Corner detection quantity amplifying device based on friction transmission

Abstract

The invention discloses a rotation angle detection quantity amplifying device based on friction transmission, and aims to solve the problems that an existing rotation angle detection device is difficult to be directly applied to the medical field or the aerospace field due to overlarge size, and the cost is relatively high. The pressing wheels are evenly distributed between the driving wheel and the driven wheel in the circumferential direction, each pressing wheel is connected with one pressing assembly, the driving shaft is connected with the driving limiting assembly, and the driven limiting assembly is connected with the driven shaft. The device is matched with an existing low-precision sensor, the low-error high-power amplification and detection effect of the rotating angle of the rotating shaft can be achieved, the rotating angle detection amount is amplified, the rotating angle detection precision is improved, high-precision measurement of the rotating angle through the low-precision sensor is achieved, and the device has breakthrough significance in the field of angle sensing and control. And the method has extremely high commercial value. The invention belongs to the technical field of high-precision angle measurement.

Description

Technical Field

[0001] The invention relates to a rotation angle detection quantity amplifying device, in particular to a rotation angle detection quantity amplifying device based on friction transmission. The invention belongs to the technical field of high-precision angle measurement. Background Art

[0002] Rotational angle measurement is an important branch of the field of measurement technology. It has been widely used in various occasions, especially in aerospace, medical equipment and other fields. The demand for high-precision rotational angle detection is extremely widespread, and the detection resolution usually needs to reach the micro-arc level, that is, within a few arc seconds.

[0003] However, the high-precision photoelectric code disks widely used in rotation angle detection today generally have the problem of large size. The outer diameter of the photoelectric code disk will increase with the improvement of accuracy. When the accuracy reaches within 10 arc seconds, the outer diameter of the photoelectric code disk is usually close to 200mm. Due to its large size, it is difficult to directly apply it to the medical or aerospace fields. In addition, high-precision photoelectric code disks have disadvantages such as high cost and high price, which are not conducive to the advancement of research. Summary of the invention

[0004] The present invention aims to solve the problem that the existing rotation angle detection device is too large to be directly applied in the medical field or the aerospace field, and the high cost is not conducive to research advancement, and thus proposes a rotation angle detection amplification device based on friction transmission.

[0005] The technical solution adopted by the present invention to solve the above problems is:

[0006] The present invention includes a driving wheel shaft, a plurality of clamping wheels, a driven wheel shaft, a clamping assembly, an active end limit assembly and a driven end limit assembly, wherein the driving wheel shaft includes a driving wheel and a driving shaft, the driven wheel shaft includes a driven wheel and a driven shaft, the driven wheel is arranged in the driving wheel, the plurality of clamping wheels are evenly distributed between the driving wheel and the driven wheel along the circumferential direction, each clamping wheel is connected to one of the clamping assemblies, the driving shaft is connected to the active limit assembly, and the driven limit assembly is connected to the driven shaft.

[0007] Furthermore, the clamping assembly includes a thrust bearing, a clamping spring, an adjusting bolt and a clamping end cover. The thrust bearing is installed on the axle of the clamping wheel, one side of the thrust bearing is in contact with the clamping wheel, and the other side is in contact with the clamping spring. The clamping end cover is fixedly installed on the driven end housing, and one end of the adjusting bolt passes through the threaded hole of the clamping end cover and presses against one end of the clamping spring.

[0008] Furthermore, the active limit assembly includes an active end cover, an active end locking nut, an active end angular contact ball bearing and an active end housing. The active end housing is installed on the outside of the active wheel shaft. The active end locking nut and the active end angular contact ball bearing are sequentially mounted on the active shaft from the outside to the inside. The active end cover is located on the outside of the active end locking nut and is fixedly connected to the active end housing.

[0009] Furthermore, the driven end limiting assembly includes a driven end end cover, a driven end locking nut, a driven end angular contact ball bearing and a driven end housing. The driven end housing is installed on the outside of the driven wheel shaft, and the two ends of the driven end housing are respectively fixedly connected to the two ends of the driving end housing; the driven end cover, the driven end locking nut and the driven end angular contact ball bearing are sequentially mounted on the driven shaft from the outside to the inside, and the driven end cover is fixedly connected to the driven end housing.

