groove. C. Seamless steel pipe and mold assembly: First, assemble the No. 1 core box and the No. 2 core box. The position of the oil pipe has been pre-positioned in the No. 1 core box. The first connecting section of the seamless steel pipe is matched with the No. 1 positioning groove, and the second connecting section is matched with the No. 2 positioning groove. The seamless steel pipe moves along the No. 2 positioning groove to the bottom of the No. 1 positioning groove until the No. 1 connecting section and the No. 1 positioning groove are fully matched. D. Fill the No. 2 positioning groove with sand and mud; seal the part of the No. 2 positioning groove corresponding to the outer side of the No. 2 connecting section, fill it completely with sand and mud and scrape it flat to ensure the flatness of the outer end face of the bearing seat. E. Proceed with casting, unpacking, sand removal, and heat treatment in sequence; F. Remove the first and second connecting sections by machining or flame cutting.

2. The method for forming a bearing housing with a small-diameter curved oil pipe according to claim 1, characterized in that, In step A, before step C, the seamless steel pipe is polished to remove the surface oxide scale.

3. The method for forming a bearing housing with a small-diameter curved oil pipe according to claim 1, characterized in that, In step A, the wall thickness of the seamless steel pipe is obtained using the calculation method for internal chills.

4. The method for forming a bearing housing with a small-diameter curved oil pipe according to claim 1, characterized in that, The first connecting segment and the second connecting segment are cylindrical tube structures.

5. A bearing housing with a small-diameter curved oil pipe, characterized in that, The bearing housing is cast using the bearing housing forming method with small-diameter curved oil pipe as described in any one of claims 1 to 4.

6. A mold for a bearing housing with a small-diameter curved oil pipe, characterized in that, The mold is used in the forming method of small-diameter curved oil pipe as described in any one of claims 1 to 4.

7. A mold for a bearing housing with a small-diameter curved oil pipe according to claim 6, characterized in that, The second positioning groove adopts a U-shaped groove, and the groove width of the second positioning groove is set to match the outer diameter of the curved oil pipe.

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