A cycloid gear meshing clearance detection method and detection tooling

Abstract

The present invention discloses a detection method and a detection tooling for the meshing clearance of a cycloidal gear, which relates to the technical field of oil pumps and solves the technical problem of inaccurate detection of the meshing clearance between an existing gear and a gear ring. The detection steps are as follows: First, an elastic wire is inserted into the clearance between the gear and the gear ring, and the elastic wire passes through the meshing part of the gear and the gear ring. When the driving gear and the gear ring mesh and rotate, the elastic wire moves along with the movement at the clearance between the gear and the gear ring. The elastic wire generates static friction on the side walls between the gear and the gear ring. Under the action of the static friction force, the elastic wire is stretched and generates an elastic force. One end of the elastic wire is connected with a tension sensor for measuring the tension of the elastic wire. According to the relationship between the tension value generated by the elastic wire passing through the meshing clearance measured by the tension sensor and the meshing clearance, it can be judged whether the meshing clearance between the gear and the gear ring is qualified. A detection component is arranged at the meshing clearance between the gear and the gear ring to improve the overall detection accuracy.

Description

Technical Field

[0001] The present invention relates to the technical field of oil pumps, and more specifically to the technical field of a cycloidal gear meshing clearance detection method and a detection tooling. Background Art

[0002] An oil pump is a pump that is both light and compact, and there are three main categories: in-line type, distributor type, and unit type. An oil pump requires a power source to operate, and the camshaft at its lower part is driven by the engine crankshaft gear.

[0003] During the start-up process of the oil pump, there is a short-term air extraction condition. If the meshing clearance between the gear / toothed ring is too large, the vacuum suction of the gas cannot be completed, and the oil pump cannot start normally.

[0004] Therefore, in order to ensure full inspection of the meshing clearance between the gear and the toothed ring and the maximum meshing clearance is less than 0.08, the present invention provides a detection method applicable to the meshing clearance of cycloidal gears in a gear oil pump. Summary of the Invention

[0005] The purpose of the present invention is: to solve the above technical problems, the present invention provides a cycloidal gear meshing clearance detection method and a detection tooling.

[0006] The present invention specifically adopts the following technical solutions to achieve the above purpose:

[0007] A cycloidal gear meshing clearance detection method includes the following detection steps:

[0008] S1. Insert an elastic wire into the gap between the gear and the toothed ring, and the elastic wire passes through the meshing part of the gear and the toothed ring;

[0009] S2. Drive the gear and the toothed ring to mesh and rotate. The elastic wire moves along with the movement in the gap between the gear and the toothed ring. The elastic wire generates static friction on the side walls between the gear and the toothed ring. Under the action of the static friction force, the elastic wire is stretched and generates an elastic force;

[0010] S3. One end of the elastic wire is connected with a tension sensor for measuring the elastic force of the elastic wire;

[0011] S4. Compare the maximum peak value of the elastic force generated by the elastic wire passing through the meshing clearance measured by the tension sensor with the preset qualified elastic force threshold value to determine whether the meshing clearance between the gear and the toothed ring is qualified.

[0012] As a further preferred solution, in step S4, the preset qualified elastic force is the minimum limit value F1 and the maximum limit value F2. The maximum peak value of the elastic force generated by the elastic wire passing through the meshing clearance measured by the tension sensor is F. Then the specific steps for determining whether the meshing clearance between the gear and the toothed ring is qualified are as follows:

[0013] Judge whether F1 ≤ F ≤ F2. If so, it means that the elastic force value F measured by the tension sensor is within the range of F1 and F2 of the preset qualified elastic force, then it is determined that the meshing clearance between the gear and the gear ring meets the requirements, and the meshing clearance between the gear and the gear ring is qualified; otherwise, it is unqualified.

[0014] As a further preferred solution, the maximum tension F generated by the elastic wire passing through the meshing clearance measured by the tension sensor and the meshing clearance X satisfy the following relational expression:

[0015]

[0016] In the formula:

[0017] Y is the Young's modulus of the elastic wire;

[0018] L is the effective initial length of the elastic wire;

[0019] d is the initial diameter of the elastic wire;

[0020] ε is the correction coefficient of this measurement system, which is corrected according to the test data.

[0021] As a further preferred solution, the elastic wire is a composite polyurethane fiber.

[0022] As a further preferred solution, the composite fiber elastic wire is composed of multiple polyurethane fibers woven in a "crossed spiral wrapping structure".

