Gear involute artifact for realizing value transfer of large gears

Abstract

A method for using a gear involute artifact for realizing value transfer of large gears, comprising six surfaces: an involute profile cylindrical surface (1) used for transferring parameters, a datum bottom surface (2) and a datum top surface (3) symmetrically arranged on the upper and lower sides, a tooth root datum surface (4) and a tooth tip datum surface (5) arranged in parallel on the front and rear sides, and an alignment datum surface (6) arranged opposite to the involute profile cylindrical surface (1), wherein the distance from the tooth root datum surface (4) to the center of a corresponding base circle is a design distance D. For different measurement instruments, large gear measurement methods comprise a generating method, a polar coordinate method, and a Cartesian coordinate method, which can meet the requirements for value traceability of large gear measurement, are simple measurement methods and have high measurement precision, can meet the calibration of high-precision large-gear measurement instruments, are convenient for transportation, installation and adjustment, and thus have good market application prospects and promotion value.

Description

A tooth profile involute template for realizing large gear value transmission Technical Field

[0001] The invention belongs to the technical field of gear precision measurement, and in particular relates to a tooth profile involute template for realizing large gear quantity transmission. Background Art

[0002] Gears are key transmission components in large equipment. With their widespread application in ships, heavy-load helicopters, new energy equipment, and other fields, and with growing market demand, the requirements for their performance and quality are becoming increasingly stringent. Gear measurement, a key step in ensuring that gears meet performance requirements, plays a crucial role in ensuring the normal operation and service life of machinery and equipment.

[0003] High-precision measurement of large gears typically utilizes methods such as off-site measurement (using a three-dimensional coordinate measuring machine or a gear measuring center), on-machine measurement, and side-mounted measurement. Due to differences in instrument structure and error sources, these different measurement methods can produce discrepancies in measurement results, making mutual verification impossible. To achieve uniformity in involute tooth profile measurements, an involute template is typically used as a physical reference for traceability, transfer, and comparison of involute tooth profile deviations.

[0004] Typically, involute templates are certified by the National Metrology Institute and given corresponding calibration values. Gear measuring instruments are then calibrated using these certified involute templates. Only after the gear instruments have been calibrated and corrected using the standard involute templates can they measure gears. Furthermore, regarding the template specifications for calibrating high-precision gear profile measuring instruments, ISO 18653:2003 also states that "when calibrating gear measuring equipment, the base circle radius of the involute template used should be greater than 50% of the measuring range of the instrument being calibrated." However, the base circle radius of the involute template products most commonly used in industry today is less than 200mm. Using templates with a small base circle radius to calibrate large gear measuring instruments is not in compliance with the standard.

[0005] Internationally, in 2010, due to the urgent need for wind turbine gear measurement, the German National Metrology Institute (Physikalisch-Technische Bundesanstalt, PTB) developed a 50° sector tooth template with a top circle diameter of 1000mm, a template weight of 450kg, a normal module of 20mm, a pressure angle of 20°, and a tooth width of 400mm. It contains three different types of gear teeth: left-handed 20°, right-handed 10°, and straight teeth. It can be used for tracing involutes and helices, and calibrating gears with a diameter of 1000mm. It needs to be used with a counterweight during the calibration process in enterprises.

[0006] In 2018, Germany's PTB released the world's largest involute template in the form of a ring gear. The base circle diameter is about 2000mm and the weight is 2.7 tons. There is only one of them. Because the large gear involute template is too large, it is inconvenient to transport and adjust during use. Its accuracy is easily affected by temperature and support conditions, and it can only be used in a laboratory environment.

[0007] The invention patent (CN201610847011.2) discloses a large gear involute template composed of an involute template block and a sector-shaped base circle block. This is an involute template for large gears with a base circle radius rb>400mm, including an involute template block, a sector-shaped base circle block, auxiliary support ball screws, locating pins, and connecting screws, which are used to calibrate the involute tooth profile deviation measurement accuracy of gear measuring instruments. However, in principle, this mechanical structure can be separated from the core shaft during use. As the base circle radius to be transferred increases, its size also needs to be continuously increased. The use and manufacturing still have the problems of the above solution. Therefore, it is only an idea, and no industrial application has been seen in the market.

