A machine case positioning structure and positioning method

Abstract

The application discloses a machine case positioning structure and a positioning method, wherein the positioning structure comprises a first machine case part and a second machine case part arranged in two parts; a plurality of first through holes are uniformly distributed along the circumference of the first machine case part, and the first through holes penetrate the first machine case part along a first direction; the second machine case part is provided with second through holes with the same aperture at positions corresponding to the first through holes; a positioning bolt is fitted in the gaps between the first through holes and the second through holes; the head of the positioning bolt abuts against the end face of the second machine case; the part of the positioning bolt located in the first through hole and the second through hole is provided as a positioning section; the cross-sectional shape of the positioning section perpendicular to the first direction is an ellipse; the long axis size of the ellipse is 0.005-0.02 mm smaller than the aperture of the first through hole; and the part of the positioning bolt extending out of the first through hole is screw-connected with a nut. The positioning bolt can be used to realize the precise positioning and connection fastening function of the first machine case part and the second machine case part, and the structure is more compact.

Description

Technical Field

[0001] This invention relates to the field of aero-engine technology, specifically to a casing positioning structure and positioning method. Background Technology

[0002] Power-split drive reducers offer advantages such as compact structure, large transmission ratio, high load capacity, and high reliability, and are widely used in aero-engines. To facilitate the assembly of rotating components such as gear shafts, the casing of power-split drive reducers is often a split casing. The first and second casing sections provide bearing mounting holes for the support bearings at both ends of the rotating components such as gear shafts. The installation and positioning accuracy between the first and second casing sections significantly affects the determination of the position of the rotating components such as gear shafts. Most existing split casing positioning structures are as follows... Figure 1 As shown, a cylindrical stop 11 is protruding on the end face of the first housing part 1 facing the second housing part 2, and a cylindrical stop groove 21 is recessed on the end face of the second housing part 2 facing the first housing part 1. The cylindrical stop 11 and the cylindrical stop groove 21 are initially positioned by clearance fit. A positioning pin 3 is provided on the first housing part 1. The end of the positioning pin 3 facing the second housing part 2 is clearance fit in the positioning hole of the second housing part 2 for secondary positioning. Then, the mounting edges of the first housing part 1 and the second housing part 2 are fastened with bolts to transmit the load.

[0003] The aforementioned positioning structure, designed to facilitate the disassembly and assembly of the first and second housings, requires a minimum clearance in the positioning position. This results in poor installation and positioning accuracy, leading to poor coaxiality between the bearing mounting holes of rotating components such as gear shafts and poor bearing seat hole position accuracy. Consequently, this results in poor rotational accuracy of rotating components such as gear shafts, which in turn affects the load-sharing performance and gear pair meshing performance of the multi-branch power split gear train. Consequently, the power split transmission reducer suffers from insufficient load-bearing capacity and transmission performance. Summary of the Invention

[0004] Therefore, the technical problem to be solved by the present invention is to overcome the defects of poor installation positioning accuracy of the positioning structure of the casing in the prior art, which affects the load sharing performance and gear pair meshing performance of the multi-branch power split gear train, resulting in insufficient load-bearing capacity and transmission performance of the power split transmission configuration reducer. Thus, a casing positioning structure and positioning method are provided.

[0005] According to a first aspect of the present invention, a casing positioning structure includes:

[0006] The first casing portion has a plurality of first through holes arranged at intervals along the circumference, and the first through holes penetrate the first casing portion along a first direction;

[0007] The second casing is separately disposed from the first casing. A second through hole is formed through the second casing along a first direction. The second through hole corresponds to the first through hole and is set to have the same diameter.

[0008] A positioning bolt is fitted with a clearance fit in the first and second through holes. The head of the positioning bolt abuts against the end face of the second housing portion away from the first housing portion. The portion of the positioning bolt located in the first and second through holes is configured as a positioning section. The cross-sectional shape of the positioning section perpendicular to the first direction is elliptical, and the major axis of the ellipse is 0.005 mm to 0.02 mm smaller than the diameter of the first through hole.

[0009] The nut is threaded onto the portion of the positioning bolt that extends beyond the first through hole and abuts against the end face of the first housing portion opposite to the second housing portion.

[0010] According to the casing positioning structure of the present invention, at least the following technical effects are achieved:

[0011] By setting the cross-sectional shape of the positioning section perpendicular to the first direction to an ellipse, and the major axis of the ellipse being 0.005 mm to 0.02 mm smaller than the diameter of the first through hole, during the assembly and connection of the first and second housing parts into a single unit, the positioning bolts are sequentially passed through the second and first through holes and extended to the external threaded nut of the first housing part for locking. During the threaded connection of the nut, because the gap between the outer arc surface of the positioning section arranged relative to each other along the major axis of the ellipse and the inner wall of the first and second through holes is always maintained between 0.005 mm and 0.02 mm, the precise positioning of the first and second housing parts is achieved through the cooperation between the positioning section and the first and second through holes, so that the first and second housing parts are connected and fastened into a high-precision integral housing. This positioning structure utilizes positioning bolts on both the first and second housings to achieve precise positioning and fastening of the two housings, resulting in a more streamlined structure. It also ensures the installation and positioning accuracy of the first and second housings, thereby guaranteeing the coaxiality between the bearing mounting holes and the positional accuracy of the bearing housing holes for rotating components such as gear shafts installed within them. This improves the load-sharing performance and gear meshing performance of the multi-branch power split gear train, ensuring that the load-bearing capacity and transmission performance of the power split transmission reducer meet requirements. Furthermore, because the major axis of the ellipse is larger than its minor axis, the clearance between the outer arc surface of the positioning section, arranged along the minor axis of the ellipse, and the inner walls of the first and second through holes is relatively large. This facilitates the installation and removal of the positioning bolts within the first and second through holes, enabling easy assembly and disassembly of the first and second housings, meeting the disassembly and assembly requirements of a split housing.

