A pedestal structure for a swing axis spreader saddle and a method of forming the same

Abstract

The application discloses a bottom structure for a swing shaft type spreader saddle and a forming method thereof. The bottom structure comprises a bottom body and a bearing key. The bottom body is a non-tempered structure and has an upwardly protruding cross beam for supporting a saddle body of the spreader saddle. The bearing key is a tempered structure and is connected to the cross beam of the bottom body. The bearing surface of the bearing key exposed to the top side of the bottom body has an arc-shaped curved surface structure. When the saddle body of the spreader saddle is placed on the bottom structure, the bearing surface of the bearing key and the bottom of the saddle body form a relative rolling fit relationship. The application effectively reduces the forming technical difficulty of the bottom structure of the spreader saddle supported by the bottom supporting cross beam, is good in economy, and is beneficial to the popularization and application of the spreader saddle supported by the bottom supporting cross beam in a suspension bridge structure.

Description

Technical Field

[0001] This invention relates to the cable saddle assembly structure of suspension bridges, specifically a base structure for a pendulum-type cable saddle, and a method for forming the base structure. Background Technology

[0002] The cable saddle is a crucial load-bearing component in a suspension bridge structure that supports, steers, and disperses the main cable. It mainly consists of an upper and lower saddle body and a base. To accommodate changes in the load on the main cable, the saddle body and the base form a relatively rolling pendulum-like engagement. That is, the saddle body can swing forward and backward on the base along the extension direction of the main cable, depending on the stress on the main cable.

[0003] For a long time, the saddle body and base of the swing-shaft type cable saddle have been connected by an upper bearing plate fitted in a groove at the bottom of the saddle body, a lower bearing plate fitted in a groove at the top of the base, and multiple tapered steel pins inserted between the upper and lower bearing plates at intervals along the transverse direction of the base (relative to the longitudinal direction of the main cable extension). The bottom surface of the upper bearing plate is a flat structure; the top surface of the lower bearing plate is an arc-shaped curved structure; the tapered steel pins are divided into cylindrical and tapered sections along their shaft length. The cylindrical section is used to fit into the lower bearing plate, and the tapered section is used to fit into the upper bearing plate, thereby creating a linear contact fit between the bottom plane of the upper bearing plate and the top arc surface of the lower bearing plate, achieving a movable connection of the saddle body with relative rolling fit on the base. The working principle of this swing-shaft connection technology of the cable saddle is as follows:

[0004] When the upper bearing plate is in a horizontal position, the circumference of the tapered section of the tapered steel pin (especially the upper part of the tapered steel pin) does not contact the circular hole of the upper bearing plate, but forms a certain annular space gap.

[0005] When the bottom plane of the upper bearing plate rotates at a certain angle along the top arc surface of the lower bearing plate, the tapered steel pin comes into contact with and squeezes the wall of the circular hole in the upper bearing plate, thereby restricting the upper bearing plate from continuing to rotate along the arc surface of the lower bearing plate.

[0006] The swing shaft connection technology of the cable saddle has several drawbacks. First, its complex structure and numerous components make manufacturing and installation inconvenient. Second, the tapered steel pins used for positioning and limiting the saddle body experience significant compression and shear forces during use. These forces, acting as a key component of the movable connection structure, can lead to fatigue damage over long-term service, affecting the safety and reliability of the entire suspension bridge structure. Third, it limits the saddle body's rotation angle on the base, potentially making rotation difficult. This makes it difficult for the cable saddle to reliably and flexibly adjust to changes in the dynamic loads on the suspension bridge, affecting the uniformity of stress in the main cable strands and further compromising the safety and reliability of the suspension bridge structure.

[0007] In view of this, the applicant previously disclosed a cable saddle structure in which a crossbeam protruding from the base serves as the swing axis to support the saddle body, as detailed in Chinese patent documents entitled "A Swing Axis Type Cable Saddle" (Publication No. CN105220614 A, Publication Date January 6, 2016) and "A Novel Swing Axis Type Cable Saddle" (Publication No. CN 217758339U, Publication Date November 8, 2022). This technology effectively solves the technical problems existing in the aforementioned swing axis connection technology with a conical steel pin structure.

[0008] However, through repeated research, the applicant discovered that the main cable load borne by the saddle body of the cable saddle is initially transferred to the supporting beam on the base, resulting in high contact stress at the top curved surface of the supporting beam. To ensure the base can withstand high loads, the supporting beam must achieve the required surface hardness (the contact surface hardness must be no less than HB300). The design involved integrally casting the base and supporting beam from low-alloy steel or alloy steel, followed by overall heat treatment. However, during actual manufacturing, it was observed that numerous capillary cracks appeared on the non-machined surfaces of this base after heat treatment, and these cracks were difficult to repair, hindering product quality control. The summary analysis suggests that low-alloy steel or alloy steel has poor castability, easily leading to micro-crack defects on the surface after casting, which are further amplified after heat treatment. Furthermore, the high carbon equivalent of low-alloy steel or alloy steel results in poor weldability, making welding repair of crack defects difficult.

[0009] Therefore, in order to promote the application of the cable saddle technology supported by the base support beam and improve the product quality of the base, it is necessary to design a more feasible and reliable base structure. Summary of the Invention

[0010] The technical objective of this invention is to provide a base structure for a swing-axis type cable saddle that is easy to form with high quality, and a method for forming the base structure, taking into account the special characteristics of the swing-axis type cable saddle technology supported by the base support beam and the shortcomings of the prior art.

[0011] The technical objective of this invention is achieved through the following technical solution: a base structure for a swing-axis type cable saddle, comprising a base body, wherein the base body has an upwardly protruding crossbeam that serves as a support for the cable saddle body;

[0012] The base body is a non-heat-treated structure;

[0013] The base structure also includes a heat-treated bearing key, which is connected to the crossbeam of the base body and exposed on the top side of the base body with an arc-shaped curved surface.

[0014] When the saddle body of the cable saddle is placed on the base structure, the bearing surface of the bearing key and the bottom of the saddle body form a relative rolling fit relationship.

[0015] The above-mentioned technical measures address the unique characteristics of the swing-axis cable saddle technology supported by the base support beam. The base structure is formed by separately assembling the base body and the bearing key. The base body used for anchoring does not require high contact hardness tempering treatment, while the bearing key of the relative rolling support cable saddle body is formed with high contact hardness tempering treatment. The two are differentiated according to the functional division in engineering applications, ensuring that components with different functions are formed using more suitable materials and processes. In this way, on the one hand, the molding material of the base body can be selected and appropriate heat treatment can be carried out. That is, the base body does not need to form a direct contact fit with the cable saddle body, and therefore does not need to form a high contact hardness on the base body for relative rolling fit. This effectively ensures the molding quality of the base body and avoids crack defects. On the other hand, the molding material of the load-bearing key can be selected and appropriate heat treatment can be carried out. That is, the load-bearing key needs to form a direct relative rolling contact fit with the cable saddle body, and a high contact hardness needs to be formed on the load-bearing key for relative rolling fit, so that the load-bearing key meets the high hardness technical requirements of the contact surface of the direct load-bearing saddle body. Thus, while ensuring molding quality, the molding technical difficulty of the base structure of the swing-axis cable saddle supported by the base support beam is effectively reduced. It is economical and conducive to the vigorous promotion and application of the swing-axis cable saddle supported by the base support beam in suspension bridge structures.

[0016] As one of the preferred embodiments, the top side of the crossbeam of the base body has a keyway with a downwardly concave structure;

[0017] The lower part of the bearing key has a key body, which is fitted into the keyway at the top of the crossbeam in an interference fit in the width direction, and the upper part of the bearing key extends out from the top of the crossbeam.

[0018] The above-mentioned technical measures use an interference fit structure to enable the load-bearing keys with different molding structures to be stably and reliably assembled on the base body. The base body provides stable positioning and support for the load-bearing keys, so as to reliably bear the load of the cable saddle body transmitted by the load-bearing keys.

[0019] Furthermore, the upper part of the bearing key has wings that extend outward from both sides of the key body in the width direction, and the top surface of the wings and the top surface of the key body together form a bearing surface with an arc-shaped curved surface structure.

[0020] The bearing key, which is interference-fitted into the keyway at the top of the crossbeam, has its wings on both sides in the width direction corresponding to the edges of the keyway in the width direction in a surface contact manner.

[0021] The above-mentioned technical measures enable the bearing key to form a T-shaped structure in the width direction. On the one hand, this effectively enhances the assembly stability of the bearing key on the base body. On the other hand, the top side surface of the bearing key reliably and fully forms the arc-shaped curved surface of the rolling support cable saddle body. On the other hand, under the cover and wrapping of the top side of the bearing key, the base body and the supported cable saddle body are prevented from making contact and fit, and the position of the base body on the relative rolling fit between the bearing key and the cable saddle body is also prevented.

[0022] Furthermore, the keyway depth at the top of the crossbeam is at least 1 / 2 of the maximum height of the bearing key;

[0023] Furthermore, the effective mounting height of the key body of the carrier key is at least 1 / 2 of the maximum height of the carrier key;

[0024] When the bearing key is interference-fitted into the keyway at the top of the crossbeam, the bottom surface of the bearing key body and the bottom surface of the keyway form a surface contact fit.

[0025] The above-mentioned technical measures can reliably enhance the assembly stability of the bearing key on the base body. Under the premise of meeting the requirement of high hardness contact support for the cable saddle body, it is beneficial to reduce the height of the bearing key and make the forming structure of the bearing key more compact.

[0026] Furthermore, the two end faces of the bearing key have an internal groove-shaped air venting groove.