[0010] Furthermore, the driving wheel and the driving shaft are integrally formed.

[0011] Furthermore, the driven wheel and the driven shaft are integrally formed.

[0012] Furthermore, the number of the clamping wheels is three.

[0013] The beneficial effects of the present invention are:

[0014] 1. The present invention is combined with the existing low-precision sensor to achieve low-error high-multiple amplification and detection effect of the rotation angle of the shaft, amplify the angle detection amount, improve the rotation angle detection accuracy, and realize high-precision measurement of the rotation angle using a low-precision sensor.

[0015] 2. The present invention does not have motion gap and return error, can achieve ultra-high precision amplification effect on the rotation angle, and will not cause a decrease in detection accuracy due to angle amplification.

[0016] 3. The present invention has a simple structure, is easy to process and assemble, can be mass-produced, and has a wide range of applications. Compared with directly using a high-precision sensor, the present device can significantly reduce the cost of corner detection.

[0017] 4. The present invention has a compact structure, with an axial length of less than 40 mm and a radial length of less than 70 mm, which greatly reduces the space occupied by the photoelectric encoder and can be widely used in various occasions including medical equipment and space fields.

[0018] 5. The present invention can be used alone or in series with multiple devices, and can achieve exponential growth in magnification within the precision control range.

[0019] 6. Through material selection, the present invention is insensitive to temperature changes and can be applied to a variety of high and low temperature environments.

[0020] 7. Each friction wheel adopts inclined surface contact. Under the action of the positive pressure of the compression spring, the contact surface will produce axial locking force and radial compression force to ensure the stability of the friction wheel transmission and the reliability of the axial limit. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is the overall structural principle diagram of the present invention;

[0022] Figure 2 for Figure 1 Side view of

[0023] Figure 3 Schematic diagram of friction wheel inclined surface contact;

[0024] Figure 4 It is a schematic diagram of the structure of the driving wheel shaft and the driven wheel shaft;

[0025] Figure 5 This is a schematic diagram of the compression force decomposition. DETAILED DESCRIPTION

[0026] Specific implementation method 1: Combination Figures 1 to 5 To illustrate this embodiment, Figure 1-2 As shown, this embodiment includes a transmission assembly, a clamping assembly, an active end limit assembly and a driven end limit assembly.

[0027] The transmission assembly consists of a driving wheel shaft 1, a pressure wheel 2 and a driven wheel shaft 3; the driving wheel shaft 1 includes a driving wheel 1-1 and a driving shaft 1-2, one side of the driving wheel 1-1 is provided with a friction surface 1-3, and the other side is integrally formed with the driving shaft 1-2, the driven wheel shaft 3 includes a driven wheel 3-1 and a driven shaft 3-2, the driven wheel 3-1 is located in the middle of the friction surface 1-3 of the driving wheel 1-1, the outer end of the driven wheel 3-1 is integrally formed with the driven shaft 3-2, a plurality of pressure wheels 2 are evenly distributed in the friction surface 1-3 of the driving wheel 1-1 and are located on the outer side of the driven wheel 3-1, the driving wheel 1-1 is in contact with the pressure wheel 2 inside, and the pressure wheel 2 is driven to rotate by friction transmission, the pressure wheel 2 is in contact with the driven wheel 3-1 outside, and the driven wheel shaft 3 is driven to rotate by friction transmission, thereby completing the motion transmission and realizing a fixed multiple amplification of the rotation angle of the rotating shaft.

[0028] In order to ensure that the amplifying device has no motion clearance and return error, the driving wheel shaft 1 and the driven wheel shaft 3 need to be processed as an integrated whole, that is, the driving wheel 1-1 and the driving shaft 1-2 are different parts of the same part, and the whole is the driving wheel shaft 1; similarly, the driven wheel shaft 3 is also an integrated part, such as Figure 4 shown.

[0029] Preferably, there are three clamping wheels 2. To minimize the influence of force deformation on transmission accuracy and avoid overall deviation caused by unbalanced bending moments between the driving wheel shaft 1 and the driven wheel shaft 3, three clamping wheels are evenly distributed around the circumference to jointly apply the same clamping force.

