A device and method for measuring the transmission error of a double ratio belt drive

Abstract

The application relates to the technical field of transmission mechanism performance measurement, in particular to a double-transmission-ratio belt transmission mechanism transmission error measuring device and method, which comprises an optical self-collimator, mechanical limiting and two reflecting mirrors; wherein the two reflecting mirrors are arranged on a large belt pulley and a small belt pulley of the belt transmission mechanism respectively and rotate with the corresponding belt pulleys; the light beam output by the optical self-collimator is reflected to the reflecting mirror on the small belt pulley through the reflecting mirror on the large belt pulley, and the reflecting mirror on the small belt pulley returns the light beam to the optical self-collimator through the reflecting mirror on the large belt pulley; the mechanical limiting is installed on the large belt pulley and used for limiting the rotation angle of the large belt pulley. The measuring device is flexible to install, and the optical self-collimator is used to improve the transmission error measurement precision.

Description

Technical Field

[0001] The present invention relates to the technical field of transmission mechanism performance measurement, and in particular to a transmission error measurement device and method for a double transmission ratio belt transmission mechanism. Background Art

[0002] Belt drives are a common mechanical transmission method, characterized by their simple structure, low cost, strong adaptability, and a wide range of transmission ratios. They are widely used in various mechanical transmission structures. Transmission error is a key indicator of a transmission mechanism's performance. The transmission error of a belt drive is primarily affected by the error in the pulley diameter. The greater the difference between the pulley diameter and the theoretical diameter, the greater the transmission error.

[0003] The traditional method of measuring the pulley diameter to calculate the transmission error is affected by the accuracy of the dimensional measurement tool itself and the pulley installation error, and cannot reflect the transmission error under the actual motion state of the mechanism. The method of measuring the transmission error by installing a high-precision angle encoder on each transmission shaft has the disadvantages of inconvenient installation and long measurement cycle due to the high installation requirements of the encoder itself and the limitations of the mechanical structure.

[0004] Therefore, it is necessary to provide a transmission error measurement device and method for a double transmission ratio belt transmission mechanism to solve the above problems. Summary of the Invention

[0005] The present invention provides a device and method for measuring the transmission error of a double-transmission-ratio belt transmission mechanism, so as to solve the problems that the existing method of calculating the transmission error by measuring the pulley diameter is affected by the factors of the accuracy of the dimensional measuring tool itself and the pulley installation error, and cannot reflect the transmission error under the actual movement state of the mechanism; and the method of measuring the transmission error by installing a high-precision angle encoder on each transmission shaft has the disadvantages of inconvenient installation and long measurement cycle due to the high installation requirements of the encoder itself and the limitations of the mechanical structure shape.

[0006] The present invention provides a device and method for measuring transmission errors of a double transmission ratio belt transmission mechanism, which adopts the following technical solutions, including:

[0007] Photoelectric autocollimator, mechanical limiter and two reflectors;

[0008] Among them, two reflectors are respectively arranged on the large pulley and the small pulley of the belt transmission mechanism, and rotate with the corresponding pulleys; the light beam output by the photoelectric autocollimator is reflected by the reflector on the large pulley to the reflector on the small pulley, and the reflector on the small pulley returns the light beam to the photoelectric autocollimator through the reflector on the large pulley; the mechanical limit is installed on the large pulley to limit the rotation angle of the large pulley.

[0009] Preferably, a first reflector is fixed on the axle of the large pulley, and the first reflector is arranged vertically. A second reflector is fixed on the axle of the small pulley, and the angle between the second reflector and the horizontal plane is 45°; the optical axis of the photoelectric autocollimator is parallel to the second reflector.

[0010] Preferably, an angle encoder is also provided on the large pulley.

[0011] Preferably, the length of the second reflector is at least times the distance from the center of the large pulley to the center of the small pulley.

[0012] A method for measuring transmission error of a double transmission ratio belt transmission mechanism, comprising:

[0013] Install a first reflector and a second reflector, and adjust the two reflectors so that the included angle between the reflective surfaces of the two reflectors is an acute angle;

[0014] Place the photoelectric autocollimator and adjust its angle and position so that the light beam it emits is reflected by the first reflector, vertically incident on the second reflector, and then returns to the photoelectric autocollimator along the original path;

[0015] The belt transmission mechanism is rotated within the angle range corresponding to the upper limit position and the lower limit position of the mechanical limit, and the angle deviation between the outgoing light and the incident light is obtained using a photoelectric autocollimator according to the rotation angle of the large pulley of the belt transmission mechanism;

[0016] The transmission error of the belt transmission mechanism is obtained according to the angular deviation between the outgoing light and the incident light and the rotation angle of the large pulley.

[0017] Preferably, the transmission error of the belt transmission mechanism is:

[0018] a-2=β / (2 θ)

[0019] Where β represents the angular deviation between the outgoing light and the incident light; a-2 represents the transmission error of the belt drive mechanism; and θ represents the rotation angle of the large pulley within the angular range from the upper limit position to the lower limit position of the mechanical limit.