[0008] In summary, through analysis of the structures of existing large base circle radius involute templates, it was found that the core geometric elements of the involute template are the involute tooth profile surface and the base circle center. The mechanical structure of the template is specifically designed to ensure the relative position between the base circle center and the high-precision involute tooth profile cylindrical surface. Sector-shaped involute templates use a reference hole to represent the base circle center, and the sector-shaped solid part ensures the precise position of the involute tooth profile surface relative to the base circle center. Ring-shaped templates use a high-precision cylindrical surface to represent the base circle center, and the ring-shaped structure ensures the position of each metering tooth surface relative to the base circle center.

[0009] Constrained by the mechanical structure of the physical sample itself, no matter what form it is, as the value of the base circle radius being transferred increases, the volume and weight of its physical structure will inevitably increase significantly, which will make the sample difficult to manufacture, the accuracy stability difficult to ensure, and the use and comparison difficult. Moreover, as a physical benchmark for value comparison, the involute sample with a large base circle radius needs to be frequently transported between various national metrology rooms, laboratories and enterprises. Its huge structure makes transportation difficult, and its shape accuracy changes due to the influence of temperature and load. Due to the lack of a large base circle radius involute sample with a light structure, good accuracy stability and easy use and comparison, the large diameter involute gear tooth profile value transfer system cannot be established, and the measurement results of large gears cannot be traced, which in turn restricts the improvement of the manufacturing level of large gears (diameter greater than 500mm). Summary of the Invention

[0010] The present invention aims to provide a tooth profile involute template for realizing large gear measurement transfer, so as to overcome the problems existing in the prior art, such as bulky structure, difficulty in maintaining precision stability, unsuitability for measurement comparison, and inability to establish a large diameter involute gear tooth profile measurement transfer system.

[0011] In order to achieve the purpose of the present invention, the solution of the present invention is: a tooth profile involute template for realizing large gear value transmission, including six surfaces, an involute tooth profile cylindrical surface for transmitting parameters, a reference bottom surface and a reference top surface symmetrically arranged on the upper and lower sides, a root reference surface and a tooth top reference surface arranged parallel on the front and rear sides, and an alignment reference surface arranged opposite to the involute tooth profile cylindrical surface; the distance from the root reference surface to the center of the corresponding base circle is the design distance D.

[0012] Furthermore, the above-mentioned involute tooth profile cylindrical surfaces include two oppositely arranged surfaces, which are symmetrical with respect to the alignment reference plane.

[0013] Furthermore, the base circle radius transmitted by the above template is equivalent to the size of the corresponding standard gear being measured, and the measured length of the template includes the starting and end points of the corresponding standard gear, which is 1.5 to 2 times the involute length of the corresponding standard gear.

[0014] Furthermore, the thickness of the above-mentioned reference bottom surface and reference top surface is 10 mm to 20 mm, and the tooth surface extends 2 to 3 mm toward the inside of the base circle along the involute tangent line at the base circle.

[0015] Furthermore, the spatial positioning of the template is determined by its own reference surface, and the flatness of the reference bottom surface and the reference top surface symmetrically arranged on the upper and lower sides is not greater than 0.5μm, and the surface roughness Ra is not greater than 0.2μm; the tooth root reference surface and the tooth top reference surface arranged parallel to the front and rear sides are the positioning surfaces of the template, with a flatness of not greater than 0.5μm, a perpendicularity to the reference bottom surface of not greater than 0.5μm, and a surface roughness Ra of not greater than 0.2μm; the shape error of the involute tooth profile cylinder (1) is not greater than 3.0μm, and the surface roughness Ra is not greater than 0.2μm; the flatness of the alignment reference surface (6) is not greater than 0.2μm, the perpendicularity to the reference bottom surface (2) is not greater than 0.4μm, and the surface roughness Ra is not greater than 0.2μm.

[0016] Compared with the prior art, the advantages of the present invention are:

[0017] 1. This invention proposes a large-base-circle-radius involute template, replacing the design concept of using bulky mechanical structures to ensure the relative position of the involute tooth profile and the base circle center. The template's dimensions are limited to the size of a single gear tooth and do not increase with the base circle radius. The transferred value can be determined based on the base circle parameters of the gear being measured, which helps reduce calibration errors and ensures more reliable value transfer.