[0030] Preferably, the three clamping wheels 2, the driving wheel 1-1 and the driven wheel 3-1 are all made of the same material to ensure the same thermal expansion coefficient, thereby avoiding transmission errors caused by different relative deformation ratios due to temperature changes.

[0031] Preferably, the wheel surface of the clamping wheel 2 is coated with a layer of tungsten carbide coating, which can avoid cold welding caused by long-term contact of the same material and greatly improve the friction coefficient between the friction wheels, thereby ensuring the reliability of the friction transmission and avoiding slipping.

[0032] In the present embodiment, each clamping assembly is composed of a thrust bearing 4, a clamping spring 5, an adjusting bolt 6 and a clamping end cover 7; the thrust bearing 4 cooperates with the clamping wheel 2, one side of the thrust bearing 4 contacts the clamping wheel 2, and the other side contacts the clamping spring 5; the clamping end cover 7 is fixedly mounted on the driven end housing 15 and has a threaded hole, the adjusting bolt 6 is mounted on the clamping end cover 7 through the threaded hole and can achieve axial displacement through threaded cooperation; the clamping spring 5 is acted upon by the adjusting bolt 6, and its own length will change with the displacement of the adjusting bolt 6, thereby generating positive pressures of different sizes on the clamping wheel 2, and the clamping wheel 2 is subjected to force and fits tightly with the driving wheel 1-1 and the driven wheel 3-1, thereby generating a clamping effect and ensuring the reliability and stability of the friction transmission.

[0033] The three clamping components are evenly distributed around the circumference, and the positive pressure of each clamping component is controlled by each adjusting bolt 6. The adjusting screw 6 of the clamping part needs to be anti-loosening measures to avoid changes in the clamping force caused by loosening of the screw during work. This can be handled by matching anti-loosening nuts, applying thread glue, etc.

[0034] In this embodiment, in order to ensure the stability of the friction wheel transmission and the reliability of the axial limit, the inner contour of the friction surface 1-3 of the driving wheel 1-1 is gradually expanded from the inside to the outside; the outer contour of the clamping wheel 2 is gradually expanded from left to right; the outer contour of the driven wheel 3-1 is gradually contracted from left to right; the transmission between the driving wheel 1-1 and the clamping wheel 2, and the transmission between the clamping wheel 2 and the driven wheel 3-1 are all inclined contact, and the friction transmission cross-section diagram is as shown in Figure 3 As shown, the positive pressure applied to the clamping wheel 2 by the clamping spring 5 is decomposed into an axial locking force and a radial clamping force when the clamping wheel 2 is in contact with the inclined surface of the driven wheel 3-1, such as Figure 5 The axial locking force limits the friction wheel axially and eliminates the axial clearance inside the device; the radial clamping force ensures the contact reliability of the friction pair and avoids slipping.

[0035] The active end limiting assembly includes an active end cover 8, an active end locking nut 9, an active end angular contact ball bearing 10, an active end housing 11, and an active wheel shaft 1-2 cooperates with the active end angular contact ball bearing 10. The inner ring of the active end angular contact ball bearing 10 is locked with the active wheel 1-1 under the action of the active end locking nut 9, and the outer ring of the bearing cooperates with the shaft hole of the active end housing 11 to complete radial limiting, and is in close contact with the active end cover 8 to complete axial limiting; the active end cover 8 is installed on the active end housing 11 by bolts; the active end housing 11 and the driven end housing 15 are connected and fixed by bolts;

[0036] The driven end limiting assembly includes a driven end cover 12, a driven end locking nut 13, a driven end angular contact ball bearing 14, and a driven end housing 15; the driven wheel shaft 3 cooperates with the driven end angular contact ball bearing 14, and is locked with the inner ring of the bearing under the action of the driven end locking nut 13; the driven end angular contact ball bearing 14 cooperates with the bearing hole reserved on the driven end housing 15 to achieve radial limiting while achieving axial limiting by contacting with the outer ring of the bearing; the driven end cover 12 is installed on the driven end housing 15 by bolts.