[0020] Preferably, during the rotation process, the angle between the reflection surfaces of the two reflectors is made acute.

[0021] Preferably, an angle encoder is used to obtain the rotation angle of the large pulley.

[0022] The beneficial effects of the present invention are:

[0023] The present invention aims at the characteristics of a belt transmission mechanism with a theoretical transmission ratio of two and utilizes the principle of plane reflection of light to propose a transmission error measurement method for a double transmission ratio belt transmission mechanism. The parallel light emitted by the photoelectric autocollimator is reflected by a first reflector installed on the axle of the large pulley, and then vertically enters the second reflector installed on the axle of the small pulley and returns to the photoelectric autocollimator along the original path. By rotating the double belt transmission mechanism, the transmission error can be measured according to the angle between the incident light and the outgoing light. The advantages of this method are that the measuring device is flexible and convenient to install, and the use of the photoelectric autocollimator equipment improves the transmission error measurement accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0025] Figure 1 Schematic diagram of the overall structure of a transmission error measuring device for a double transmission ratio belt transmission mechanism according to the present invention;

[0026] Figure 2 It is a schematic diagram of the angles before and after the large pulley of a belt transmission mechanism rotates in a method for measuring transmission error of a double transmission ratio belt transmission mechanism of the present invention.

[0027] In the figure: 1. Photoelectric autocollimator; 2. Large pulley; 3. Small pulley; 4. Belt; 5. First reflector; 6. Second reflector; 7. Mechanical limit. DETAILED DESCRIPTION

[0028] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0029] An embodiment of a transmission error measuring device for a double transmission ratio belt transmission mechanism of the present invention is as follows: Figure 1As shown, it includes: a photoelectric autocollimator 1, a mechanical limit 7, a first reflector 5 and a second reflector 6; wherein, the two reflectors are respectively arranged on the large pulley 2 and the small pulley 3 of the belt transmission mechanism, and the large pulley 2 and the small pulley 3 are connected by a belt 4, and rotate with the corresponding pulleys; the light beam output by the photoelectric autocollimator 1 is reflected by the reflector on the large pulley 2 to the reflector on the small pulley 3, and the reflector on the small pulley 3 returns the light beam to the photoelectric autocollimator 1 through the reflector on the large pulley 2; the mechanical limit 7 is installed on the large pulley 2, and is used to limit the rotation angle of the large pulley 2.

[0030] Specifically, a first reflector 5 is fixed on the axle of the large pulley 2, and the first reflector 5 is vertically arranged. A second reflector 6 is fixed on the axle of the small pulley 3, and the angle between the second reflector 6 and the horizontal plane is 45°; the optical axis of the photoelectric autocollimator 1 is parallel to the second reflector 6.

[0031] Specifically, the large pulley 2 is further provided with an angle encoder, and the rotation angle of the large pulley 2 is obtained through the angle encoder.

[0032] A method for measuring transmission error of a double transmission ratio belt transmission mechanism, comprising:

[0033] Step 1: Install the first reflector 5 and the second reflector 6 so that the reflective surfaces of the two reflectors are parallel to the axis of the corresponding pulley axle, and the angle between the reflective surfaces of the two reflectors is an acute angle, wherein the first reflector 5 and the second reflector 6 are both one-dimensional angle-adjustable reflectors.

[0034] Step 2: Place the photoelectric autocollimator 1 and adjust the angle and position of the photoelectric autocollimator 1 so that the light beam emitted by the photoelectric autocollimator 1 is reflected by the first reflector 5 and then vertically incident on the second reflector 6 and then returns to the photoelectric autocollimator 1 along the original path;

[0035] Step 3. Rotate the belt transmission mechanism within the angular range corresponding to the upper limit position and the lower limit position of the mechanical limit 7, and use the photoelectric autocollimator 1 to obtain the angular deviation between the outgoing light and the incident light according to the rotation angle of the large pulley 2 of the belt transmission mechanism; it should be noted that the angle between the two reflectors should always be kept acute during the rotation process, so that the transmission error of the large pulley within the range of no more than 90° can be measured in a single measurement process. If the transmission error within other rotation ranges of the large pulley needs to be measured, the initial installation angle of the first reflector 5 and the mechanical limit 7 can be adjusted, and step 2 can be executed again.

