Lower shaft seat comprehensive testing fixture

Abstract

The utility model belongs to the technical field of testing fixture, and relates to a comprehensive testing fixture for lower shaft seat. The utility model discloses a bottom plate, the bottom plate center place is equipped with the anti -interference hole and the positioning hole of intercommunication, three inlay block setting through -holes that distribute along the bottom plate center point annular array are equipped with in the bottom plate, workpiece radial hole detection subassembly for detecting the radial step hole of lower bearing seat is installed in the inlay block setting through -hole. The utility model discloses in the use process, through setting up three workpiece radial hole detection subassembly and three workpiece axial hole detection pieces that distribute along the annular array on the bottom plate, can carry out detection to three radial detection holes and three axial detection holes of lower bearing seat simultaneously, compared with the traditional detection mode one by one, greatly shortens the detection time, improves the detection efficiency, especially applicable to the rapid detection in batch production.

Description

Technical Field

[0001] This utility model belongs to the field of inspection tool technology and relates to a comprehensive inspection tool for a lower shaft seat. Background Technology

[0002] The lower bearing housing of a scroll compressor is a key component, primarily used to support moving parts such as the scroll plate, ensuring structural stability and precision during compression. Its structural design must meet requirements for precise positioning and load-bearing capacity, and it typically works in conjunction with the main bearing housing to improve the overall operating efficiency of the compressor. As a core component supporting moving parts and coordinating lubrication and pressure balance, the lower bearing housing of a scroll compressor must balance positioning accuracy, load-bearing capacity, and system efficiency in its structural design. The radial holes (evenly distributed along the circumference) of the lower bearing housing are core functional holes, primarily connecting the main bearing housing's oil drainage system to the bearing clearance, introducing high-pressure lubricating oil into the friction surface. For example, the oil drainage pipe of the main bearing housing chamber delivers oil to the lower bearing through the radial holes. Another function is pressure balance; by connecting the inner and outer chambers of the bearing housing, it alleviates pressure fluctuations during compressor operation, preventing seal failure or vibration caused by localized high pressure. Typically, the three radial holes are evenly distributed along the circumference at an angle of 120 degrees, and their position and dimensions require high precision. During mass production, it is frequently necessary to check the position and dimensional accuracy of the holes. The three axial holes on the three spokes of the lower bearing housing of the spiral compressor primarily serve a positioning function, helping to achieve precise alignment with the main bearing housing or other components, thus improving assembly accuracy. The position and dimensions of these three axial holes also require high precision. During mass production, it is frequently necessary to check the positional and dimensional accuracy of these three axial holes.

[0003] Traditional inspection methods often employ a single tool to inspect each hole individually. This approach is not only inefficient but also susceptible to human error in achieving accurate results. For instance, using calipers or other general measuring tools is cumbersome, and the accuracy depends heavily on the operator's skill and experience. Furthermore, while coordinate measuring machines (CMMs) offer high precision, their high cost and slow speed make them unsuitable for the rapid inspection needs of mass production. Therefore, there is an urgent need for a tool that can quickly and accurately inspect the position and dimensional accuracy of multiple holes in the lower bearing housing, thereby improving production efficiency and product quality while reducing inspection costs.

[0004] To overcome the shortcomings of existing technologies, people have continuously explored and proposed various solutions. For example, a Chinese patent discloses a gauge for the outer diameter of the lower bearing housing of a scroll compressor [Application No.: 202322100155.X]. This gauge includes a base plate with multiple feet fixed to its bottom surface and three pads fixed to its top surface. These three pads correspond one-to-one with the positions of the three spokes of the lower bearing housing. The top surface of each pad provides support for the outer edge of the spokes. Positioning plates are fixed to two of the pads, and a dial indicator is mounted on the third pad. When the outer diameters of two spokes contact one side of each of the two positioning plates, the dial indicator probe contacts the outer diameter of the other spoke. However, this solution still cannot quickly and accurately perform centralized inspection of the position and dimensional accuracy of multiple holes in the lower bearing housing, resulting in low inspection efficiency. Utility Model Content

[0005] The purpose of this utility model is to address the above-mentioned problems by providing a comprehensive inspection tool for lower shaft seats.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A comprehensive inspection fixture for a lower bearing seat includes a base plate. Interconnected anti-interference holes and positioning holes are formed at the center of the base plate. Three insert mounting through holes are arranged in a circular array along the center point of the base plate. A workpiece radial hole detection assembly for detecting radial stepped holes in the lower bearing seat is installed within each insert mounting through hole. Three workpiece axial detection holes are also arranged in a circular array along the center point of the base plate. Workpiece axial detection elements for detecting axial stepped holes in the lower bearing seat are installed within each workpiece axial hole detection hole. The positions of the workpiece axial hole detection elements correspond to those of the workpiece radial hole detection assembly.

