Internal expansion positioning structure for welding of sun gear hub gear

Abstract

The utility model relates to the technical field of sun gear manufacturing, and discloses a sun gear hub gear welding internal expansion positioning structure, which comprises a positioning component, a positioning component and a positioning component, the positioning component comprises a mounting plate, a positioning part arranged on the mounting plate and a regulation and control part connected to the mounting plate, and the regulation and control part is used for regulating the positioning state of the positioning part; the pressing assembly is arranged outside the positioning assembly and used for pressing the gear hub and positioning the gear hub in the vertical position; and the supporting part is connected to the positioning assembly and the pressing assembly and used for supporting the positioning assembly and the pressing assembly. The positioning part is arranged, in the initial state, the two internal expansion positioning blocks conduct preliminary positioning on the gear hub and support the gear, after the gear hub and the gear are placed, the positioning pressing head is pressed downwards, the positioning pressing head and the internal expansion positioning blocks jointly conduct accurate positioning on the gear hub, the gear is clamped and fixed through the two internal expansion positioning blocks along with downward movement of the positioning pressing head, and the gear is clamped and fixed through the internal expansion positioning blocks. And through size matching among the gear hub, the gear, the positioning pressure head and the internal expansion positioning block, positioning is more accurate.

Description

Technical Field

[0001] The utility model relates to the technical field of sun wheel manufacturing, and more specifically to a sun wheel hub gear welding internal expansion positioning structure. Background Art

[0002] The sun gear is a key component in a mechanical transmission system, usually used in a gearbox or transmission case to transmit power and torque to achieve the transmission of different speeds or torques. In the manufacturing process of some sun gears, the hub and the gear need to be welded together and processed into a sun gear assembly part to meet specific engineering requirements.

[0003] At present, during the welding process of the gear hub and the gear, a center positioning rod is often used to perform axial positioning of the gear hub and the gear. In order to ensure that the gear hub and the gear can be smoothly inserted into the center positioning rod, a gap is left between the gear hub and the gear and the center positioning rod. During the sliding process, the center axis of the center positioning rod, the gear hub and the gear do not coincide, so that the center lines of the finally welded gear hub and the gear do not coincide. This is caused by inaccurate positioning of the gear hub and the gear, resulting in poor welding effect and low quality of the finished product. Utility Model Content

[0004] The utility model provides a sun gear hub gear welding internal expansion positioning structure, which solves the technical problems in the related art of using a central positioning rod to perform axial positioning on the hub and the gear, resulting in inaccurate positioning, poor welding effect and low quality of finished products.

[0005] According to one aspect of the utility model, a sun gear hub gear welding internal expansion positioning structure is provided, comprising:

[0006] The positioning assembly includes a mounting plate, a positioning portion disposed on the mounting plate, and a regulating portion connected to the mounting plate, wherein the regulating portion is used to adjust the positioning state of the positioning portion, the positioning portion includes a positioning axis, and at least two inner expansion positioning blocks are arranged around the positioning axis, and the inner expansion positioning blocks move outward along the center of the positioning axis to position the gear hub in a horizontal position;

[0007] The middle area of ​​the internal expansion positioning block is used to position the gear;

[0008] A pressing assembly is arranged outside the positioning assembly and is used to press the gear hub to position the gear hub in a vertical position;

[0009] The supporting part is connected to the positioning assembly and the pressing assembly and is used to support the positioning assembly and the pressing assembly.

[0010] Preferably, the positioning portion includes two symmetrically arranged internal expansion positioning blocks, each of which has a placement groove, which is used to place the gear, and each of the internal expansion positioning blocks has a first positioning surface, a first support surface, a second positioning surface and a second support surface. The first positioning surface is used to preliminarily position the gear hub, the first support surface is used to support the gear hub, the second positioning surface is used to precisely position the gear, and the second support surface is used to support the gear.

[0011] Preferably, the first positioning surface is located on the outer surface of the inner expansion positioning block, the first supporting surface is located on the top surface of the inner expansion positioning block, the second positioning surface is located on the side wall of the placement groove, and the second supporting surface is located on the bottom surface of the placement groove.

[0012] Preferably, the regulating part includes two guide members connected to the top of the mounting plate and a plurality of lifting members arranged between the two guide members. The two guide members are symmetrically arranged on both sides of the positioning part. The two guide members have an inverted eight-shaped guide block group on one side close to each other. The two inner expansion positioning blocks are provided with guide grooves corresponding to the guide block groups, and the guide grooves on the same side of the two inner expansion positioning blocks correspond to the guide block group of the same guide member.