[0036] Step 4: Obtain the transmission error of the belt transmission mechanism based on the angular deviation between the outgoing light and the incident light and the rotation angle of the large pulley 2. The specific steps are as follows:

[0037] Reference Figure 2Assume that the angle between the reflection surfaces of the first reflector 5 and the second reflector 6 is 45° when the first reflector 5 and the second reflector 6 are initially installed, the rotation angle of the large pulley 2 is θ, and the actual transmission ratio of the current double belt transmission mechanism is a. Then the rotation angle of the small pulley 3 is a. θ, according to the properties of the triangle and the law of plane reflection of light, the following formula can be obtained:

[0038] ∠ABD=∠BAO+∠BOA=45°+θ(1)

[0039] ∠CBO=∠ABD=45°+θ(2)

[0040] ∠BOC=∠BOA+∠AOC=θ+45°-a θ(3)

[0041] ∠BCO=180-∠BOC-∠CBO=90+(a-2) θ(4)

[0042] ∠OCD=180-∠BCO=90-(a-2) θ(5)

[0043] ∠ODC=180-∠OCD-∠BOC=45+(2a-3) θ(6)

[0044] Then the angle between the outgoing light and the incident light is:

[0045] β=∠ODC-∠ABD=2 (a-2) θ(7)

[0046] According to formula (7), when the output light at the two positions is rotated by θ1 and θ2 respectively from the initial 45° position, the angle between them satisfies:

[0047] β2-β1=2 (a-2) (θ2-θ1)(8)

[0048] According to formula (8), when the angle between the initial positions of the reflection surfaces of the two reflectors is not 45°, the transmission error a-2 of the double belt transmission mechanism can also be calculated based on the rotation angle range θ of the large pulley 2 and the deviation β between the outgoing light and the incident light measured by the photoelectric autocollimator 1. The formula is as follows:

[0049] a-2=β / (2 θ)(9)

[0050] In actual use, if the space of the transmission mechanism allows, a high-precision angle encoder can be installed on the large pulley shaft to replace the mechanical limit with a known angle range. The large pulley 2 is rotated and the rotation angle is read with the angle encoder, and the transmission error is then obtained based on this measurement method.

[0051] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A device for measuring transmission error of a double transmission ratio belt transmission mechanism, characterized in that: include: A photoelectric autocollimator (1), a mechanical limiter (7) and two reflectors; Wherein, two reflectors are respectively arranged on a large pulley (2) and a small pulley (3) of the belt transmission mechanism and rotate with the corresponding pulleys; the light beam output by the photoelectric autocollimator (1) is reflected to the reflector on the small pulley (3) via the reflector on the large pulley (2), and the reflector on the small pulley (3) returns the light beam to the photoelectric autocollimator (1) via the reflector on the large pulley (2); a mechanical limiter (7) is installed on the large pulley (2) and is used to limit the rotation angle of the large pulley (2); A first reflector (5) is fixed on the axle of the large pulley (2), and the first reflector (5) is vertically arranged. A second reflector (6) is fixed on the axle of the small pulley (3), and the angle between the second reflector (6) and the horizontal plane is 45 degrees. The optical axis of the photoelectric autocollimator (1) is parallel to the second reflector (6).

2. The transmission error measuring device of a double transmission ratio belt transmission mechanism according to claim 1, characterized in that: An angle encoder is also provided on the large pulley (2).

3. The transmission error measuring device of a double transmission ratio belt transmission mechanism according to claim 1, characterized in that: The length of the second reflector (6) is at least twice the distance from the center of the large pulley (2) to the center of the small pulley (3).

4. A method for measuring transmission error of a double transmission ratio belt transmission mechanism, characterized in that: The error measurement is performed using the double transmission ratio belt transmission mechanism transmission error measuring device according to any one of claims 1 to 3, wherein the measurement steps include: Installing a first reflector (5) and a second reflector (6), and adjusting the two reflectors so that the angle between the reflective surfaces of the two reflectors is an acute angle, wherein the optical axis of the photoelectric autocollimator (1) is parallel to the second reflector (6); Place the photoelectric autocollimator (1) and adjust its angle and position so that the light beam emitted by it is reflected by the first reflector (5) and then vertically enters the second reflector (6) and then returns to the photoelectric autocollimator (1) along the original path; The belt transmission mechanism is rotated within the angle range corresponding to the upper limit position and the lower limit position of the mechanical limit (7), and the angle deviation between the outgoing light and the incident light is obtained using the photoelectric autocollimator (1) according to the rotation angle of the large pulley (2) of the belt transmission mechanism; According to the angular deviation between the outgoing light and the incident light, the rotation angle of the large pulley (2) is used to obtain the transmission error of the belt transmission mechanism.

5. The method for measuring transmission error of a double transmission ratio belt transmission mechanism according to claim 4, characterized in that: The transmission error of the belt drive mechanism is: a-2=β / (2) (i) Where β represents the angular deviation between the outgoing light and the incident light; a-2 represents the transmission error of the belt drive mechanism; and θ represents the rotation angle of the large pulley within the angular range from the upper limit position to the lower limit position of the mechanical limit.

6. The method for measuring transmission error of a double transmission ratio belt transmission mechanism according to claim 4, characterized in that: During the rotation process, the angle between the reflection surfaces of the two reflectors is made acute.

7. The method for measuring transmission error of a double transmission ratio belt transmission mechanism according to claim 4, characterized in that: The angle encoder is used to obtain the rotation angle of the large pulley.

Images