CN110188475B - Flexible gear measuring and evaluating method based on rigid gear parameters in working state - Google Patents

Abstract

The invention relates to a flexible gear measuring and evaluating method under a working state based on rigid gear parameters, which comprises the following steps: 1. calculating to obtain an angle parameter alpha of a meshing area and a gear tooth pair number 4N-2 participating in meshing; 2, taking the basic parameters of the rigid wheel as the detection parameters of the flexible wheel, and taking the design tooth shape of the rigid wheel as the theoretical tooth shape of the flexible wheel; 3. measuring actual coordinate points of the tooth forms at two sides of different gear teeth of the evaluated flexible gear in different working states; simultaneously evaluating the performance of the flexible gear; 4. measuring the ith gear tooth form actual coordinate point and the tooth form error of the ith gear tooth, which has a delta angle with the major diameter of the wave generator, on the flexible gear, when-alpha is greater than delta and is less than alpha, the ith gear tooth is in a meshing working state, otherwise, the ith gear tooth is in a non-meshing state; 5. repeating the step 4;6. and comprehensively evaluating the quality of the flexible gear. The method provided by the invention aims at reflecting the comprehensive error, and not only comprises the design and processing tooth profile errors, but also comprises the influence on a wave generator; the problem that the performance of the flexible gear cannot be measured and evaluated in the prior art is solved.

Description

A measurement and evaluation method for flexible splines under working conditions based on rigid spline parameters

technical field

The invention relates to the technical field of harmonic gear transmission detection, in particular to a method for measuring and evaluating a flexible spline under a working state based on rigid spline parameters.

Background technique

The harmonic gear reducer mainly includes a rigid wheel with internal teeth, a flexible spline with external teeth that can produce radial elastic deformation during operation, and an elliptical wave generator installed inside the flexible spline. The harmonic gear reducer has many advantages such as simple structure, small size, light weight and high transmission efficiency. In the application field of harmonic transmission, especially in the field of industrial robots, the requirements for the accuracy and space size of harmonic gear transmission are extremely strict. Shape design, processing, flexspline deformation and stress research, etc.

Among them, the tooth shape of the flexspline has a great influence on the performance of the harmonic gear drive, and simulation methods are often used to study it at present. Firstly, the tooth profile of the flexspline is designed and processed according to the conventional gear design method. Then, based on the mechanism of the wave generator on the deformation of the flexspline, the tooth profile of the flexspline is modeled, and the tooth profile of the rigid wheel is calculated according to the tooth profile of the flexspline. the design of. At present, the mathematical modeling theory of flexspline tooth profile is complicated, and many assumptions and simplifications are often adopted, such as the fact that the flexspline tooth profile has no machining error, the flexspline tooth profile is rigid without deformation, and the length of the flexible thin-walled neutral line is constant. There is a certain gap. Due to the deformation of the flexspline when it is working, the data of the flexspline measured and evaluated according to ordinary gears cannot represent the working performance of the flexspline. At present, there is a lack of detection and error evaluation methods for the tooth profile of the flexspline in the working state, and the comprehensive transmission accuracy of the harmonic gear reducer is often tested using a comprehensive test bench, and the influence of the flexspline on the transmission accuracy cannot be determined.

Contents of the invention

The invention provides a flexible spline measurement and evaluation method under working conditions based on rigid spline parameters to solve the problem that the performance of the flexible spline cannot be measured and evaluated in the prior art.

In order to achieve the above object, the solution provided by the present invention is:

A method for measuring and evaluating a flexible spline under working conditions based on rigid spline parameters, comprising the following steps:

1) Establish the Oxy coordinate system based on the parameters of the rigid wheel, O coincides with the center of rotation of the rigid wheel, the tooth of the flexible wheel is symmetrical to the X axis, and the direction of the long axis of the wave generator is consistent with the direction of the X axis, and the short axis of the wave generator It is consistent with the Y-axis direction; under the action of the wave generator, the flexspline deforms, and the gear teeth near the long axis of the wave generator participate in meshing, and the teeth far away from the long axis of the wave generator do not participate in meshing. The meshing area can be obtained by calculation The angle parameter α and the number of tooth pairs involved in meshing 4N-2;

