The torque on the shaft of a running motor is determined either by measuring the reaction torque of the brake stator, which is equal to it, or by measuring the angle of twist of the connecting shaft under the influence of the transmitted torque. In any case, testers face certain difficulties in obtaining reliable measurement results due to the fact that brake dynamometers operate under conditions of increased vibration and sharply changing loads, sometimes bordering on shock, especially in unsteady operating conditions of an internal combustion engine.

To determine the amount of torque developed by the test engine, various mechanical, hydraulic and electrical dynamometers are used. Their structural diagram, as well as other measuring devices, consists of primary, intermediate and output links. The types of dynamometers are classified according to the most characteristic link. Often only this characteristic link is considered a dynamometer, which is not correct.

Mechanical dynamometers find the widest application. They are made in the form of lever systems with pendulum, less often with spring scales. Previously, multi-lever scales of the decimal type were mainly used for these purposes. And now they are also being used in testing powerful low-speed stationary engines.

Dynamometer with lever scales Since such scales are not reversible, a special reversing device is provided in the intermediate link of the dynamometer, which operates as follows. When the force P applied to the brake lever is directed upward, then, acting on rod 8, through lever 7 it is transmitted to rod 6, moving it down, and through lever 5 and rod 4 it loads the rocker arm 2 of the scales. When directed downward, the force P, bypassing the reverse device, directly acts on the rod 6 in the same direction, consequently loading the balance beam regardless of the direction of rotation of the rotor and brake. Weight 3 ensures balancing of the balance beam when the weight is positioned at the zero division of its ideals, and the balancing of the force P and determination of its value is achieved by moving the weight / along the rocker arm. In modern weighing devices of this type, the rater weight / is moved using a special tracking mechanism, which allows you to automatically balance the load and remotely monitor the scale readings.

To reduce friction losses, the lever system is made on prisms that are sensitive to shocks and subject to wear. Therefore, when not in operation and especially when starting the engine, it is recommended to block the lever system with a device specially designed for this purpose.

The accuracy and sensitivity of lever scales significantly exceeds what is required from mechanisms for determining the force on the brake lever. However, their reliability and maneuverability are low even with the presence of an automatic tracking system. Therefore, in laboratories of automobile and tractor engines, exclusive preference is given to less accurate and non-precise ones. so sensitive, but more durable, fast-acting and stable in terms of readings, pendulum scales and dynamometers based on them.

Pendulum dynamometers are compact, clear, easy to operate and allow you to automatically balance the acting force P without moving the weight.

Pendulum scales do not distort readings under the influence of residual deformations, like spring scales, for example, and, being reversible, allow you to measure the load in any direction of rotation of the brake rotor. Having the ability to absorb minor vibrations, the pendulum does not make it difficult to count during random load fluctuations, which is inherent in lever scales. But just like other similar devices, it is important for them to reduce friction in the joints and balance the own weight of the pendulum rods.

However, in such a simple design, the pendulum mechanism is not entirely convenient, since it has an uneven reference scale. Therefore, to align the reference scale, the sector-quadrant is profiled according to the law r=a sin a/a, taking a as the initial value.

Dynamometers with a weighing head, in comparison with conventional pendulum ones, have greater measurement accuracy (errors do not exceed 0.1-5-0.2%) and are sensitive enough, which allows them to be used in scientific research work.

The basis of such dynamometers is a weighing head, most often a two-pendulum one, in combination with lever scales. However, double-pendulum heads are not reversible, so the same reversing device is inserted into the intermediate link of the dynamometer as in conventional dynamometers with lever scales (see Fig. IV.2). In essence, dynamometers with a "weighing head" are mechanisms with lever scales, to the rocker arm 1 of which a dial weighing head is connected. The head perceives only part of the measured force that is not balanced by the movable weight 2, and thanks to this allows you to observe the change in load within its dial. Weight 2 is sometimes used to expand the measurement range, as, for example, in VKM-type weighing devices.

Weighing heads with a dial reading device are convenient and very reliable in operation, although they require careful protection of their joints and hinges from moisture and dust and even more careful elimination of backlash in them.