[0037] Specific implementation method two: In this implementation method, in order to reduce the impact of temperature changes on the transmission accuracy of the device, it is necessary to select materials with the same or similar thermal expansion coefficients as the internal parts of the amplifying device as much as possible, such as the combination of titanium alloy TC4 and alloy steel; in order to ensure that cold welding does not occur when the materials of the other parts except the friction wheel are the same, molybdenum disulfide should be coated between the same materials to avoid direct contact.

[0038] The present invention is a high-precision device and should be fully run-in before being put into actual use, and the actual magnification should be tested and calibrated; for each individual magnifying device, a separate magnification test and calibration should be performed, and after being put into use, calculations should be strictly performed according to the magnification calibration value.

[0039] The present invention can be used as a single amplifying device, or multiple devices can be used in series, and the comprehensive amplification factor is the product of the calibration factors of each amplifying device. The other components and connection relationships of this embodiment are the same as those of the first embodiment.

[0040] Specific implementation method three: In this implementation method, the number of the clamping wheels 2 can be four or six evenly distributed along the circumferential direction, and each clamping wheel 2 is equipped with a clamping assembly. The other components and connection relationships of this implementation method are the same as those of specific implementation methods one or two.

[0041] The installation process of each component of the present invention is as follows:

[0042] The driving end housing 11 is a fixed part, and the driving wheel shaft 1 cooperates with the driving end angular contact ball bearing 10, and is tightly fitted with the inner ring of the bearing under the action of the driving end locking nut 9; the driving end cover 8 is installed on the driving end housing 11 by bolts, and contacts and cooperates with the outer ring of the driving end angular contact ball bearing 10, which plays a role in limiting and positioning it;

[0043] The clamping wheel 2 cooperates with the thrust bearing 4 and fits tightly under the action of the clamping spring 5. The whole is installed on the driven end housing 15 through the shaft hole, and is positioned and limited by the friction surface 1-3 with the driving wheel 1-1; the adjusting bolt 6 is installed on the clamping end cover 7 through threaded connection, and the clamping end cover 7 is installed on the driven end housing 15 through bolts;

[0044] The driven wheel shaft 3 cooperates with the driven end angular contact ball bearing 14, and fits tightly with the inner ring of the bearing under the action of the driven end locking nut 13; the driven end cover 12 is installed on the driven end housing 15 by bolts; the driven end housing 15 is connected to the active end housing 11 by bolts, and the active end housing 11 is connected to the target to be measured as a fixing part;

[0045] The rotating shaft to be detected is connected to the driving shaft 1-2 through a coupling, and the low-precision angle sensor is connected to the driven shaft 3-2.

[0046] Working principle:

[0047] a The driving wheel shaft 1 is the input, and the driven wheel shaft 3 is the output. The rotation angle of the driving wheel shaft 1 is driven by friction wheels with different transmission radius to achieve a multiple amplification effect.

[0048] bIn actual applications, the driving wheel shaft 1 should be connected to the rotating shaft, motor output shaft and other rotating devices to be detected, and the driven wheel shaft 3 should be connected to the existing low-precision angle sensor. The low-precision angle sensor can be any model that meets the accuracy standard after matching the magnification, such as the Witson VTD68K08 photoelectric encoder.

[0049] cDuring the working process, the clamping part will always apply a certain clamping force, there is no movement gap inside the device, the friction wheel always maintains close contact, it has stability and reliability, and there will be no return error.

[0050] dTheoretical amplification ratio K=R1×R2 / (R2×R3)=R1 / R3=10; wherein R1, R2, and R3 are the transmission radii of the driving wheel shaft 1, the pressure wheel 2, and the driven wheel shaft 3, respectively, that is, the radius size of each friction wheel.

[0051] Working process:

[0052] The shaft to be measured rotates a certain angle θ, which is transmitted to the driving wheel shaft 1 through the coupling to make it rotate the same angle θ. The driving wheel shaft 1 drives the clamping wheel 2 to rotate, and the clamping wheel 2 drives the driven wheel shaft 3 to rotate. From the transmission ratio of the friction gear system, it can be seen that the amplification ratio is k, and the rotation angle of the driven wheel shaft 3 is kθ. At this time, the input angle of the angle sensor increases from θ to kθ, achieving a multiple increase. The low-precision sensor cannot distinguish θ, but can distinguish kθ, thereby realizing the detection of high-precision rotation angle by the low-precision angle sensor.