[0023] A cycloidal gear meshing clearance detection tooling, including a detection workbench, on which a gear ring and a gear that is in clearance fit with the gear ring are installed, and a clearance detection component for detecting the meshing clearance between the gear ring and the gear is installed on the detection workbench.

[0024] As a further preferred solution, the clearance detection component includes a positioning ring, a composite fiber elastic wire, and a tension sensor component. Among them, the composite fiber elastic wire passes through the positioning ring and is connected to the input end of the tension sensor component. The positioning ring ensures the initial length of the elastic wire and enables the elastic wire to pass through the meshing point of the gear and the gear ring, and the positioning ring is fixedly supported on the detection workbench.

[0025] As a further preferred solution, the tension sensor component is a high-precision tension sensor.

[0026] The beneficial effects of the present invention are as follows:

[0027] In the present invention, in order to ensure that when the cycloidal gear meshes with the gear ring, its maximum meshing clearance meets the actual requirements, a detection component for whether the meshing clearance between the gear and the gear ring is qualified is set at the meshing clearance between the gear and the gear ring, avoiding that the meshing clearance between the gear and the gear ring is too large in the later stage and the vacuum pumping of gas cannot be completed, and improving the overall convenience of detection.

[0028] The present invention provides a method for detecting the meshing clearance of cycloidal gears, summarizes the relationship between the elastic force value F generated by the elastic wire passing through the meshing clearance and the meshing clearance, and then determines whether the meshing clearance meets the actual requirements. The force value that meets the requirements is determined by the pulling force value of the limit value of the meshing clearance. The force value is the safe area. Subsequently, by checking whether the maximum value of the tension sensor is within the safe area, it can be judged whether the meshing clearance is qualified. Compared with manual measurement, this solution improves the overall detection accuracy.

[0029] In the present invention, the measurement workbench can simulate all the meshing clearances between the gear and the gear ring under working conditions. The force value of the elastic wire measured by the tension sensor passing through the meshing clearance can be analyzed and calculated to obtain the true meshing clearance between the gear and the gear ring. This measurement process can achieve full-automatic measurement of the meshing clearance except for loading and unloading the gear and gear ring, greatly improving the detection efficiency of the meshing clearance of cycloidal gears.

[0030] In the present invention, the elastic wire is woven by multiple polyurethane fibers in a "crossed spiral wrapping structure". The fiber has a tensile ultimate strength, and at the same time has high extensibility and resilience, and has a certain fatigue strength to ensure the stability of the measurement results. Description of the Drawings

[0031] Figure 1 is a schematic cross-sectional structure diagram of the cycloidal gear meshing clearance detection tooling of the present invention;

[0032] Figure 2 is a schematic assembly structure diagram of the gear ring and the gear of the present invention;

[0033] Figure 3 is a schematic diagram of the change of the force value F of the present invention;

[0034] Reference numerals: 1 - detection workbench, 2 - gear ring, 3 - gear, 4 - clearance detection assembly. Detailed Embodiments

[0035] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Usually, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0036] Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the present invention claimed, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the scope of protection of the present invention.

[0037] Embodiment 1

[0038] As Figures 1 - 3 shown, this embodiment provides a method for detecting the meshing clearance of a cycloidal gear, and the detection steps are as follows:

[0039] S1. Insert an elastic wire into the clearance between the gear and the gear ring, and the elastic wire passes through the meshing part of the gear and the gear ring;

[0040] S2. Drive the gear and the gear ring to mesh and rotate. The elastic wire moves along with the movement at the clearance between the gear and the gear ring. The elastic wire generates static friction on the side walls between the gear and the gear ring. Under the action of the static friction force, the elastic wire is stretched and generates an elastic force;

[0041] S3. One end of the elastic wire is connected with a tensile sensor for measuring the elastic force of the elastic wire;

[0042] S4. Compare the elastic force value generated by the elastic wire passing through the meshing clearance measured by the tensile sensor with the preset qualified elastic force threshold value to determine whether the meshing clearance between the gear and the gear ring is qualified.