[0008] In the aforementioned lower bearing integrated inspection fixture, the workpiece radial hole detection component includes an insert disposed in the insert placement through hole, the insert being interference-fitted with the insert placement through hole, the insert having a radial detection hole along the radial direction of the base plate, and a radial detection rod inserted into the radial detection hole.

[0009] In the aforementioned lower bearing integrated inspection fixture, the radial inspection rod consists of a first large-diameter end, a first intermediate section, and a first small-diameter end. A step is formed between the first large-diameter end and the first intermediate section, and another step is formed between the first intermediate section and the first small-diameter end. The diameter of the first large-diameter end is larger than the diameter of the first intermediate section, and the diameter of the first intermediate section is larger than the diameter of the first small-diameter end.

[0010] In the aforementioned lower bearing housing integrated inspection fixture, the outer circular surface of the first large diameter end is knurled, the first intermediate section is clearance-fitted with the radial inspection hole in the insert, and the shapes of the first intermediate section and the first small diameter end are adapted to the shape of the radial stepped hole of the lower bearing housing.

[0011] In the aforementioned lower bearing integrated inspection fixture, the insert mounting hole is rectangular, and the insert is made of Cr12MoV material.

[0012] In the aforementioned lower bearing integrated inspection fixture, the workpiece axial hole detection component includes an axial detection rod installed in the workpiece axial detection hole, wherein the axis of the axial detection rod is perpendicular to the axis of the radial detection rod.

[0013] In the aforementioned lower bearing integrated inspection fixture, the axial inspection rod consists of a second large diameter end, a second intermediate section, and a second small diameter end. A step is formed between the second large diameter end and the second intermediate section, and another step is formed between the second intermediate section and the second small diameter end. The diameter of the second large diameter end is larger than the diameter of the second intermediate section, and the diameter of the second intermediate section is larger than the diameter of the second small diameter end.

[0014] In the aforementioned lower bearing housing integrated inspection fixture, the outer circular surface of the second large diameter end is knurled, the second small diameter end is clearance-fitted with the axial inspection hole of the workpiece in the base plate, and the shape of the second intermediate section and the second small diameter end is adapted to the shape of the axial stepped hole of the lower bearing housing.

[0015] In the aforementioned lower bearing integrated inspection fixture, the diameter of the anti-interference hole is smaller than the diameter of the positioning hole, and the anti-interference hole is located below the positioning hole.

[0016] In the aforementioned lower bearing integrated inspection fixture, the base plate is disc-shaped, and three radial inspection rods are evenly distributed along the circumference of the base plate at an angle of 120 degrees, and three axial inspection rods are evenly distributed along the circumference of the base plate at an angle of 120 degrees.

[0017] Compared with existing technologies, the advantages of this utility model are:

[0018] 1. In use, this utility model can simultaneously detect the three radial holes and three axial holes of the lower bearing seat by setting three workpiece radial hole detection components and three workpiece axial hole detection components arranged in a ring array on the base plate. Compared with the traditional method of detecting one by one, it greatly shortens the detection time and improves the detection efficiency, and is especially suitable for rapid detection in mass production.

[0019] 2. The various detection components of the gauge in this utility model are matched with the corresponding hole shapes of the lower bearing seat. By inserting the gauge for detection, it is possible to intuitively and accurately determine whether the size and position of the hole meet the requirements, thereby reducing human measurement errors and improving the stability of detection accuracy.

[0020] 3. Low cost of this utility model: This inspection tool is mainly composed of simple parts such as base plate, insert, and inspection rod. The structural design is simple and clear, without the need for complicated processing technology and expensive materials, resulting in low manufacturing cost. At the same time, it is easy to maintain and repair, reducing the inspection cost investment of enterprises.