[0013] Preferably, the guide block group consists of two guide rails fixed on the mounting plate, the guide grooves slide in cooperation with the guide rails, and the internal expansion positioning block is driven by the lifting member to move outward along the center of the positioning axis to position the gear hub horizontally.

[0014] Preferably, the regulating part further comprises a plurality of supporting columns arranged between the two guide members, the plurality of supporting columns are all fixedly mounted on the mounting plate, and the top surfaces of the plurality of supporting columns are on the same horizontal plane.

[0015] Preferably, the clamping assembly includes two symmetrically arranged cylinders connected to the supporting part, a pressure plate fixedly connected to the output ends of the two cylinders, and a positioning pressure head connected to the bottom of the pressure plate, the positioning pressure head having a first through groove extending therethrough, the bottom end of the positioning pressure head having a clamping plate corresponding to the clamping groove of the gear hub, and the pressure plate having a second through groove extending therethrough corresponding to the first through groove.

[0016] Preferably, the clamping assembly further comprises a plurality of symmetrically distributed limiting members, and the plurality of limiting members are all fixedly mounted on the supporting portion.

[0017] Preferably, the clamping assembly further comprises a guide post connected to the bottom surface of the pressing plate, and the guide post is slidably sleeved with the supporting portion.

[0018] The beneficial effects of the utility model are:

[0019] The utility model is provided with a positioning part. In the initial state, the two inner expansion positioning blocks can perform preliminary positioning on the gear hub so that the clamping plate of the positioning pressure head can enter the clamping groove of the gear hub. At the same time, the two inner expansion positioning blocks provide support for the gear. After the gear hub and the gear are placed, the positioning pressure head is pressed down. When the clamping plate of the positioning pressure head is engaged with the clamping groove of the gear hub, the inner expansion positioning blocks and the positioning pressure head jointly perform precise positioning of the gear hub. As the positioning pressure head moves downward, the two inner expansion positioning blocks clamp the gear and precisely position it. Through the dimensional coordination among the gear hub, the gear, the positioning pressure head and the inner expansion positioning blocks, the positioning is more precise, thereby improving the welding effect and the quality of the finished product. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the overall structure of the sun gear hub gear welding internal expansion positioning structure provided by the utility model;

[0021] Figure 2 It is a front and cross-sectional schematic diagram of the sun gear hub gear welding internal expansion positioning structure provided by the utility model;

[0022] Figure 3 It is a side cross-sectional schematic diagram of the sun gear hub gear welding internal expansion positioning structure provided by the utility model after positioning is completed;

[0023] Figure 4 It is a three-dimensional structural schematic diagram of the internal expansion positioning block in the sun gear hub gear welding internal expansion positioning structure provided by the utility model;

[0024] Figure 5 It is a side cross-sectional schematic diagram of a positioning portion in the sun gear hub gear welding internal expansion positioning structure provided by the utility model when it is in a first state;

[0025] Figure 6 It is a side cross-sectional schematic diagram of a positioning portion in the sun gear hub gear welding internal expansion positioning structure provided by the utility model when it is in a first state;

[0026] Figure 7 yes Figure 2 A magnified view of the structure at center A;

[0027] Figure 8 It is a three-dimensional structural schematic diagram of the gear hub provided by the utility model;

[0028] Fig. 9 It is a three-dimensional structural schematic diagram of the gear provided by the utility model;

[0029] Fig.10 It is a three-dimensional structural schematic diagram of a hub gear welding part provided by the utility model.

[0030] In the figure: 1. Positioning assembly; 2. Clamping assembly; 3. Support part; 4. Gear hub; 5. Gear; 6. Positioning axis;

[0031] 100, mounting plate; 110, positioning part; 111, inner expansion positioning block; 1111, clamping plate; 1112, slide plate; 112, placement groove; 113, first positioning surface; 114, first supporting surface; 115, second positioning surface; 116, second supporting surface; 117, guide groove; 120, regulating part; 121, guide member; 1211, guide block group; 1212, guide rail; 122, lifting member; 1221, ejector rod; 1222, spring; 123, support column;

[0032] 200, cylinder; 210, pressure plate; 211, second through slot; 220, positioning pressure head; 221, first through slot; 222, clamping plate; 230, limiting member; 240, guide column. DETAILED DESCRIPTION

[0033] The subject matter described herein will now be discussed with reference to example embodiments. It should be understood that the discussion of these embodiments is to enable those skilled in the art to better understand and implement the subject matter described herein. The functions and arrangements of the elements discussed may be changed without departing from the scope of protection of the present specification. Each example may omit, replace or add various processes or components as needed. In addition, the features described relative to some examples may also be combined in other examples.