To ensure the necessary measurement accuracy, weighing devices are selected in accordance with the power of the object being tested. Thus, weighing devices of the VKM type are equipped with dial heads that make it possible to measure forces up to 10, 25, 40, 80 and 120 kgf or more, and the use of a movable weight 2 expands the limits of their measurement to 20, 40, 50, 100 and 170 kgf. The choice of the required unit of measurement in kgf or kgf-m depends on which one was used as the basis for calibrating the scale of the brake weight device. The division value of the scale of the weighing head can express both the fractions of the product P1 and P. Sometimes both scales are applied to the dial at the same time.

The design of the weighing heads, as a rule, allows them to be rotated about a vertical axis to any position. This allows you to observe the readings from the most advantageous angle, regardless of the location of the tester. The relatively large dimensions of the dial and reading divisions do not make observations difficult even at some distance. If necessary, the dial is illuminated with light bulbs, binoculars are used, as well as special optical devices with analog-to-digital converters, which ensure reliable remote transmission or reading of readings.

power engine motor torque

Hydraulic dynamometers, or mesdozas, as they are often called after the name of the main measuring unit, are distinguished by their captivating simplicity.

They are based on a housing 5, filled with liquid and closed by an elastic diaphragm 4, sealed using a pressure ring 2. The piston 3 presses on the diaphragm under the action of a measured force P, and the resulting pressure is recorded by a pressure gauge 6.

When measuring pressures up to 10 kgf/cm2, the mesdoza diaphragm is made of high-strength rubberized fabric 0.3-0.8 mm thick or beryllium bronze 0.05-0.06 mm thick, which has a linear characteristic and is not burdened by hysteresis phenomena. To measure higher pressures, oil and petrol resistant rubber 2-3 mm thick or thin sheet steel is used. Various oils, technical glycerin and other liquids are used as working fluids.

In addition to simplicity, static mesdoses are distinguished by a wide measurement range, including a very high pressures. However, temperature has a significant influence on mesdos readings. environment due to the fact that the volumetric expansion coefficient of liquids is greater than that of metals. When it changes external conditions Air can also be released from the liquid, which dissolves in it in amounts up to approximately 10% under normal conditions, and with increasing pressure its solubility increases linearly. Therefore, before each test, the medose must be tared and spilled as often as possible using taps.

The indicated disadvantages of non-flowing mesdoses can be eliminated by using more complex hydraulic devices, the so-called flow-through and compensating diaphragm mesdoses.

Electric dynamometers in general are devices in which the deformation of an elastic element causes a change in a certain electrical parameter underlying the measurement, torque or circumferential force.

For these purposes, many of the electrical methods discussed above for measuring non-electrical quantities are suitable, functionally connecting the measured quantities with those sent to the measuring circuit. But in practice, motor testing most often uses measuring transducers based on changes in ohmic resistance, capacitance, inductance, induction and photoelectric effects under the influence of an input non-electrical quantity. The input mechanical quantity is the torsion of the connecting shaft of the brake system, the angular movement of the parts of the measuring couplings, or the deformation of the elastic element, the so-called dynamometer link, on which the brake lever acts. The most commonly used method involves measuring the angle of twist of the connecting shaft. Dynamometers of this type are also called torsion bars.

Known various ways measuring torques transmitted from the engine to the load through a rotating elastic shaft. Among them, methods based on the conversion of the measured moment into the deformation of an elastic element, made in the form of shafts (torso ions), spiral springs, braces, etc., are widely used. Conversion of deformation ( mechanical stress) of an elastic element into an electrical signal can be carried out using strain-resistive, inductive, magnetoelastic and other measuring transducers.

Methods for measuring torque using sensors outside a rotating shaft, based on measuring the angle of twist of an elastic element under the influence of the measured torque, are characterized by higher measurement accuracy and ease of implementation.

There is a known method for measuring torque [Odinets S.S., Topilin G.E. Torque measuring equipment. Instrument maker's library. M.: "Machine Building", 1977.160 pp.], implemented using a torsiometer with magnetic recording, which consists of an elastic element, two magnetic heads, a board with electronic circuits, an active filter and a phase meter. The elastic element is secured at the ends using two brass flanges, which act as magnetic drums. The outer surfaces of the flanges are coated with a magnetic emulsion of iron oxide (Fe 2 O 3). In the absence of a measured torque, pulses are periodically synchronously recorded on the ferromagnetic surface of each flange. Under the action of the measured moment, the elastic element twists. The flanges rotate, and a phase shift occurs in the pulses read by the magnetic heads, proportional to the measured torque. The magnitude of the resulting phase shift is converted into voltage direct current. The value of the measured torque is read on the scale of a direct current device.