[0021] Other advantages, objectives and features of this invention will be partly apparent from the following description, and partly understood by those skilled in the art through study and practice of this invention. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of this utility model.

[0023] Figure 2 This is a cross-sectional schematic diagram of the present invention.

[0024] Figure 3 This is a schematic diagram of the detection status of this utility model.

[0025] Figure 4 This is a cross-sectional view of the detection state of this utility model.

[0026] In the figure: 1. Base plate; 2. Anti-interference hole; 3. Positioning hole; 4. Insert mounting through hole; 5. Workpiece radial hole detection assembly; 6. Workpiece axial detection hole; 7. Workpiece axial hole detection component; 8. Insert; 9. Radial detection rod; 9a. First large diameter end; 9b. First intermediate section; 9c. First small diameter end; 10. Axial detection rod; 10a. Second large diameter end; 10b. Second intermediate section; 10c. Second small diameter end; 100. Lower bearing seat. Detailed Implementation

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

[0028] like Figure 1-4 As shown, a comprehensive inspection fixture for a lower bearing seat includes a base plate 1. An anti-interference hole 2 and a positioning hole 3 are interconnected at the center of the base plate 1. Three insert mounting through holes 4 are arranged in a circular array along the center point of the base plate 1. A workpiece radial hole detection component 5 for detecting the radial stepped holes of the lower bearing seat 100 is installed within the insert mounting through holes 4. Three workpiece axial detection holes 6 are arranged in a circular array along the center point of the base plate 1. Workpiece axial detection elements 7 for detecting the axial stepped holes of the lower bearing seat 100 are installed within the workpiece axial detection holes 6. The positions of the workpiece axial detection elements 7 and the workpiece radial hole detection component 5 correspond to those of the workpiece axial hole detection component 5.

[0029] In this embodiment, the base plate 1 is the basic load-bearing component of the entire inspection fixture. It is disc-shaped. At the center of the base plate 1, there is an anti-interference hole 2 and a positioning hole 3, which are interconnected. The anti-interference hole 2 is located below the positioning hole 3, and the diameter of the anti-interference hole 2 is smaller than the diameter of the positioning hole 3. During inspection, the outer circumferential positioning surface of the large diameter end of the lower bearing seat 100 being tested forms a clearance fit with the positioning hole 3, realizing the initial positioning of the lower bearing seat on the base plate. The anti-interference hole 2 can prevent interference with other parts of the lower bearing seat 100 being tested during the inspection process. Three insert mounting through holes 4 are provided in the base plate 1. These three through holes are distributed in a circular array along the center point of the base plate 1 for installing the workpiece radial hole detection component 5. At the same time, the base plate 1 also has Three workpiece axial detection holes 6 are provided, which are also arranged in a ring array along the center point of the base plate 1 and correspond to the position of the workpiece radial hole detection component 5. The workpiece axial detection component 7 is installed in the workpiece axial detection hole 6 to detect the axial stepped hole of the lower bearing seat 100. The anti-interference hole 2 and the positioning hole 3 at the center cooperate with each other to achieve accurate positioning of the lower bearing seat and avoid detection interference, providing a stable foundation for subsequent detection. The three ring array of inserts are used to house the through hole 4 and the workpiece axial detection hole 6, respectively, and the radial and axial detection components are installed accordingly. This allows for simultaneous detection of the three radial stepped holes and the three axial stepped holes of the lower bearing seat, realizing centralized detection of multiple parts and greatly improving detection efficiency.

[0030] Combination Figure 1-4 As shown, the workpiece radial hole detection assembly 5 includes an insert 8 disposed in the insert placement through hole 4. The insert 8 is interference-fitted with the insert placement through hole 4. The insert 8 has a radial detection hole 8a opened along the radial direction of the base plate 1. A radial detection rod 9 is inserted into the radial detection hole 8a.

[0031] Specifically, the workpiece radial hole detection assembly 5 consists of an insert 8 and a radial detection rod 9. The insert 8 is installed in the insert mounting through hole 4, and the two adopt an interference fit. This fit ensures that the insert 8 remains stable during the detection process and will not be displaced due to the insertion and removal of the detection rod. The insert 8 has a radial detection hole 8a along the radial direction of the base plate 1. The radial detection rod 9 can be inserted into the radial detection hole 8a. The interference fit between the insert 8 and the insert mounting through hole 4 ensures the stable positional accuracy of the radial detection hole 8a and provides precise guidance for the radial detection rod 9. By inserting the radial detection rod 9 into the radial detection hole 8a and the radial stepped hole of the lower bearing seat, the size and position of the radial stepped hole can be quickly determined to be qualified. The structure is simple and the detection is reliable.

