CN211927266U - Gear transmission tooth surface friction measuring system - Google Patents

Abstract

The utility model discloses a measuring system for gear drive tooth surface friction, which belongs to the field of gears. The system includes a transmission mechanism, a load mechanism, a laser displacement sensor, an angle sensor and a server. The transmission mechanism is connected to the load mechanism through a gear pair, and the server is electrically connected to the laser displacement sensor and the angle sensor. The laser displacement sensor is used to detect the displacement of the transmission mechanism. The angle sensor is used to detect the wheel rotation angle signal of the gear pair; the transmission mechanism is also connected to a power source; the transmission mechanism at least includes a transmission shaft, and the laser displacement sensor can measure the bending deformation displacement of the transmission shaft.

Description

A measuring system for gear tooth surface friction

technical field

The utility model belongs to the field of gears, and in particular relates to a measuring system for gear transmission tooth surface friction.

Background technique

The statements herein merely provide background related to the present disclosure and do not necessarily constitute prior art.

Gear is an important basic part of mechanical equipment, and the main transmission form of most complete sets of machinery is gear transmission. The transmission performance and service life of the gear mechanism directly affect the working accuracy and reliability of the mechanical equipment. Since the gear transmission transmits motion and power based on the continuous meshing between the teeth, friction will inevitably occur on the meshing tooth surfaces. Tooth surface friction is an important excitation source for gear vibration and noise. Tooth surface friction accelerates the occurrence of early gear failures, which in turn aggravate tooth surface friction and further lead to gear damage. The tooth surface friction will not only reduce the transmission performance of the gear, but also shorten the working life of the gear. Therefore, it is urgent to analyze the real change law of tooth surface friction in the process of gear meshing through experiments, and to further study the mechanism of tooth surface friction and the influence of different parameters on tooth surface friction, so as to reduce the harm caused by tooth surface friction.

The inventor found that the test method of tooth surface friction can be divided into a direct test method and an indirect test method. The direct test method of tooth surface friction generally refers to the resistance strain gauge method. The test process is easily affected by temperature. If the temperature is too high, the strain gauge will be thermally deformed, resulting in experimental errors. Collision will cause additional deformation of the tooth surface, causing test errors. The indirect test method of tooth surface friction can be applied to different gear transmission types and special working environments, mainly including equivalent torque method, equivalent gravity pendulum method and photoelasticity method. The equivalent torque method defaults that the energy loss of the system comes from the tooth surface friction, ignoring the friction between the bearing and the shaft and other contact areas and the energy loss caused by factors such as oil churning, so the measurement accuracy is relatively low. The equivalent gravity pendulum method ignores the influence of factors such as air resistance, and cannot be measured in real time. The obtained friction coefficient of the tooth surface cannot reflect the real friction behavior of the tooth surface in the continuous meshing process. The photoelasticity test process is relatively complicated, and the requirements for the test device and technicians are very high; and the steel material generally used for gears does not have birefringence effect, even if it is made into a photoelastic material gear model, it is difficult to guarantee its test results. It is the same as the tooth surface friction characteristics of real gear transmission; in addition, in the process of measurement, it is inconvenient to use optical sensors for direct measurement.

Utility model content

In view of the deficiencies in the prior art, the purpose of this utility model is to provide a measurement system for gear transmission tooth surface friction, which is less affected by temperature, has small test errors, and has high measurement accuracy, which meets the needs of real-time detection, and is very useful for testing devices and technology. Personnel requirements are low.

In order to achieve the above object, the present invention is realized through the following technical solutions:

In the first aspect, an embodiment of the present invention provides a gear transmission tooth surface friction measurement system, including a transmission mechanism, a load mechanism, a laser displacement sensor, an angle sensor and a server, the transmission mechanism is connected to the load mechanism through a gear pair, and the server is electrically connected to the laser displacement sensor and the angle sensor, wherein the laser displacement sensor is used to detect the displacement of the transmission mechanism, and the angle sensor is used to detect the wheel rotation angle signal of the gear pair; the transmission mechanism is also connected to a power source; the transmission mechanism at least includes a transmission The laser displacement sensor can measure the bending deformation displacement of the transmission shaft.