[0034] In order to better understand the present invention, Figure 1-Figure 10 The sun gear hub gear welding internal expansion positioning structure of this embodiment is described in detail.

[0035] like Figure 1 , Figure 5 , Figure 6 , Figure 8 , Fig. 9 and Fig.10 As shown, the sun gear hub gear welding internal expansion positioning structure includes:

[0036] The positioning assembly 1 includes a mounting plate 100, a positioning portion 110 disposed on the mounting plate 100, and a regulating portion 120 connected to the mounting plate 100, wherein the regulating portion 120 is used to adjust the positioning state of the positioning portion 110, the positioning portion 110 includes a positioning axis 6, and at least two inner expansion positioning blocks 111 are arranged around the positioning axis 6, and the inner expansion positioning blocks 111 move outward along the center of the positioning axis 6 to position the gear hub 4 in a horizontal position;

[0037] The middle area of ​​the inner expansion positioning block 111 is used to position the gear 5;

[0038] The pressing assembly 2 is arranged outside the positioning assembly 1 and is used to press the gear hub 4 to position the gear hub 4 in a vertical position;

[0039] The supporting portion 3 is connected to the positioning assembly 1 and the pressing assembly 2 , and is used to support the positioning assembly 1 and the pressing assembly 2 .

[0040] In the initial state, the positioning portion 110 is in the first state. At this time, the gear hub 4 and the gear 5 are placed on the positioning portion 110, and the gear hub 4 is located on the outside of the gear 5. The positioning portion 110 preliminarily positions the gear hub 4 and the gear 5. Subsequently, the clamping assembly 2 is pressed down to clamp the gear hub 4, and drives the gear hub 4, the gear 5 and the positioning portion 110 to move downward synchronously. During this process, the regulating portion 120 adjusts the positioning portion 110 to be in the second state. At this time, the clamping assembly 2 and the positioning portion 110 jointly accurately position the gear hub 4, and the positioning portion 110 accurately positions the gear 5.

[0041] like Figure 1 , Figure 4 , Figure 5 and Figure 6 As shown, the positioning portion 110 includes two symmetrically arranged internal expansion positioning blocks 111, each of the internal expansion positioning blocks 111 has a placement groove 112, the placement groove 112 is used to place the gear 5, and the internal expansion positioning blocks 111 have a first positioning surface 113, a first supporting surface 114, a second positioning surface 115 and a second supporting surface 116. The first positioning surface 113 is used to preliminarily position the gear hub 4, the first supporting surface 114 is used to support the gear hub 4, the second positioning surface 115 is used to accurately position the gear 5, and the second supporting surface 116 is used to support the gear 5.

[0042] The first positioning surface 113 is located on the outer surface of the inner expansion positioning block 111 , the first supporting surface 114 is located on the top surface of the inner expansion positioning block 111 , the second positioning surface 115 is located on the side wall of the placement groove 112 , and the second supporting surface 116 is located on the bottom of the placement groove 112 .

[0043] When the positioning portion 110 is in the first state, the two inner expansion positioning blocks 111 are in a separated state. After the gear hub 4 and the gear 5 are placed on the positioning portion 110, the first positioning surface 113 fits with at least a portion of the inner side surface of the gear hub 4, and the gear hub 4 is preliminarily positioned. In the process of the regulating portion 120 adjusting the positioning portion 110 from the first state to the second state, the two inner expansion positioning blocks 111 approach each other, and the first positioning surface 113 separates from the inner side surface of the gear hub 4 until the second positioning surface 115 fits with at least a portion of the outer side surface of the gear 5, and the gear 5 is accurately positioned.