The main disadvantage of this method is the complexity of its implementation, associated with the need to create a system of strictly aligned magnetic drums with a ferromagnetic coating and magnetic heads that read the signal.

The closest to the invention in technical essence is a method for determining the mechanical torque transmitted by a rotating shaft [RF Patent No. 2183013, cl. G 01 L 3/04, 1999], in which two identical disks with marks (gear rims) are installed on the shaft, spaced at a base distance and rigidly connected to the shaft, the rotation speed of each disk (rim) is converted using two independent magnetic sensors into two sinusoidal signals, the phase difference of these signals is recorded, by the change of which the magnitude of the mechanical torque transmitted by the shaft is judged, and the sensors used in the torque measurement system are pre-installed at one of the disks, the shaft is rotated, the phase difference of the sinusoidal signals of the sensors is recorded depending on shaft rotation speed with a constant load on the shaft, the resulting phase difference is taken into account when subsequently determining the phase difference of the signals from two sensors, the value of which is proportional to the mechanical torque transmitted by the shaft. In this case, in laboratory conditions, for a specific pair of sensors, the frequency component Ud (n) is determined in a regression model, which is subsequently used to calculate and introduce corrections into the final result for a specific value of the shaft rotation speed.

The main disadvantage of this method is the high complexity of setup associated with the need to build a regression model, and the need to introduce amendments to the final result for a specific value of shaft rotation speed can significantly complicate the electrical part of the device that implements this method. It is also significant that when generating a sinusoidal signal due to gears, it is impossible to obtain the same signal shape when the rotation speed changes. The harmonic spectrum changes significantly, especially in the region of low rotational speeds. In this regard, additional errors will appear when measuring the phase of the fundamental harmonic.

The objective of the proposed time-pulse method for measuring torque is to increase the measurement accuracy and simplify the technical implementation of the method.

The task is achieved by the fact that two coaxial shafts are connected through an elastic element, one tooth is rigidly installed on the motor shaft and on the load element shaft in such a way that the angular displacement between them along the circumference is zero, and parallel to the centerline of these shafts on a common with the engine and by the load mechanism, two magnetic sensors are installed on the base, generating pulsed bipolar signals at the moments of teeth passing near the cores of the magnetic sensors, from which the time interval between the moments of passing through zero pulses of the electromotive force (emf) of the magnetic sensors (t) and the period are determined full revolution of the motor shaft (T), while the torque is determined through the ratio of these time intervals.

Figure 1 shows an oscillogram of the e pulse. d.s. magnetic sensor(e md).

The proposed method is carried out as follows. Two coaxial shafts are connected through an elastic element. One tooth each is rigidly installed on the motor shaft and on the load element shaft. In the absence of torque, the circumferential angular displacement between the first and second teeth is zero. Parallel to the centerline of the shafts, on a common base with the engine and the load mechanism, two magnetic sensors are installed in such a way that when the shafts rotate, at the moment any of the teeth passes through the magnetic field of the corresponding sensor, the latter generates a bipolar voltage pulse (pulses of positive and negative polarity, as is known, always have the same value of volt-second areas, and the moment the emf pulse passes through zero corresponds to the minimum distance between the top of the tooth and the core of the magnetic sensor).

If the torque is not zero, the elastic element is deformed (twisted), and the angle between the first and second teeth becomes non-zero. The time interval between the pulses of the first and second magnetic sensors will be directly proportional to the angle of twist of the elastic element (i.e., torque) and inversely proportional to the circular speed of rotation of the teeth. As can be seen from the above, this time interval t will be determined by the following expression:

where dl is the length of the circle sector between the first and second teeth, determined by the angle of torsion of the elastic element;

circular speed of rotation of the teeth;

R d - radius of the circle described by the tip of the tooth;

T is the period of rotation of the motor shaft.

The angle of twist of the elastic element depends on the moment applied to it and on its rigidity, then

where M is the engine torque;

K 1 - coefficient depending on the elastic properties of the elastic element, its geometry and radius R d.