As a further technical solution, the laser displacement sensor includes a first laser displacement sensor and a second laser displacement sensor, the first laser displacement sensor can emit laser light along the friction force direction of the gear pair, and the second displacement sensor can be along the meshing force of the gear pair. emits laser light in the direction.

As a further technical solution, the loading mechanism adopts a magnetic powder loader.

As a further technical solution, the transmission mechanism includes an input shaft and an output shaft, the input shaft and the output shaft are kept parallel, the input shaft is connected to the driving gear, and the output shaft is connected to the driven gear.

As a further technical solution, the input shaft can also be connected with an eccentric wheel, and when the eccentric wheel is in contact with the output shaft, the gear pair is separated.

As a further technical solution, the angle sensor is sleeved on the transmission mechanism, and when the transmission mechanism is installed with an eccentric wheel, the initial position of the angle sensor is the same as the eccentric direction of the eccentric wheel.

As a further technical solution, the laser displacement sensor is installed on a rotating bracket, and the emission direction of the laser displacement sensor can be changed.

In the second aspect, the technical solution of the present utility model also provides a method for measuring the friction of the gear transmission tooth surface, using the measurement system of the gear transmission tooth surface friction described in any one of the technical solutions of the first aspect, including the following steps:

Test the bending stiffness of the input shaft;

Displacement test of the input shaft in the direction of friction force and meshing force;

Calculate error displacement and actual deformation;

Calculate the friction force and friction coefficient, and convert the angular domain of the friction force and friction coefficient signals.

The beneficial effects of the above-mentioned embodiments of the present utility model are as follows:

1) In the solution provided by the utility model, the laser displacement sensor and the angle sensor are used to measure together, which gets rid of the traditional resistance measurement method and is less affected by temperature; The collision will cause additional deformation of the tooth surface, and the indirect measurement by the laser displacement sensor in the utility model can avoid the change of the current conductivity caused by this deformation and reduce the measurement error.

2) In the scheme provided by the utility model, the friction between the bearing and the shaft and other contact areas and the energy loss caused by factors such as oil churning are considered, and the laser displacement sensor is used for real-time measurement, and the obtained tooth surface friction coefficient can reflect the continuous meshing. The real friction behavior of the tooth surface during the process.

3) In the solution provided by the utility model, considering that the steel material generally used for gears does not have birefringence effect, two laser displacement sensors are used, and one laser displacement sensor can measure the position of the input shaft connected to the gear pair. Bending deformation displacement in the direction of friction force, another laser displacement sensor can measure the bending deformation displacement of the input shaft connected to the gear pair in the direction of meshing force, which avoids the error caused by direct measurement, and also allows the laser displacement sensor. Measurement is easier.

Description of drawings

The accompanying drawings, which constitute a part of the present invention, are used to provide further understanding of the present invention, and the schematic embodiments and descriptions of the present invention are used to explain the present invention, and do not constitute an improper limitation of the present invention.

Fig. 1 is the overall schematic diagram of the system according to one or more embodiments of the present invention,

2 is a schematic diagram of the eccentric disk installation and the measuring direction of the laser displacement sensor according to one or more embodiments of the present invention,

3 is a schematic diagram of the measurement direction of the laser displacement sensor according to one or more embodiments of the present invention,

FIG. 4 is a schematic diagram of the position of the engagement force measured by the laser displacement sensor according to one or more embodiments of the present invention,

5 is a schematic diagram of additional displacement measured by the laser displacement sensor in the direction of friction force under the action of the meshing force at the position shown in FIG. 4 according to one or more embodiments of the present invention,

6 is a schematic diagram of the position of the friction force measured by the laser displacement sensor according to one or more embodiments of the present invention,

7 is a schematic diagram of additional displacement measured by the laser displacement sensor in the direction of the meshing force under the action of the friction force at the position shown in FIG. 6 according to one or more embodiments of the present invention.

In the figure: 1. Bottom plate, 2. Motor, 3. First coupling, 4. First bearing seat, 5. Angle sensor, 6. Support, 7. Input shaft, 8. Driving gear, 9. First Magnetic base bracket, 10, first laser displacement sensor, 11, first lock nut, 12, output shaft, 13, second lock nut, 14, driven gear, 15, second laser displacement sensor, 16, first Two magnetic seat brackets, 17, second bearing seat, 18, second coupling, 19, magnetic powder loader, 20, eccentric disc.