[0027] The bearing key, which is interference-fitted into the keyway at the top of the crossbeam, connects the inside and outside of the keyway through air venting grooves at both ends, allowing air to be expelled from the keyway during the interference fit of the bearing key.

[0028] The above-mentioned technical measures can effectively squeeze out the air in the keyway of the base body during the interference fit process of the bearing key and the base body, ensuring that the bearing key is fully and completely interference fitted in the keyway and avoiding air blockage.

[0029] Furthermore, at both ends of the crossbeam along its length, there are stoppers that extend upward beyond the edge of the keyway in its width direction;

[0030] Furthermore, when the bearing key is interference-fitted into the keyway at the top of the crossbeam, the end stops at both ends of the crossbeam in the longitudinal direction extend upward beyond the bearing surface of the bearing key;

[0031] When the saddle body of the cable saddle is placed on the base structure, the bearing surface of the bearing key between the two end stops of the crossbeam forms a relative rolling fit with the bottom of the saddle body.

[0032] The above-mentioned technical measures, without hindering the interference fit of the load-bearing key, can reliably limit the lateral movement of the saddle body assembled in engineering applications through the protruding stops at both ends of the crossbeam, reducing the need for separate limiting structures in the later assembly. Moreover, compared with separate limiting structures, since the stops and the base body are integrally formed, the overall integrity is good and the stress strength is high.

[0033] Furthermore, the keyway length at the top of the crossbeam is ≥2m;

[0034] The load-bearing key, which is interference-fitted into the keyway at the top of the crossbeam, is divided into several relatively independent segments along its length, with each segment having a length of 0.5 to 1.5 m.

[0035] Multiple load-bearing key segments are sequentially mated in the keyway according to their relative positions, and the mating gap between two adjacent load-bearing key segments is ≤0.05mm.

[0036] The above-mentioned technical measures are designed for the special application of large cable saddle structures in suspension bridges. Without affecting the relative rolling support of the load-bearing key to the cable saddle body, they facilitate the processing and forming of the load-bearing key, including reducing the technical difficulty of forging and forming the load-bearing key and reducing the technical difficulty of heat treatment of the load-bearing key.

[0037] As one of the preferred options, the base body is a cast structure of low-carbon steel, having a base plate, a crossbeam and multiple supporting ribs.

[0038] The bottom plate has a rectangular shape when viewed from above.

[0039] The crossbeams are arranged along the length of the base plate at the center of the width of the base plate;

[0040] The supporting stiffeners are divided into two groups; multiple supporting stiffeners in each group are arranged at intervals along the length of the crossbeam between the base plate and the crossbeam. The outline of the supporting stiffeners is a triangular or trapezoidal structure with a narrow top and a wide bottom, and the top side of the supporting stiffeners is lower than the top side of the crossbeam.

[0041] The base body of the above-mentioned technical measures, based on its load-bearing function in engineering applications, has low stress on the cable saddle body. It can be made of low-carbon steel by casting and undergoing normalizing and tempering heat treatment, thereby obtaining a high-quality casting blank that meets the technical requirements of engineering applications and is not prone to cracking. In addition, due to the low carbon equivalent of low-carbon steel, it has good weldability, is easy to repair defects, and is easy to process.

[0042] The base structure of the above-mentioned technical measures forms an integrated triangular support between the crossbeam and the base plate through the supporting stiffeners, which is stable under force and does not interfere with the assembly of the crossbeam to the load-bearing key.

[0043] As one preferred option, the load-bearing key is a forged structure of low-alloy steel or alloy steel. Based on its load-bearing function in engineering applications, this technical measure utilizes low-alloy steel or alloy steel with denser structure and higher strength, forged and tempered, to achieve a surface hardness that meets design requirements. Furthermore, the forged load-bearing key is less prone to cracking, and after overall machining, there is almost no need for defect repair, resulting in excellent quality.

[0044] A method for forming the base structure of the above-mentioned swing-axis type cable saddle, wherein the forming method is to first form the base body and the bearing key separately, and then to insert the bearing key into the corresponding base body by interference fit.

[0045] The molding of the base body includes the following process steps:

[0046] Step 1. According to the design structure of the base body, the base body blank is formed by mold casting using low carbon steel;

[0047] Step 2. The cast base body blank is subjected to normalizing heat treatment and tempering heat treatment in sequence;

[0048] The normalizing heat treatment process is as follows:

[0049] Step ①. When the temperature inside the heat treatment furnace is ≤300℃, place the base body blank into the heat treatment furnace;

[0050] Step ②. Raise the temperature inside the heat treatment furnace to 600-650℃ at a heating rate of ≤80℃ / h, and hold for 2-3 hours;

[0051] Step ③. Raise the temperature inside the heat treatment furnace to 885~915℃ at a heating rate of ≤80℃ / h, hold at that temperature for (δ / 100mm)*4h, and then remove and cool.

[0052] The tempering heat treatment process is as follows:

[0053] Step ①. When the temperature inside the heat treatment furnace is ≤300℃, place the base body blank that has undergone normalizing heat treatment into the heat treatment furnace;

[0054] Step ②. Raise the temperature inside the heat treatment furnace to 590~610℃ at a heating rate of ≤70℃ / h, hold at that temperature for (δ / 100mm)*4h, and then remove and cool.

[0055] Step 3. According to the design structure of the load-bearing key assembly, a concave keyway is precision machined at the top of the crossbeam of the base body blank after tempering heat treatment, so that the dimensional tolerance of the keyway in the width direction matches the interference fit technical requirements of the load-bearing key assembly.

[0056] Step 4. Perform ultrasonic and magnetic particle testing on the machined surfaces of the base body until they pass the inspection;

[0057] The forming of the bearing key includes the following process steps:

[0058] Step A. According to the design structure of the load-bearing key, form the load-bearing key blank by forging using low-alloy steel or alloy steel;

[0059] Step B. According to the design structure of the bearing key, rough machine the forging from Step A to the rough bearing key;

[0060] Step C. Perform ultrasonic and magnetic particle testing on the machined surfaces of the rough-machined key until they pass the test;

[0061] Step D. The rough load-bearing key parts that have passed the flaw detection are subjected to quenching and tempering heat treatment and induction surface hardening treatment in sequence;

[0062] The quenching and tempering heat treatment process is as follows:

[0063] Step ①. When the temperature inside the quenching and tempering furnace is ≤300℃, place the rough key bearing component into the quenching and tempering furnace;

[0064] Step ②. Raise the temperature inside the conditioning furnace to 600-650℃ at a heating rate of ≤80℃ / h, and hold for 2-3 hours;

[0065] Step ③. Raise the temperature in the tempering furnace to 845~875℃ at a heating rate of ≤80℃ / h, hold at that temperature for (δ / 100mm)*4h, and then remove it for thorough water cooling or oil cooling to complete the quenching heat treatment.

[0066] Step 4. When the temperature inside the tempering furnace is ≤300℃, place the rough load-bearing key that has undergone quenching heat treatment into the tempering furnace;

[0067] Step 5. Raise the temperature in the tempering furnace to 550~570℃ at a heating rate of ≤70℃ / h, hold at that temperature for (δ / 100mm)*4h, then remove and cool to complete the tempering heat treatment;

[0068] The induction surface hardening process is as follows:

[0069] Step ①. When the inductor temperature is 140-160℃, place the rough key bearing that has undergone heat treatment into the inductor;

[0070] Step ②. Increase the temperature of the inductor to 640~660℃ at a heating rate of ≤80℃ / h to fully preheat the bearing key rough part;

[0071] Step ③. Raise the inductor temperature to 850~870℃ at a heating rate of ≤80℃ / h, and heat and cool the bearing key rough part with high-pressure water jet to complete the inductor surface hardening treatment.

[0072] Step 4. When the inductor temperature is ≤100℃, place the rough bearing key that has completed the induction surface hardening treatment into the inductor, raise the inductor temperature to 390~410℃ at a heating rate of ≤70℃ / h, hold at the temperature for (δ / 100mm)*4h, and then take it out to cool, thus completing the induction tempering treatment.

[0073] Alternatively, when the temperature inside the heat treatment furnace is ≤100℃, place the rough bearing key that has undergone induction surface hardening into the heat treatment furnace, raise the temperature inside the heat treatment furnace to 390~410℃ at a heating rate of ≤70℃ / h, hold for (δ / 100mm)*4h, and then take it out to cool, thus completing the overall furnace tempering treatment.

[0074] Step E. Perform finishing on the tempered and tempered bearing key rough part to make the dimensional tolerance of the bearing key in the width direction match the interference fit technical requirements of the base body assembly;

[0075] The interference fit of the bearing key on the base body includes the following process steps:

[0076] Step I. Place the carrier bond into liquid nitrogen for uniform cooling and shrinkage;

[0077] Step II. Embed the cooled and shrunken bearing key into the keyway at the top of the crossbeam on the base body;

[0078] If the bearing key is a relatively independent multi-segment, the multi-segment bearing key is embedded into the keyway on the top of the crossbeam of the base body in sequence according to the arrangement position. The fit clearance between two adjacent bearing key segments is ≤0.05mm, which is checked with a feeler gauge.

[0079] Step III. Perform precision machining on the bottom plane of the base body according to the anchoring design structure;

[0080] The top surface of the bearing key on the base body is precision machined into an arc shape according to the design structure of the rolling swing shaft and its relationship with the bottom plane of the base body.