[0043] In the above structure, in order to ensure that when the cycloidal gear meshes with the gear ring, its maximum meshing clearance meets the actual requirements, and the actual requirement for the maximum meshing clearance is less than 0.08 mm. Therefore, an elastic wire is installed at the meshing position between the gear and the gear ring and passes through this meshing clearance. The initial diameter of the elastic wire is slightly larger than the designed maximum meshing clearance, ensuring that all the clearances to be measured can be covered. At the same time, during the rotation of the gear and the gear ring, in the clearance at the meshing part of the gear and the gear ring, when the elastic wire passes through the narrow slit of the meshing clearance, it generates static friction with the side wall of the clearance. Under the action of the friction force, the elastic wire is stretched and becomes thinner, with its diameter shrinking. Then, the elastic wire pulls the tensile sensor connected to it, and thus the elastic force value is measured. At the next moment, the static friction force is not sufficient to overcome the component force of the elastic force generated by the elastic deformation of the elastic wire itself, and the elastic wire passes through the meshing clearance at this time. Subsequently, the elastic wire returns to its original state. This measurement process can realize the full-automatic measurement of the meshing clearance except for loading and unloading the gear and the gear ring, greatly improving the detection efficiency of the meshing clearance of the cycloidal gear.

[0044] Working principle: After the gear under test is assembled onto the workbench, the micro DC motor drives the gear to rotate slowly at a speed of 6 r / min. Under the meshing action of the gear and the gear ring, the gear ring rotates around the center of the gear ring at a speed of 4.8 r / min. During this process, the meshing clearances between the tooth tips of different teeth of the gear and the high points of the tooth profiles between different two teeth of the gear ring will appear periodically, realizing the recurrence of all the meshing clearances of the gear / gear ring.

[0045] Preferably, in step S4, the preset qualified elastic force is the minimum limit value F1 and the maximum limit value F2. The maximum peak value of the elastic force generated by the elastic wire passing through the meshing gap measured by the tensile force sensor is F. The specific steps for judging whether the meshing gap between the gear and the gear ring is qualified are as follows:

[0046] Judge whether F1≤F≤F2. If so, it means that the measured elastic force value F by the tensile force sensor is within the range of F1 and F2 of the preset qualified tensile force, then it is determined that the meshing gap between the gear and the gear ring meets the requirements, and the meshing gap between the gear and the gear ring is qualified; otherwise, it is unqualified;

[0047] As a further preference, the maximum value F of the elastic force generated by the elastic wire passing through the meshing gap measured by the tensile force sensor and the meshing gap X satisfy the following relational formula:

[0048]

[0049] In the formula:

[0050] Y is the Young's modulus of the elastic wire;

[0051] L is the effective initial length of the elastic wire;

[0052] d is the initial diameter of the elastic wire;

[0053] ε is the correction coefficient of this measurement system, which is corrected according to the test data.

[0054] Preferably, the elastic wire is a composite polyurethane fiber.

[0055] Preferably, the composite fiber elastic wire is composed of multiple polyurethane fibers woven in a "cross spiral wrapping structure", which can enhance the tensile ultimate strength of the fiber, and at the same time has high extensibility and resilience, and has a certain fatigue strength to ensure the stability of the measurement results.

[0056] As Figure 2 shown, the gear 2 rotates slowly at a speed of 6 r / min, and the gear ring rotates around the center of the gear ring at a speed of 4.8 r / min. At the elastic wire, at the moment T1-T2, the minimum meshing gap appears between the tooth tip A of the gear and the tooth tip a of the gear ring. The elastic wire pulls the tensile force sensor connected to it, and then measures its tensile force value. The maximum peak value of the tensile force at the gap at A / a is within the qualified range between F1 and F2. Therefore, the meshing of the gear and the gear ring at A / a meets the requirements. As time goes by, at the moment T3-T4, the minimum meshing gap appears between the tooth tip B of the gear and the tooth tip b of the gear ring. At this time, the meshing gap at B / b is measured, and the maximum peak value of the tensile force of the meshing gap at B / b is within the qualified range between F1 and F2. Subsequently, each meshing gap between the gear and the gear ring is gradually detected one by one to ensure that all the meshing gaps between the gear and the gear ring are inspected and the maximum meshing gap is less than 0.08.

[0057] Embodiment 2:

[0058] A cycloidal gear meshing clearance detection tooling, including a detection workbench. A gear ring 2 and a gear 3 in clearance fit with the gear ring 2 are installed on the detection workbench 1. A clearance detection component 4 for detecting the meshing clearance between the gear ring 2 and the gear ring 2 is installed on the detection workbench 1;

[0059] The clearance detection component 4 includes a positioning ring, a composite fiber elastic wire, and a force sensor component. Among them, the composite fiber elastic wire passes through the positioning ring and is connected to the input end of the force sensor component. The positioning ring ensures the initial length of the elastic wire and enables the elastic wire to pass through the meshing point of the gear and the gear ring. There are two positioning rings, which are respectively located on the upper and lower sides of the meshing clearance, and the two positioning rings are fixedly supported on the detection workbench;

[0060] As a further preference, the force sensor component is a high-precision tensile sensor, which can measure the elastic force generated by the elastic wire.