Expressing the value of the measured torque from expression (3) taking into account (1) and (2), we obtain:

where is the proportionality coefficient.

Thus, by measuring the time intervals t and T using electronic chronometers using the known K 2 according to formula (4), the torque is determined.

Figure 2 shows one of the possible options practical implementation of the proposed method. The device contains magnetic sensors 1 and 2, short pulse formers 3 and 4, an R-S trigger 5, a smoothing R-C filter 6 and a reset button 7.

The device works as follows. Before starting the installation, the reset button 7 is pressed to transfer the R-S trigger 5 to its original state. When the shafts rotate, bipolar voltage pulses of magnetic sensors 1 and 2 are supplied to short pulse formers 3 and 4, at the outputs of which rectangular pulses of negative polarity appear, and the moments of formation of the leading edges of the pulses correspond to the moments of zero crossing of the corresponding bipolar pulses of the magnetic sensors. Signals from the outputs of rectangular pulse shapers 3 and 4 control the operation of the R-S trigger 5 in such a way that the duration of the positive pulse at its output corresponds to the time interval t between the moments of the zero crossing of the magnetic sensor pulses. The output of the R-S trigger 5 is connected to the input of the smoothing R-C filter 6, the time constant of which is r=R·C>T. If this filter is not loaded (load current is zero), then, as is known, the average voltage value at the output of the R-C filter (U cp) will be equal to

From (5) we obtain

where U 0 is the amplitude value of the voltage pulse at the output of R-S trigger 5 (U 0 must be stable); - proportionality coefficient.

Consequently, by measuring the average value of the output voltage of the R-C filter, it is possible to determine the amount of torque from the known value of the coefficient K 3.

The proposed method, as can be seen from the above, allows you to measure the amount of torque regardless of the shaft rotation speed. In terms of metrological characteristics, the proposed method has advantages over the known ones. This is due to the fact that measuring torque is reduced to measuring time intervals, which can be carried out with high accuracy. In addition, to implement this method, a simpler and reliable design torque sensor.

In technology, rotation of bodies is often encountered: carriage wheels, machine shafts, steamship propellers, etc. rotate. In all these cases, moments of forces act on the bodies. In this case, it is often impossible to indicate any one specific force that creates a torque and its shoulder, since the torque is created not by one force, but by many forces that have different shoulders. For example, in an electric motor, electromagnetic forces are applied to the turns of the armature winding at different distances from the axis of rotation; their combined action creates a certain torque, which causes rotation of the armature and the motor shaft connected to it. In such cases, there is no point in talking about strength and leverage. The only thing that matters is the resulting moment of force. Therefore, there is a need to directly measure the moment of force.

To measure a moment of force, it is enough to apply another known moment of force to the body, which would balance the moment being measured. If equilibrium is achieved, then it means that both moments of forces are equal in absolute value and opposite in sign. For example, to measure the torque developed by an electric motor, blocks 2 compressed with bolts are put on motor pulley 1 so that the pulley can rotate with friction under the blocks. The pads are attached to a long rod, to the end of which a dynamometer is attached (Fig. 120). The axis of the pads coincides with the axis of the motor. When the motor rotates, the frictional moment acting from the pulley on the pads rotates the pads with the rod at a certain angle in the direction of rotation of the motor. In this case, the dynamometer stretches somewhat and an opposite moment begins to act on the pads from the side of the dynamometer, equal to the product of the tension force of the dynamometer on the shoulder. The tension force of the dynamometer is equal in magnitude and opposite in direction to the force acting from the rod on the dynamometer (Fig. 120). Since the pads are at rest, the torque developed by the motor must be equal in absolute value and opposite in sign to the moment of tension of the dynamometer. So, at a given speed, the motor develops a torque equal to .

Rice. 120. Measuring the moment of force created by an electric motor

When measuring very small torques (for example, in sensitive galvanometers and other physical measuring instruments) the measured torque is compared with the torque acting on the side of the twisted thread. The measuring system, under the influence of a torque, is suspended on a long thin thread, metal or fused quartz. By turning, the measuring system twists the thread. Such deformation causes the appearance of forces that tend to unwind the thread and, therefore, have a torque. When the measured moment becomes equal to the moment of the twisted thread, equilibrium is established. By the angle of twist at equilibrium, one can judge the torque of the thread and, therefore, the measured torque. The relationship between thread torque and twist angle is determined by calibrating the device.