2) The basic parameters of the rigid spline are used as the detection parameters of the flexible spline, and the designed tooth profile of the rigid spline is used as the theoretical tooth profile of the flexible spline;

3) According to the ordinary gear detection method, the actual coordinate points of the double-sided tooth profile of the different gear teeth of the flexspline to be evaluated under different working conditions are measured; at the same time, the performance evaluation of the flexspline is performed;

4) Measure the actual coordinate point of the tooth shape of the i-th tooth on the flexspline and the long diameter of the wave generator at an angle of δ and its tooth shape error. When -α<δ<α, the i-th tooth is at meshing working state, otherwise the i-th gear tooth is in a non-meshing state;

5) Repeat step 4) to measure and obtain the actual coordinate points of the tooth profiles on both sides of the gear teeth in different working states of meshing, meshing, and meshing;

6) Comprehensively evaluate the quality of the flexspline according to the tooth profile information under different working conditions.

Further, the basic parameters of the rigid wheel in the above step 2) include the rigid wheel modulus, the number of teeth, the pressure angle, the diameter of the root circle and the diameter of the addendum circle.

Further, in the above step 6), the flexspline quality refers to the performance indicators of each gear tooth shape, tooth pitch, tooth thickness, top clearance, side clearance, meshing logarithm, and whether there is interference.

Regardless of the influence of the shape of the wave generator on the flexible spline, the meshing transmission performance between the flexible spline and the rigid spline should be paid attention to. The method provided by the invention is aimed at reflecting comprehensive errors, not only including design and processing tooth shape errors, but also including the influence on the wave generator. Compared with prior art, the advantage of the present invention is:

1) Therefore, the present invention proposes a flexible spline measurement and evaluation method based on rigid spline parameters under working conditions, which can directly simplify the mathematical theoretical model of the flexible spline, and realize direct evaluation of the performance of the harmonic gear drive.

2) The present invention obtains the theoretical line shape of the theoretical flex spline tooth profile based on the tooth profile of the rigid spline, that is, the zero-error transmission line profile, and the established flex spline tooth profile model has no principle error.

3) According to the method provided by the present invention, different gear tooth profiles under all working conditions can be measured, and the tooth profile of the flexspline in the full mesh state can be measured for tooth profile, tooth pitch, tooth thickness, top clearance, side clearance, and meshing logarithm. , Whether there is interference and other performance evaluation; at the same time, the tooth shape in the full mesh state can provide the basis for the design of the wave generator.

Description of drawings

Figure 1 is a schematic diagram of the initial position of the wave generator and the first tooth and the measurement coordinate system;

Figure 2 is a schematic diagram of the incomplete meshing position of the first tooth after the wave generator rotates relative to the flexspline;

Figure 3 is a schematic diagram of the measurement results of the tooth profile of the flexspline under different working conditions.

Detailed ways

The method of the present invention will be described in detail below in conjunction with the accompanying drawings and specific implementation examples.

Example:

A method for measuring and evaluating a flexible spline under working conditions based on rigid spline parameters, comprising the following steps:

Step 1), see Figure 1, on the reduction gear of the harmonic gear, first establish the Oxy coordinate system based on the parameters of the rigid wheel, O coincides with the center of rotation of the rigid wheel, the tooth of the flexible wheel is symmetrical to the X axis, and the wave generator The direction of the long axis of the wave generator is consistent with the direction of the X axis, and the short axis of the wave generator is consistent with the direction of the Y axis; The gear teeth near the long axis of the generator do not participate in the meshing, that is, the gear teeth in the four gray areas that are symmetrical to the X axis participate in the meshing. Through calculation, the angle parameter α of the meshing area and the number of pairs of teeth participating in the meshing 4N-2 can be obtained;

Step 2), the basic parameters of the rigid spline are used as the detection parameters of the flexible spline, and the designed tooth shape of the rigid spline is used as the theoretical tooth shape of the flexible spline. The basic parameters of the rigid spline include the rigid spline modulus, the number of teeth, the pressure angle, and the dedendum circle diameter and addendum circle diameter;