[0081] The aforementioned forming method is designed for the base structure. The base body, characterized by low contact stress, is cast from low-carbon steel and subjected to normalizing and tempering heat treatment. This yields a high-quality cast blank that meets engineering application requirements, is less prone to cracking, has good weldability, and is easy to repair for defects. The load-bearing key, characterized by high contact stress, is forged from denser, higher-strength low-alloy steel or alloy steel and subjected to specific quenching and tempering treatment. This results in a load-bearing key with excellent comprehensive mechanical properties, high surface contact hardness, and meets the design requirements for relative rolling load bearing. Furthermore, the forged load-bearing key is less prone to cracking, and after overall machining, there is almost no need for defect repair, resulting in superior quality.

[0082] The beneficial technical effects of this invention are as follows: Addressing the unique characteristics of the swing-axis cable saddle technology supported by the base support beam, the above-mentioned technical measures combine the base structure into a base body and a bearing key in separate components. The base body used for anchoring does not require high contact hardness tempering treatment, while the bearing key, relative to the rolling support cable saddle body, is formed with high contact hardness tempering treatment. The two components are differentiated according to their functional divisions in engineering applications, ensuring that components with different functions are formed using more suitable materials and processes. Specifically, for the base body with low contact stress, low-carbon steel can be cast and subjected to normalizing and tempering heat treatment, resulting in a high-quality cast blank that meets the technical requirements of engineering applications, is less prone to cracking, has good weldability, and is easy to repair defects. For the bearing key with high contact stress, denser, higher-strength low-alloy steel or alloy steel can be forged and tempered, resulting in a surface hardness that meets the design requirements. Furthermore, the forged bearing key is less prone to cracking, and after overall processing, there is almost no need for defect repair, resulting in excellent quality. In this way, on the one hand, the molding material of the base body can be selected and appropriate heat treatment can be carried out. That is, the base body does not need to form a direct contact fit with the cable saddle body, and therefore does not need to form a high contact hardness on the base body for relative rolling fit. This effectively ensures the molding quality of the base body and avoids crack defects. On the other hand, the molding material of the load-bearing key can be selected and appropriate heat treatment can be carried out. That is, the load-bearing key needs to form a direct relative rolling contact fit with the cable saddle body, and a high contact hardness needs to be formed on the load-bearing key for relative rolling fit, so that the load-bearing key meets the high hardness technical requirements of the contact surface of the direct load-bearing saddle body. Thus, while ensuring molding quality, the molding technical difficulty of the base structure of the swing-axis cable saddle supported by the base support beam is effectively reduced. It is economical and conducive to the vigorous promotion and application of the swing-axis cable saddle supported by the base support beam in suspension bridge structures. Attached Figure Description

[0083] Figure 1 This is an exploded structural diagram of the present invention.

[0084] Figure 2 for Figure 1 The cross-sectional view of the structure after it is assembled into a whole.

[0085] Figure 3 This is another exploded structural diagram of the present invention.

[0086] Figure 4 Normalizing process curve for the base body blank after proper heat treatment.

[0087] Figure 5 A tempering process curve diagram for tempering heat treatment of the base body blank.

[0088] Figure 6 Quenching process curve for tempering heat treatment of rough parts for bearing keys.

[0089] Figure 7 Tempering process curve for heat treatment of load-bearing key rough parts.

[0090] Figure 8 A surface hardening process curve for induction surface hardening of the bearing key rough part.

[0091] Figure 9 A tempering process curve for induction surface hardening of the bearing key rough part.

[0092] The symbols in the diagram mean: 1—base body; 11—base plate; 12—crossbeam; 13—support rib plate; 14—stop; 15—keyway; 16—edge; 2—load-bearing key; 21—key body; 22—load-bearing surface; 23—ventilation groove; 24—wing. Detailed Implementation

[0093] This invention relates to the saddle assembly structure of suspension bridges, specifically a base structure for a pendulum-type cable saddle, and a method for forming this base structure. The main technical solution of this invention will be described in detail below with reference to several embodiments. Embodiment 1 is illustrated in conjunction with the accompanying drawings—that is… Figure 1 , Figure 2 , Figure 4 , Figure 5 , Figure 6 , Figure 7 , Figure 8 and Figure 9 The technical solution of the present invention will be clearly and thoroughly explained; Embodiment 2 is illustrated in conjunction with the accompanying drawings. Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 , Figure 8 and Figure 9 The technical solution of the present invention is clearly and in detail explained; although other embodiments are not shown in separate drawings, their main structure can still be referred to the drawings of Embodiment 1 or Embodiment 4.

[0094] It should be noted that the accompanying drawings of this invention are schematic, and unnecessary details have been simplified to clarify the technical objectives of this invention, so as to avoid obscuring the technical solutions contributed by this invention to the prior art. Furthermore, the terms "approximately" or "basically" used below to refer to quantities or fit relationships mean that reasonable assembly and processing errors are allowed in the industry, and do not literally describe absolute quantities or fit relationships.

[0095] Example 1

[0096] See Figure 1 , Figure 2 , Figure 4 , Figure 5 , Figure 6 , Figure 7 , Figure 8 and Figure 9 As shown, the present invention is a base structure for a swing-axis cable saddle supported by a base support beam, which includes a relatively independently formed base body 1 and a bearing key 2.

[0097] Specifically, the base body 1 is a non-quenched and tempered structure cast from low-carbon steel, comprising a base plate 11, a crossbeam 12, and multiple supporting stiffeners 13. The top view of the base plate 11 is rectangular. The crossbeam 12 is arranged along the length of the base plate 11 at the center of its width, protruding upwards on the base plate 11, and serves as the assembly load-bearing key 2 to support the cable saddle body. The supporting stiffeners 13 are divided into two groups; multiple supporting stiffeners 13 in each group are evenly spaced along the length of the crossbeam 12 between the base plate 11 and the corresponding sides of the crossbeam 12. The outline of the supporting stiffeners 13 is a trapezoidal structure with a narrow top and a wide bottom. In order not to hinder the assembly of the load-bearing key 2 by the crossbeam 12 and the support of the cable saddle body in engineering applications, the top edge of the supporting stiffener 13 is lower than the top edge of the crossbeam 12, forming a height difference. This height difference should match the assembly height of the load-bearing key 2 on the crossbeam 12 to ensure that the saddle bodies supported by the load-bearing key 2 can generate a relative rolling fit that meets the design technical requirements on the top side of the load-bearing key 2 without obstruction. Anchoring holes are provided on the base plate 11 between adjacent supporting stiffeners 13 or on the base plate 11 outside the supporting stiffeners 13.

[0098] On the top side of the crossbeam 12 of the aforementioned base body 1, a keyway 15 with a downwardly concave structure is formed, that is, the keyway 15 is a recessed groove structure on the top side of the crossbeam 12. The depth of the keyway 15 at the top of the crossbeam 12 is greater than 1 / 2 of the maximum height of the bearing key 2 described below. The length of the keyway 15 at the top of the crossbeam 12 is approximately 2m, and the specific dimensions are determined according to the design requirements of the cable saddle in engineering applications.

[0099] At both ends of the aforementioned crossbeam 12 along its length, there is a stop 14 integral with the crossbeam 12, extending upward beyond the width edge 16 of the keyway 15, and the extension height of the stop 14 also meets the following conditions:

[0100] When the bearing key 2 is interference-fitted into the keyway 15 at the top of the crossbeam 12, the end stops 14 at both ends of the crossbeam 12 in the longitudinal direction extend upward beyond the bearing surface 22 of the bearing key 2.

[0101] When the saddle body of the cable saddle is placed on the base structure, the bearing surface 22 of the bearing key 2 between the two end stops 14 of the crossbeam 12 forms a relative rolling fit with the bottom of the saddle body. The two end stops 14 of the crossbeam 12 are located on the outer side of the two transverse ends of the saddle body, and maintain the required distance for relative rolling fit with the corresponding transverse ends of the saddle body.

[0102] The support key 2 is a quenched and tempered structure forged from low-alloy steel. Its lower part has a key body 21 that matches the keyway 15 at the top of the crossbeam 12 in both the width and length directions. Its upper part has wings 24 extending outwards from both sides of the key body 21 in the width direction, giving the entire outline a T-shape. The height of the key body 21 is greater than half the maximum height of the support key 2 and matches the depth of the keyway 15 at the top of the crossbeam 12. The outward width of each wing 24 on each side of the support key 2 matches the width of the corresponding side edge 16 of the keyway 15 at the top of the crossbeam 12. The top surfaces of the two wings 24 and the top surface of the key body 21 of the aforementioned bearing key 2 together constitute the top side surface of the bearing key 2. The top side surface is a raised arc-shaped curved surface structure in the width direction that conforms to the relative rolling of the saddle pendulum axis - that is, a cylindrical structure. The specific curvature parameters are determined in a conventional manner according to the design requirements of the specific saddle. In other words, the top side of the bearing key 2 forms a bearing surface 22 with an arc-shaped curved surface structure to support the saddle body of the saddle during assembly with the base body 1.

[0103] Since the aforementioned bearing key 2 and the keyway 15 on the top of the crossbeam 12 of the base body 1 need to form an interference fit, in order to ensure the reliability of the interference fit and avoid air blocking the interference fit accuracy in the keyway 15, at least one air venting groove 23 with an inner groove type structure is formed at both ends of the bearing key 2 along its length direction. The forming position does not affect the relative rolling bearing of the bearing key 2 on the cable saddle body.

[0104] The aforementioned support key 2, via its lower key body 21, is fitted into the keyway 15 at the top of the crossbeam 12 of the base body 1 using an interference fit in both the width and length directions. During the interference fit process, the air in the keyway 15 is discharged by connecting the inside and outside of the keyway 15 through the air vents 23 at both ends. After the key is properly fitted, the bottom surface of the key body 21 of the support key 2 forms a surface contact fit with the bottom surface of the keyway 15. The wings 24 on both sides of the support key 2 in the width direction also sit on the edges 16 on both sides of the keyway 15 in a surface contact manner. The upper part of the support key 2 extends from the top of the crossbeam 12, and the support surface 22 on the top side of the support key 2 is exposed on the top side of the base body 1.