TORQUE MEASUREMENT

When studying and monitoring the operation of various devices and units (engines, pumps, compressors, generators, etc.), it is often necessary to measure the torque on the device shaft.

The torque on the electric motor shaft can be approximately measured with a conventional wattmeter while simultaneously measuring the rotational speed. Torque is uniquely determined by power and rotation speed from known dependencies. However, here it should be borne in mind that by measuring the current and voltage that determine power, we determine not the actual power on the motor shaft, but its electrical power, which can be converted into mechanical power only if the electromechanical characteristics of the electric motor are known sufficiently accurately. This is not always possible, therefore this measurement method is used only in the case when the torque transmitted (or consumed by the object driven by the engine) is not the subject of study.

If torque needs to be measured accurately enough, two methods are mainly used: measurement using so-called motor scales and measurement using strain gauge torque sensors.

Motor scales are a platform mounted on an axis on which the object being tested is installed (Fig. 17.1).

When using counterweights (Fig. 17.1 A ) it is almost impossible to measure variable torque and accurately select the weight of loads 4, because the platform in this embodiment is unstable, and failure to meet the condition F∙R = M KR may cause it to fluctuate.

When using strain gauges 6 (Fig. 17.1 b ) there is no problem of instability, and when installing 6 sensors on both sides with Δ ~ 0 the device can measure torque, changing not only the magnitude, but also the direction.

The industry also produces fixed torque strain gauges, which can be used in devices resembling motor scales (Fig. 17.2).

In this design, the strain gauge 9 can measure a torque that varies in magnitude and direction. The axis of the electric motor 7 coincides with the axis of the bearing 6 and sensor 9 with maximum accuracy.

Rotating torque load cells are also available, which require the use of current collectors for their applications.

In both stationary and rotating strain gauges, the measurement is most often made by strain gauges glued to the elastic shaft in the direction of its “twisting” under the influence of torque. As a rule, modern industrial sensors have secondary devices calibrated in units of torque (N∙m) and equipped with a digital output to a computer.

In laboratory conditions, when for some objective reason it is not possible to use ready-made torque strain gauges, you can use a simple sensor, the diagram of which is shown in Fig. 17.3.

The torque creates a force on the measuring beam 3, which leads to a change in the resistance of the main measuring strain gauge glued to the side surface of the beam. The compensation strain gauge is glued on top and does not undergo tension or compression when the beam bends.

As a beam 4 with strain gauges 5, you can also use a ready-made beam-type strain gauge.

The signal from strain gauges (or from an industrial strain gauge) is supplied to the ring conductors of the current collecting device 7, and then, using graphite brushes, is transmitted to a secondary device (strain station), after which it is output to an indicating device, or through an ADC to a computer.

The use of a ready-made beam-type strain gauge is preferable, because there is no need for calibration. In addition, many serial strain gauges immediately have an amplifier and an ADC, and therefore its signal can be directly sent to a computer.

When measuring the parameters of rotating objects, very often there is a need to fix the rotation speed (frequency of double strokes), as well as certain positions of the object shaft, for example, the top or bottom dead center of piston machines, the extreme positions of hydraulic or pneumatic cylinders, etc. For this purpose, optoelectronic pairs, magnetically controlled sealed contacts (reed switches) and induction sensors are most often used.

In cases of application optoelectronic pair To control the rotation speed or shaft positions, a disk with a narrow slot is put on the rotating shaft of the device and a light source is installed on one line on one side of the disk, and a receiver (photoresistor or photodiode) is installed on the other side, which are included in the corresponding measuring circuits. When a slot passes between the light source and the light receiver, the electrical parameters of the latter change, and a signal appears, which is recorded by the measuring equipment. To determine the rotation speed, such signals are counted per unit of time, or the time interval between adjacent signals is determined. The light passage of a narrow slit is selected within a few tenths of a millimeter and depends on the brightness of the light source, the sensitivity of the receiver, the rotation speed and the distance of the optoelectronic pair from the axis of rotation. The greater this distance, the wider the gap can be. The response frequency of such a device is hundreds of Hz.