The mutual spacing or size is exaggerated in order to show the position of each part, and the schematic diagram is for illustration only.

Detailed ways

It should be noted that the following detailed descriptions are all exemplary and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

It should be noted that the terminology used herein is for describing specific embodiments only, and is not intended to limit the exemplary embodiments according to the present invention. As used herein, the singular form is also intended to include the plural form unless the invention clearly dictates otherwise, and it should also be understood that when the terms "comprising" and/or "comprising" are used in this specification, it indicates the presence of features, steps, operations, devices, components and/or combinations thereof;

In order to facilitate the description, if the words "up", "down", "left" and "right" appear in the present utility model, it only means that the directions of up, down, left and right are consistent with the drawings themselves, and do not limit the structure. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

Terminology explanation part: the terms "installation", "connected", "connected", "fixed" and other terms in the present utility model should be understood in a broad sense, for example, it can be a fixed connection or a detachable connection, or as a whole; It can be a mechanical connection, an electrical connection, a direct connection, or an indirect connection through an intermediate medium, an internal connection between two elements, or an interaction relationship between the two elements. In other words, the specific meanings of the above terms in the present invention can be understood according to specific situations.

As described in the background art, in view of the deficiencies in the prior art, the purpose of the present invention is to provide a measurement system for gear transmission tooth surface friction, which is less affected by temperature, has small test errors, and has high measurement accuracy, which meets the requirements of real-time detection. Requires low requirements on test equipment and technicians.

Example 1

In a typical embodiment of the present invention, as shown in FIG. 1 , a measurement system for gear transmission tooth surface friction includes two laser displacement sensors and an angle sensor 5 , and the device to be measured includes a driving device, an input Shaft 7, output shaft 12, load device and a pair of meshing gear pairs; the gear pair includes meshing driving gear 8 and driven gear 14, the driving gear 8 is mounted on the input shaft 7, and the driven gear 14 is mounted on the output shaft 12 The drive device is connected to and drives the input shaft 7, and the load device is connected to the output shaft 12. The angle sensor 5 measures the angular displacement θ( _t ) of the driving gear 8, and the two laser displacement sensors measure the displacements δm( _t ) and δf(t) of the input shaft 7 in the directions of meshing force and friction force, respectively.

In a specific implementation scenario, the drive device adopts a motor 2, the motor 2 is fixedly connected to the base plate 1, the output shaft 12 of the motor 2 is connected to one end of the first coupling 3, and the other end of the first coupling 3 Connect the transmission shaft, the transmission shaft is provided with a first bearing seat 4 to support the movement of the transmission shaft, the other end of the transmission shaft is connected to the driving gear 8 through the support 6 provided on the base, and the driving gear 8 and the input shaft 7 pass through the first lock The tightening nut 11 is fixed, and the transmission shaft is used as the input shaft 7, which can transmit the torque of the motor 2 to the driving gear 8. The driving gear 8 meshes with the driven gear 14, and the driven gear 14 is connected to the output shaft 12. The output shaft 12 and the driven gear 14 is fixedly connected by the second locking nut 13, the output shaft 12 is also connected by the second bearing seat 17, and is connected by the second coupling 18, and the second coupling 18 is connected with the power input shaft 7 of the magnetic powder loader 19.

It can be understood that, in this embodiment, the magnetic powder loader 19 described above is used as the loading device.

The two laser displacement sensors are the first laser displacement sensor 10 and the second laser displacement sensor 15 respectively. It can be understood that the first laser displacement sensor 10 is used to detect and measure the displacement δm( _t ) of the input shaft 7 in the direction of the meshing force. ), the second laser displacement sensor 15 is used to detect the displacement δ _f (t) of the input shaft 7 in the direction of the friction force.

The first laser displacement sensor 10 is installed on the first magnetic base bracket 9, the first laser displacement sensor 10 is located on one side of the driving gear 8; the second laser displacement sensor 15 is installed on the second word bracket, and the second laser displacement sensor 15 is located in One side of the driven gear 14 . The first magnetic base bracket 9 is installed on the base, and the second magnetic base support 16 is installed on the base. The magnetic seat bracket is an existing component, and its specific structure will not be repeated here.