[0044] like Figure 1 , Figure 3 , Figure 4 , Figure 5 and Figure 6 As shown, the regulating part 120 includes two guide members 121 connected to the top of the mounting plate 100, and a plurality of lifting members 122 arranged between the two guide members 121, the two guide members 121 are symmetrically arranged on both sides of the positioning part 110, and the two guide members 121 have an inverted eight-shaped guide block group 1211 on one side close to each other, and the two inner expansion positioning blocks 111 are provided with guide grooves 117 corresponding to the guide block group 1211, and the guide grooves 117 on the same side of the two inner expansion positioning blocks 111 correspond to the guide block group 1211 of the same guide member 121.

[0045] The guide block assembly 1211 is composed of two guide rails 1212, which are fixed on the mounting plate 100. The guide groove 117 slides in cooperation with the guide rail 1212. The inner expansion positioning block 111 is driven by the lifting member 122 to move outward along the center of the positioning axis 6 to position the gear hub 4 in a horizontal position.

[0046] When the gear hub 4 and the gear 5 are not placed, the plurality of lifting members 122 lift up the two inner expansion positioning blocks 111 , and the positioning portion 110 is in the first state.

[0047] In this embodiment, multiple lifting members 122 are symmetrically distributed below the two inner expansion positioning blocks 111. The inner expansion positioning blocks 111 include a clamping plate 1111 and a slide plate 1112. The clamping plate 1111 can be fixedly installed on the top of the slide plate 1112 by fastening bolts. The first positioning surface 113, the first supporting surface 114, the second positioning surface 115 and the second supporting surface 116 are all located on the surface of the clamping plate 1111. The guide groove 117 is opened on the slide plate 1112. The lifting member 122 is configured as a combination of a push rod 1221 and a spring 1222. The push rod 1221 is penetrated into the mounting plate 100, and the push rod 1221 extends out of the top surface of the mounting plate 100. The top end of the spring 1222 is fixedly connected to the bottom end of the push rod 1221, and the bottom end of the spring 1222 is fixedly arranged in the groove of the support part 3 below the mounting plate 100.

[0048] like Figure 1 , Figure 2 and Figure 7 As shown, the regulating portion 120 further includes a plurality of supporting columns 123 disposed between the two guide members 121 . The plurality of supporting columns 123 are all fixedly mounted on the mounting plate 100 , and the top surfaces of the plurality of supporting columns 123 are on the same horizontal plane.

[0049] The clamping assembly 2 is pressed downward to drive the gear hub 4, the gear 5 and the positioning portion 110 to move downward synchronously until the bottom surfaces of the two inner expansion positioning blocks 111 are respectively in contact with the top surfaces of the corresponding support columns 123. At this time, the positioning portion 110 is in the second state, the two inner expansion positioning blocks 111 are at the same height, and the second positioning surfaces 115 of the two clamping plates 1111 are in contact with at least a portion of the outer surface of the gear 5, thereby accurately positioning the gear 5.

[0050] like Figure 1 , Figure 2 and Figure 3 As shown, the clamping assembly 2 includes two symmetrically arranged cylinders 200 connected to the support part 3, a pressure plate 210 fixedly connected to the output ends of the two cylinders 200, and a positioning pressure head 220 connected to the bottom of the pressure plate 210. The positioning pressure head 220 is penetrated by a first through groove 221. The bottom end of the positioning pressure head 220 has a card plate 222 corresponding to the card groove of the gear hub 4, and the pressure plate 210 is penetrated by a second through groove 211 corresponding to the first through groove 221.

[0051] The cylinder 200 drives the pressure plate 210 to move downward, and the positioning pressure head 220 moves downward synchronously with the pressure plate 210 until the clamping plate 222 of the positioning pressure head 220 engages with the clamping groove of the gear hub 4. The positioning pressure head 220 and the internal expansion positioning block 111 jointly accurately position the gear hub 4. The cylinder 200 drives the pressure plate 210 and the positioning pressure head 220 to continue to move downward. The positioning pressure head 220 can push the gear hub 4, the gear 5 and the positioning part 110 to move downward synchronously, so that the two internal expansion positioning blocks 111 clamp the gear 5. After the positioning of the gear hub 4 and the gear 5 is completed, a welding robot can be used to weld the connection between the gear hub 4 and the gear 5 through the first through groove 221 and the second through groove 211. The welding robot can use laser welding to weld the gear hub 4 and the gear 5 together.