[0012] Preferably, both the first through hole and the second through hole are connected with sleeves by interference fit. The sleeves are made of high-temperature alloy material. The positioning bolts are fitted with the inner hole of the sleeves by clearance. The major axis of the ellipse is 0.005 mm to 0.02 mm smaller than the diameter of the inner hole of the sleeve.

[0013] Preferably, the sleeve and the positioning bolt are made of the same material, and the sleeve is configured as a steel sleeve;

[0014] And / or, the nut is configured as a self-locking nut;

[0015] And / or, a sealing ring is provided at the abutment of the first casing portion and the second casing portion;

[0016] And / or, a washer is provided at the contact point between the screw head of the positioning bolt and the second housing portion;

[0017] And / or, the minor axis dimension of the ellipse is 0.1 mm to 0.2 mm smaller than the diameter of the inner bore of the sleeve.

[0018] Preferably, the ellipse includes a major axis arc segment, a minor axis arc segment, another major axis arc segment, and a minor axis arc segment connected sequentially along the circumference. The gap between the major axis arc segment and the inner hole of the sleeve is 0.005 mm to 0.02 mm. A tangent oblique segment is provided between the major axis arc segment and the minor axis arc segment. The tangent oblique segment and the minor axis arc segment, as well as the tangent oblique segment and the major axis arc segment, are all connected by an arc transition.

[0019] Preferably, a positioning mounting platform is provided on the outer side wall of the positioning bolt, and the positioning mounting platform forms the screw head of the positioning bolt; the positioning bolt also includes a second external thread, which is coaxially disposed on the end face of the positioning mounting platform opposite to the nut.

[0020] Preferably, one outer wall of the positioning mounting platform is configured as a positioning cut edge, which is arranged parallel to the short axis direction of the positioning segment; during assembly, the positioning cut edge is parallel to the radial direction of the outer circular contour of the second housing portion perpendicular to the first direction.

[0021] Preferably, the second housing portion is recessed with a mounting groove opposite to the end face of the first housing portion. The mounting groove is connected to the second through hole and is used for gap fitting of the positioning mounting platform. The inner wall of the mounting groove is provided with a positioning part. During assembly, the positioning cut edge is parallel to the positioning part.

[0022] Preferably, the positioning bolt has a positioning mounting head coaxially disposed on the end face away from the nut, the positioning mounting head forming the screw head of the positioning bolt, and a positioning mark is disposed on the end face away from the nut, the positioning mark being arranged parallel to the long axis of the positioning segment, and one end of the positioning mark extending through the axis of the positioning mounting head; during assembly, the positioning mark is tangent to the outer circular contour of the second housing portion perpendicular to the first direction.

[0023] Preferably, the width of the major axis arc segment is 50% to 60% of the major axis dimension of the ellipse.

[0024] According to a second aspect of the present invention, a positioning method is provided, in which a split-type casing is positioned and connected using the casing positioning structure provided in the first aspect, the positioning method comprising the following steps:

[0025] Select the corresponding number of positioning bolts and nuts according to the size of the cross-sectional dimensions of the first and second casings perpendicular to the first direction;

[0026] The positioning bolts are inserted one by one into the first and second through holes with a clearance fit, such that the major axis of the ellipse is tangent to the outer circle contour of the second casing part perpendicular to the first direction, and the gap between the arc surface of the positioning section arranged opposite to each other along the major axis of the ellipse and the inner wall of the first through hole is 0.005 mm to 0.02 mm.

[0027] Connect the nut threadedly to the portion of the positioning bolt that extends beyond the first through hole until it abuts against the end face of the first casing that is away from the second casing, and then tighten it.