[0032] The radial detection rod 9 consists of a first large diameter end 9a, a first intermediate section 9b, and a first small diameter end 9c. A step is formed between the first large diameter end 9a and the first intermediate section 9b, and another step is formed between the first intermediate section 9b and the first small diameter end 9c. The diameter of the first large diameter end 9a is larger than the diameter of the first intermediate section 9b, and the diameter of the first intermediate section 9b is larger than the diameter of the first small diameter end 9c.

[0033] In this embodiment, the three-section stepped structure design is adapted to the shape of the radial stepped hole of the lower bearing seat 100. The sections with different diameters correspond to the parts with different diameters of the radial stepped hole. By checking the fit between each section of the test rod and the corresponding part of the radial stepped hole, the dimensional accuracy of each section of the radial stepped hole can be comprehensively judged. Compared with a test rod with a single diameter, the test is more comprehensive and accurate.

[0034] Combination Figure 2 , Figure 4 As shown, the outer surface of the first large diameter end 9a is knurled, the first intermediate section 9b is clearance-fitted with the radial detection hole 8a in the insert 8, and the shapes of the first intermediate section 9b and the first small diameter end 9c are adapted to the shape of the radial stepped hole of the lower bearing seat 100.

[0035] In this embodiment, the knurling treatment of the first large-diameter end 9a increases the friction when gripping the instrument, making it easier for operators to insert and remove the test rod and improving operational convenience. The clearance fit between the first intermediate section 9b and the radial test hole 8a ensures smooth insertion of the test rod and also guarantees positional accuracy during testing. The first intermediate section 9b and the first small-diameter end 9c, which are adapted to the shape of the radial stepped hole, allow for a direct assessment of whether the size of the radial stepped hole is up to standard by observing whether it can be inserted smoothly and the tightness of the fit after insertion, resulting in accurate and reliable test results.

[0036] The insert 8 has a rectangular through-hole 4 and is made of Cr12MoV material.

[0037] In this embodiment, the rectangular insert with the through hole 4 cooperates with the insert 8. Compared with the circular hole, it can better restrict the circumferential rotation of the insert 8, ensuring the directional accuracy of the radial detection hole 8a is stable. The Cr12MoV material has high hardness, high wear resistance and good heat treatment performance, which makes the insert 8 less prone to wear and deformation during long-term use. It can maintain the dimensional accuracy of the radial detection hole 8a for a long time, extend the service life of the inspection tool and reduce maintenance costs.

[0038] Combination Figure 2 , Figure 4 As shown, the workpiece axial hole detection component 7 includes an axial detection rod 10 installed in the workpiece axial detection hole 6, and the axis of the axial detection rod 10 is perpendicular to the axis of the radial detection rod 9.

[0039] In this embodiment, the axial detection rod 10 is installed in the axial detection hole 6 of the workpiece, which provides stable support and positioning. The design of the axial and radial detection rod axes being perpendicular to each other corresponds to the stepped holes in the axial and radial directions of the lower bearing seat 100, respectively, realizing the detection of holes in different directions. The detection range is more comprehensive and meets the detection requirements of multi-directional holes in the lower bearing seat.

[0040] The axial detection rod 10 is composed of a second large diameter end 10a, a second intermediate section 10b, and a second small diameter end 10c. A step is formed between the second large diameter end 10a and the second intermediate section 10b, and another step is formed between the second intermediate section 10b and the second small diameter end 10c. The diameter of the second large diameter end 10a is larger than the diameter of the second intermediate section 10b, and the diameter of the second intermediate section 10b is larger than the diameter of the second small diameter end 10c.

[0041] In this embodiment, the three-section stepped structure is adapted to the shape of the axial stepped hole of the lower bearing seat 100. The segments with different diameters correspond to the parts with different diameters of the axial stepped hole, which can comprehensively detect the dimensional accuracy of each segment of the axial stepped hole and ensure that the machining quality of the axial stepped hole meets the requirements.