[0018] 2. The large base radius tooth profile involute template proposed in this invention can transmit a base radius exceeding the maximum base diameter of 2000mm for existing gear templates. Furthermore, due to its small size and ease of manufacturing, its manufacturing precision is comparable to that of small and medium-sized involute templates, meeting the traceability requirements of large gear measurement values.

[0019] 3. The sample proposed in the present invention has a small size and is therefore insensitive to temperature changes, making it convenient for comparison of measurement values ​​between metrology rooms, laboratories and enterprises in various countries. The shape accuracy of the sample is not affected by the environment, temperature and load during transportation, and its own accuracy is highly stable, which is conducive to reducing the uncertainty of measurement value transfer.

[0020] 4. The tooth profile involute template proposed in the present invention fills the gap of standard measuring instruments in the measurement transmission system of large-diameter involute gears and improves the measurement traceability system of large gears with a diameter greater than 500 mm.

[0021] 5. The present invention has the advantages of simple structure, simple measurement method and high measurement accuracy. It can meet the calibration of high-precision large gear measuring instruments, and is easy to transport, install and adjust. It has good market application prospects and promotion value. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] FIG1 is a diagram showing the overall structure of a sample of Example 1;

[0023] FIG2 is an axonometric view taken along the direction A of FIG1 ;

[0024] FIG3 is a schematic diagram of a template positioning reference surface in Example 1;

[0025] FIG4 is a diagram showing the overall structure of the sample of Example 2;

[0026] FIG5 is an axonometric view taken along the line A of FIG4 ;

[0027] FIG6 is a schematic diagram of the template positioning reference plane of Example 2.

[0028] The figure numbers are as follows: 1-involute tooth profile cylinder; 2-reference bottom surface; 3-reference top surface; 4-tooth root reference surface; 5-tooth top reference surface; 6-alignment reference surface; 7-reference surface where the tooth root reference surface is located; 8-reference surface where the reference bottom surface is located; 9-reference surface where the alignment reference surface is located. DETAILED DESCRIPTION

[0029] The method of the present invention is described in detail below with reference to the accompanying drawings.

[0030] Example 1, see Figures 1 and 2: A tooth profile involute template with a large base circle radius comprises an involute cylinder 1 for transmitting parameters, a reference bottom surface 2 and a reference top surface 3 symmetrically arranged on the upper and lower sides, a tooth root reference surface 4 and a tooth tip reference surface 5 parallel to each other on the front and rear sides, and an alignment reference surface 6 oppositely arranged from the involute tooth profile cylinder 1. The involute shape of the tooth profile template depends on the size of the base circle. Therefore, the tooth profile involute template provided by the present invention incorporates the parameter of the base circle center position as a characteristic parameter of the template. That is, the distance from the template's tooth root reference surface 4 to the corresponding base circle center is used as the design distance D to characterize this parameter.

[0031] Referring to FIG. 3 , based on the structure, the present invention provides three mutually perpendicular reference surfaces 7 , including a tooth root reference surface, a reference surface 8 , and an alignment reference surface 9 .

[0032] Example 2, see Figures 4 and 5: A tooth profile involute template with a large base circle radius, with the alignment reference plane 6 as the plane of symmetry. The template in this embodiment includes two oppositely disposed involute tooth profile cylinders 1, symmetrically provided with a reference bottom surface 2 and a reference top surface 3 on the upper and lower sides, and parallel front and rear surfaces provided with a tooth root reference surface 4 and a tooth tip reference surface 5. The involute shape of the tooth profile template depends on the size of the base circle. Therefore, the tooth profile involute template provided by the present invention introduces the parameter of the base circle center position as a characteristic parameter of the template, that is, the distance from the template's tooth root reference surface 4 to the corresponding base circle center is used as the design distance D to characterize this parameter.

[0033] See FIG. 6 : Based on the structure, the present invention provides three mutually perpendicular reference surfaces 7 where the tooth root reference surface is located, a reference surface 8 where the reference bottom surface is located, and a reference surface 9 where the alignment reference surface is located.

[0034] In the embodiments 1 and 2, the base circle radius transmitted by the template is equivalent to the size of the corresponding standard gear being measured, and the measured length of the template includes the starting point and end point of the corresponding standard gear, which is 1.5 to 2 times the involute length of the corresponding standard gear.