[0028] According to a positioning method of the present invention, at least the following technical effects are achieved:

[0029] By setting the cross-sectional shape of the positioning section perpendicular to the first direction to an ellipse, and the major axis of the ellipse being 0.005 mm to 0.02 mm smaller than the diameter of the first through hole, during the assembly and connection of the first and second housing parts into a single unit, the positioning bolts are sequentially passed through the second and first through holes and extended to the external threaded nut of the first housing part for locking. During the threaded connection of the nut, because the gap between the outer arc surface of the positioning section arranged relative to each other along the major axis of the ellipse and the inner wall of the first and second through holes is always maintained between 0.005 mm and 0.02 mm, the precise positioning of the first and second housing parts is achieved through the cooperation between the positioning section and the first and second through holes, so that the first and second housing parts are connected and fastened into a high-precision integral housing. This positioning method utilizes positioning bolts on both the first and second housings to achieve precise positioning and fastening of the two housings, simplifying the process. It also ensures the installation and positioning accuracy of the first and second housings, thereby guaranteeing the coaxiality between the bearing mounting holes and the positional accuracy of the bearing housing holes for rotating components such as gear shafts installed within them. This improves the load-sharing performance and gear meshing performance of the multi-branch power split gear train, ensuring that the load-bearing capacity and transmission performance of the power split transmission reducer meet requirements. Furthermore, because the major axis of the ellipse is larger than its minor axis, the clearance between the outer arc surface of the positioning section, arranged along the minor axis of the ellipse, and the inner walls of the first and second through holes is relatively large. This facilitates the installation and removal of the positioning bolts within the first and second through holes, enabling the assembly and disassembly of the first and second housings and meeting the disassembly requirements of a split housing.

[0030] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0031] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0032] Figure 1 A schematic diagram of the existing casing positioning structure;

[0033] Figure 2 This is a schematic diagram of a casing positioning structure according to a first embodiment of the present invention;

[0034] Figure 3 for Figure 2 An exploded view of the positioning bolts and two sleeves in the middle;

[0035] Figure 4 This is a schematic diagram of the assemblies of the positioning section and the sleeve in a casing positioning structure according to an embodiment of the present invention, viewed in cross-section perpendicular to a first direction.

[0036] Figure 5 This is a schematic diagram of the positioning segment in a casing positioning structure according to an embodiment of the present invention, viewed in cross-section perpendicular to a first direction;

[0037] Figure 6 This is a schematic diagram of the positioning bolts in a casing positioning structure according to a first embodiment of the present invention, viewed in cross-section perpendicular to a first direction;

[0038] Figure 7 This is a schematic diagram of the mounting groove in a casing positioning structure according to a first embodiment of the present invention;

[0039] Figure 8 This is a schematic diagram of a casing positioning structure according to a second embodiment of the present invention;

[0040] Figure 9 for Figure 8 An exploded view of the positioning bolts and two sleeves in the middle;

[0041] Figure 10 This is a side view of the positioning bolt in a casing positioning structure according to a second embodiment of the present invention, viewed along a first direction.

[0042] Explanation of reference numerals in the attached figures:

[0043] 1-First casing section, 11-Cylindrical stop, 12-Sealing ring;

[0044] 2-Second casing section, 21-Cylindrical surface stop groove, 22-Mounting groove, 221-Positioning part;

[0045] 3-Positioning pin;

[0046] 4-Positioning bolt, 41-Positioning section, 411-Long axis arc section, 412-Short axis arc section, 413-Tangent oblique section, 42-Positioning mounting table, 421-Positioning cut edge, 43-Second external thread, 44-Positioning mounting head, 441-Positioning mark, 45-First external thread;

[0047] 5-Nuts;

[0048] 6-Sleeve;

[0049] 7-Washer. Detailed Implementation

[0050] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0051] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0052] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0053] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0054] The positioning structure of most existing split-type casings is as follows: Figure 1As shown, the cylindrical surface stop 11 often uses a small clearance fit with the cylindrical surface stop groove 21 to ensure positioning accuracy. However, in order to facilitate the disassembly and assembly of the first housing part 1 and the second housing part 2, the clearance cannot be too small. Therefore, the positioning accuracy of this positioning method is poor. Furthermore, the materials of the first housing part 1 and the second housing part 2 are usually magnesium alloy or aluminum alloy. Magnesium and aluminum alloys have a large coefficient of thermal expansion. At the working temperature, due to the thermal expansion of the materials of the first housing part 1 and the second housing part 2, the actual fit clearance will increase. Since the clearance of the positioning pin 3 is generally relatively large, and the connecting bolts also use a large clearance fit, both are greater than the clearance of the positioning fit section of the cylindrical surface stop 11. Therefore, under the action of working load, the position between the first housing part 1 and the second housing part 2 may shift to a certain extent along the load direction. The amount of shift is the actual clearance value of the stop in the working state, thus affecting the positioning effect between the first housing part 1 and the second housing part 2. In order to address the shortcomings of existing positioning structures in terms of poor installation positioning accuracy for the first housing part 1 and the second housing part 2, a housing positioning structure and positioning method according to the following embodiments are provided.

[0055] Example 1

[0056] like Figures 2 to 7 The diagram shows a casing positioning structure provided in this embodiment, including a first casing portion 1 and a second casing portion 2, which are separately configured. The first casing portion 1 has a plurality of first through holes evenly distributed circumferentially, preferably nine in this case. The first through holes penetrate the first casing portion 1 along a first direction. The second casing portion 2 has a second through hole formed along the first direction, corresponding to the first through holes and having the same diameter. Positioning bolts 4 are fitted into the first and second through holes with clearance, and the screw heads of the positioning bolts 4 abut against the second casing portion 2 away from the first casing portion 1. On the end face of the casing 1, one end of the positioning bolt 4, away from the threaded head, extends to the outside of the first casing 1 and forms a first external thread 45. The portion of the positioning bolt 4 located within the first through hole and the second through hole is configured as a positioning section 41. The cross-sectional shape of the positioning section 41 perpendicular to the first direction is elliptical, and the major axis of the ellipse is 0.005 mm to 0.02 mm smaller than the diameter of the first through hole. A nut 5 is threaded onto the first external thread 45, and the nut 5 abuts against the end face of the first casing 1 away from the second casing 2. It is understood that the first direction mentioned in this embodiment refers to... Figure 2 The first direction in the middle.