[0052] In this embodiment, the output end at the top of the cylinder 200 is fixedly connected to the pressure plate 210 through a connecting piece. The cross-section of the clamping plate 222 is a circular ring. The bottom end of the clamping plate 222 has a rounded corner to facilitate the clamping plate 222 to smoothly enter the clamping groove of the gear hub 4. The first through groove 221 and the second through groove 211 are coaxially arranged, and the first through groove 221 and the second through groove 211 are both inverted truncated cones.

[0053] like Figure 1 As shown, the clamping assembly 2 further includes a plurality of symmetrically distributed limiting members 230 , and the plurality of limiting members 230 are all fixedly mounted on the supporting portion 3 .

[0054] The limiting member 230 can limit the pressing plate 210 to prevent the pressing plate 210 from driving the positioning pressure head 220 to press down excessively, causing the two inner expansion positioning blocks 111 to clamp the gear 5 excessively and damage the gear 5.

[0055] like Figure 1and Figure 2 As shown, the clamping assembly 2 further includes a guide post 240 connected to the bottom surface of the pressing plate 210 , and the guide post 240 is slidably sleeved with the support portion 3 .

[0056] In this embodiment, two guide pillars 240 are provided, and the two guide pillars 240 are symmetrically distributed. A through hole corresponding to the guide pillars 240 is opened on the support part 3. The guide pillars 240 play a guiding role to ensure the stability of the pressing process of the pressing plate 210 and the positioning pressure head 220.

[0057] The present embodiment proposes an internal expansion positioning structure for welding a sun gear hub gear. In an initial state, a plurality of push rods 1221 lift up two internal expansion positioning blocks 111, and two clamping plates 1111 are in a separated state. The gear hub 4 is first placed on the clamping plate 1111, and the first supporting surface 114 of the clamping plate 1111 provides support for the gear hub 4. The first positioning surface 113 of the clamping plate 1111 fits at least a portion of the inner side surface of the gear hub 4 to preliminarily position the gear hub 4. Then, the gear hub 4 is passed through the center hole of the gear hub 4 and placed in the placement groove 112 between the two internal expansion positioning blocks 111, and the first supporting surface 114 of the clamping plate 1111 provides support for the gear 5.

[0058] The output ends of the two cylinders 200 are controlled to shorten synchronously, driving the pressing plate 210 to move downward, and the positioning pressure head 220 moves downward synchronously with the pressing plate 210. When the clamping plate 222 of the positioning pressure head 220 is engaged with the clamping groove of the gear hub 4, the positioning pressure head 220 and the clamping plate 1111 jointly accurately position the gear hub 4. The cylinder 200 drives the pressing plate 210 and the positioning pressure head 220 to continue to move downward, and the positioning pressure head 220 pushes the gear hub 4, the gear 5 and the positioning part 110 to move downward synchronously. During the process, the two slides 1112 push the top rod 1221 downward, the spring 1222 is compressed, and the two slides 1112 approach each other under the action of the guide block group 1211 until the bottom surface of the slide 1112 fits with the top surface of the support column 123, and the two clamps 1111 move synchronously with the two slides 1112 and clamp the gear 5, and the second positioning surface 115 of the clamp 1111 fits with at least a portion of the outer surface of the gear 5 to accurately position the gear 5.

[0059] Subsequently, the gear hub 4 and the gear 5 are welded together through an external welding device. After welding is completed, the output ends of the two cylinders 200 are controlled to extend synchronously, driving the pressure plate 210 to move upward, and the positioning pressure head 220 moves up synchronously with the pressure plate 210 to return to the initial position. During this process, the spring 1222 extends under the action of its own restoring force, pushing the push rod 1221 to move upward, and the push rod 1221 pushes the gear hub 4, the gear 5 and the positioning part 110 to move upward synchronously, and the two slides 1112 move away from each other under the action of the guide block group 1211, and the two clamping plates 1111 move synchronously with the two slides 1112 to release the clamping of the gear 5, remove the gear hub gear welding parts, and then the welding of the next set of gear hub 4 and gear 5 can be carried out.

[0060] The embodiments of the present utility model are described above in conjunction with the accompanying drawings, but the present embodiment is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present embodiment, ordinary technicians in this field can also make many forms without departing from the purpose of the present embodiment and the scope of protection of the claims, all of which are within the protection of the present embodiment.