[0105] The combined base structure described above, when assembled with the cable saddle body, has its connecting groove at the bottom of the saddle body straddling the bearing surface 22 of the bearing key 2. The edges of the connecting groove on both sides in the width direction form a spaced fit with the top side of the support rib plate 13 of the base body 1. The specific structural form of the connecting groove can be found in the prior art disclosed in the background section. This creates a relative rolling fit between the bearing surface 22 of the bearing key 2 and the bottom of the cable saddle body.

[0106] The molding method for the base structure of the aforementioned swing-axis cable saddle is to first mold the base body and the bearing key separately, and then insert the bearing key into the corresponding base body with an interference fit.

[0107] The forming method of the base body includes the following process steps:

[0108] Step 1. According to the design structure of the base body, the base body blank is formed by mold casting using low carbon steel;

[0109] The low-carbon steel material of the cast base body is the same low-carbon steel material used for casting conventional cable saddle bases.

[0110] Step 2. The cast base body blank is subjected to normalizing heat treatment and tempering heat treatment in sequence;

[0111] The specific process of the normalizing heat treatment is as follows:

[0112] Step ①. Place the base body blank into the heat treatment furnace at a temperature of approximately 280℃;

[0113] Step ②. Raise the temperature inside the heat treatment furnace to approximately 630°C at a heating rate of approximately 80°C / h, and hold at that temperature for approximately 2.3 hours;

[0114] Step ③. Raise the temperature inside the heat treatment furnace to approximately 900°C at a heating rate of approximately 80°C / h, hold at this temperature for approximately (δ / 100mm)*4 hours, and then remove and air-cool; the aforementioned letter δ represents the workpiece thickness, the same applies below;

[0115] The specific process of the tempering heat treatment is as follows:

[0116] Step ①. When the temperature inside the heat treatment furnace is about 280℃, place the base body blank that has undergone normalizing heat treatment into the heat treatment furnace;

[0117] Step ②. Raise the temperature inside the heat treatment furnace to about 600°C at a heating rate of about 65°C / h, hold at that temperature for about (δ / 100mm)*4h, and then remove and air cool.

[0118] Step 3. According to the design structure of the load-bearing key assembly, the keyway with an inward concave structure is precision machined at the top of the crossbeam of the base body blank after tempering heat treatment. The corners of the keyway are transitioned with a fillet R so that the dimensional tolerances of the keyway in the width and length directions match the interference fit technical requirements of the load-bearing key assembly.

[0119] Step 4. The machined surfaces of the base body are subjected to ultrasonic and magnetic particle testing until they pass the inspection.

[0120] The forming method of the load-bearing key includes the following process steps:

[0121] Step A. According to the design structure of the load-bearing key, the load-bearing key blank is formed by forging using conventional low-alloy steel;

[0122] Step B. According to the design structure of the load-bearing key, rough machine the forging from Step A to the rough T-type load-bearing key using machining.

[0123] Step C. Perform ultrasonic and magnetic particle testing on the machined surfaces of the rough-machined key until they pass the test;

[0124] Step D. The rough load-bearing key parts that have passed the flaw detection are subjected to quenching and tempering heat treatment and induction surface hardening treatment in sequence;

[0125] The specific process of the quenching and tempering heat treatment is as follows:

[0126] Step ①. When the temperature inside the quenching and tempering furnace is about 280℃, place the rough key bearing component into the quenching and tempering furnace;

[0127] Step ②. Raise the temperature inside the conditioning furnace to approximately 630°C at a heating rate of approximately 60°C / h, and hold at that temperature for approximately 2.3 hours;

[0128] Step ③. Raise the temperature in the tempering furnace to about 860°C at a heating rate of about 60°C / h, hold for about (δ / 100mm)*4h, then remove and thoroughly cool by immersion in cold water to complete the quenching heat treatment.

[0129] Step 4. When the temperature inside the tempering furnace is about 280℃, place the rough load-bearing key that has undergone quenching heat treatment into the tempering furnace;

[0130] Step 5. Raise the temperature inside the tempering furnace to about 560°C at a heating rate of about 60°C / h, hold at that temperature for about (δ / 100mm)*4h, then remove and air cool to complete the tempering heat treatment;

[0131] The specific process of the induction surface hardening treatment is as follows:

[0132] Step ①. When the inductor temperature is approximately 150°C, place the rough key component that has undergone heat treatment into the inductor;

[0133] Step ②. Increase the temperature of the inductor to approximately 650°C at a heating rate of approximately 60°C / h to fully preheat the bearing key rough part;

[0134] Step ③. Raise the temperature of the inductor to about 860°C at a heating rate of about 60°C / h, and heat and cool the rough key bearing part with high-pressure water jet to complete the surface hardening treatment of the inductor.

[0135] Step 4. When the temperature inside the heat treatment furnace is about 90°C, place the rough key bearing that has undergone induction surface hardening into the heat treatment furnace;

[0136] The temperature inside the heat treatment furnace is raised to 400℃ at a heating rate of about 60℃ / h, held at that temperature for about (δ / 100mm)*4h, and then taken out and cooled to complete the overall furnace tempering treatment.

[0137] Step E. The tempered and tempered rough key is precision machined to ensure that the dimensional tolerances of the key in the width and length directions match the interference fit requirements of the base body assembly.

[0138] The interference fit of the bearing key on the base body includes the following process steps:

[0139] Step 1. Place the support key into the cooling tank and slowly pour liquid nitrogen into the cooling tank to ensure that the support key is cooled and shrinks evenly;

[0140] Observe the shrinkage of the carrier bond. When the carrier bond reaches the shrinkage amount required for interference fit, stop the liquid nitrogen supply.

[0141] Step II. Embed the cooled and shrunken bearing key into the keyway at the top of the crossbeam on the base body to complete the base structure assembly;

[0142] Step III. The bottom plane of the base body is precision machined according to the anchoring design structure until it meets the design technical requirements;

[0143] The top surface of the bearing key on the base body is machined into an arc shape according to the design structure of the rolling swing shaft and the bottom plane of the base body, until it meets the design technical requirements.

[0144] Example 2

[0145] The present invention is a base structure for a swing-axis cable saddle supported by a base support beam, which includes a relatively independently formed base body and a load-bearing key.

[0146] Specifically, the base body is a non-quenched and tempered structure cast from low-carbon steel, consisting of a base plate, a crossbeam, and multiple supporting stiffeners. The base plate has a rectangular top view. The crossbeam is arranged along the length of the base plate at its center width, protruding upwards to support the cable saddle body for assembling the load-bearing key. The supporting stiffeners are divided into two groups; multiple supporting stiffeners in each group are evenly spaced along the length of the crossbeam between the corresponding sides of the base plate and the crossbeam. The supporting stiffeners have a triangular structure, narrow at the top and wide at the bottom. To avoid hindering the assembly of the load-bearing key by the crossbeam and the support of the cable saddle body in engineering applications, the top edge of the supporting stiffener is lower than the top edge of the crossbeam, creating a height difference. This height difference should match the assembly height of the load-bearing key on the crossbeam to ensure that the saddle bodies supported by the load-bearing key can achieve a relative rolling fit that meets design requirements on the top side of the load-bearing key without obstruction. Anchoring holes are provided in the base plate between adjacent supporting stiffeners or on the base plate outside the supporting stiffeners.

[0147] The top side of the crossbeam of the aforementioned base body has a downwardly recessed keyway, meaning the keyway is a countersunk groove on the top side of the crossbeam, with the edges of the keyway at the same height. The depth of the keyway at the top of the crossbeam is greater than half the maximum height of the load-bearing key described below. The length of the keyway at the top of the crossbeam is approximately 2m, with the specific dimensions determined according to the design requirements of the cable saddle in the engineering application.

[0148] The bearing key is a quenched and tempered structure forged from alloy steel. Its lower part has a key body that matches the keyway at the top of the crossbeam in both the width and length directions. Its upper part has wings extending outwards from all sides of the key body, giving the entire outline a T-shape. The height of the bearing key body is greater than half the maximum height of the bearing key and matches the depth of the keyway at the top of the crossbeam. The outward width of each wing of the bearing key matches the width of the corresponding side edge of the keyway at the top of the crossbeam. The top surfaces of the two wings and the top surface of the key body together constitute the top side surface of the bearing key. This top side surface is a raised arc-shaped curved surface structure in the width direction, conforming to the relative rolling of the saddle's pendulum axis—that is, a cylindrical structure. The specific curvature parameters are determined conventionally according to the design requirements of the specific saddle. In other words, the top side of the bearing key forms an arc-shaped curved bearing surface to support the saddle body during assembly with the base body.

[0149] Since the aforementioned bearing key and the keyway on the top of the crossbeam of the aforementioned base body need to form an interference fit, in order to ensure the reliability of the interference fit and avoid air blocking the interference fit accuracy in the keyway, at least one air venting groove with an inner groove structure is formed at each of the two end faces of the bearing key in the length direction. The upper end of the air venting groove passes through the corresponding wing. This forming position does not affect the relative rolling bearing of the bearing key on the cable saddle body.

[0150] The aforementioned load-bearing key, via its lower key body, is interference-fitted into the keyway at the top of the crossbeam of the base body in both the width and length directions. During the interference fit, air is expelled from the keyway by air vents at both ends, connecting the inside and outside of the keyway. After fitting, the bottom surface of the load-bearing key body and the bottom surface of the keyway form a surface contact fit. The wings around the load-bearing key also rest on the edges of the keyway in a surface contact manner. The upper part of the load-bearing key extends from the top of the crossbeam, with the load-bearing surface on the top side of the load-bearing key exposed on the top side of the base body.