[0057] In this embodiment, the housing positioning structure sets the cross-sectional shape of the positioning segment 41 perpendicular to the first direction to an ellipse, and the major axis of the ellipse is 0.005 mm to 0.02 mm smaller than the diameter of the first through hole. During the assembly and connection of the first housing part 1 and the second housing part 2 into a whole, the positioning bolt 4 passes through the second through hole and the first through hole in sequence and extends to the external threaded connection nut 5 of the first housing part 1 for locking connection. During the threaded connection of the nut 5, because the gap between the outer arc surface of the positioning segment 41 arranged relative to each other along the major axis of the ellipse and the inner wall of the first through hole and the second through hole is always maintained between 0.005 mm and 0.02 mm, the precise positioning of the first housing part 1 and the second housing part 2 is achieved through the cooperation relationship between the positioning segment 41 and the first through hole and the second through hole, so that the first housing part 1 and the second housing part 2 are connected and fastened into a whole housing with high positioning accuracy. The positioning structure of this embodiment can achieve precise positioning and connection fastening of the first housing 1 and the second housing 2 using the positioning bolts 4 of the first housing 1 and the second housing 2. The structure is more streamlined and the disassembly and assembly operations are more convenient. It also ensures the installation and positioning accuracy of the first housing 1 and the second housing 2, thereby ensuring the coaxiality between the bearing mounting holes of the rotating parts such as gear shafts installed in the first housing 1 and the second housing 2 and the position accuracy of the bearing mounting holes. This improves the load sharing performance and gear pair meshing performance of the multi-branch power split gear train, and ensures that the load-bearing capacity and transmission performance of the power split transmission configuration reducer meet the requirements. Meanwhile, because the major axis of the ellipse is larger than the minor axis, the gap between the outer arc surface of the positioning section 41, which is arranged relative to the minor axis of the ellipse, and the inner wall of the first and second through holes is relatively large. This facilitates the installation and removal of the positioning bolts 4 in the first and second through holes, thereby improving the convenience of disassembling the first and second housing parts 1 and 2 on the basis of precise positioning and assembly of the first housing part 1 and the second housing part 2. It also has good disassembly and assembly properties, meeting the needs of precise positioning and assembly of split housings and convenient disassembly.

[0058] It should be noted that the major axis direction and minor axis direction mentioned in this embodiment refer to Figure 4 The second and third directions in the process.

[0059] The number of first through holes, second through holes, positioning bolts 4 and nuts 5 is the same. In application, the number of first through holes can be reasonably increased or decreased according to the size of the cross-sectional area of ​​the first housing part 1 or the second housing part 2 perpendicular to the first direction. For example, in other embodiments, the number of first through holes is set to two, three, four, five, six, ten, eleven or other numbers.

[0060] It should be further noted that the casing positioning structure of this embodiment is not limited to power split transmission reducers, but can also be applied to reducers of other aero engines.

[0061] Optionally, the nut 5 is a self-locking nut, which effectively prevents loosening and improves the locking connection effect between the first housing 1 and the second housing 2. Specifically, the nut 5 and the positioning bolt 4 are made of the same material, and the nut 5 is a steel nut. The steel nut and the positioning bolt 4 have the same coefficient of thermal expansion, which ensures that the precision thread fit between the nut 5 and the positioning bolt 4 does not change at operating temperatures, ensuring that the first housing 1 and the second housing 2 maintain a high degree of connection tightness at operating temperatures.

[0062] like Figure 2 and Figure 3 As shown, optionally, a sleeve 6 is interference-fitted into both the first and second through holes. The sleeve 6 is made of high-temperature alloy material, and the positioning bolt 4 is clearance-fitted into the inner hole of the sleeve 6. The major axis dimension of the ellipse is 0.005 mm to 0.02 mm smaller than the diameter of the inner hole of the sleeve 6. By interfering with the high-temperature alloy sleeve 6 in the first and second through holes, the high-temperature alloy sleeve 6 has a smaller coefficient of thermal expansion compared to the aluminum alloy first housing part 1 and second housing part 2. That is, the sleeve 6 has a smaller amount of thermal expansion at the operating temperature of the reducer equipped with the housing positioning structure of this embodiment. This ensures that the precision fit clearance between the sleeve 6 and the positioning section 41 remains basically unchanged at the operating temperature, thus ensuring that the first housing part 1 and the second housing part 2 maintain high positioning accuracy at the operating temperature. Furthermore, the sleeve 6 has a large amount of interference with the first and second through holes, so that the amount of thermal expansion generated by the first housing part 1 and the second housing part 2 at the operating temperature is always less than the amount of interference, thereby ensuring that the sleeve 6 will not fall off safely at the operating temperature. Specifically, the interference fit between the sleeve 6 and the first through hole and the second through hole is determined by calculation based on the operating temperature and the thermal expansion of the material, ensuring that the thermal expansion of the first casing 1 and the second casing 2 at the operating temperature is always less than the interference fit.