Step 3), according to the ordinary gear detection method, measure and obtain the actual coordinate points of the bilateral tooth profile of the first gear tooth in the meshing state on the flexspline;

Step 4), as shown in Figure 2, measure the actual coordinate point of the tooth profile of the i-th tooth at the position where the difference between the long diameter of the flexspline and the wave generator is δ, and its tooth profile error, when -α<δ<α , the i-th gear tooth is in the meshing working state, otherwise the i-th gear tooth is in the non-meshing state;

Step 5), repeating step 4) can measure and obtain the actual coordinate points of the tooth shape on both sides of the gear teeth in different working states of meshing in, meshing and meshing out;

Step 6), according to the gear tooth shape information under different working conditions, comprehensively evaluate the quality of the flexspline; for example, the tooth shape, tooth pitch, tooth thickness, head clearance, side clearance, meshing interference etc.

Refer to Fig. 3, which is the tooth shape error curve of each tooth calculated by taking the design tooth shape of the rigid wheel as the theoretical tooth shape; When there is a gap in the tooth shape of the gear, it means that there is a backlash in the transmission process; when the actual tooth shape intersects with the tooth shape of the rigid wheel, it means that there is interference; the difference between the backlash on the same side of adjacent teeth is the adjacent tooth pitch deviation ; The sum of the left and right backlash of the same tooth is the tooth thickness deviation; when the tooth top of the flex spline is lower than the top of the rigid wheel, it is an interference state; when the tooth top of the flex spline is lower than the top of the rigid wheel, it is a non-meshing state , the number of meshing teeth is 2N-1 of all the teeth located in the tooth top of the rigid wheel, and the total number of meshing pairs is 4N-2.

The above uses specific examples to illustrate the present invention, which is only used to help understand the present invention, and is not intended to limit the present invention. For those skilled in the technical field to which the present invention belongs, some simple deduction, deformation or replacement can also be made according to the idea of the present invention.

Claims (2)

1. a flexible spline measurement and evaluation method based on the working condition of rigid spline parameters, is characterized in that, comprises the following steps: 1) Establish the Oxy coordinate system based on the parameters of the rigid wheel, O coincides with the center of rotation of the rigid wheel, the tooth of the flexible wheel is symmetrical to the X axis, and the direction of the long axis of the wave generator is consistent with the direction of the X axis, and the short axis of the wave generator It is consistent with the Y-axis direction; under the action of the wave generator, the flexspline deforms, and the gear teeth near the long axis of the wave generator participate in meshing, and the teeth far away from the long axis of the wave generator do not participate in meshing. The meshing area can be obtained by calculation The angle parameter α and the number of tooth pairs involved in meshing 4N-2; 2) The basic parameters of the rigid spline are used as the detection parameters of the flexible spline, and the designed tooth profile of the rigid spline is used as the theoretical tooth profile of the flexible spline; 3) According to the ordinary gear detection method, the actual coordinate points of the double-sided tooth profile of the different gear teeth of the flexspline to be evaluated under different working conditions are measured; at the same time, the performance evaluation of the flexspline is performed; 4) Measure the actual coordinate point of the tooth shape of the i-th tooth on the flexspline and the long diameter of the wave generator at an angle of δ and its tooth shape error. When -α<δ<α, the i-th tooth is at meshing working state, otherwise the i-th gear tooth is in a non-meshing state; 5) Repeat step 4) to measure and obtain the actual coordinate points of the tooth profiles on both sides of the gear teeth in different working states of meshing, meshing, and meshing; 6) Comprehensively evaluate the quality of the flexspline according to the tooth profile information under different working conditions; The basic parameters of the rigid wheel in the step 2) include the rigid wheel module, the number of teeth, the pressure angle, the diameter of the root circle and the diameter of the addendum circle. 2. according to the flexspline measurement and evaluation method under the working state based on rigid spline parameters of claim 1, it is characterized in that, in above-mentioned step 6), flexspline quality refers to each gear tooth profile, pitch, tooth Performance indicators of thickness, top clearance, side clearance, meshing logarithm, and presence or absence of interference.

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