Road equipment manufacturer Caterpillar will increase production of excavators in Russia. According to experts, investments in increasing capacity may exceed 300 million rubles. The project is being implemented against the backdrop of growing sales of construction equipment in Russia.
According to the Russian representative office of Caterpillar, the plant in Tosno has been assembling two models of crawler excavators for several years: Cat 320D, which is most often used for digging pits and dismantling reinforced concrete structures, and Cat 336DL, which is suitable for excavation and landscaping work.
will invest 1.5 billion rubles in the construction of a fish breeding complex in the Leningrad region Investments
will invest 1.5 billion rubles in the construction of a fish breeding complex in the Leningrad region
32273
Editorial
In the near future, Caterpillar plans to start producing two more models of excavators. The company declined to comment in detail. According to market participants, we may be talking about assembling wheeled excavators, which are more convenient when working on flat surfaces, in contrast to tracked vehicles. The project is expected to begin in 2020. The volume of investment in the project may amount to about 300 million rubles.
The American company Caterpillar produces road construction equipment, energy and mining equipment. In Russia, the company operates a production of bodies for mining dump trucks in Novosibirsk and an assembly plant in Tosno - Caterpillar-Tosno LLC. During the first quarter of 2020, the plant in the Leningrad region produced 15 excavators, five chassis for dump trucks and 1.5 thousand parts for road construction equipment. Currently, according to experts, Catrepillar produces on average about 80-100 excavators per year. The turnover of Caterpillar-Tosno LLC in 2015 amounted to 2 billion rubles.
The company mainly exports its products (more than 50%) to European and Asian countries. Parts for equipment are supplied to the corporation’s factories in Europe. As representatives of Caterpillar-Tosno LLC have already stated, product exports will not decrease for now. Nevertheless, experts believe that the market for road construction equipment in Russia has overcome the recession and the American corporation will be able to increase sales within the country. The production of two new models of excavators will allow the company to change and replace some positions in the import of its products, analysts say.
The company will also export new machines. “Foreign manufacturers reduce the cost of products for the markets of Europe and other countries by assembling and producing equipment in Russia. This allows companies to offer their products in foreign markets at a lower price,” says Managing Director of Donex LLC (excavator production) Aren Khachatryan.
ETS Holding acquired the largest distributor of spare parts for excavators Mergers and acquisitions
Grew up
The excavator market in Russia in 2020 amounted to 1.8 thousand machines, despite the fact that at the peak of demand the capacity was more than 7 thousand machines. Including more than 1 thousand machines were imported, estimates the chairman of the committee of manufacturers of road construction equipment and special equipment of the Association of European Businesses (AEB) Andrey Komov.
He adds that 90% of excavators were supplied by large international companies (both imported and produced at Russian factories of corporations). In Russia, Caterpillar, Hitachi, Komatsu and Volvo have factories producing excavators. Russian companies produced 131 excavators last year, which is 40 more than in 2020. These are the Kovrov Excavator Plant, Saransk Excavator Plant, Donex, and Uralvagonzavod.
AEB notes that this year the road construction equipment market finally overcame a four-year crisis: sales in the first quarter increased by 29%, growth was ensured by all types of machines. Experts predict that by the end of 2020, growth will remain at the same level.
The reasons for the drop in demand in previous years are considered to be the general economic situation, high interest rates on loans, and recycling fees for special equipment. The latter was introduced in 2016. It ranges from 450 thousand to 6 million rubles per car, these amounts are paid by manufacturers and suppliers of equipment.
Constraining factors in the industry are the lack of investment in construction projects from the state, as well as constantly changing localization conditions. Due to the opacity of industry regulation mechanisms, manufacturers who planned to invest are forced to slow down this process, which ultimately negatively affects the special equipment market, says Sergei Kharitonov, development director at JCB in Russia (special equipment production).
Now the main reasons for the growth of the road construction equipment segment are the stabilization of the economy and pent-up demand. On average, construction companies updated their fleet of equipment more than 7 years ago; now they need new machines, says Aren Khachatryan.