[0042] Combination Figure 1-4 As shown, the outer surface of the second large diameter end 10a is knurled, the second small diameter end 10c is clearance-fitted with the workpiece axial detection hole 6 in the base plate 1, and the shapes of the second intermediate section 10b and the second small diameter end 10c are adapted to the shape of the axial stepped hole of the lower bearing seat 100.

[0043] In this embodiment, the knurling of the second large diameter end 10a makes it easier for operators to hold and insert / remove the probe, improving operational convenience. The clearance fit between the second small diameter end 10c and the axial detection hole 6 of the workpiece ensures smooth insertion and positional accuracy of the axial detection rod. The second intermediate section 10b and the second small diameter end 10c are compatible with the shape of the axial stepped hole. The insertion status can be used to visually determine whether the size of the axial stepped hole is qualified, making the detection accurate and efficient.

[0044] Combination Figure 1-2 As shown, the diameter of the anti-interference hole 2 is smaller than the diameter of the positioning hole 3, and the anti-interference hole 2 is located below the positioning hole 3.

[0045] In this embodiment, the positioning hole 3 is used to cooperate with the outer circle positioning surface of the large diameter end of the lower bearing seat 100 to achieve positioning. The relatively large diameter can better accommodate the positioning surface. The anti-interference hole 2 has a smaller diameter and is located at the bottom. It can provide space for the protruding part below the lower bearing seat 100 without affecting the positioning function, avoid collision and interference with the base plate 1 during testing, and ensure the smooth progress of the testing process.

[0046] Combination Figure 1-2As shown, the base plate 1 is disc-shaped, with three radial detection rods 9 evenly distributed along the circumference of the base plate 1 at an angle of 120 degrees, and three axial detection rods 10 evenly distributed along the circumference of the base plate 1 at an angle of 120 degrees.

[0047] In this embodiment, the disc-shaped base plate 1 facilitates the processing and installation of the detection components. The structure is symmetrical and stable. The three radial detection rods and the three axial detection rods are evenly distributed at 120 degrees, corresponding to the positions of the radial and axial stepped holes evenly distributed on the lower bearing seat 100. This enables symmetrical and comprehensive detection of the lower bearing seat, ensuring the uniformity and accuracy of the detection, and avoiding missed detections or misjudgments caused by uneven distribution of detection points.

[0048] The working principle of this utility model is as follows:

[0049] The bearing housing 100 to be tested is placed on the base plate 1, with the outer circumferential positioning surface of the large diameter end of the bearing housing 100 in clearance fit with the positioning hole 3 on the base plate 1. Simultaneously, the three small planes at the distal ends of the three spokes of the bearing housing 100 are made to fit against the upper plane of the base plate 1, thus completing the positioning of the bearing housing on the fixture. The anti-interference hole 2 prevents interference with the bearing housing 100. During testing, first insert one axial detection rod 10 into the corresponding axial detection hole 6 on the bearing housing 100 and the base plate 1, then insert the other two axial detection rods 10 and three radial detection rods 9. If all the detection rods can... If all the test bars are successfully inserted, it indicates that the positions and dimensions of the three axial test holes and three radial test holes of the lower bearing housing 100 meet the design requirements, meaning the tested lower bearing housing 100 is qualified. If any test bar cannot be inserted smoothly, or if there is obvious looseness or excessive gap after insertion, it indicates that the position or size of the corresponding hole is deviated, and the tested lower bearing housing 100 is unqualified. This working principle of judging the quality of parts based on the matching insertion of test bars and holes is simple, direct, and highly efficient. It can quickly and accurately inspect the quality of the lower bearing housing, providing strong support for quality control in the production process.

[0050] The specific embodiments described herein are merely illustrative examples illustrating the spirit of this utility model. Those skilled in the art to which this utility model pertains may make various modifications or additions to the described specific embodiments or use similar methods to replace them, without departing from the spirit of this utility model.

[0051] Although this document frequently uses terms such as base plate 1, anti-interference hole 2, positioning hole 3, insert mounting through hole 4, workpiece radial hole detection assembly 5, workpiece axial detection hole 6, workpiece axial hole detection component 7, insert 8, radial detection rod 9, first large diameter end 9a, first intermediate section 9b, first small diameter end 9c, axial detection rod 10, second large diameter end 10a, second intermediate section 10b, second small diameter end 10c, and lower bearing seat 100, the possibility of using other terms is not excluded. The use of these terms is merely for the convenience of describing and explaining the essence of this utility model; interpreting them as any additional limitation would contradict the spirit of this utility model.