[0035] The thickness of the reference bottom surface 2 and the reference top surface 3 of the template is 10mm~20mm, and the tooth surface extends 2~3mm into the base circle along the involute tangent at the base circle to prevent the loss of involute expansion length caused by chamfering or machining collapse at the root of the involute template.

[0036] The spatial positioning of the template is determined by its own reference surface. The flatness of the reference bottom surface 2 and the reference top surface 3, which are symmetrically arranged on the upper and lower sides, is no more than 0.5μm, and the surface roughness Ra is no more than 0.2μm. The tooth root reference surface 4 and the tooth top reference surface 5, which are arranged parallel to each other on the front and rear sides, are the positioning surfaces of the template. The flatness is no more than 0.5μm, the perpendicularity to the reference bottom surface 2 is no more than 0.5μm, and the surface roughness Ra is no more than 0.2μm. The shape error of the involute tooth profile cylinder (1) is no more than 3.0μm, and the surface roughness Ra is no more than 0.2μm. The flatness of the alignment reference surface (6) is no more than 0.2μm, the perpendicularity to the reference bottom surface (2) is no more than 0.4μm, and the surface roughness Ra is no more than 0.2μm.

[0037] For different measuring instruments, large gear measurement methods mainly include the generating method, the polar coordinate method, and the rectangular coordinate system method. The following describes the specific use of the tooth profile involute template provided by the present invention for realizing large gear value transmission in two cases:

[0038] 1) When the unfolding method and the polar coordinate method are used for measurement, the present invention provides three mutually perpendicular reference surfaces 7 where the tooth root reference surfaces are located, a reference surface 8 where the reference bottom surface is located, and a reference surface 9 where the alignment reference surface is located, which are parallel to the coordinate system established with the rotation center origin of the measurement system. The center position of the base circle corresponding to the template is adjusted to coincide with the rotation center origin of the measurement system, and the distance from the tooth root reference surface 4 to the rotation center of the measurement system is ensured to be the designed distance D, and the correct position of the template is completed. After the position of the template is determined, the template rotates with the workbench, and the probe of the large gear measuring instrument follows to measure the tooth profile deviation of the involute tooth profile. The performance of the tooth surface deviation measurement of the instrument is evaluated by the tooth profile deviation, and the traceability of the base circle radius is achieved.

[0039] 2) When the rectangular coordinate method is used for measurement, the reference plane 7 where the three mutually perpendicular tooth root reference planes are located, the reference plane 8 where the reference bottom plane is located, and the reference plane 9 where the alignment reference plane are located are provided by the present invention and are parallel to the coordinate system established with the center of rotation origin of the measurement system. Adjust the position of the center of the base circle corresponding to the template to coincide with the center of rotation origin of the measurement system, and ensure that the distance from the tooth root reference plane 4 to the center of rotation of the measurement system is the designed distance D, and then the correct position of the template is completed. After the position is determined, the template does not move, and only the probe of the large gear measuring instrument moves to measure the tooth profile deviation of the involute tooth profile at any position. After completing the measurement of the first position, the rotary table drives the template to rotate to any angle and measure again. Repeat the steps, and measure at least two positions to comprehensively measure the measurement results to evaluate the performance of the instrument's tooth profile deviation measurement and achieve traceability of the base circle radius.

[0040] Before use, in a constant temperature environment of 20±1℃, use special equipment to precisely measure the tooth profile involute template and determine the base circle radius r of the tooth profile involute template. b0 , accurate to 0.1μm; if the involute tooth profile inclination deviation of the tooth profile involute template is not zero during the measurement process, it can be compensated to the base circle radius r b0 and the compensated r b As the base circle information parameter of the large gear involute template, that is, the calibration value of the template.

[0041] The above description is merely the technical method and implementation method of the present invention. The protection scope of the present invention is not limited thereto. Any equivalent replacement or change made by any person based on the technical solution and inventive concept of the present invention is covered by the protection scope of the present invention.