[0063] Specifically, the end face of the sleeve 6 along the first direction needs to be slightly lower than the end face of the first housing portion 1 along the first direction and slightly lower than the end face of the second housing portion 2 along the first direction, or the end face of the sleeve 6 along the first direction is flush with the end face of the first housing portion 1 along the first direction and the end face of the second housing portion 2 along the first direction.

[0064] Optionally, the sleeve 6 and the positioning bolt 4 are made of the same material, with the sleeve 6 being a steel sleeve. The steel sleeve and the positioning bolt 4 have the same coefficient of thermal expansion, ensuring that the precision fit between the sleeve 6 and the positioning bolt 4 remains unchanged at operating temperatures, thus ensuring that the first housing 1 and the second housing 2 maintain high positioning accuracy at operating temperatures. The steel sleeve is less prone to deformation and wear, effectively guaranteeing the positioning accuracy of the assembled housing after long-term use, as well as ensuring the positioning accuracy after disassembly and reassembly. This ensures good consistency in positioning accuracy after disassembly and reassembly, avoiding the need for re-inspection due to inconsistent installation positioning accuracy after disassembly and reassembly, reducing labor and costs. Furthermore, when the inner hole of the sleeve 6 is worn or damaged, the sleeve 6 can be directly replaced without replacing the first housing 1 and the second housing 2. Replacing the sleeve 6 still guarantees the positioning accuracy between the first housing 1 and the second housing 2. Specifically, each positioning bolt 4 and the corresponding second through hole are marked or numbered so that during disassembly and reassembly, they can be assembled in their original positions according to the corresponding marks or numbers, which can ensure the consistency of positioning accuracy during disassembly and reassembly.

[0065] Optionally, the minor axis of the ellipse is 0.1 mm to 0.2 mm smaller than the diameter of the inner hole of the sleeve 6, so that the outer arc surface of the positioning section 41 arranged opposite to each other along the minor axis of the ellipse maintains a large gap with the inner wall of the sleeve 6, so as to facilitate assembly and disassembly.

[0066] like Figure 4 and Figure 5 As shown, optionally, the ellipse includes a major axis arc segment 411, a minor axis arc segment 412, a major axis arc segment 411, and a minor axis arc segment 412 connected sequentially along the circumference. The gap between the major axis arc segment 411 and the inner hole of the sleeve 6 is 0.005 mm to 0.02 mm. A tangent oblique segment 413 is provided between the major axis arc segment 411 and the minor axis arc segment 412. The tangent oblique segment 413 and the minor axis arc segment 412, as well as the tangent oblique segment 413 and the major axis arc segment 411, are all connected by arc transitions. By using a tangent oblique section 413 to transition between the long axis arc segment 411 and the short axis arc segment 412, the gap between the connection point of the long axis arc segment 411 and the short axis arc segment 412 and the inner hole of the sleeve 6 is greater than the gap between the long axis arc segment 411 and the inner hole of the sleeve 6. This allows the casing positioning structure of this embodiment to have better disassembly and assembly capabilities, meeting the needs of precise positioning and assembly of split casings as well as convenient disassembly. After assembly, as... Figure 4As shown, the major axis of the positioning section 41 is tangent to the outer circular contour of the second housing 2 perpendicular to the first direction, and the minor axis of the positioning section 41 is arranged radially parallel to the outer circular contour of the second housing 2 perpendicular to the first direction. This ensures that the positioning bolt 4 maintains sufficient positioning contact area with the inner hole of the corresponding sleeve 6 regardless of its circumferential angle position in the second housing 2, thus guaranteeing the positioning effect. Simultaneously, by using arc transitions at the connections between the tangent oblique section 413 and the minor axis arc section 412, and between the tangent oblique section 413 and the major axis arc section 411, it is possible to avoid scratching operators, reduce stress concentration, and improve the structural strength of the positioning section 41. It can be understood that the two major axis arc sections 411 are symmetrically arranged along the major axis of the ellipse, and the two minor axis arc sections 412 are symmetrically arranged along the minor axis of the ellipse.

[0067] like Figure 5 As shown, optionally, the width L of the major axis arc segment 411 is 50% to 60% of the major axis dimension of the ellipse, preferably 55%. Prototype experiments have verified that when the width L of the major axis arc segment 411 is 55% of the major axis dimension of the ellipse, the positioning contact surface between the major axis arc segment 411 and the inner wall of the corresponding sleeve 6 is sufficient and ensures a good positioning effect. In specific applications, the width L of the major axis arc segment 411 can also be 50% or 60% of the major axis dimension of the ellipse.