[0151] The combined base structure described above, when assembled with the cable saddle body, has its connecting groove at the bottom of the saddle body straddling the bearing surface of the bearing key. The edges of the connecting groove on both sides in the width direction form a spaced fit with the top side of the support ribs of the base body. The specific structural form of the connecting groove can be found in the prior art disclosed in the background section. This creates a relative rolling fit between the bearing surface of the bearing key and the bottom of the cable saddle body.

[0152] The molding method for the base structure of the aforementioned swing-axis cable saddle is to first mold the base body and the bearing key separately, and then insert the bearing key into the corresponding base body with an interference fit.

[0153] The forming method of the base body includes the following process steps:

[0154] Step 1. According to the design structure of the base body, the base body blank is formed by mold casting using low carbon steel;

[0155] The low-carbon steel material of the cast base body is the same low-carbon steel material used for casting conventional cable saddle bases.

[0156] Step 2. The cast base body blank is subjected to normalizing heat treatment and tempering heat treatment in sequence;

[0157] The specific process of the normalizing heat treatment is as follows:

[0158] Step ①. Place the base body blank into the heat treatment furnace at a temperature of approximately 290°C;

[0159] Step ②. Raise the temperature inside the heat treatment furnace to approximately 650°C at a heating rate of approximately 70°C / h, and hold at that temperature for approximately 2 hours;

[0160] Step ③. Raise the temperature inside the heat treatment furnace to approximately 915°C at a heating rate of approximately 70°C / h, hold at this temperature for approximately (δ / 100mm)*4 hours, and then remove and air cool.

[0161] The specific process of the tempering heat treatment is as follows:

[0162] Step ①. Place the base body blank that has undergone normalizing heat treatment into the heat treatment furnace at a temperature of approximately 290°C.

[0163] Step ②. Raise the temperature inside the heat treatment furnace to approximately 610°C at a heating rate of approximately 68°C / h, hold at that temperature for approximately (δ / 100mm)*4 hours, and then remove and air-cool.

[0164] Step 3. According to the design structure of the load-bearing key assembly, the keyway with an inward concave structure is precision machined at the top of the crossbeam of the base body blank after tempering heat treatment. The corners of the keyway are transitioned with a fillet R so that the dimensional tolerances of the keyway in the width and length directions match the interference fit technical requirements of the load-bearing key assembly.

[0165] Step 4. The machined surfaces of the base body are subjected to ultrasonic and magnetic particle testing until they pass the inspection.

[0166] The forming method of the load-bearing key includes the following process steps:

[0167] Step A. According to the design structure of the load-bearing key, the load-bearing key blank is formed by forging using conventional alloy steel;

[0168] Step B. According to the design structure of the load-bearing key, rough machine the forging from Step A to the rough T-type load-bearing key using machining.

[0169] Step C. Perform ultrasonic and magnetic particle testing on the machined surfaces of the rough-machined key until they pass the test;

[0170] Step D. The rough load-bearing key parts that have passed the flaw detection are subjected to quenching and tempering heat treatment and induction surface hardening treatment in sequence;

[0171] The specific process of the quenching and tempering heat treatment is as follows:

[0172] Step ①. When the temperature inside the quenching and tempering furnace is approximately 290℃, place the rough key bearing component into the quenching and tempering furnace;

[0173] Step ②. Raise the temperature inside the conditioning furnace to approximately 650°C at a heating rate of approximately 70°C / h, and hold at that temperature for approximately 2 hours;

[0174] Step ③. Raise the temperature in the tempering furnace to about 875°C at a heating rate of about 70°C / h, hold at that temperature for about (δ / 100mm)*4h, then remove it and immerse it in cooling oil for thorough oil cooling to complete the quenching heat treatment.

[0175] Step 4. When the temperature inside the tempering furnace is about 290℃, place the rough load-bearing key that has undergone quenching heat treatment into the tempering furnace;

[0176] Step 5. Raise the temperature inside the tempering furnace to about 570°C at a heating rate of about 70°C / h, hold at that temperature for about (δ / 100mm)*4h, then remove and air-cool to complete the tempering heat treatment;

[0177] The specific process of the induction surface hardening treatment is as follows:

[0178] Step ①. When the inductor temperature is approximately 160℃, place the rough key component that has undergone heat treatment into the inductor;

[0179] Step ②. Increase the temperature of the inductor to approximately 660°C at a heating rate of approximately 70°C / h to fully preheat the bearing key component;

[0180] Step ③. Raise the temperature of the inductor to about 870°C at a heating rate of about 70°C / h, and heat and cool the rough key component with high-pressure water jet to complete the surface hardening treatment of the inductor.

[0181] Step 4. When the inductor temperature is approximately 100°C, place the rough key component that has undergone induction surface hardening into the inductor;

[0182] The inductor temperature was raised to approximately 410°C at a heating rate of approximately 70°C / h, and held at that temperature for approximately (δ / 100mm)*4h before being removed and air-cooled to complete the induction tempering process.

[0183] Step E. The tempered and tempered rough key is precision machined to ensure that the dimensional tolerances of the key in the width and length directions match the interference fit requirements of the base body assembly.

[0184] The interference fit of the bearing key on the base body includes the following process steps:

[0185] Step 1. Place the support key into the cooling tank and spray liquid nitrogen onto the surface of the support key inside the cooling tank to ensure that the support key is cooled and shrinks evenly;

[0186] Observe the shrinkage of the carrier bond. When the carrier bond reaches the shrinkage amount required for interference fit, stop the liquid nitrogen supply.

[0187] Step II. Embed the cooled and shrunken bearing key into the keyway at the top of the crossbeam on the base body to complete the base structure assembly;

[0188] Step III. The bottom plane of the base body is precision machined according to the anchoring design structure until it meets the design technical requirements;

[0189] The top surface of the bearing key on the base body is machined into an arc shape according to the design structure of the rolling swing shaft and the bottom plane of the base body, until it meets the design technical requirements.

[0190] Example 3

[0191] The present invention is a base structure for a swing-axis cable saddle supported by a base support beam, which includes a relatively independently formed base body and a load-bearing key.

[0192] Specifically, the base body is a non-quenched and tempered structure cast from low-carbon steel, consisting of a base plate, a crossbeam, and multiple supporting stiffeners. The base plate has a rectangular top view. The crossbeam is arranged along the length of the base plate at its center width, protruding upwards to support the cable saddle body for assembling the load-bearing key. The supporting stiffeners are divided into two groups; multiple supporting stiffeners in each group are evenly spaced along the length of the crossbeam between the corresponding sides of the base plate and the crossbeam. The supporting stiffeners have a trapezoidal structure, narrow at the top and wide at the bottom. To avoid hindering the assembly of the load-bearing key by the crossbeam and the support of the cable saddle body in engineering applications, the top edge of the supporting stiffener is lower than the top edge of the crossbeam, creating a height difference. This height difference should match the assembly height of the load-bearing key on the crossbeam to ensure that the saddle bodies supported by the load-bearing key can achieve a relative rolling fit that meets design requirements on the top side of the load-bearing key without obstruction. Anchoring holes are provided in the base plate between adjacent supporting stiffeners or on the base plate outside the supporting stiffeners.

[0193] The top side of the crossbeam of the aforementioned base body has a downwardly recessed keyway, i.e., the keyway on the top side of the crossbeam is a recessed groove structure. The depth of the keyway at the top of the crossbeam is greater than 2 / 3 of the maximum height of the load-bearing key described below. The length of the keyway at the top of the crossbeam is approximately 2m, with the specific dimensions determined according to the design requirements of the cable saddle in the engineering application.

[0194] At both ends of the aforementioned crossbeam along its length, there are stop heads integral with the crossbeam, extending upwards beyond the keyway's width edge, and the extension height of the stop heads also meets the following conditions:

[0195] When the following load-bearing key is interference-fitted into the keyway at the top of the crossbeam, the end stops at both ends of the crossbeam in the longitudinal direction extend upward beyond the load-bearing surface of the load-bearing key.

[0196] When the saddle body of the cable saddle is placed on the base structure, the bearing surface of the bearing key between the two ends of the crossbeam forms a relative rolling fit with the bottom of the saddle body. The two ends of the crossbeam are located on the outer side of the two transverse ends of the saddle body, maintaining the required distance for relative rolling fit with the corresponding transverse ends of the saddle body.

[0197] The bearing key is a quenched and tempered structure forged from low alloy steel. Its entire body is a square column structure. The lower part serves as the key body, which matches the keyway at the top of the crossbeam in both the width and length directions. The upper surface forms the top side surface of the bearing key. This top side surface is a raised arc-shaped curved surface structure in the width direction that conforms to the relative rolling of the saddle's pendulum axis - that is, a cylindrical structure. The specific curvature parameters are determined in a conventional manner according to the design requirements of the specific saddle. In other words, the top side of the bearing key forms an arc-shaped curved surface bearing surface to support the saddle body during assembly with the base body.

[0198] Since the aforementioned bearing key and the keyway at the top of the crossbeam of the aforementioned base body need to form an interference fit, in order to ensure the reliability of the interference fit and avoid air blocking the interference fit accuracy in the keyway, at least one air venting groove with an inner groove structure is formed at each of the two end faces of the bearing key in the length direction. The forming position does not affect the relative rolling bearing of the bearing key on the cable saddle body.