It can be understood that since the laser displacement sensor is detected by laser, the detection laser emitted by the first laser detector can be irradiated on the input shaft 7, and the detection laser emitted by the second laser detector can be irradiated on the input shaft 7. superior.

The angle sensor 5 is attached to the input shaft 7 .

Both the laser displacement sensor and the angle sensor 5 are connected to the server to transmit the collected data to the server, and the server analyzes the data.

Please refer to FIG. 2 , in this embodiment, an eccentric disc 20 is also included. It can be understood that the eccentric disc 20 can be used as an eccentric wheel to provide eccentric force for the input shaft, and the eccentric disc 20 is installed on the driving gear 8 during use. When the eccentric disc 20 is installed, the gear pair is separated; as the eccentric disc 20 rotates, it can provide eccentric force for the input shaft, so as to facilitate the bending stiffness test of the input shaft and adjust the first laser displacement sensor The measurement direction of 10 is the eccentric direction of the disk (the eccentricity direction marked in FIG. 2 ), that is, the angle corresponding to the initial position of the angle sensor 5 . Start the motor 2 and measure the bending deformation displacement of the input shaft 7 . According to the signal measured by the angle sensor 5 and the signal measured by the laser displacement sensor, the maximum bending deformation displacement of the input shaft 7 under the action of the centrifugal force of the disc is extracted.

Example 2

In a typical implementation of the present utility model, please refer to FIG. 2 to FIG. 5 . This embodiment discloses a method for measuring the friction of the gear transmission tooth surface. Measurement system, including the following steps:

Step 1, the bending stiffness test of the input shaft 7 . The gear pair is disengaged, an eccentric disc 20 is installed at the position of the driving gear 8, and the measurement direction of a laser displacement sensor is adjusted to be the disc eccentric direction, that is, the angle corresponding to the initial position of the angle sensor 5. Start the motor 2 and measure the bending deformation displacement of the input shaft 7 . According to the signal measured by the angle sensor 5 and the signal measured by the laser displacement sensor, the maximum bending deformation displacement δ _s of the input shaft 7 under the action of the centrifugal force of the disc is extracted, and the eccentric mass and eccentric distance of the disc are set as m and e respectively, and the motor 2 The rotational speed is ω, and the centrifugal force of the eccentric disc 20 is:

F _c =mω ² e (1)

where F _c is the centrifugal force, m is the mass of the eccentric disc, ω is the angular velocity of the eccentric disc, and e is the eccentricity of the eccentric disc;

The bending stiffness of the input shaft 7 at the measuring point is:

Always, k _s is the bending stiffness and δ _s is the bending deformation displacement.

Step 2, the displacement test of the input shaft 7 in the direction of the friction force and the meshing force. Install the driving gear 8 and mesh with the driven gear 14 normally. Adjust the measurement directions of the two laser displacement sensors on the input shaft 7 to be the direction of friction force and the direction of meshing force, respectively, and the measurement points in step 1 are on the same circle. Start motor 2 and apply load torque to test. The signals measured by the first laser displacement sensor 10 and the second laser displacement sensor 15 on the input shaft 7 are respectively δ _f (t) and δ _m (t), and the rotational angle signal of the driving gear 8 measured by the angle sensor 5 is θ ( t).

Step 3, Error displacement and actual deformation calculation. The displacement in the direction of the friction force obtained by the laser displacement sensor test includes the displacement under the action of the friction force and the error displacement under the action of the meshing force; similarly, the displacement in the direction of the meshing force obtained by the laser displacement sensor test includes the displacement under the action of the meshing force and friction. Error displacement under force. Assuming that the error displacements of the input shaft 7 in the direction of the friction force and the meshing force under the action of the meshing force and the friction force are respectively a _f (t) and a _m (t), then the input shaft 7 moves along the direction of the friction force under the action of the friction force. The actual deformation e _f (t) on and the actual deformation e _m (t) of the input shaft 7 in the direction of the meshing force under the action of the meshing force are calculated as:

e _f (t) = δ _f (t) - a _f (t) (3)

e _m (t) = δ _m (t) - a _m (t) (4)

Suppose the radius of the input shaft 7 is R _b , according to the geometric position relationship of the output shaft 12 before and after the deformation under the action of the force, the error displacements a _m (t) and a _f (t) under the action of the meshing force and the friction force are calculated as:

By combining formulas (3) and (5), it can be obtained that the actual deformation of the input shaft 7 in the direction of the friction force under the action of the friction force is:

By combining formulas (4) and (6), the actual deformation of the input shaft 7 along the direction of the meshing force under the action of the meshing force can be obtained

Step 4, friction force and friction coefficient calculation.