Claims

1. A comprehensive inspection fixture for a lower shaft seat, comprising a base plate (1), characterized in that, The base plate (1) has an interconnected anti-interference hole (2) and a positioning hole (3) at its center. The base plate (1) has three insert mounting through holes (4) arranged in a ring array along the center point of the base plate (1). The insert mounting through holes (4) are equipped with a workpiece radial hole detection component (5) for detecting the radial step hole of the lower bearing seat (100). The base plate (1) has three workpiece axial detection holes (6) arranged in a ring array along the center point of the base plate (1). The workpiece axial detection holes (6) are equipped with a workpiece axial hole detection component (7) for detecting the axial step hole of the lower bearing seat (100). The workpiece axial hole detection component (7) is positioned corresponding to the workpiece radial hole detection component (5).

2. The lower shaft seat integrated inspection fixture according to claim 1, characterized in that, The workpiece radial hole detection assembly (5) includes an insert (8) disposed in the insert placement through hole (4). The insert (8) is interference-fitted with the insert placement through hole (4). The insert (8) has a radial detection hole (8a) along the radial direction of the base plate (1). A radial detection rod (9) is inserted into the radial detection hole (8a).

3. The lower shaft seat integrated inspection fixture according to claim 2, characterized in that, The radial detection rod (9) consists of a first large diameter end (9a), a first intermediate section (9b) and a first small diameter end (9c). A step is formed between the first large diameter end (9a) and the first intermediate section (9b), and another step is formed between the first intermediate section (9b) and the first small diameter end (9c). The diameter of the first large diameter end (9a) is larger than the diameter of the first intermediate section (9b), and the diameter of the first intermediate section (9b) is larger than the diameter of the first small diameter end (9c).

4. The lower shaft seat integrated inspection fixture according to claim 3, characterized in that, The outer surface of the first large diameter end (9a) is knurled, the first intermediate section (9b) is clearance-fitted with the radial detection hole (8a) in the insert (8), and the shapes of the first intermediate section (9b) and the first small diameter end (9c) are adapted to the shape of the radial stepped hole of the lower bearing seat (100).

5. The lower shaft seat integrated inspection fixture according to any one of claims 2-4, characterized in that, The insert has a rectangular through hole (4) and the insert (8) is made of Cr12MoV material.

6. The lower shaft seat integrated inspection fixture according to claim 2, characterized in that, The workpiece axial hole detection component (7) includes an axial detection rod (10) installed in the workpiece axial detection hole (6), and the axis of the axial detection rod (10) is perpendicular to the axis of the radial detection rod (9).

7. The lower shaft seat integrated inspection fixture according to claim 6, characterized in that, The axial detection rod (10) is composed of a second large diameter end (10a), a second intermediate section (10b), and a second small diameter end (10c). A step is formed between the second large diameter end (10a) and the second intermediate section (10b), and another step is formed between the second intermediate section (10b) and the second small diameter end (10c). The diameter of the second large diameter end (10a) is larger than the diameter of the second intermediate section (10b), and the diameter of the second intermediate section (10b) is larger than the diameter of the second small diameter end (10c).

8. The comprehensive inspection fixture for the lower shaft seat according to claim 7, characterized in that, The outer surface of the second large diameter end (10a) is knurled, the second small diameter end (10c) is clearance-fitted with the workpiece axial detection hole (6) in the base plate (1), and the shapes of the second intermediate section (10b) and the second small diameter end (10c) are adapted to the shape of the axial stepped hole of the lower bearing seat (100).

9. The lower shaft seat integrated inspection fixture according to claim 1, characterized in that, The diameter of the anti-interference hole (2) is smaller than the diameter of the positioning hole (3), and the anti-interference hole (2) is located below the positioning hole (3).

10. The lower shaft seat integrated inspection fixture according to claim 6, characterized in that, The base plate (1) is disc-shaped, and three radial detection rods (9) are evenly distributed along the circumference of the base plate (1) at an angle of 120 degrees, and three axial detection rods (10) are evenly distributed along the circumference of the base plate (1) at an angle of 120 degrees.

Images