Reed switches very simple in design and reliable in operation. They are two elastic conductors with magnetic properties, placed in a common glass (or any other dielectric) capsule (Fig. 17.4)

When a magnetic field is applied to the reed switch, its contacts are attracted to each other and the reed switch begins to pass through electricity. Reed switches are fairly miniature devices; the capsule diameter can be less than 2 mm with a length of 5-6 mm. Their response frequency can be hundreds of Hz.

The operation of the reed switch is most often controlled permanent magnet, which is attached to the movable part of the device, the position of which they want to fix. When the magnet approaches the reed switch, its contacts close. In Fig. 17.5. given simplest scheme control the operation of the reed switch.

The disadvantage of reed switches is the inability to work with high currents, but in in this case, when using it as a sensor, you can limit the current to only tens of milliamps. Another drawback is the limited number of operations before contact destruction. It is about 10 8 – 10 10 times or more.

The simplest induction sensor is an inductance coil wound on a steel core made of soft magnetic (easily remagnetizable) steel. When the sensor enters an alternating (changing) magnetic field, an induced emf appears in the coil, which is the output signal of the sensor. The connection circuit for such a sensor is similar to the connection circuit for a reed switch (Fig. 17.6).

Like an optoelectronic sensor, this device has no moving parts and does not wear out during operation. The main disadvantage of such sensors is the significant dependence of the signal level on the rate of change of the magnetic field, and therefore it cannot be used to monitor slowly moving (including rotating) objects.

1. The principle of active radar.
2. Pulse radar. Principle of operation.
3. Basic time relations of pulse radar operation.
4.Types of radar orientation.
5. Formation of a sweep on the PPI radar.
6. The principle of operation of the induction lag.
7.Types of absolute lags. Hydroacoustic Doppler log.
8.Flight data recorder. Description of work.
9. Purpose and operating principle of AIS.
10.Transmitted and received AIS information.
11.Organization of radio communications in AIS.
12.Composition of shipboard AIS equipment.
13. Structural diagram of ship's AIS.
14. Operating principle of SNS GPS.
15.The essence of differential GPS mode.
16. Sources of errors in GNSS.
17. Block diagram of a GPS receiver.
18. Concept of ECDIS.
19.Classification of ENC.
20.Purpose and properties of the gyroscope.
21. The principle of operation of the gyrocompass.
22. The principle of operation of a magnetic compass.

Electronic thermometers are widely used as temperature meters. Familiarize yourself with contact and non-contact digital thermometers can be found on the website http://mera-tek.ru/termometry/termometry-elektronnye. These devices mainly provide temperature measurement at technological installations thanks to high measurement accuracy and high recording speed.

Electronic potentiometers, both indicating and recording, use automatic current stabilization in the potentiometer circuit and continuous thermocouple compensation.

Connection of current-carrying conductors- Part technological process cable connections. Multi-wire conductors with a cross-sectional area from 0.35 to 1.5 mm 2 are connected by soldering after twisting the individual wires (Fig. 1). If they are restored using insulating tubes 3, then before twisting the wires they must be put on the core and moved to the cut of the sheath 4.

Rice. 1. Connection of cores by twisting: 1 - conductive core; 2 - core insulation; 3 — insulating tube; 4 - cable sheath; 5 - tinned wires; 6 - soldered surface

Solid wires They are overlapped, fastened before soldering with two bands of two or three turns of tinned copper wire with a diameter of 0.3 mm (Fig. 2). You can also use special wago 222 415 terminals, which have become very popular today due to their ease of use and reliability of operation.

When installing electrical actuators their housing must be grounded with a wire with a cross-section of at least 4 mm 2 through a grounding screw. The connection point of the grounding conductor is thoroughly cleaned, and after connection, a layer of CIATIM-201 grease is applied to it to protect it from corrosion. Upon completion of installation, check the value, which should be at least 20 MOhm, and the grounding device, which should not exceed 10 Ohm.

Rice. 1. Electrical connection diagram of the sensor unit of a single-turn electrical mechanism. A - amplifier block BU-2, B - magnetic sensor block, B - electric actuator

The sensor block of single-turn electrical actuators is installed according to the electrical connection diagram shown in Fig. 1, with a wire with a cross-section of at least 0.75 mm 2. Before installing the sensor, it is necessary to check its functionality according to the diagram shown in Fig. 2.

