EA042094B1 - STAND FOR MEASURING PROPELLER THRUST AND REACTIVE TORQUE AND DYNAMIC CHARACTERISTICS OF PROPELLER WITH ENGINE - Google Patents

Description

Technical area

The invention relates to devices for measuring thrust and propeller torque and can be used in the development of stands for testing propulsion devices for air and water. The stand can also be used to test mixing devices using propellers, turbines, etc.

Prior Art

A device for determining the characteristics of the propeller of an air robot CN 204064694 U is known, which contains a torque sensor and an S-type thrust sensor. The lower end of the S-type thrust sensor is fixed to the base of the test rig, and the upper end is rigidly connected to the base of the torque sensor. The propeller motor is mounted on the base, while the axis of the motor, torque sensor and S-type thrust sensor are installed on the same line.

Such a stand scheme is quite simple, but each sensor experiences, in addition to the measured load, an additional uncharacteristic load, which can distort the measurement results or reduce the measurement accuracy. In addition, the operation of an engine with a propeller introduces disturbances associated with inaccuracies in manufacturing, imbalance, etc., which is also recorded by sensors and superimposed on the main measured parameters.

The UAV test stand CN 106143949 B contains an engine mounting base that is mounted directly on the torque sensor. The torque sensor is mounted on a pair of plates with linear bearings.

The bearings are mounted on linear guides that are mounted on the base. The thrust sensor is located between the base and the lower pair of plates.

In this device, the thrust measurement sensor works in pure tension and can give good measurement results. The torque sensor works on a combined tensile and torsion load, which can reduce the accuracy of the measurement results, or a more expensive torque sensor that is not sensitive to tensile force must be used.

Devices for measuring propeller thrust and reaction torque are known, in which the components of the total load from the propeller are preliminarily separated into pure torsion and linear load, which are then measured by specialized sensors.

The combined mechanism for measuring the torque of the screw propeller CN 104316290 A contains a motor base, which is mounted on a movable plate through weight sensors. The movable plate is mounted on linear guides and connected to a draft sensor.

In this device, the thrust sensor works in pure tension and can give good measurement results. The torque sensor operates on a combined load.

Known devices for measuring thrust and reactive torque, in which the load from the propeller is divided into reactive torque and thrust, each type of load is fed to its sensor. This simplifies the measurement process and improves its accuracy.

The CN 201974262 U microminiature aircraft power test system consists of an engine support that is mounted on a shaft coaxial with the axis of rotation of the propeller engine under test. The engine support has the ability to swing and move along the shaft. The engine mount contains a lever that presses against a force sensor to measure the reaction torque of the propeller. The engine is connected to the body of the device by means of a thrust sensor.

A device for measuring thrust and torque of a small-sized engine with a CN 202511930 U propeller contains an engine mounting frame that is mounted on a guide that is mounted on a plain bearing and is connected on one side to a torque sensor and a thrust sensor on the other side.

Torque/Traction Separation Mechanism and Test Platform CN 102288912 B contains a plate for mounting a propeller motor, which is connected to a movable platform mounted on four linear bearings on guides mounted on the top plate. The movable platform is connected to the top plate through a force sensor. The top plate is mounted on the shaft on rolling bearings, and the end of the shaft is connected to the torque sensor.

Propeller thrust and torque measurement device CN 205066989 U includes a mounting bracket mounted on bearings, on which a mounting plate for a propeller engine is mounted on the thrust sensor. A lever is installed on the bracket, which, when rotated, presses on the force sensor to measure the reactive torque of the propeller.

The prototype of the invention is a device for measuring the torque of a small engine CN 104483053 A. The device contains a base and a movable element with a motor base mounted for movement relative to the base, on which an engine with a propeller and a lever is installed, with which a force sensor is associated to determine the reactive torque, A

- 1 042094 also connected to the movable element and the base force sensor for measuring thrust.

The disadvantages of the prototype are the complexity of the design and the large mass of the movable element, including a common base plate, bearing assemblies, a rod, a steel plate with a double lever and a force sensor. A large moving mass dampens (dampens) the variable component of the load that occurs during the operation of the engine and propeller, which leads to a decrease in measurement accuracy under variable loads.

Brief summary of the invention

The technical result is to simplify the design of the stand, improve the accuracy of measurements of the dynamic component of thrust and reactive moment of the propeller and its dynamic characteristics.

Technical task

The objective of the invention is to eliminate the above disadvantages, namely, simplifying the design of the stand, improving the accuracy of measurements of the dynamic component of thrust and reactive moment of the propeller and its dynamic characteristics.

The solution of the problem

EFFECT: technical result provides a stand for measuring thrust and reaction torque of a propeller and dynamic characteristics of a propeller with an engine, containing a base and a movable element mounted with the ability to move relative to the base with a motor base on which the engine with a propeller is installed, and a lever with which the sensor is associated forces to determine the reactive moment, as well as a force sensor connected to the movable element for measuring thrust, in which, in accordance with the proposed solution, the movable element is made in the form of a shaft and is installed on at least one support of rotation and linear movement along the axis of the shaft with the possibility of moving relative to base and rotation around its own axis.

In addition, the rotation and linear motion bearing is a limited stroke linear bearing, or a limited stroke Linear Rotary Bushing, or a gas static radial bearing, or a hydrostatic radial bearing, or a radial bearing which is in turn mounted on a linear bearing, or linear bearing, which in turn is mounted on a radial bearing.

In addition, the lever is coupled to a force sensor for measuring the reactive moment by means of a rolling element, or a flexible rod, or a rigid rod, which is installed through spherical joints.

In addition, the lever is connected to a force sensor for measuring a reactive moment of a linear type through a spherical joint.

In addition, a roller is installed at the end of the lever, the direction of movement of which coincides with the direction of the axis of the shaft, while the roller is associated with a force sensor for measuring the reactive moment.