[0199] The aforementioned load-bearing key is fitted into the keyway at the top of the crossbeam of the base body via an interference fit in both the width and length directions. The upper load-bearing surface and the keyway form stepped fits at their respective edges in the width direction. The height of these stepped fits should allow for unobstructed relative rolling contact between the load-bearing cable saddle and the upper outer periphery of the key. During the interference fit, air is expelled from the keyway by air vents at both ends, connecting the interior and exterior. After fitting, the bottom surface of the lower key body forms a surface contact with the bottom surface of the keyway, and the upper part of the key extends from the top of the crossbeam, with the load-bearing surface on the top side of the key exposed on the top side of the base body.

[0200] The combined base structure described above, when assembled with the saddle body, has its connecting groove at the bottom of the saddle body straddling the bearing surface of the bearing key. The edges of the connecting groove on both sides in the width direction form a spaced fit with the edge of the keyway of the base body. The specific structural form of the connecting groove can be found in the prior art disclosed in the background section. This creates a relative rolling fit between the bearing surface of the bearing key and the bottom of the saddle body.

[0201] The molding method for the base structure of the aforementioned swing-axis cable saddle is to first mold the base body and the bearing key separately, and then insert the bearing key into the corresponding base body with an interference fit.

[0202] The forming method of the base body includes the following process steps:

[0203] Step 1. According to the design structure of the base body, the base body blank is formed by mold casting using low carbon steel;

[0204] The low-carbon steel material of the cast base body is the same low-carbon steel material used for casting conventional cable saddle bases.

[0205] Step 2. The cast base body blank is subjected to normalizing heat treatment and tempering heat treatment in sequence;

[0206] The specific process of the normalizing heat treatment is as follows:

[0207] Step ①. Place the base body blank into the heat treatment furnace at a temperature of approximately 300℃;

[0208] Step ②. Raise the temperature inside the heat treatment furnace to approximately 640°C at a heating rate of approximately 80°C / h, and hold at that temperature for approximately 2.5 hours;

[0209] Step ③. Raise the temperature inside the heat treatment furnace to approximately 910°C at a heating rate of approximately 80°C / h, hold at that temperature for approximately (δ / 100mm)*4 hours, and then remove and air-cool.

[0210] The specific process of the tempering heat treatment is as follows:

[0211] Step ①. When the temperature inside the heat treatment furnace is about 300℃, place the base body blank that has undergone normalizing heat treatment into the heat treatment furnace;

[0212] Step ②. Raise the temperature inside the heat treatment furnace to approximately 590°C at a heating rate of approximately 70°C / h, hold at this temperature for approximately (δ / 100mm)*4 hours, then remove and air cool.

[0213] Step 3. According to the design structure of the load-bearing key assembly, the keyway with an inward concave structure is precision machined at the top of the crossbeam of the base body blank after tempering heat treatment. The corners of the keyway are transitioned with a fillet R so that the dimensional tolerances of the keyway in the width and length directions match the interference fit technical requirements of the load-bearing key assembly.

[0214] Step 4. The machined surfaces of the base body are subjected to ultrasonic and magnetic particle testing until they pass the inspection.

[0215] The forming method of the load-bearing key includes the following process steps:

[0216] Step A. According to the design structure of the load-bearing key, the load-bearing key blank is formed by forging using conventional low-alloy steel;

[0217] Step B. According to the design structure of the load-bearing key, rough machine the forging from Step A to the rough square column load-bearing key using machining.

[0218] Step C. Perform ultrasonic and magnetic particle testing on the machined surfaces of the rough-machined key until they pass the test;

[0219] Step D. The rough load-bearing key parts that have passed the flaw detection are subjected to quenching and tempering heat treatment and induction surface hardening treatment in sequence;

[0220] The specific process of the quenching and tempering heat treatment is as follows:

[0221] Step ①. When the temperature inside the quenching and tempering furnace is about 300℃, place the rough key bearing component into the quenching and tempering furnace;

[0222] Step ②. Raise the temperature inside the conditioning furnace to approximately 640°C at a heating rate of approximately 80°C / h, and hold at that temperature for approximately 2.5 hours;

[0223] Step ③. Raise the temperature in the tempering furnace to about 850℃ at a heating rate of about 80℃ / h, hold for about (δ / 100mm)*4h, then remove and thoroughly cool by immersion in cold water to complete the quenching heat treatment.

[0224] Step 4. When the temperature inside the tempering furnace is about 300℃, place the rough load-bearing key that has undergone quenching heat treatment into the tempering furnace;

[0225] Step 5. Raise the temperature inside the tempering furnace to about 565°C at a heating rate of about 70°C / h, hold at that temperature for about (δ / 100mm)*4h, then remove and air cool to complete the tempering heat treatment.

[0226] The specific process of the induction surface hardening treatment is as follows:

[0227] Step ①. When the inductor temperature is approximately 155℃, place the rough key bearing that has undergone heat treatment into the inductor;

[0228] Step ②. Increase the temperature of the inductor to approximately 655°C at a heating rate of approximately 80°C / h to fully preheat the bearing key component;

[0229] Step ③. Raise the temperature of the inductor to about 865°C at a heating rate of about 80°C / h, and heat and cool the rough key component with high-pressure water jet to complete the surface hardening treatment of the inductor.

[0230] Step 4. When the temperature inside the heat treatment furnace is about 95°C, place the rough key bearing that has undergone induction surface hardening into the heat treatment furnace;

[0231] The temperature inside the heat treatment furnace is raised to about 405°C at a heating rate of about 70°C / h. After holding at this temperature for about (δ / 100mm)*4h, the furnace is removed and cooled to complete the overall furnace tempering treatment.

[0232] Step E. The tempered and tempered rough key is precision machined to ensure that the dimensional tolerances of the key in the width and length directions match the interference fit requirements of the base body assembly.

[0233] The interference fit of the bearing key on the base body includes the following process steps:

[0234] Step 1. Place the support key into the cooling tank and slowly pour liquid nitrogen into the cooling tank to ensure that the support key is cooled and shrinks evenly;

[0235] Observe the shrinkage of the carrier bond. When the carrier bond reaches the shrinkage amount required for interference fit, stop the liquid nitrogen supply.

[0236] Step II. Embed the cooled and shrunken bearing key into the keyway at the top of the crossbeam on the base body to complete the base structure assembly;

[0237] Step III. The bottom plane of the base body is precision machined according to the anchoring design structure until it meets the design technical requirements;

[0238] The top surface of the bearing key on the base body is machined into an arc shape according to the design structure of the rolling swing shaft and the bottom plane of the base body, until it meets the design technical requirements.

[0239] Example 4

[0240] See Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 , Figure 8 and Figure 9 As shown, the present invention is a base structure for a swing-axis cable saddle supported by a base support beam, which includes a relatively independently formed base body 1 and three relatively independent bearing keys 2.

[0241] Specifically, the base body 1 is a non-quenched and tempered structure cast from low-carbon steel, comprising a base plate 11, a crossbeam 12, and multiple supporting stiffeners 13. The top view of the base plate 11 is rectangular. The crossbeam 12 is arranged along the length of the base plate 11 at the center of its width, protruding upwards on the base plate 11, and serves as the assembly load-bearing key 2 to support the cable saddle body. The supporting stiffeners 13 are divided into two groups; multiple supporting stiffeners 13 in each group are evenly spaced along the length of the crossbeam 12 between the base plate 11 and the corresponding sides of the crossbeam 12. The outline of the supporting stiffeners 13 is a trapezoidal structure with a narrow top and a wide bottom. In order not to hinder the assembly of the load-bearing key 2 by the crossbeam 12 and the support of the cable saddle body in engineering applications, the top edge of the supporting stiffener 13 is lower than the top edge of the crossbeam 12, forming a height difference. This height difference should match the assembly height of the load-bearing key 2 on the crossbeam 12 to ensure that the saddle bodies supported by the load-bearing key 2 can generate a relative rolling fit that meets the design technical requirements on the top side of the load-bearing key 2 without obstruction. Anchoring holes are provided on the base plate 11 between adjacent supporting stiffeners 13 or on the base plate 11 outside the supporting stiffeners 13.

[0242] On the top side of the crossbeam 12 of the aforementioned base body 1, a keyway 15 with a downwardly concave structure is formed, that is, the keyway 15 is a recessed groove structure on the top side of the crossbeam 12. The depth of the keyway 15 at the top of the crossbeam 12 is greater than 1 / 2 of the maximum height of the bearing key 2 described below. The length of the keyway 15 at the top of the crossbeam 12 is approximately 3.6m, and the specific dimensions are determined according to the design requirements of the cable saddle in engineering applications.

[0243] At both ends of the aforementioned crossbeam 12 along its length, there is a stop 14 integral with the crossbeam 12, extending upward beyond the width edge 16 of the keyway 15, and the extension height of the stop 14 also meets the following conditions:

[0244] When the bearing key 2 is interference-fitted into the keyway 15 at the top of the crossbeam 12, the end stops 14 at both ends of the crossbeam 12 in the longitudinal direction extend upward beyond the bearing surface 22 of the bearing key 2.

[0245] When the saddle body of the cable saddle is placed on the base structure, the bearing surface 22 of the bearing key 2 between the two end stops 14 of the crossbeam 12 forms a relative rolling fit with the bottom of the saddle body. The two end stops 14 of the crossbeam 12 are located on the outer side of the two transverse ends of the saddle body, and maintain the required distance for relative rolling fit with the corresponding transverse ends of the saddle body.

[0246] The bearing key 2 consists of three relatively independent segments with the same structure and basically the same size. The length of each segment is about 1 / 3 of the length of the keyway 15 mentioned above, that is, 1.2m.