[0068] like Figure 2 , Figure 5 , Figure 6 and Figure 7 As shown, optionally, a positioning mounting platform 42 protrudes from the outer wall of the positioning bolt 4, and the positioning mounting platform 42 forms the threaded head of the positioning bolt 4; the positioning bolt 4 also includes a second external thread 43, which is coaxially disposed on the end face of the positioning mounting platform 42 opposite to the nut 5. By adding a second external thread 43 to the end of the positioning bolt 4 opposite to the nut 5, it is easier to connect with other housings or other components.

[0069] like Figure 6As shown, optionally, one outer wall of the positioning mounting platform 42 is configured as a positioning cut edge 421, which is arranged parallel to the minor axis direction of the positioning segment 41. During the assembly and connection of the first housing 1 and the second housing 2 into a single unit, by observing the position of the positioning cut edge 421, it is ensured that the positioning cut edge 421 is parallel to the radial direction of the outer circular contour of the second housing 2 perpendicular to the first direction. This ensures that after assembly, the major axis direction of the positioning segment 41 is tangent to the outer circular contour of the second housing 2 perpendicular to the first direction, and the minor axis direction of the positioning segment 41 is arranged parallel to the radial direction of the outer circular contour of the second housing 2 perpendicular to the first direction. This ensures that the positioning bolt 4, regardless of its circumferential angular position in the second housing 2, maintains sufficient positioning contact area with the inner hole of the corresponding sleeve 6, thereby ensuring the positioning effect.

[0070] like Figure 2 and Figure 7 As shown, optionally, the second housing portion 2 is recessed with a mounting groove 22 away from the end face of the first housing portion 1. The mounting groove 22 is connected to the second through hole and is used for the positioning mounting platform 42 to be fitted into the gap. The inner wall of the mounting groove 22 is provided with a positioning part 221. During the process of assembling the first housing portion 1 and the second housing portion 2 into a whole, the positioning part 221 provides a reference benchmark. By observing that the positioning cut edge 421 is parallel to the positioning part 221, it can be ensured that the positioning cut edge 421 is parallel to the radial direction of the outer circle contour of the second housing portion 2 perpendicular to the first direction, which further simplifies the positioning and installation process.

[0071] To improve the sealing effect at the contact point between the first housing part 1 and the second housing part 2, a sealing ring 12 may optionally be provided at the contact point between the first housing part 1 and the second housing part 2.

[0072] Example 2

[0073] like Figures 8 to 10The diagram shows a casing positioning structure provided in this embodiment. The difference between this embodiment and Embodiment 1 lies in the specific structure of the positioning bolt 4. In this embodiment, a positioning mounting head 44 is coaxially arranged on the end face of the positioning bolt 4 away from the nut 5. The positioning mounting head 44 forms the threaded head of the positioning bolt 4. A positioning mark 441 is provided on the end face of the positioning mounting head 44 away from the nut 5. The positioning mark 441 is arranged parallel to the long axis of the positioning segment 41, and one end of the positioning mark 441 extends through the axis of the positioning mounting head 44. When the first casing part 1 and... During the assembly of the second housing 2, the position of the positioning mark 441 is observed to ensure that the positioning mark 441 is tangent to the outer circular contour of the second housing 2 perpendicular to the first direction. This ensures that after assembly, the major axis of the positioning section 41 is tangent to the outer circular contour of the second housing 2 perpendicular to the first direction, and the minor axis of the positioning section 41 is parallel to the radial arrangement of the outer circular contour of the second housing 2 perpendicular to the first direction. This ensures that the positioning bolt 4, regardless of its circumferential angle position in the second housing 2, maintains sufficient positioning contact area with the inner hole of the corresponding sleeve 6, thereby guaranteeing the positioning effect.

[0074] To improve the locking effect of positioning bolt 4, such as Figure 1 As shown, optionally, a washer 7 is provided at the contact point between the screw head of the positioning bolt 4 and the second housing portion 2. Specifically, the washer 7 and the positioning bolt 4 are made of the same material, and the washer 7 is a steel washer. The steel washer and the positioning bolt 4 have the same coefficient of thermal expansion, which can ensure that the tight fit between the washer 7 and the positioning bolt 4 does not change at the operating temperature, ensuring that the first housing portion 1 and the second housing portion 2 maintain a high degree of connection tightness at the operating temperature.

[0075] Example 3

[0076] This embodiment provides a positioning method that uses the casing positioning structure described in Embodiment 1 or Embodiment 2 to position and connect a split casing. The positioning method includes the following steps:

[0077] Select the corresponding number of positioning bolts 4 and nuts 5 according to the size of the cross-sectional dimensions of the first casing 1 and the second casing 2 perpendicular to the first direction;

[0078] The positioning bolts 4 are inserted one by one into the first and second through holes with a clearance fit, such that the major axis of the ellipse is tangent to the outer circle contour of the second casing 2 perpendicular to the first direction, and the gap between the arc surface of the positioning section 41 arranged opposite to each other along the major axis of the ellipse and the inner wall of the first through hole is 0.005 mm to 0.02 mm.

[0079] The nut 5 is threaded onto the portion of the positioning bolt 4 that extends beyond the first through hole until it abuts against the end face of the first casing 1 away from the second casing 2, and is then locked in place.