In addition, the lever can be made of a magnetic material, a permanent magnet is installed in the direction of the lever action on the force sensor to measure the reactive moment, the distance between the lever and the magnet can be adjusted.

In addition, a plate of magnetic material or a permanent magnet can be installed on the lever, a permanent magnet is installed in the direction of the influence of the lever on the force sensor to measure the reactive moment, the distance between the plate of magnetic material or the permanent magnet and the magnet can be adjusted.

In addition, a permanent magnet can be installed on the lever, from the side opposite to the direction of the lever action, a second magnet is installed on the force sensor to measure the reactive moment, and the magnets are installed with the same poles to each other and the distance between them can be adjusted.

In addition, in the direction of the action of the lever on the force sensor for measuring the reactive moment, the lever can be pulled by a tension spring, the tension of which can be adjusted.

In addition, a coaxial force sensor is installed at the end of the shaft to measure the thrust of the propeller, the second end of which is connected to a self-aligning thrust or double-row spherical bearing, which is installed between two walls that limit its longitudinal movement, but do not limit the radial movement.

In addition, a lever is installed on the shaft, the end of the shaft is connected to a self-aligning thrust or double-row spherical bearing, which is installed between two walls that limit its longitudinal movement, but do not limit radial movement, strain gauges are installed on the shaft surface in the gap between the lever and the thrust bearing.

In addition, a lever in the form of a C-shaped bracket is installed on the end of the shaft, which interacts with a force sensor for measuring propeller thrust and a force sensor for measuring reactive torque.

Positive effects of the invention

Thus:

a fairly simple stand was developed to measure the thrust and reaction torque of the propeller

- 2 042094 with a minimum number of parts included in it, in which each sensor receives only loads characteristic of this sensor;

The stand has a minimum mass of moving parts, which, together with the use of sliding pairs on rolling pairs or exposure through a magnetic field or a gas (hydraulic) layer, makes it possible to increase the accuracy of measurements, especially of the variable values of thrust and reaction torque of the propeller.

Brief description of the drawings

The essence of the invention is illustrated by the following graphic material:

In FIG. 1 shows a general view of the stand for measuring thrust and propeller torque.

In FIG. 2a shows a support assembly using limited stroke linear bearings.

In FIG. 2b shows a support assembly using a linear swivel bushing with limited travel.

In FIG. 2c shows a support assembly using radial gas-static or hydrostatic bearings.

In FIG. 2d shows a support assembly in which the shaft is mounted in radial bearings, which in turn are mounted in linear bearings.

In FIG. 2d shows a support assembly in which the shaft is mounted in linear bearings, which in turn are mounted in radial bearings.

In FIG. 3a shows a variant of pairing the lever with a force sensor by means of a ball and a variant of pressing the lever to the force sensor with a permanent magnet, view along arrow A of Fig. 1.

In FIG. 3b shows a variant of pairing the lever with a force sensor by means of a flexible rod and a variant of pressing the lever to the force sensor using a magnetic plate and a permanent magnet, view along arrow A of Fig. 1.

In FIG. 3c shows a variant of pairing the lever with a force sensor by means of a rigid rod and a variant of pressing the lever to the force sensor with the help of two magnets that are turned towards each other with the same poles, view along arrow A of Fig. 1.

In FIG. 3d shows a variant of coupling the lever with a linear force sensor by means of a spherical hinge and a variant of pressing the lever to the force sensor with the help of a tension spring, view along arrow A of Fig. 1.

In FIG. 4 shows a general view of the stand for measuring the thrust and reaction torque of the propeller with strain gauges mounted on the shaft.

In FIG. 5 shows a general view of the stand for measuring thrust and torque of a propeller with a C-bracket.

Description of Embodiments

Stand for measuring the thrust and reaction torque of the propeller and the dynamic characteristics of the propeller with the engine, version of Fig. 1, contains a base 1, at least one support unit 2 with at least one support (not shown in Fig. 1) of rotation and linear movement, on which a shaft 3 is installed, which can move relative to the base 1 and rotate around its own axis and acting as a moving element. Motor base 4 and lever 5 are mounted on shaft 3, which is coupled with force sensor 6 mounted on base 1 for measuring reactive moment by means of roller 7 or a similar element containing rotation body. On the other side of the lever 5 there is a pressure roller 8, which can be spring-loaded. When testing on the motor base 4, an engine 9 with a propeller 10 is installed in such a way that the engine shaft 9 and, accordingly, the axis of rotation of the propeller 10 are installed coaxially or parallel to the shaft 3. A force sensor 11 is installed at the opposite end of the motor base 4 of the shaft 3 for measuring the thrust of the propeller 10, the second end of the force sensor 11 for measuring the thrust of the propeller 10 is mounted on a self-aligning double-row spherical bearing 12, which is located between two walls 13, limiting its longitudinal movement, but not limiting the radial movement.

In the shown in FIG. 1 and other versions of the stand, a left-hand rotation propeller 10 is installed when viewed from the side of the propeller 10. In this case, the propeller will create a thrust directed from right to left along the axis of the shaft 3 according to FIG. 1, the reactive torque will be directed clockwise, i.e. the direction of action of the lever 5 on the force sensor 6 for measuring the reactive moment will be down, on the sensor 6. Accordingly, the pressure roller 8, which is located on top of the lever, is on the side opposite to the direction of the lever action on the force sensor for measuring the reactive moment.

Motor base 4 has engine 9 attachment points and can be universal or replaceable for each type of tested engine 9 with propeller 10.

Motor base 4, shaft 3 and lever 5 can be made of light alloy or polymer materials, and also have an internal cavity to lighten the weight. At the same time, they must have sufficient rigidity for the loads to be tested in order to ensure operability.