[0247] Each load-bearing key segment is a quenched and tempered alloy steel forging structure. Its lower part has a key body 21 that matches the keyway 15 at the top of the crossbeam 12 in the width direction, and its upper part has wings 24 extending outwards from both sides of the key body 21 in the width direction. The overall outline is T-shaped. The height of the key body 21 of the load-bearing key segment is greater than half the maximum height of the load-bearing key segment and matches the depth of the keyway 15 at the top of the crossbeam 12. The outward width of each wing 24 of the load-bearing key segment matches the width of the corresponding side edge 16 of the keyway 15 at the top of the crossbeam 12. The top surfaces of the two wings 24 and the top surface of the key body 21 of the aforementioned bearing key segment together constitute the top side surface of the bearing key segment. The top side surface is a raised arc-shaped curved surface structure in the width direction that conforms to the relative rolling of the saddle pendulum axis - that is, a cylindrical structure. The specific curvature parameters are determined in a conventional manner according to the design requirements of the specific saddle. In other words, the top side of the bearing key segment forms a bearing surface 22 with an arc-shaped curved surface structure to support the saddle body of the saddle during assembly with the base body 1.

[0248] Since the aforementioned bearing key segment and the keyway 15 at the top of the crossbeam 12 of the base body 1 need to form an interference fit, in order to ensure the reliability of the interference fit and avoid air blocking the interference fit accuracy in the keyway 15, at least one air venting groove 23 with an inner groove type structure is formed at the outer end face of the two outer bearing key segments in the length direction. The forming position does not affect the relative rolling bearing of the entire bearing key 2 on the cable saddle body.

[0249] Each of the aforementioned load-bearing key segments is fitted into the keyway 15 at the top of the crossbeam 12 of the base body 1 via the lower key body 21 in an interference fit manner. The three load-bearing key segments are sequentially mated within the keyway 15 according to their relative interference fit arrangements. During the interference fit process, the air vents 23 at the outer ends of the two outer load-bearing key segments connect the interior and exterior of the keyway 15, allowing air to be expelled from the keyway 15. The fit clearance between two adjacent load-bearing key segments within the keyway 15 is ≤0.05mm, as verified by a feeler gauge. After being installed in place, the bottom surfaces of the key bodies 21 of the three bearing key segments and the bottom surfaces of the keyways 15 form a surface contact relationship. The wings 24 on both sides of the width direction of each bearing key segment also sit on the edges 16 on both sides of the width direction of the keyway 15 in a surface contact manner. The upper parts of the three bearing key segments extend from the top of the crossbeam 12. The top bearing surfaces of the three bearing key segments are flush and fit together, forming the bearing surface 22 of the bearing cable saddle body. The bearing surface 22 is exposed on the top side of the base body 1.

[0250] The combined base structure described above, when assembled with the cable saddle body, has its connecting groove at the bottom of the saddle body straddling the bearing surface 22 of the three-section combined bearing key 2. The edges of the connecting groove on both sides in the width direction form a spaced fit with the top side of the supporting rib plate 13 of the base body 1. The specific structural form of the connecting groove can be found in the prior art disclosed in the background section. This allows the common bearing surface 22 of the three-section bearing key 2 to form a relative rolling fit with the bottom of the cable saddle body.

[0251] The molding method for the base structure of the above-mentioned swing-axis type cable saddle is to first mold the base body and the three load-bearing key segments separately, and then to sequentially press-fit the three load-bearing key segments onto the corresponding base body.

[0252] The forming method of the base body includes the following process steps:

[0253] Step 1. According to the design structure of the base body, the base body blank is formed by mold casting using low carbon steel;

[0254] The low-carbon steel material of the cast base body is the same low-carbon steel material used for casting conventional cable saddle bases.

[0255] Step 2. The cast base body blank is subjected to normalizing heat treatment and tempering heat treatment in sequence;

[0256] The specific process of the normalizing heat treatment is as follows:

[0257] Step ①. Place the base body blank into the heat treatment furnace at a temperature of approximately 260°C.

[0258] Step ②. Raise the temperature inside the heat treatment furnace to approximately 600°C at a heating rate of approximately 65°C / h, and hold at that temperature for approximately 3 hours;

[0259] Step ③. Raise the temperature inside the heat treatment furnace to approximately 885°C at a heating rate of approximately 65°C / h, hold at that temperature for approximately (δ / 100mm)*4 hours, and then remove and air-cool.

[0260] The specific process of the tempering heat treatment is as follows:

[0261] Step ①. When the temperature inside the heat treatment furnace is about 260℃, place the base body blank that has undergone normalizing heat treatment into the heat treatment furnace;

[0262] Step ②. Raise the temperature inside the heat treatment furnace to approximately 590°C at a heating rate of approximately 60°C / h, hold at that temperature for approximately (δ / 100mm)*4h, then remove and air cool.

[0263] Step 3. According to the design structure of the load-bearing key assembly, the keyway with an inward concave structure is precision machined at the top of the crossbeam of the base body blank after tempering heat treatment. The corners of the keyway are transitioned with a fillet R so that the dimensional tolerances of the keyway in the width and length directions match the interference fit technical requirements of the load-bearing key assembly.

[0264] Step 4. The machined surfaces of the base body are subjected to ultrasonic and magnetic particle testing until they pass the inspection.

[0265] The forming method for the load-bearing key segment includes the following process steps:

[0266] Step A. According to the design structure of the load-bearing key segment, the load-bearing key segment blank is formed by forging using conventional alloy steel;

[0267] Step B. According to the design structure of the load-bearing key segment, rough machine the forging from Step A to the rough T-shaped load-bearing key segment using machining.

[0268] Step C. Perform ultrasonic and magnetic particle testing on the machined surfaces of the bearing key segment rough part until it meets the requirements;

[0269] Step D. The rough parts of the load-bearing key segment that have passed the flaw detection are subjected to quenching and tempering heat treatment and induction surface hardening treatment in sequence;

[0270] The specific process of the quenching and tempering heat treatment is as follows:

[0271] Step ①. When the temperature inside the quenching and tempering furnace is about 260℃, place the rough key segment bearing material into the quenching and tempering furnace;

[0272] Step ②. Raise the temperature inside the conditioning furnace to approximately 600°C at a heating rate of approximately 75°C / h, and hold at that temperature for approximately 3 hours;

[0273] Step ③. Raise the temperature in the tempering furnace to about 845℃ at a heating rate of about 75℃ / h, hold at that temperature for about (δ / 100mm)*4h, then remove it and immerse it in cooling oil for thorough oil cooling to complete the quenching heat treatment.

[0274] Step 4. When the temperature inside the tempering furnace is about 260℃, place the rough load-bearing keyway that has undergone quenching heat treatment into the tempering furnace;

[0275] Step 5. Raise the temperature inside the tempering furnace to about 550°C at a heating rate of about 65°C / h, hold at that temperature for about (δ / 100mm)*4h, then remove and air-cool to complete the tempering heat treatment.

[0276] The specific process of the induction surface hardening treatment is as follows:

[0277] Step ①. When the inductor temperature is approximately 140℃, place the rough key segment bearing material that has undergone quenching and tempering heat treatment into the inductor;

[0278] Step ②. Increase the temperature of the inductor to approximately 640°C at a heating rate of approximately 65°C / h to fully preheat the bearing key segment rough part;

[0279] Step ③. Raise the temperature of the inductor to about 850°C at a heating rate of about 65°C / h, and heat and cool the rough part of the bearing key segment with high-pressure water jet to complete the surface hardening treatment of the inductor.

[0280] Step 4. When the temperature inside the heat treatment furnace is about 85°C, place the rough key bearing that has undergone induction surface hardening into the heat treatment furnace;

[0281] The temperature inside the heat treatment furnace is raised to about 390°C at a heating rate of about 65°C / h. After holding at this temperature for about (δ / 100mm)*4h, the furnace is removed and cooled to complete the overall furnace tempering treatment.

[0282] Step E. The tempered and quenched bearing key segment rough part is precision machined to make the dimensional tolerance of the bearing key segment in the width direction match the interference fit technical requirements of the base body assembly;

[0283] The combined length of the three key segments is matched with the length of the keyway on the base body.

[0284] The interference fit of the three load-bearing key segments on the base body includes the following process steps:

[0285] Step 1. Place the first load-bearing key segment into the cooling tank, and spray liquid nitrogen onto the surface of the load-bearing key segment in the cooling tank to ensure that the load-bearing key segment is cooled and shrinks evenly;

[0286] Observe the shrinkage of the first load-bearing key segment. When the first load-bearing key segment reaches the shrinkage required for interference fit, stop the liquid nitrogen supply.

[0287] Step II. Embed the cooled and shrunken load-bearing key segment into the keyway at the top of the crossbeam on the base body to complete the assembly of the first load-bearing key segment on the base body;

[0288] Repeat steps I and II to complete the assembly of the second load-bearing key segment on the base body. The fit clearance between the first and second load-bearing key segments should be controlled within 0.05mm and checked with a feeler gauge.

[0289] Repeat steps I and II to complete the assembly of the third load-bearing key segment on the base body. The fit clearance between the third load-bearing key segment and the second load-bearing key segment should be controlled within 0.05mm and checked with a feeler gauge.

[0290] Step III. The bottom plane of the base body is precision machined according to the anchoring design structure until it meets the design technical requirements;

[0291] The top surface of the bearing key on the base body is machined into an arc shape according to the design structure of the rolling swing shaft and the bottom plane of the base body, until it meets the design technical requirements.

[0292] The above embodiments are only used to illustrate the present invention and are not intended to limit it.

[0293] Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications can still be made to the above embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the present invention.