[0080] The positioning method of this embodiment sets the cross-sectional shape of the positioning segment 41 perpendicular to the first direction to be elliptical, and the major axis of the ellipse is 0.005 mm to 0.02 mm smaller than the diameter of the first through hole. During the assembly and connection of the first housing part 1 and the second housing part 2 into a whole, the positioning bolt 4 passes through the second through hole and the first through hole in sequence and extends to the external threaded connection nut 5 of the first housing part 1 for locking. During the threaded connection of the nut 5, because the gap between the outer arc surface of the positioning segment 41 arranged relative to each other along the major axis of the ellipse and the inner wall of the first through hole and the second through hole is always maintained between 0.005 mm and 0.02 mm, the precise positioning of the first housing part 1 and the second housing part 2 is achieved through the cooperation relationship between the positioning segment 41 and the first through hole and the second through hole, so that the first housing part 1 and the second housing part 2 are connected and fastened into a whole housing with high positioning accuracy. The positioning method of this embodiment utilizes the positioning bolts 4 of the first housing 1 and the second housing 2 to achieve precise positioning and connection fastening of the first housing 1 and the second housing 2. The method is more streamlined and the disassembly and assembly operations are more convenient. It also ensures the installation and positioning accuracy of the first housing 1 and the second housing 2, thereby ensuring the coaxiality between the bearing mounting holes of the rotating components such as gear shafts installed in the first housing 1 and the second housing 2, and the positional accuracy of the bearing mounting holes. This improves the load-sharing performance and gear pair meshing performance of the multi-branch power split gear train, ensuring that the load-bearing capacity and transmission performance of the power split transmission configuration reducer meet the requirements. At the same time, because the major axis of the ellipse is larger than the minor axis, the gap between the outer arc surface of the positioning section 41 arranged relative to each other along the minor axis of the ellipse and the inner wall of the first and second through holes is relatively large. This facilitates the installation and removal of the positioning bolts 4 in the first and second through holes, thereby facilitating the assembly and disassembly of the first housing 1 and the second housing 2, meeting the disassembly and assembly requirements of the split housing.

[0081] Optionally, before inserting the positioning bolts 4 into the first and second through holes one by one with a clearance fit, the following steps are also included:

[0082] A sleeve 6 is interference-fitted in each of the first and second through holes. The sleeve 6 is made of high-temperature alloy material. The interference amount between the sleeve 6 and the first and second through holes is calculated based on the working temperature and the thermal expansion of the material.

[0083] The interference fit determined by calculations based on operating temperature and material thermal expansion ensures that the thermal expansion of the first housing 1 and the second housing 2 at operating temperature is always less than the interference fit between them and the sleeve 6, thus ensuring that the sleeve 6 will not fall off safely at operating temperature. At the same time, the high-temperature alloy sleeve 6 has a smaller coefficient of thermal expansion than the aluminum alloy first housing 1 and the second housing 2, meaning that the thermal expansion of the sleeve 6 at the operating temperature of the reducer is smaller. This ensures that the precision fit clearance between the sleeve 6 and the positioning section 41 remains basically unchanged at operating temperature, thus ensuring that the first housing 1 and the second housing 2 maintain high positioning accuracy at operating temperature.

[0084] Specifically, in the positioning method, a steel sleeve and a steel positioning bolt are selected as the sleeve 6 and the positioning bolt 4.

[0085] By selecting steel as the material for both the sleeve 6 and the positioning bolt 4, they have the same coefficient of thermal expansion. This ensures that the precision fit between the sleeve 6 and the positioning bolt 4 remains unchanged under operating temperatures, guaranteeing that the first housing 1 and the second housing 2 maintain high positioning accuracy even under operating temperatures. The steel sleeve is also resistant to deformation and wear, effectively ensuring the positioning accuracy of the assembled housing after long-term use, as well as the positioning accuracy after disassembly and reassembly. This ensures good consistency in positioning accuracy during disassembly and reassembly, avoiding the need for re-inspection after disassembly and reassembly of the first housing 1 and the second housing 2, thus reducing labor and costs.

[0086] In specific applications, the first housing 1 and the second housing 2 can be precisely positioned and connected into one unit using only the positioning bolts 4 and nuts 5 described in Embodiment 1, or only the positioning bolts 4 and nuts 5 described in Embodiment 2. Alternatively, the positioning bolts 4 described in Embodiment 1 and the positioning bolts 4 and nuts 5 described in Embodiment 2 can be used simultaneously to precisely position and connect the first housing 1 and the second housing 2 into one unit. Furthermore, the positioning bolts 4 described in Embodiment 1 and ordinary bolts and nuts 5 can be used to precisely position and connect the first housing 1 and the second housing 2 into one unit. In some embodiments, the positioning bolts 4 described in Embodiment 2 and ordinary bolts and nuts 5 are used to precisely position and connect the first housing 1 and the second housing 2 into one unit. In some embodiments, the positioning bolts 4 described in Embodiment 1, the positioning bolts 4 described in Embodiment 2, and ordinary bolts and nuts 5 are used to precisely position and connect the first housing 1 and the second housing 2 into one unit.