- 3 042094

The bearing assembly 2 includes at least one bearing of rotation and linear movement along the axis of the shaft 3 from the following listed devices: a linear bearing with a limited stroke (Fig. 2a); linear rotary bushing with limited stroke (Fig. 2b); radial gas-static bearing; radial hydrostatic bearing (Fig. 2c); a radial bearing, which in turn is mounted on a linear bearing (Fig. 2d); a linear bearing, which in turn is mounted on a radial bearing (Fig. 2e).

The support unit 2 (Fig. 2a) on linear bearings of limited stroke contains a housing 14, inside which two bearings of rotation and linear movement are installed in the form of linear bearings 15 of limited stroke, separated from each other by a spacer sleeve 16. Linear bearings 15 of limited stroke consist of an outer ring 17, cage 18 and balls 19. Cage 18 is shorter than outer ring 17, the difference between their lengths is half the allowable linear travel. Shaft 3 enters linear bearing 15 and contacts with balls 19. Such bearing unit 2 contains two bearings of rotation and linear movement and provides unlimited freedom of rotational movement of shaft 3 and linear movement of shaft 3, the value of which is sufficient for the operation of the stand.

The support unit 2 (Fig. 2b) on linear swivel bushings contains a housing 14 and one support in the form of a linear swivel bushing 20 with a limited stroke, which consists of an outer ring 17, a separator 18 and balls 19. The difference between a linear swivel bushing 20 from the limited stroke linear bearing 15 lies in the length of the outer ring 17 and the cage 18. The linear swivel sleeve 20 is much longer than the limited stroke linear bearing 15, has a significantly higher load capacity and can replace two bearings. The separator 18 is made shorter than the outer ring 17, the difference in their lengths is half the value of the allowable linear stroke. The shaft 3 is in contact with the balls 19. This bearing unit 2 contains one support and provides unlimited freedom of rotational movement of the shaft 3 and linear movement of the shaft 3, the value of which is sufficient for the operation of the stand.

The support unit 2 (Fig. 2c) on radial gas-static bearings contains a housing 14 and one or two supports in the form of a gas-static bearing, the housing of which coincides with the housing 14 of the support unit 2, where one or two perforated or porous inserts 21 and fittings 22 for supplying compressed air. Shaft 3 is installed in the central hole of the liners 21 with a small gap. Such a support unit 2 provides unlimited freedom of rotational and linear movement of the shaft 3.

The support unit 2 on radial hydrostatic bearings has no fundamental differences in design from the support unit 2 on radial gas-static bearings. The difference lies in the ratio of the dimensions of the parts and work using pressurized oil. Such a support unit 2 provides unlimited freedom of rotational and linear movement of the shaft 3.

The bearing unit 2 (Fig. 2d) contains a housing 14 and two combined bearings, in which the shaft 3 is installed in radial bearings 23, which in turn are installed in linear bearings 25 with the help of bushings 24. The radial bearing 23 can be ball, roller or needle , linear bearing 25 - ball. Radial bearing 23 provides unlimited freedom of rotational movement of shaft 3, linear bearing 25 - unlimited freedom of linear movement in the axial direction of bushings 24, radial bearings 23 and shaft 3.

Support assembly 2 (Fig. 2e) contains a housing 14 and two combined bearings, in which the shaft 3 is installed in linear bearings 25, which in turn are installed in radial bearings 23. Radial bearing 23 can be ball, roller or needle, linear bearing 25 - ball. Radial bearing 23 provides unlimited freedom of rotational movement of linear bearing 25 and shaft 3, linear bearing 25 - unlimited freedom of linear movement in the axial direction of shaft 3.

The support nodes 2 presented above are made in a single housing 14 and are sufficient to hold the shaft 3 in the working position. A variant of the execution of the stand is possible, in which two support nodes 2 are used, each of which contains one support. There are other versions of the support nodes 2, providing rotational and linear movement of the shaft 3 with minimal friction.

The lever 5 can be installed on the shaft 3 directly next to the motor base 4, between the supports or support nodes 2 or at the end of the shaft 3 opposite from the motor base 4 (Fig. 1) and is mated with its end to the force sensor 6 for measuring the reactive moment. In FIG. 1, the lever 5 is connected to the force sensor 6 by means of a roller 7, the direction of movement of which coincides with the direction of the axis of the shaft 3. The roller 7 is cylindrical or with a convex generatrix mounted on the end of the lever 5 on rolling bearings (not shown). The pressure roller 8 is located on the side opposite to the direction of action of the lever 5 on the force sensor 6 for measuring the reactive moment, and has a cylindrical or convex generatrix surface, and is mounted rigidly.

There are also the following versions of the stand for measuring thrust and reactive moment of the propeller, in which the lever 5 is mated with the force sensor 6 for measuring the reactive moment and is pressed against it by one of the following devices.

In the embodiment of the stand of Fig. 3a, the linkage of the end of the lever 5 with the force sensor 6 for measuring the reactive moment is carried out by means of a rolling element. This may be a ball 26 or a roller (not shown) that is installed between the end of the lever 5 and the force sensor 6 to measure the reactive moment. In this case, the direction of rolling of the roller (not shown) must coincide with the direction of the axis of shaft 3.

The lever 5 is made of a magnetic material, in the direction of the lever action on the force sensor 6 for measuring the reactive moment, a permanent magnet 28 is installed on the rack 27, the distance between the lever 5 and the magnet 28 can be adjusted by changing the height of the rack 27.

The lever 5 can also be coupled to the force sensor 6 via a flexible link 29, FIG. 3b. In this case, the force sensor 6 for measuring the reaction torque is mounted on the post 30, i. e. on the other side of the lever 5 than in the embodiment of FIG. 1. As a flexible rod 29, a steel cable, a metal string, a wire having a high tensile rigidity but sufficient flexibility, etc. can be used.