Claims

1. A base structure for a swing-axis type cable saddle, comprising a base body (1), wherein the base body (1) has an upwardly protruding crossbeam (12) for supporting the cable saddle body. Its features are: The base body (1) is a non-heat-treated structure; The base structure also includes a load-bearing key (2) with a tempered structure. The load-bearing key (2) is connected to the crossbeam (12) of the base body (1). The load-bearing key (2) is exposed on the top side of the base body (1) with an arc-shaped curved surface structure. The top side of the crossbeam (12) of the base body (1) has a keyway (15) with a downward concave structure. The lower part of the bearing key (2) has a key body (21), which is fitted into the keyway (15) at the top of the crossbeam (12) in an interference fit in the width direction. The upper part of the bearing key (2) extends out from the top of the crossbeam (12). The bearing key (2) has an internal groove-shaped air vent (23) at both ends of its length. The bearing key (2) is interference-fitted into the keyway (15) at the top of the crossbeam (12), and the inside and outside of the keyway (15) are connected by the air dissipation grooves (23) at both ends, so that the air in the keyway (15) is discharged in the interference fit of the bearing key (2); When the saddle body of the cable saddle is placed on the base structure, the bearing surface (22) of the bearing key (2) forms a relative rolling fit with the bottom of the saddle body.

2. The base structure for the pendulum-type cable saddle according to claim 1, characterized in that: The upper part of the bearing key (2) has wings (24) extending outward from both sides of the width direction of the key body (21). The top surface of the wings (24) and the top surface of the key body (21) together form a bearing surface (22) with an arc-shaped curved surface structure. The bearing key (2) is interference-fitted into the keyway (15) at the top of the crossbeam (12), and the wings (24) on both sides of the width direction are respectively located on the edges (16) on both sides of the keyway (15) in a face-to-face manner.

3. The base structure for the pendulum-type cable saddle according to claim 2, characterized in that: The depth of the keyway (15) at the top of the crossbeam (12) is at least 1 / 2 of the maximum height of the bearing key (2); Furthermore, the effective mounting height of the key body (21) of the carrier key (2) is at least 1 / 2 of the maximum height of the carrier key (2); When the bearing key (2) is interference-fitted into the keyway (15) at the top of the crossbeam (12), the bottom surface of the key body (21) of the bearing key (2) and the bottom surface of the keyway (15) form a surface contact fit relationship.

4. The base structure for the pendulum-type cable saddle according to claim 2 or 3, characterized in that: At both ends of the crossbeam (12) in the length direction, there are stop heads (14) that extend upward beyond the keyway (15) in the width direction edge (16). Furthermore, when the bearing key (2) is interference-fitted into the keyway (15) at the top of the crossbeam (12), the end caps (14) at both ends of the crossbeam (12) in the length direction extend upward beyond the bearing surface (22) of the bearing key (2). When the saddle body of the cable saddle is placed on the base structure, the bearing surface (22) of the bearing key (2) between the two end stops (14) of the crossbeam (12) forms a relative rolling fit with the bottom of the saddle body.

5. The base structure for the pendulum-type cable saddle according to claim 2 or 3, characterized in that: The keyway (15) at the top of the crossbeam (12) has a length ≥2m; The bearing key (2) is interference-fitted into the keyway (15) at the top of the crossbeam (12), and is divided into several relatively independent segments in the length direction, with each bearing key segment having a length of 0.5 to 1.5 m; Multiple load-bearing key segments are sequentially mated in the keyway (15) according to their relative arrangement positions, and the mating gap between two adjacent load-bearing key segments is ≤0.05mm.

6. The base structure for the pendulum-type cable saddle according to claim 1, characterized in that: The base body (1) is a cast structure of low carbon steel, with a base plate (11), a crossbeam (12) and multiple supporting stiffeners (13). The bottom plate (11) has a rectangular structure when viewed from above; The crossbeam (12) is arranged along the length of the base plate (11) at the center of the width of the base plate (11); The supporting stiffeners (13) are divided into two groups; multiple supporting stiffeners (13) in each group are arranged at intervals between the bottom plate (11) and the crossbeam (12) along the length direction of the crossbeam (12). The outline of the supporting stiffeners (13) is a triangular or trapezoidal structure with a narrow top and a wide bottom, and the top side of the supporting stiffeners (13) is lower than the top side of the crossbeam (12).

7. The base structure for the pendulum-type cable saddle according to claim 1, 2 or 3, characterized in that: The bearing key (2) is a forged structure of low alloy steel or alloy steel.

8. A method for molding a base structure for a pendulum-type cable saddle as described in any one of claims 1 to 7, characterized in that, The molding method is to first mold the base body and the bearing key separately, and then insert the bearing key into the corresponding base body with an interference fit. The molding of the base body includes the following process steps: Step 1. According to the design structure of the base body, the base body blank is formed by mold casting using low carbon steel; Step 2. The cast base body blank is subjected to normalizing heat treatment and tempering heat treatment in sequence; The normalizing heat treatment process is as follows: Step ①. When the temperature inside the heat treatment furnace is ≤300℃, place the base body blank into the heat treatment furnace; Step ②. Raise the temperature inside the heat treatment furnace to 600-650℃ at a heating rate of ≤80℃ / h, and hold for 2-3 hours; Step ③. Raise the temperature inside the heat treatment furnace to 885~915℃ at a heating rate of ≤80℃ / h, hold at that temperature for (δ / 100mm)*4h, and then remove and cool. The tempering heat treatment process is as follows: Step ①. When the temperature inside the heat treatment furnace is ≤300℃, place the base body blank that has undergone normalizing heat treatment into the heat treatment furnace; Step ②. Raise the temperature inside the heat treatment furnace to 590~610℃ at a heating rate of ≤70℃ / h, hold at that temperature for (δ / 100mm)*4h, and then remove and cool. Step 3. According to the design structure of the load-bearing key assembly, a concave keyway is precision machined at the top of the crossbeam of the base body blank after tempering heat treatment, so that the dimensional tolerance of the keyway in the width direction matches the interference fit technical requirements of the load-bearing key assembly. Step 4. Perform ultrasonic and magnetic particle testing on the machined surfaces of the base body until they pass the inspection; The forming of the bearing key includes the following process steps: Step A. According to the design structure of the load-bearing key, form the load-bearing key blank by forging using low-alloy steel or alloy steel; Step B. According to the design structure of the bearing key, rough machine the forging from Step A to the rough bearing key; Step C. Perform ultrasonic and magnetic particle testing on the machined surfaces of the bearing key rough part until it meets the requirements; Step D. The rough load-bearing key parts that have passed the flaw detection are subjected to quenching and tempering heat treatment and induction surface hardening treatment in sequence; The quenching and tempering heat treatment process is as follows: Step ①. When the temperature inside the quenching and tempering furnace is ≤300℃, place the rough key bearing component into the quenching and tempering furnace; Step ②. Raise the temperature inside the conditioning furnace to 600-650℃ at a heating rate of ≤80℃ / h, and hold for 2-3 hours; Step ③. Raise the temperature in the tempering furnace to 845~875℃ at a heating rate of ≤80℃ / h, hold at that temperature for (δ / 100mm)*4h, and then remove it for thorough water cooling or oil cooling to complete the quenching heat treatment. Step 4. When the temperature inside the tempering furnace is ≤300℃, place the rough load-bearing key that has undergone quenching heat treatment into the tempering furnace; Step 5. Raise the temperature in the tempering furnace to 550~570℃ at a heating rate of ≤70℃ / h, hold at that temperature for (δ / 100mm)*4h, then remove and cool to complete the tempering heat treatment; The induction surface hardening process is as follows: Step ①. When the inductor temperature is 140-160℃, place the rough key bearing that has undergone quenching and tempering heat treatment into the inductor; Step ②. Increase the temperature of the inductor to 640~660℃ at a heating rate of ≤80℃ / h to fully preheat the bearing key rough part; Step ③. Raise the inductor temperature to 850~870℃ at a heating rate of ≤80℃ / h, and heat and cool the bearing key rough part with high-pressure water jet to complete the inductor surface hardening treatment. Step 4. When the inductor temperature is ≤100℃, place the rough bearing key that has completed the induction surface hardening treatment into the inductor, raise the inductor temperature to 390~410℃ at a heating rate of ≤70℃ / h, hold at the temperature for (δ / 100mm)*4h, and then take it out to cool, thus completing the induction tempering treatment. Alternatively, when the temperature inside the heat treatment furnace is ≤100℃, place the rough bearing key that has undergone induction surface hardening into the heat treatment furnace, raise the temperature inside the heat treatment furnace to 390~410℃ at a heating rate of ≤70℃ / h, hold for (δ / 100mm)*4h, and then take it out to cool, thus completing the overall furnace tempering treatment. Step E. Perform finishing on the tempered and tempered bearing key rough part to make the dimensional tolerance of the bearing key in the width direction match the interference fit technical requirements of the base body assembly; The interference fit of the bearing key on the base body includes the following process steps: Step I. Place the carrier bond into liquid nitrogen for uniform cooling and shrinkage; Step II. Embed the cooled and shrunken bearing key into the keyway at the top of the crossbeam on the base body; If the bearing key is a relatively independent multi-segment, the multi-segment bearing key is embedded into the keyway on the top of the crossbeam of the base body in sequence according to the arrangement position. The fit clearance between two adjacent bearing key segments is ≤0.05mm, which is checked with a feeler gauge. Step III. Perform precision machining on the bottom plane of the base body according to the anchoring design structure; The top surface of the bearing key on the base body is precision machined into an arc shape according to the design structure of the rolling swing shaft and its relationship with the bottom plane of the base body.

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