Claims

1. A method for using a tooth profile involute template for realizing large gear value transmission, wherein the tooth profile involute template used in the large gear value transmission has the following structure: comprising six surfaces, an involute tooth profile cylinder (1) for transmitting parameters, a reference bottom surface (2) and a reference top surface (3) symmetrically arranged on the upper and lower sides, a tooth root reference surface (4) and a tooth top reference surface (5) arranged parallel on the front and rear sides, and an alignment reference surface (6) arranged opposite to the involute tooth profile cylinder (1), wherein the distance from the tooth root reference surface (4) to the center of the corresponding base circle is a design distance D, and wherein: For different measuring instruments, the large gear measurement methods include the generating method, polar coordinate method and rectangular coordinate system method. When the generating method and the polar coordinate method are used for measurement, the reference surface (7) where the three mutually perpendicular tooth root reference surfaces are located, the reference surface (8) where the reference bottom surface is located, and the reference surface (9) where the alignment reference surface are located are provided, and are parallel to the coordinate system established with the rotation center origin of the measurement system; the base circle center position corresponding to the template is adjusted to coincide with the rotation center origin of the measurement system, and the distance from the tooth root reference surface (4) to the rotation center of the measurement system is ensured to be the designed distance D, and the correct position of the template is completed; after the position of the template is determined, the template rotates with the workbench, and the probe of the large gear measuring instrument follows, and the tooth profile deviation of the involute tooth profile is measured. The performance of the tooth surface deviation measurement of the instrument is evaluated through the tooth profile deviation, and the traceability of the base circle radius is achieved; When measuring by the rectangular coordinate method, the reference surface (7) where the three mutually perpendicular tooth root reference surfaces of the template are located, the reference surface (8) where the reference bottom surface is located, and the reference surface (9) where the alignment reference surface are located are provided to be parallel to the coordinate system established with the rotation center origin of the measurement system; the base circle center position corresponding to the template is adjusted to coincide with the rotation center origin of the measurement system, and the distance from the tooth root reference surface (4) to the rotation center of the measurement system is ensured to be the designed distance D, and the correct position of the template is completed; after the position is determined, the template does not move, and only the probe of the large gear measuring instrument moves, and the tooth profile deviation of the involute tooth profile is measured at any position; after completing the measurement of the first position, the rotary table drives the template to rotate to any angle and measure again; repeat the steps, and through the measurement of at least two positions, the performance of the instrument tooth profile deviation measurement can be evaluated by comprehensive measurement results, and the traceability of the base circle radius can be achieved.

2. The method for using the tooth profile involute template for realizing large gear value transmission according to claim 1, characterized in that: The involute tooth profile cylindrical surfaces (1) include two surfaces that are arranged opposite to each other and have an alignment reference surface (6) as a symmetry surface.

3. The method for using the tooth profile involute template for realizing large gear value transmission according to claim 1 or 2, characterized in that: The base circle radius transmitted by the template is equivalent to the size of the corresponding standard gear being measured. The measured length of the template includes the starting point and end point of the corresponding standard gear, which is 1.5 to 2 times the involute length of the corresponding standard gear.

4. The method for using the tooth profile involute template for realizing large gear value transmission according to claim 3, characterized in that: The thickness of the reference bottom surface (2) and the reference top surface (3) is 10 mm to 20 mm, and the tooth surface extends 2 to 3 mm toward the inside of the base circle along the involute tangent line at the base circle.

5. The method for using the tooth profile involute template for realizing large gear value transmission according to claim 4, characterized in that: The spatial positioning of the template is determined by its own reference surface. The flatness of the reference bottom surface (2) and the reference top surface (3) symmetrically arranged on the upper and lower sides is not greater than 0.5μm, and the surface roughness Ra is not greater than 0.2μm. The tooth root reference surface (4) and the tooth top reference surface (5) arranged parallel on the front and rear sides are the positioning surfaces of the template. The flatness is not greater than 0.5μm, the perpendicularity to the reference bottom surface (2) is not greater than 0.5μm, and the surface roughness Ra is not greater than 0.2μm. The shape error of the involute tooth profile cylinder (1) is not greater than 3.0μm, and the surface roughness Ra is not greater than 0.2μm. The flatness of the alignment reference surface (6) is not greater than 0.2μm, the perpendicularity to the reference bottom surface (2) is not greater than 0.4μm, and the surface roughness Ra is not greater than 0.2μm.

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