If the lever 5 is made of a non-magnetic material or a material with weak magnetic properties, a plate 31 of magnetic material or a permanent magnet is installed on the lower plane of the lever 5 (Fig. 3b), in the direction of the lever action on the force sensor 6 for measuring the reactive moment on the rack 27 is installed a permanent magnet 28 or a plate of magnetic material. The distance between the plate 31 of magnetic material and the magnet 28 can be adjusted by changing the height of the rack 27. It is also possible to install the magnet 28 on the lower plane of the lever 5 and the rack 27, in this case the magnets 28 are directed towards each other with different poles.

The lever 5 (Fig. 3c) can also be coupled to the force sensor 6 by means of a rigid rod 32, which is connected to the lever 5 and the force sensor 6 to measure the reactive moment using spherical joints 33, articulated bearings (not shown) or a swivel head with a built-in bearing with a double row of balls (not shown). The force sensor 6 for measuring the reactive moment is mounted on the support 30 and is located on the other side than in the embodiment of FIG. 1.

In this embodiment, a permanent magnet 28 is installed on the upper plane of the lever 5, from the side opposite to the direction of action of the lever 5, a second magnet 28a is installed on the bracket 27 to measure the reactive moment, and the magnets 28 and 28a are installed with the same poles to each other and the distance between them can be adjusted by changing the height of the bracket 27.

In FIG. 3d, a force sensor 6 is used to measure the reactive moment of a linear type and is connected to the lever 5 and the bracket 34 using spherical joints 33, swivel bearings (not shown) or swivel heads with an integrated bearing with a double row of balls (not shown).

The preload on the force sensor 6 for measuring the reactive moment is created by the spring 35, which is installed in the direction of the action of the lever 5 on the force sensor 6 for measuring the reactive moment and is connected to the lever 5 by means of a screw 36 and a nut 37. The tension of the spring 35 is adjusted by screwing (screwing) nuts 37 and a change in the protrusion of the screw 36.

All presented in Figs 1, 3a-3d options for pairing the lever 5 with the force sensor 6 for measuring the reactive moment and the options for pressing the lever 5 to the force sensor 6 for measuring the reactive moment are independent of each other and can be combined with each other. There are other options for pairing the lever 5 with the force sensor 6 for measuring the reactive moment and options for pressing the lever 5 to the force sensor 6 for measuring the reactive moment, which ensure the absence or minimization of friction between the lever 5 and the force sensor 6 for measuring the reactive moment and the pressing device and the lever 5, the required preload of the force sensor 6 to measure the reactive torque.

All presented in Figs 1, 3a-3d options for pressing the lever 5 to the force sensor 6 to measure the reactive moment can be used to create a preload of the sensor 11 to measure the thrust of the propeller 10. To do this, they are installed in such a way that the force they create stretches the sensor 11 to measure the thrust of the propeller 10 when it is in tension or is compressed if it is in compression.

The force sensor 6 for measuring the reaction torque in FIG. 1 is shown as a beam-type transducer operating in bending. It is also possible to use a compression sensor made in the form of a cylindrical washer, etc.

A force sensor 11 for measuring the thrust of the propeller 10 in FIG. 1 is shown as a cylindrical type tensile linear sensor. It is also possible to use a linear type tensile sensor with S-shaped and other body shapes. In the event that the stand is used to determine the thrust of the propeller 10 directed to the force sensor 11 for measuring thrust, a linear type compression sensor is used.

In FIG. 1 shows a force sensor 6 for measuring the reaction torque and a force sensor 11 for measuring the thrust of the propeller 10 of strain gauge type. It is possible to use force sensors, the operation of which is based on other physical principles. Preference is given to sensors having high frequency characteristics, such as piezoelectric sensors. It is also possible to sequentially install sensors with different frequency characteristics, which makes it possible to increase the range of measured frequencies of change in thrust and reactive torque.

Stand for measuring the thrust and reaction torque of the propeller and the dynamic characteristics of the propeller with the engine, version of Fig. 4, contains a base 1, at least one support unit 2 with at least one support (not shown in Fig. 4) of rotation and linear movement, on which a shaft 3 is installed, which can move relative to the base 1 and rotate around its own axis and acting as a moving element. A motor base 4 and a lever 5 are installed on the shaft 3, which is coupled with a force sensor 6 installed on the base 1 to measure the reactive moment by means of a roller 7 or a similar element containing a rotation body. The lever 5 is made of a magnetic material, under the lever 5 (in the direction of the lever action on the force sensor for measuring the reactive moment) a permanent magnet 28 is installed on the rack 27. When testing, an engine 9 with a propeller 10 is installed on the motor base 4. At the end of the shaft 3 a self-aligning double-row spherical bearing 12 is installed, which is located between two walls 13, limiting its longitudinal movement, but not limiting the radial movement. On the shaft 3, between the lever 5 and the spherical bearing 12, strain gauges 38 are installed.

Figure 5 shows a variant of the bench for measuring the thrust and reaction torque of the propeller and the dynamic characteristics of the propeller with the engine, in which the lever 5 is made in the form of a C-shaped bracket that interacts with the force sensor 6 to determine the reaction moment and with the sensor 11 to measure propeller thrust 10 beam type.

Stand for measuring the thrust and reaction torque of the propeller and the dynamic characteristics of the propeller with the engine, version of Fig. 5, contains a base 1, at least one support unit 2 with at least one support of rotation and linear movement (not shown in Fig. 5), on which a shaft 3 is installed, which can move relative to the base 1 and rotate around its own axis and acting as a moving element. A motor base 4 is installed on the shaft 3, a lever 5 in the form of a C-shaped bracket is installed at the other end, which interacts with a force sensor 6 to determine the reactive torque and with a sensor 11 to measure the thrust of the propeller 10. When testing, an engine is installed on the motor base 4 9 with a propeller 10. The lever 5 interacts with the force sensor 6 to measure the reactive moment by means of a roller 7 installed at the end, the direction of movement of which coincides with the direction of the axis of the shaft 3. The lever 5 can be made of magnetic material, under the lever 5 (in the direction of action lever on the force sensor for measuring the reactive moment) on the rack 27 is mounted a permanent magnet 28 similarly to Fig. 3a. As the sensor 11 for measuring the thrust of the propeller 10, a beam force sensor is used similarly to the sensor 6 for measuring the reactive moment. The lever 5 interacts with the sensor 11 for measuring the thrust of the propeller 10 through the rolling body ball 26. On the reverse side of the sensor 11 for measuring the thrust of the propeller 10, a bracket 39 with a pressure screw 40 is installed. The pressure screw acts on the sensor 11 for measuring the thrust of the propeller 10 through the rolling body - ball 26. Both balls 26 are installed coaxially with shaft 3.