[0053] For example, the parameters of the device are matched. Through parameter allocation, the magnification of the amplifying device can be theoretically calculated. Now assume that the resolution of the low-precision photoelectric encoder is insufficient, and at least 10 times the angle magnification effect needs to be achieved. The transmission radius of the driving wheel shaft 1 is R1 = 25mm, the transmission radius of the clamping wheel 2 is R2 = 11.25mm, and the transmission radius of the driven wheel shaft 3 is R3 = 2.5mm. At this time, the radial size of the device can be controlled within 60mm, and the axial size can be controlled within 40mm. The theoretical magnification ratio K = R1×R2 / (R2×R3) = R1 / R3 = 10, which meets the multiple requirements.

[0054] The size of the amplifying device may also be other values ​​within the required range, such as an outer diameter of 100 mm, an outer diameter of 50 mm, etc.

[0055] The above is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technician familiar with this profession can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent replacement and improvement made to the above embodiments without departing from the content of the technical solution of the present invention, based on the technical essence of the present invention, within the spirit and principles of the present invention, still fall within the protection scope of the technical solution of the present invention.

Claims

1. A rotation angle detection quantity amplification device based on friction transmission, characterized in that: The rotation angle detection quantity amplification device based on friction transmission comprises a driving wheel shaft (1), a plurality of clamping wheels (2), a driven wheel shaft (3), a clamping assembly, a driving end limit assembly and a driven end limit assembly, wherein the driving wheel shaft (1) comprises a driving wheel (1-1) and a driving shaft (1-2), the driven wheel shaft (3) comprises a driven wheel (3-1) and a driven shaft (3-2), the driven wheel (3-1) is arranged inside the driving wheel (1-1), the plurality of clamping wheels (2) are evenly distributed between the driving wheel (1-1) and the driven wheel (3-1) along the circumferential direction, each clamping wheel (2) is connected to one of the clamping assemblies, the driving shaft (1-2) is connected to the active limit assembly, and the driven limit assembly is connected to the driven shaft (3-2).

2. The rotation angle detection quantity amplification device based on friction transmission according to claim 1 is characterized in that: The clamping assembly comprises a thrust bearing (4), a clamping spring (5), an adjusting bolt (6) and a clamping end cover (7); the thrust bearing (4) is mounted on the axle of the clamping wheel (2); one side of the thrust bearing (4) is in contact with the clamping wheel (2) and the other side is in contact with the clamping spring (5); the threaded hole of the adjusting bolt (6) passes through the clamping end cover (7) and is pressed against one end of the clamping spring (5).

3. The rotation angle detection quantity amplification device based on friction transmission according to claim 1 is characterized in that: The active limiter assembly comprises an active end cover (8), an active end locking nut (9), an active end angular contact ball bearing (10) and an active end housing (11); the active end housing (11) is mounted on the outside of the active wheel shaft (1); the active end locking nut (9) and the active end angular contact ball bearing (10) are sequentially mounted on the active shaft (1-2) from the outside to the inside; the active end cover (8) is located on the outside of the active end locking nut (9) and is fixedly connected to the active end housing (11).

4. The rotation angle detection quantity amplification device based on friction transmission according to claim 1 is characterized in that: The driven limiter assembly comprises a driven end cover (12), a driven end locking nut (13), a driven end angular contact ball bearing (14) and a driven end housing (15); the driven end housing (15) is mounted on the outside of the driven wheel shaft (3); the driven end cover (12), the driven end locking nut (13) and the driven end angular contact ball bearing (14) are sequentially mounted on the driven shaft (3-2) from the outside to the inside; and the driven end cover (12) is fixedly connected to the driven end housing (15).

5. The rotation angle detection quantity amplification device based on friction transmission according to claim 1, characterized in that: The driving wheel (1-1) and the driving shaft (1-2) are integrally formed.

6. The rotation angle detection quantity amplification device based on friction transmission according to claim 1, characterized in that: The driven wheel (3-1) and the driven shaft (3-2) are integrally formed.

7. The rotation angle detection quantity amplification device based on friction transmission according to claim 1, characterized in that: The number of the clamping wheels (2) is three.

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