21.03.2019

Types of gas analyzers

Using gas in furnaces, various devices and installations, it is necessary to control the combustion process to ensure safe operation and efficient operation of equipment. In this case, the qualitative and quantitative composition of the gas environment is determined using instruments called

Power and torque are two key parameters by which high-speed engines are selected. Some people are interested in as much horsepower as possible at the heart of the car. For some, maximum torque is more important.

By which of these characteristics do professionals select cars? Does one depend on the other? What if the torque is low but the power is quite high? Not all experienced motorists will be able to answer all these questions comprehensively. And we will try.

What does engine power depend on?

“How many horses do you have?” – one of the most frequently asked questions among car enthusiasts. Traditionally, the more so-called horsepower in the engine, the faster and more powerful the car is considered. But few people know that the quantity called horsepower is not official and is not even included in the international measurement system (remember the SI system from school?).

This unit of measurement appeared in the era of the industrial revolution. One horsepower was equal to the power capable of lifting 75 kg 1 m in 1 s. This is due to the fact that at that time it was not the speed of the car that was much more important, but the speed of coal mining.

Nowadays, everyone knows “l. With." considered "illegal". The International Metrological Organization demands that it be withdrawn as quickly as possible. And the official legislative directive since 2010 allows it to be used only as an auxiliary unit of measurement.

However, it has not yet been replaced with official kilowatts. There are several reasons for this:

• 1. The banal but true expression “habit is second nature”;
• 2.Marketing of automobile companies;
• 3.Avoiding confusion.

What is the marketing of car companies? The fact is that if at least one of them switches to the official unit of measurement kW, it will lose a significant percentage of buyers due to banal confusion. After all, if we take, for example, the popular Kia Sportage crossover, its horsepower is 136 and 184 in two versions. In kilowatts – 100 and 135, respectively. Do you understand? How can they switch to an international unit of measurement if their competitors have the number 184, and they only have 135? No wonder in America they say: “Power helps sell cars.”

How is torque measured?

A moment arises when the crankshaft is braked in one of the following ways:

• hydraulic brake;
• generator;
• in any other way that can force the car to “pull”.

Yes, yes, that’s exactly how it is measured: the engine or wheels are braked. At the same time, the characteristics indicate the maximum torque that the engine can develop when the brake pedal is fully pressed. At the beginning this indicator is small, then it grows to a peak and then falls.

What is torque?

Most modern drivers, unfortunately, do not have a complete understanding of what torque is. It is measured in newton meters (N∙m) and is a quantity that is directly related to power. All that car enthusiasts know about torque is that it should be as high as possible. But then how is it different from power?

Remember: power, torque, engine speed - interdependent quantities. There are a number of formulas by which, knowing two of these parameters, you can calculate the third.

In technical terms, power is a quantity that represents how much work a motor can perform in a certain amount of time. Torque shows the potential of the engine to perform this very work. In other words, the greater the torque, the greater the resistance the motor can overcome.

Let's imagine a situation: you are driving a car with a power of 100 hp. With. There is a truck ahead and you need to overtake it as quickly as possible and return to the desired lane. To do this, your car will have to use all its power. In this case, torque is precisely the so-called leader of horsepower, which collects them all into a single herd.

Want an even simpler explanation? Let's draw an analogy with a person: his strength can be measured in newton meters, and endurance - in horsepower. That is why the real weightlifters are considered to be “low-speed” diesel engines, which slowly but decisively transport heavy loads on their “backs”. Gasoline cars, in turn, are faster, but heavy loads are not for them.

When choosing between two engines with approximately the same amount of horsepower, always give preference to the more torquey engine. Especially if the gearbox is manual. If you prefer to drive “at the limit”, know that in this case it is better to take the engine not with high speed, but with maximum torque.

Bottom line

Well, we hope you got the answers to your questions. Now you probably know which engine would be most suitable for you? And all subsequent times, when you get behind the wheel, ask about the characteristics of the car or answer questions from a fellow car enthusiast, you will be more aware of the details of the technical parameters of the car. Good luck on the roads!