Stand work.

The stand for measuring the thrust and reaction torque of the propeller is installed with the axis of the shaft 3 horizontally above the ground at a height greater than the length of the propeller blade 10 or vertically at such a height at which the propeller does not show ground effect. The engine 9 with the propeller 10 is installed on the motor base 4 in such a way that the engine shaft 9 and, accordingly, the axis of rotation of the propeller 10 are installed coaxially or parallel to the shaft 3. The lever 5 is pressed against the force sensor 6 to measure the reactive torque by means of the roller 8. This allows to eliminate the shock effect on the force sensor 6 for measuring the reactive torque and the rebound of the lever 5 after the rotation of the engine 9 is completed. Preloads on the sensors 6 improve the measurement accuracy.

The rotation of the engine 9 with the propeller 10 is started.

When the engine shaft 9 rotates, the propeller 10 installed on it creates thrust, which is directed from right to left along the shaft 3 axis. viewed from the side of the propeller 10, respectively, the reactive moment will be directed clockwise.

In addition to these forces and moments, centrifugal force may occur, directed perpendicular to the axis of rotation of the motor shaft 9, which is associated with insufficient balancing of the moving parts of the engine with a propeller 10, other forces and moments.

All the forces and moment of rotation arising from the rotation of the engine 9 with the propeller 10 are transferred to the motor base 4, and from it to the shaft 3.

The stand for measuring the thrust and reaction torque of the propeller implements such a kinematic scheme in which of all the forces that arise during the operation of the engine 9 and the propeller 10, only the necessary ones are selected for measurement and measures are taken to minimize the distortion of these forces.

- 6 042094

All forces arising during the operation of the propeller 10, directed perpendicular to the axis of rotation of the shaft 3, act radially on the bearings of rotation and linear motion (ie ball or gas-static (hydrostatic) bearings), which absorb them.

The thrust force of the propeller 10 can freely pull the shaft 3 in the direction of thrust of the propeller 10.

The reaction torque of the propeller 10, which is directed clockwise, against the rotation of the propeller 10, can freely rotate the shaft 3.

Due to the fact that the bearings of rotation and linear motion are ball or gas-static (hydrostatic) bearings, the friction of the movement of the shaft 3 along the axis and the rotation of the shaft 3 is minimal. The radial load that acts on the rotation and linear motion bearings (not shown) creates minimal friction.

The moment of rotation from the shaft 3 is transmitted to the lever 5, which, through the roller 7, acts (presses) on the force sensor 6 to determine the reactive moment with a force, the value of which is proportional to the reactive moment and inversely proportional to the length of the lever 5 in the direction from top to bottom, and bends it to a slight (fractions of a millimeter) value. The deformation of the body of the force sensor 6 to determine the reactive moment changes the resistance of the strain gauges included in them (installed on the body), which is measured by the stand measurement system. Due to the fact that the deformation has a small value, the shaft 3 rotates through a very small angle due to the action of the reactive moment. The lever 5 acts on the force sensor 6 to determine the reactive torque through the roller 7, which is mounted on bearings (not shown). This replaces the sliding friction with the rolling friction between the arm 5 and the force sensor 6 to determine the reactive torque, which significantly reduces the effect of the friction force on the measurement of the thrust force of the propeller 10.

Up to the lever 5, the shaft 3 experiences a complex stress-strain state of torsion and tension. After the lever 5, only tension remains, and therefore the thrust sensor 11 of the propeller 10 experiences and measures only linear load. The possibility of exposure to any torsion load is excluded due to the use of a self-aligning double-row spherical bearing 12, which perceives the axial load, and its installation between the walls 13 with the possibility of radial displacement eliminates the possibility of a bending load on the sensor 11 measuring the thrust of the propeller 10.

The thrust of the propeller 10 moves the shaft 3, which is the sensor 11 for measuring the thrust of the propeller 10 by a small amount (fractions of a millimeter), the resistances of the strain gauges included in them (installed on the body) change, which is measured by the stand measurement system. Thus, each force sensor 11 is subjected to a load characteristic of its measurement, which makes it possible to ensure a high measurement accuracy.

The presented solution makes it possible to reduce the mass of the moving element with the motor base 4 in comparison with known similar stands. Accordingly, a decrease in mass leads to a decrease in inertia, i.e. allows you to respond faster to changes in propeller 10 thrust and reaction torque, and therefore such a stand provides more accurate measurements of the thrust and reaction torque variables of the tested engine 9 and propeller 10, characteristic of maneuvering, i.e. dynamic characteristics of propeller 10 with engine 9.

Operation of support nodes 2.

The support unit 2 ensures the rotation and linear movement of the shaft 3. For measurements, it is important to ensure minimum friction during rotation and axial movement. For this, rotation and linear motion supports (not shown) on linear or gas-static (hydrostatic) bearings are used.

Support assembly 2, embodiment of FIG. 2a, contains two linear bearings 15 of limited stroke, which allow unlimited rotation and limited linear movement of the shaft 3 installed in them. The rotation of the shaft 3 leads to the movement of the balls 19 in a circle relative to the outer ring 17 and to the rotational movement of the separator 18. Linear movement of the shaft 3 leads to a linear movement of the balls 19 along the axis of the shaft 3 relative to the outer ring 17 and to a linear movement of the separator 18. Thus, the support assembly 2, the embodiment of FIG. 2a, allows rotation and linear movement of the shaft 3 with minimal rolling friction of the balls 19, which reduces the effect of friction forces on the measurement results, thus increasing the measurement accuracy.