[0061] In the above process, the detection workbench can simulate the installation state of the gear and the gear ring. The eccentricity of the gear and the gear ring is consistent with the working condition, achieving the effect of measuring the clearance. The micro DC motor drives the gear to rotate. Under the meshing action of the gear and the gear ring, the gear ring rotates around the center of the gear ring. The meshing clearances between the tooth tips of different teeth of the gear and the high points of the tooth profiles between different two teeth of the gear ring will reappear periodically. The positioning ring is used to limit the initial length and position of the elastic wire, ensuring that the elastic wire is at the meshing clearance, providing a specific detection device, which helps to improve the detection efficiency of the meshing clearance of the cycloidal gear pair.

[0062] It should be noted that within the elastic limit, the elastic wire has stable mechanical properties. To ensure the stability of the detection, usually the number of uses of the elastic wire is one thousand times; when the detected clearance value is less than 0.03 in a certain detection, the elastic wire must be replaced, and this clearance value is the elastic limit of this elastic wire.

[0063] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for detecting the meshing clearance of cycloidal gears, characterized in that, The detection steps are as follows: S1. Insert the elastic wire into the meshing gap between the gear and the gear ring, and the elastic wire passes through the meshing part of the gear and the gear ring; S2. Drive the gear and the gear ring to mesh and rotate. The elastic wire moves along with the movement at the meshing gap between the gear and the gear ring. Static friction is generated on the side walls between the gear and the gear ring. Under the action of the static friction force, the elastic wire is stretched and generates an elastic force; S3. One end of the elastic wire is connected with a tension sensor for measuring the elastic force of the elastic wire; S4. Compare the maximum peak value of the elastic force generated by the elastic wire passing through the meshing gap measured by the tension sensor with the preset qualified elastic force threshold value to determine whether the meshing gap between the gear and the gear ring is qualified; In step S4, the maximum peak value of the elastic force generated by the elastic wire passing through the meshing gap measured by the tension sensor is F, and the relationship with the meshing gap X is as follows: ； In the formula: Y is the Young's modulus of the elastic wire; L is the effective initial length of the elastic wire; d is the initial diameter of the elastic wire; ε is the correction coefficient of this measurement system, which is corrected according to the test data.

2. The cycloidal gear meshing clearance detection method according to claim 1, characterized in that In step S4, the preset qualified elastic force threshold values are the minimum limit value F1 and the maximum limit value F2. The maximum peak value of the elastic force generated by the elastic wire passing through the meshing gap measured by the tension sensor is F. Then the specific steps for judging whether the meshing gap between the gear and the gear ring is qualified are as follows: Judge whether F1 ≤ F ≤ F2. If so, it means that the maximum peak value of the elastic force measured by the tension sensor, F, is within the range of the minimum limit value F1 and the maximum limit value F2 of the preset qualified elastic force threshold value. Then it is determined that the meshing gap between the gear and the gear ring meets the requirements, and the meshing gap between the gear and the gear ring is qualified; otherwise, it is unqualified.

3. A cycloidal gear meshing clearance detection method according to claim 1, characterized in that, The elastic wire is a composite polyurethane fiber.

4. The cycloid gear meshing clearance detection method according to claim 3, characterized in that The elastic wire is composed of multiple composite polyurethane fibers woven in a "crossed spiral wrapping structure".

5. A cycloidal gear meshing clearance detection tooling, characterized in that, The cycloidal gear meshing gap detection method according to any one of claims 1-4 is used. It includes a detection workbench. A gear ring (2) and a gear (3) with clearance fit with the gear ring (2) are installed on the detection workbench (1). A clearance detection component (4) for detecting the meshing gap between the detection gear ring (2) and the gear ring (2) is installed on the detection workbench (1); The clearance detection component (4) includes a positioning ring, an elastic wire of composite fiber, and a tension sensor component. Among them, the elastic wire of composite fiber passes through the positioning ring and is connected to the input end of the tension sensor component. The positioning ring ensures the initial length of the elastic wire and enables the elastic wire to pass through the gear and gear ring meshing point. The positioning ring is fixedly supported on the detection workbench; The tension sensor component is a high-precision tension sensor.

Images