[0087] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A casing positioning structure, characterized in that, include: The first casing (1) has a plurality of first through holes arranged at intervals along the circumference, and the first through holes penetrate the first casing (1) along the first direction; The second casing (2) is separately disposed from the first casing (1). A second through hole is formed on the second casing (2) along the first direction. The second through hole corresponds to the first through hole and is set to the same diameter. The positioning bolt (4) is clearance-fitted into the first through hole and the second through hole. The screw head of the positioning bolt (4) abuts against the end face of the second housing part (2) away from the first housing part (1). The portion of the positioning bolt (4) located in the first through hole and the second through hole is set as a positioning section (41). The cross-sectional shape of the positioning section (41) perpendicular to the first direction is elliptical. The major axis dimension of the ellipse is 0.005 mm to 0.02 mm smaller than the diameter of the first through hole. The nut (5) is threaded onto the portion of the positioning bolt (4) extending outside the first through hole and abuts against the end face of the first housing portion (1) away from the second housing portion (2).

2. The casing positioning structure according to claim 1, characterized in that, Both the first through hole and the second through hole are connected with sleeves (6) by interference fit. The sleeves (6) are made of high temperature alloy material. The positioning bolts (4) are fitted with the inner hole of the sleeves (6) by clearance. The major axis of the ellipse is 0.005 mm to 0.02 mm smaller than the diameter of the inner hole of the sleeves (6).

3. The casing positioning structure according to claim 2, characterized in that, The sleeve (6) and the positioning bolt (4) are made of the same material, and the sleeve (6) is set as a steel sleeve; And / or, the nut (5) is configured as a self-locking nut; And / or, a sealing ring (12) is provided at the abutment of the first casing part (1) and the second casing part (2); And / or, a washer (7) is provided at the contact point between the screw head of the positioning bolt (4) and the second housing part (2); And / or, the minor axis dimension of the ellipse is 0.1 mm to 0.2 mm smaller than the diameter of the inner hole of the sleeve (6).

4. The casing positioning structure according to claim 2, characterized in that, The ellipse includes a major axis arc segment (411), a minor axis arc segment (412), a major axis arc segment (411), and a minor axis arc segment (412) connected sequentially along the circumference. The gap between the major axis arc segment (411) and the inner hole of the sleeve (6) is 0.005 mm to 0.02 mm. A tangent oblique segment (413) is provided between the major axis arc segment (411) and the minor axis arc segment (412). The tangent oblique segment (413) and the minor axis arc segment (412) are connected by an arc transition.

5. A casing positioning structure according to claim 4, characterized in that, The positioning bolt (4) has a protruding positioning mounting platform (42) on its outer side wall, which forms the screw head of the positioning bolt (4); the positioning bolt (4) also includes a second external thread (43), which is coaxially disposed on the end face of the positioning mounting platform (42) away from the nut (5).

6. A casing positioning structure according to claim 5, characterized in that, One outer wall of the positioning mounting platform (42) is configured as a positioning cut edge (421), which is arranged parallel to the short axis direction of the positioning section (41); during assembly, the positioning cut edge (421) is parallel to the radial direction of the outer circle contour of the second housing part (2) perpendicular to the first direction.

7. A casing positioning structure according to claim 6, characterized in that, The second housing part (2) is recessed with a mounting groove (22) away from the end face of the first housing part (1). The mounting groove (22) is connected to the second through hole and is used for the positioning mounting table (42) to be fitted into the gap. The inner wall of the mounting groove (22) is provided with a positioning part (221). During assembly, the positioning cut edge (421) is parallel to the positioning part (221).

8. A casing positioning structure according to claim 4, characterized in that, The positioning bolt (4) is coaxially provided with a positioning mounting head (44) on the end face away from the nut (5). The positioning mounting head (44) forms the screw head of the positioning bolt (4). The positioning mounting head (44) is provided with a positioning mark (441) on the end face away from the nut (5). The positioning mark (441) is arranged parallel to the long axis of the positioning section (41). One end of the positioning mark (441) extends through the axis of the positioning mounting head (44). During assembly, the positioning mark (441) is tangent to the outer circle contour of the second housing part (2) perpendicular to the first direction.

9. A casing positioning structure according to claim 4, characterized in that, The width of the major axis arc segment (411) is 50% to 60% of the major axis dimension of the ellipse.

10. A positioning method, characterized in that, The housing positioning structure described in any one of claims 1 to 9 is used to position and connect the split housing, and the positioning method includes the following steps: Select the corresponding number of positioning bolts (4) and nuts (5) based on the size of the cross-sectional dimensions of the first casing (1) and the second casing (2) perpendicular to the first direction; The positioning bolts (4) are inserted into the first and second through holes one by one in a clearance fit, such that the major axis of the ellipse is tangent to the outer circle of the second casing (2) perpendicular to the first direction, and the gap between the arc surface of the positioning section (41) arranged along the major axis of the ellipse and the inner wall of the first through hole is 0.005 mm to 0.02 mm. The nut (5) is threaded onto the portion of the positioning bolt (4) extending outside the first through hole until it abuts against the end face of the first casing (1) away from the second casing (2) and is then locked.

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