Support assembly 2, embodiment of FIG. 2b, contains one linear-rotary linear bushing 20 with a limited stroke, which consists of an outer ring 17, a separator 18 and balls 19, i.e. similar to 15 limited travel linear bearings. The rotation of the shaft 3 leads to the movement of the balls 19 in a circle relative to the outer ring 17 and the rotational movement of the cage 18. The linear movement of the shaft 3 leads to the linear movement of the balls 19 along the axis of the shaft 3 relative to the outer ring 17 and to the linear movement of the cage 18. Thus, the support assembly 2, the embodiment of FIG. 2b, allows rotation and linear movement of the shaft 3 with minimal rolling friction of the balls 19, which reduces the effect of friction forces on the measurement results, thus increasing the measurement accuracy.

- 7 042094

The support assembly 2 on gas-static (hydrostatic) bearings (Fig. 2c) operates when air (oil) pressure is supplied to the fittings 22. Air (oil) is supplied through the fittings 22, spreads in the volume between the housing 14 and the perforated or porous insert 21. Air ( oil) flows out through the perforated liner 21 and creates pressure in the space between the inner wall of the liner 21 and the shaft 2. This pressure causes the shaft 3 to hang in the hole of the liner 21. The shaft 3 has the ability to rotate and move linearly. This support unit 2 features the lowest friction and the least influence of friction forces on the measurement results and, accordingly, provides the highest measurement accuracy from those presented in Figs. 2a-2d devices.

The bearing assembly 2 (Fig. 2d), in which the shaft 3 is mounted on radial bearings 23, which, in turn, are mounted on linear bearings 25 with the help of bushings 24, contains two supports of rotation and linear movement combined in this way (pos. not indicated). When the shaft 3 rotates, the inner ring, balls and cage of the radial bearing 23 rotate. When the shaft 3 moves linearly, the radial bearing 23 and the sleeve 24 move linearly. shaft 3. In this case, the minimum rolling friction is realized, which reduces the influence of friction forces on the measurement results, and thus increases the measurement accuracy.

Support unit 2 (Fig. 2e), in which the shaft 3 is mounted on linear bearings 25, which in turn are mounted on radial bearings 23, contains two supports of rotation and linear movement combined in this way (pos. not indicated). When the shaft 3 rotates, the linear bearing 25, the inner ring, the balls and the cage of the radial bearing 23 rotate. When the shaft 3 moves linearly, the linear bearing balls move. The radial bearing 23 provides freedom of rotational movement of the shaft 3, the linear bearing 25 provides freedom of linear movement in the axial direction of the shaft 2. In this case, the minimum rolling friction is realized, which reduces the effect of friction forces on the measurement results, and thus increases the measurement accuracy.

The lever 5 is coupled to the force sensor 6 for measuring the reactive moment by means of a rolling element. This may be a ball 26 (FIG. 3a) or a roller (not shown), which are installed between the end of the lever 5 and the force sensor 6 to measure the reactive moment. In FIG. 1, the lever 5 is connected to the force sensor 6 for measuring the reactive moment by means of the roller 7 mounted on it, the direction of movement of which coincides with the direction of the axis of the shaft 3. The roller 7 is mounted on rolling bearings (not shown). This pairing makes it possible to minimize the friction between the lever 5 and the force sensor 6 for measuring the reactive moment and thus reduce the influence on the measurement by the sensor 11 of measuring the thrust of the propeller 10. When the lever 5 moves together with the shaft 3 along the axis of the shaft 3, the roller 7, or the ball 26, or a roller (not shown), which are installed between the end of the lever 5 and the force sensor 6 for measuring the reactive moment, roll between them, replacing the sliding friction force with rolling friction, which is much lower than the sliding friction, which reduces the influence of friction forces on the measurement results. , and thus the measurement accuracy is improved.

The operation of the devices for pressing the lever 5 to the force sensor 6 for measuring the reactive moment by the roller 8 (Fig. 1).

The purpose of the devices for pressing the lever 5 to the force sensor 6 for measuring the reactive moment by the roller 8 is to preload the force sensor 6 for measuring the reactive moment in order to exclude shock effects on it when operating at variable traction forces and to increase the measurement accuracy due to the preload of the force sensor 6.

The work of the pressure roller 8 (Fig. 1) consists in pressing the lever 5 in the direction of the lever action on the force sensor 6 to measure the reactive moment with a certain force and replacing the sliding friction with rolling friction. When the lever 5 moves together with the shaft 3 along the axis of the shaft 3, the roller 7 rolls over the lever 5, replacing the sliding friction force with rolling friction, which is much lower than the sliding friction, which reduces the effect of friction forces on the measurement results, and thus increases the measurement accuracy. .

In the embodiment of FIG. 3a, the permanent magnet 28 attracts the lever 5 with a given force without contact with it. When the lever 5 moves together in the shaft 3 along the shaft 3 axis, no friction force arises between the lever 5 and the permanent magnet 28, since there is no contact, and the magnetic force is not directed along the axis of the shaft 3. The pressing force of the lever 5 can be controlled by changing the gap between the permanent magnet 28 and lever 5 by changing the height of the rack 27.

Flexible rod 29 (Fig. 3b) is stretched from the force sensor 6 to measure the reactive moment to the lever 5, is directed perpendicular to the axis of the shaft 3 and transmits force only along the tension line. Minor movements of the lever 5 do not change the significant inclination of the flexible rod 29 and do not lead to the appearance of a significant force directed along the axis of the shaft 3. To do this, the length of the flexible rod 29 must be significantly higher than the possible movement of the lever 5 along the axis of the shaft 3.