Claims

1. The sun gear hub gear welding internal expansion positioning structure is characterized by: include: A positioning assembly (1), comprising a mounting plate (100), a positioning portion (110) disposed on the mounting plate (100), and a regulating portion (120) connected to the mounting plate (100), wherein the regulating portion (120) is used to adjust the positioning state of the positioning portion (110), the positioning portion (110) comprising a positioning axis (6), at least two inner expansion positioning blocks (111) arranged around the positioning axis (6), and the inner expansion positioning blocks (111) move outward along the center of the positioning axis (6) to position the gear hub (4) in a horizontal position; The middle area of ​​the inner expansion positioning block (111) is used to position the gear (5); A pressing component (2) is arranged outside the positioning component (1) and is used to press the gear hub (4) to position the gear hub (4) in a vertical position; The support portion (3) is connected to the positioning assembly (1) and the pressing assembly (2), and is used to support the positioning assembly (1) and the pressing assembly (2).

2. The sun gear hub gear welding internal expansion positioning structure according to claim 1, characterized in that: The positioning portion (110) comprises two symmetrically arranged inner expansion positioning blocks (111), each of the inner expansion positioning blocks (111) having a placement groove (112), the placement groove (112) being used to place the gear (5), and each of the inner expansion positioning blocks (111) having a first positioning surface (113), a first supporting surface (114), a second positioning surface (115) and a second supporting surface (116), the first positioning surface (113) being used to perform preliminary positioning of the gear hub (4), the first supporting surface (114) being used to support the gear hub (4), the second positioning surface (115) being used to perform precise positioning of the gear (5), and the second supporting surface (116) being used to support the gear (5).

3. The sun gear hub gear welding internal expansion positioning structure according to claim 2, characterized in that: The first positioning surface (113) is located on the outer surface of the inner expansion positioning block (111), the first supporting surface (114) is located on the top surface of the inner expansion positioning block (111), the second positioning surface (115) is located on the side wall of the placement groove (112), and the second supporting surface (116) is located on the bottom surface of the placement groove (112).

4. The sun gear hub gear welding internal expansion positioning structure according to claim 3, characterized in that: The regulating portion (120) comprises two guide members (121) connected to the top of the mounting plate (100), and a plurality of lifting members (122) arranged between the two guide members (121); the two guide members (121) are symmetrically arranged on both sides of the positioning portion (110); the two guide members (121) have an inverted figure-eight guide block group (1211) on one side close to each other; the two inner expansion positioning blocks (111) are each provided with a guide groove (117) corresponding to the guide block group (1211); and the guide groove (117) on the same side of the two inner expansion positioning blocks (111) corresponds to the guide block group (1211) of the same guide member (121).

5. The sun gear hub gear welding internal expansion positioning structure according to claim 4, characterized in that: The guide block group (1211) is composed of two guide rails (1212), the guide rails (1212) are fixed on the mounting plate (100), the guide grooves (117) slide in cooperation with the guide rails (1212), and the inner expansion positioning block (111) is driven by the lifting member (122) to move outward along the center of the positioning axis (6) to position the gear hub (4) in a horizontal position.

6. The sun gear hub gear welding internal expansion positioning structure according to claim 5, characterized in that: The regulating portion (120) further comprises a plurality of support columns (123) arranged between the two guide members (121); the plurality of support columns (123) are all fixedly mounted on the mounting plate (100), and the top surfaces of the plurality of support columns (123) are on the same horizontal plane.

7. The sun gear hub gear welding internal expansion positioning structure according to claim 6, characterized in that: The clamping assembly (2) comprises two symmetrically arranged cylinders (200) connected to the support portion (3), a pressing plate (210) fixedly connected to the output ends of the two cylinders (200), and a positioning pressing head (220) connected to the bottom of the pressing plate (210), the positioning pressing head (220) having a first through slot (221) passing through it, the bottom end of the positioning pressing head (220) having a clamping plate (222) corresponding to the clamping slot of the gear hub (4), and the pressing plate (210) having a second through slot (211) corresponding to the first through slot (221) passing through it.

8. The sun gear hub gear welding internal expansion positioning structure according to claim 7, characterized in that: The clamping assembly (2) further comprises a plurality of symmetrically distributed limiting members (230), wherein the plurality of limiting members (230) are all fixedly mounted on the supporting portion (3).

9. The sun gear hub gear welding internal expansion positioning structure according to claim 8, characterized in that: The clamping assembly (2) further comprises a guide post (240) connected to the bottom surface of the pressing plate (210), and the guide post (240) is slidably sleeved with the support portion (3).

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