The corresponding meshing force F _m (t) and friction force can be obtained by multiplying the deformation of the input shaft 7 in the meshing force direction and the friction force direction caused by the meshing force and friction force by the bending stiffness k _s of the input shaft 7 at the measuring point. F _f (t):

F _m (t) = k _s e _m (t) (9)

F _f (t) = k _s e _f (t) (10)

The meshing force is divided by the friction force to obtain the friction coefficient:

Step 5, angular domain conversion of friction force and friction coefficient signals.

Since the measured signal is a time domain signal, it is difficult to obtain accurate friction force and friction coefficient changes in a meshing cycle due to factors such as rotational speed fluctuations. Therefore, it is necessary to convert the time domain signal into the corresponding angular domain signal for analysis.

The obtained friction force F _f (t) and friction coefficient μ (t) are jointly processed with the rotation angle signal θ (t) measured by the angle sensor 5, and the time domain signal can be converted into the friction force signal F _f ( θ) and friction coefficient signal μ(θ).

Then, the friction force F _f (θ) and friction coefficient μ (θ) of the angular domain signal are preprocessed, and the signal is intercepted with the angle rotated by one meshing cycle as the interval, and the non-periodic components in the signal are eliminated based on the synchronous averaging technique in the angular domain. And random disturbance, the friction force F _f '(θ) and friction coefficient μ'(θ) in the angle range of one meshing cycle are obtained.

It should also be noted that, in Figures 4 to 7, O is the center point of the original position of the input shaft (before the friction force or meshing force acts), and O' is the center point of the circle after the input shaft is deformed (after the friction force or meshing force acts). D is the measuring point of the laser displacement sensor of the input shaft before the action of the friction force, D' is the point of the laser displacement sensor of the input shaft after the action of the friction force, C is the measuring point of the laser displacement sensor of the input shaft before the action of the meshing force, C' It is the measuring point of the laser displacement sensor after the input shaft acts on the meshing force.

The above descriptions are only preferred embodiments of the present utility model, and are not intended to limit the present utility model. For those skilled in the art, the present utility model may have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims (6)

1. A gear transmission tooth surface friction measuring system is characterized by comprising a transmission mechanism, a load mechanism, a laser displacement sensor, an angle sensor and a server, wherein the transmission mechanism is connected with the load mechanism through a gear pair, the server is electrically connected with the laser displacement sensor and the angle sensor, the laser displacement sensor is used for detecting the displacement of the transmission mechanism, and the angle sensor is used for detecting a wheel rotation angle signal of the gear pair; the transmission mechanism is also connected with a power source; the transmission mechanism at least comprises a transmission shaft, and the laser displacement sensor can measure the bending deformation displacement of the transmission shaft; the load mechanism adopts a magnetic powder loader.

2. The gear drive tooth surface friction measuring system according to claim 1, wherein said laser displacement sensor comprises a first laser displacement sensor and a second laser displacement sensor, the first laser displacement sensor being capable of emitting laser light in a direction of a friction force of the gear pair, and the second laser displacement sensor being capable of emitting laser light in a direction of a meshing force of the gear pair.

3. The gear drive tooth surface friction measurement system of claim 1 wherein said drive mechanism includes an input shaft and an output shaft, the input shaft and the output shaft being parallel, the input shaft being connected to the drive gear and the output shaft being connected to the driven gear.

4. A gear tooth surface friction measuring system according to claim 3, wherein said input shaft is further adapted to be connected to an eccentric, and wherein the pair of gears are disengaged when the eccentric is against the output shaft.

5. The system for measuring the friction on the tooth surface of the gear wheel as claimed in claim 1, wherein the angle sensor is sleeved on the transmission mechanism, and when the transmission mechanism is provided with the eccentric wheel, the initial position of the angle sensor is the same as the eccentric direction of the eccentric wheel.

6. The gear drive tooth surface friction measuring system according to claim 1, wherein said laser displacement sensor is mounted to a rotating bracket, and the emitting direction of said laser displacement sensor can be changed.

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