Clamping device, embodiment of Fig. 3b, works similarly to the version

- 8 042094 fig. 3a, where the role of the attracting elements is performed by a plate 31 of magnetic material or a permanent magnet and a permanent magnet 28 or a plate of magnetic material mounted on a rack 27. Moreover, if a pair of permanent magnets works, they are installed with different polarities to each other.

Rigid rod 32 (Fig. 3c) connects the force sensor 6 for measuring the reactive moment with the lever 5 through spherical joints 33, articulated bearings (not shown) or a hinge head with an integrated bearing with a double row of balls (not shown), directed perpendicular to the direction of the shaft axis 3 and transmits force only along the tension line. Slight movements of the lever 5 together with the shaft 3 lead to the rotation of the spherical joints 33, but do not change the significant inclination of the rigid rod 32 and do not lead to the appearance of a significant force directed along the axis of the shaft 3. For this, the length of the rigid rod 32 must be significantly higher than the possible movement of the lever 5 along the axis of shaft 3.

Clamping device, embodiment of Fig. 3c works by repelling the magnets 28 and 28a, which are mounted to each other with the same polarity. Accordingly, such a clamping device is installed on the side opposite to the direction of action of the lever 5 on the force sensor 6 for measuring the reactive moment. There is no contact between the magnets. The magnitude of the pressing force of the lever 5 to the force sensor 6 for measuring the reactive moment is determined by the distance between the magnets 28 and 28a and is regulated by the height of the rack 27. Since there is no contact between the magnets, there is no friction force between them when the lever 5 moves.

The force sensor 6 (Fig. 3d) for measuring the reactive moment of a linear type allows you to install it through spherical joints 33, spherical bearings (not shown) or swivel heads with an integrated bearing with a double row of balls (not shown), between the lever 5 and the rack 34 or base 1, depending on the direction of action of the reactive moment and the layout of the stand. In this embodiment, the force sensor 6 for measuring the reactive moment measures the force directed from one spherical joint 33 to another. Slight movements of the lever 5 together with the shaft 3 lead to the rotation of the spherical joints 33, but do not change the significant inclination of the force sensor 6 for measuring the reactive moment and do not lead to the appearance of a significant force directed along the axis of the shaft 3. For this, the length of the distance between the spherical joints 33 must be significantly greater than the possible movement of the lever 5 along the axis of the shaft 3.

The pressing force of the lever 5 (Fig. 3d) to the force sensor 6 for measuring the reactive moment is determined by the tension of the extension spring 35, installed on the side opposite to the direction of the lever 5 action on the force sensor 6 for measuring the reactive moment, is adjusted using the screw 36, the length of which adjustable with nut 37. The movement of the lever 5 together with the shaft 3, which is much less than the length of the extension spring 35, does not lead to significant efforts against the movement of the lever 5.

The operation of the stand for measuring the thrust and reaction torque of the propeller, the embodiment of Fig. 4.

The engine 9 with the propeller 10 is installed on the motor base 4, which is installed on the movable element of the stand - the shaft 3. The lever 5 is pressed against the force sensor 6 to measure the reactive torque by means of a permanent magnet 28. This eliminates the shock effect on the force sensor 6 for measuring the reactive torque and rebound of the lever 5 after the rotation of the motor 9. Applying a preload to the sensors improves the measurement accuracy.

The rotation of the engine 9 with the propeller 10 is started.

When the engine shaft 9 rotates, the propeller 10 installed on it creates thrust, which is directed from right to left along the shaft 3 axis. viewed from the side of the propeller 10, respectively, the reactive moment will be directed clockwise.

In addition to the indicated forces and moments, centrifugal force may occur, directed perpendicular to the axis of rotation of the motor shaft 9, which is associated with insufficient balancing of the moving parts of the engine with a propeller 10, other forces and moments.

All the forces and moment of rotation arising from the rotation of the engine 9 with the propeller 10 are transferred to the motor base 4, and from it to the shaft 3.

All forces arising during the operation of the propeller 10, directed perpendicular to the axis of rotation of the shaft 3, act radially on the bearings of rotation and linear motion (ie ball or gas-static (hydrostatic) bearings), which absorb them.

The thrust force of the propeller 10 can freely pull the shaft 3 in the direction of thrust of the propeller 10.

The moment of rotation from the shaft 3 is transmitted to the lever 5, which through the roller 7 acts on the force sensor 6 to determine the reactive moment with a force, the value of which is proportional to the reactive moment and inversely proportional to the length of the lever 5, and bends it by a small (fractions of a millimeter) value. Deformation of the body of the force sensor 6 to determine the reactive moment changes

- 9 042094 the resistance of the strain gauges included in them (installed on the body), which is measured by the bench measurement system. Due to the fact that the deformation has a small value, the shaft 3 rotates through a very small angle due to the action of the reactive moment. The lever 5 acts on the force sensor 6 to determine the reactive torque through the roller 7, which is mounted on bearings (not shown). This replaces sliding friction with rolling friction between lever 5 and force sensor 6 to determine the reactive moment, which significantly reduces the influence of friction force on the results of measuring the thrust force of propeller 10. Lever 5 has no contact with the permanent magnet 28, which presses lever 5 against the sensor 6 forces to measure the reactive moment, and therefore there is no friction force between them. The end of the shaft 3 after the lever 5 works only in tension, and therefore the strain gauges 38 installed on it register only the tension of the shaft 3 from the traction force of the propeller 10.

Stand for measuring thrust and reaction torque of a propeller, version of Fig. 5 differs from the embodiment of FIG. 1 by the fact that as the sensor 11 for measuring the thrust of the propeller 10, a beam sensor is used, similar to the sensor 6 for measuring the reactive moment. In this regard, the lever 5 is made in the form of a C-shaped bracket, which interacts with the force sensor 6 to determine the reactive moment and the sensor 11 to measure the thrust of the propeller 10.

When the engine 9 is operating with the propeller 10, the reactive torque from the shaft 3 is transmitted to the lever 5, which, through the roller 7, presses on the force sensor 6 to determine the reactive torque with a force whose value is proportional to the reactive torque and inversely proportional to the length of the lever 5, and bends it to a small (fractions of a millimeter) value. The deformation of the body of the force sensor 6 to determine the reactive moment changes the resistance of the strain gauges included in them (installed on the body), which is measured by the stand measurement system. Due to the fact that the deformation has a small value, the shaft 3 rotates through a very small angle due to the action of the reactive moment. The lever 5 acts on the force sensor 6 to determine the reactive torque through the roller 7, which is mounted on bearings (not shown). This replaces the sliding friction with the rolling friction between the lever 5 and the force sensor 6 to determine the reaction torque, which greatly reduces the influence of the friction force on the measurement of the thrust force of the propeller 10.

The lever 5 is not in contact with the force sensor 6 for measuring the reactive moment, and therefore no frictional force occurs between them.

The second end of the lever 5 through the ball 26 presses coaxially to the shaft 3 on the sensor 8 to measure the thrust of the propeller 10. The use of the ball 26 for the interaction of the lever 5 and the sensor 11 to measure the thrust of the propeller 10 excludes the possibility of transferring the torque to the sensor 11 and allows it to work on loads characteristic of it, which allows to ensure high accuracy of measurements. The sensor 11 for measuring the thrust of the propeller 10 bends by a small amount (fractions of a millimeter). The deformation of the sensor body 11 for measuring the thrust of the propeller 10 changes the resistance of the strain gauges included in them (installed on the body), which is measured by the measurement system of the stand.

Industrial Applicability

The invention can be used in the development of stands for testing propellers for air and water. The stand can also be used to test mixing devices using propellers, turbines, etc.

Patent Literature

Patent Literature 1: CN Patent 204064694 U.

Patent Literature 2: Patent CN 106143949 B.

Patent Literature 3: Patent CN 104316290 A.

Patent Literature 4: CN Patent 201974262 U.

Patent Literature 5. Patent CN 202511930 U.

Patent Literature 6: CN Patent 102288912 B.

Patent Literature 7: CN Patent 205066989 U.

Patent Literature 8: Patent CN 104483053 A.

Claims (19)

CLAIM 1. Stand for measuring thrust and reaction torque of a propeller and the dynamic characteristics of a propeller with an engine, containing a base and a movable element mounted with the ability to move relative to the base with a motor base on which the engine with a propeller is installed, and a lever with which a force sensor is associated to determine the reactive moment, as well as a force sensor connected to the movable element for measuring thrust, characterized in that the movable element is made in the form of a shaft and is installed on at least one support of rotation and linear movement along the axis of the shaft with the possibility of moving relative to the base and rotating around own axis. 2. The stand according to claim 1, characterized in that the support of rotation and linear movement is - 10 042094 limited stroke linear bearing. 3. The stand according to claim 1, characterized in that the support of rotation and linear movement is a linear-rotary linear bushing with a limited stroke. 4. Stand according to claim 1, characterized in that the support of rotation and linear movement is a radial gas-static bearing. 5. Stand according to claim 1, characterized in that the support of rotation and linear movement is a radial hydrostatic bearing. 6. Stand according to claim 1, characterized in that the support of rotation and linear movement is a radial bearing, which in turn is mounted on a linear bearing. 7. Stand according to claim 1, characterized in that the support of rotation and linear movement is a linear bearing, which in turn is mounted on a radial bearing. 8. Stand according to claim 1, characterized in that the lever is coupled with a force sensor for measuring the reactive moment by means of a rolling element. 9. Stand according to claim 1, characterized in that the lever is coupled with a force sensor for measuring the reactive moment by means of a flexible rod. 10. The stand according to claim 1, characterized in that the lever is connected to the force sensor for measuring the reactive moment by means of a rigid rod, which is installed through spherical joints. 11. Stand according to claim 1, characterized in that the lever is connected to the force sensor to measure the reactive moment of the linear type through a spherical hinge. 12. Stand according to claim 1, characterized in that a roller is installed at the end of the lever, the direction of movement of which coincides with the direction of the axis of the shaft, while the roller is associated with a force sensor for measuring the reactive moment. 13. Stand according to claim 1, characterized in that the lever is made of magnetic material, a permanent magnet is installed in the direction of the lever action on the force sensor to measure the reactive moment, the distance between the lever and the magnet can be adjusted. 14. Stand according to claim 1, characterized in that a plate of magnetic material or a permanent magnet is installed on the lever, a permanent magnet is installed in the direction of the lever action on the force sensor to measure the reactive moment, the distance between the plate of magnetic material or a permanent magnet and the magnet can be regulated. 15. The stand according to claim 1, characterized in that a permanent magnet is installed on the lever, from the side opposite to the direction of the lever action on the force sensor for measuring the reactive moment, a second magnet is installed, and the magnets are installed with the same poles to each other and the distance between them can be regulated. 16. Stand according to claim 1, characterized in that in the direction of the lever action on the force sensor for measuring the reactive moment, the lever is attracted by a tension spring, the tension of which can be adjusted. 17. Stand according to claim 1, characterized in that a coaxial force sensor is installed on the end of the shaft to measure the thrust of the propeller, the second end of which is connected to a self-aligning thrust or double-row spherical bearing, which is installed between two walls that limit its longitudinal movement, but not limiting radial movement. 18. The stand according to claim 1, characterized in that a lever is installed on the shaft, the end of the shaft is connected to a self-aligning thrust or double-row spherical bearing, which is installed between two walls that limit its longitudinal movement, but do not limit radial movement, on the surface of the shaft in the gap strain gauges are installed between the lever and the thrust bearing. 19. Stand according to claim 1, characterized in that a lever in the form of a C-shaped bracket is installed on the end of the shaft, which interacts with a force sensor for measuring propeller thrust and a force sensor for measuring reactive torque.