Electric drive of mining excavators | VolAmper
Perelygin V. Electric drive of a mining excavator
Mining excavators of the EKG or ESh type use a large number of systems, varied in purpose and operating principle. Almost all energy conversion schemes known today, such as hydraulics, pneumatics, electric drives, and electronics, have found application on these machines. The primary and main stage of energy conversion - and in modern heavy excavators this is electrical energy entering the excavator through a high-voltage supply circuit - is an electric drive.
The evolution of the electric drive of mining excavators over the past thirty years has brought some changes to the design, but there are few truly new fundamental solutions already implemented on “live” machines.
Classically, to drive the main mechanisms, DC motors with independent excitation are used, powered by adjustable generators (G–D system) or adjustable static thyristor converters (TP–D system).
An engine with an excavator (self-unloading) characteristic implies operation at the rated speed up to the maximum stopping torque, upon reaching which the engine stops but does not lose force on the drive shaft. That is, when, for example, a loaded bucket rests against a stationary mass and the force developed by the lifting winch is not enough to insert the bucket, the engine should not “tip over,” i.e., a drop in speed and a decrease in torque on the engine shaft. To maintain the highest performance of the excavator, it is desirable that the engine operates at a constant maximum speed until the start of stopping (heaviest load). This means that the mechanical characteristic (the dependence of the rotation speed on the torque on the motor shaft) must be rigid, consisting of a working section with a minimum linear dependence of the rotation speed on the torque and a non-working section corresponding to a drop in the rotation speed at the maximum stopping torque. The operating mode of DC motors is closest to this excavator mode.
From the school course, everyone knows that the excitation winding of a DC motor in the form of the main magnetic poles is located in the stator; current flows to the armature (rotor) winding through brushes and a commutator - a device that converts constant emf. supply network into variable emf. armature windings.
Regulating the rotation speed of a DC motor is possible in three ways: by changing the resistance of the armature winding, the input voltage or the excitation flux (excitation current). Changing the resistance of the armature winding for regulation is unprofitable, since it is not economical and greatly softens the mechanical characteristics. Regulation by changing the excitation flux is applicable at low load torques. The engine torque is directly proportional to the excitation flow, and in addition, a break in the excitation circuit can lead to the engine running in the absence of a significant load on the shaft, since the rotation speed is inversely proportional to the excitation flow.
Regulating the rotation speed by changing the supply voltage requires a source with an adjustable voltage.
For a long period of time, the DC motors (the main drives of the excavator) were powered by DC generators (G–D system). This is a fairly reliable and easy-to-control electric drive system; it has been used for many decades in the drives of mining excavators.
In the simplest G–D system, a change in the supply voltage (generator output voltage) occurs by changing the excitation current in the independent excitation winding of the generator (for example, using a rheostat in the excitation circuit). A decrease in the supply voltage leads to a decrease in engine speed while maintaining operating torque and rigidity of performance characteristics (true for motors with independent and parallel excitation).
A network motor is used to drive the generators. Typically, a converter unit includes one or more line motors that drive generators. Each generator provides the drive of the corresponding mechanism - drive of lifting, pressure (traction for draglines), rotation, stroke, opening of the bottom of the bucket (for ECG). The unit may include an auxiliary generator that supplies direct current to the excitation windings of motors and generators. Powerful asynchronous (EKG-5A) or synchronous AC motors (EKG-10, EKG-15, ESh-11.70, etc.) are used as a network motor.
The individual drive of the main mechanisms is automated. The operator controls only the rotation speed and reverses the engine during the digging process. The remaining control processes (stabilization of rotation speed and limiting the maximum load, formation of excavator characteristics) occur automatically. The principle of automating the control of a separate mechanism is based on a special automatic control system (ACS). The regulator here is a power magnetic amplifier (it replaces the control rheostat in the excitation circuit in the simplest circuit). In the ACS, the generator is both an amplifying and actuating element, the engine is the object of regulation, and the controlled variable is the engine speed. When controlling, the driver, wanting to set a certain engine frequency, acts on the excitation circuit of the generator, that is, changes the amount of current in its excitation winding through the command controller. To maintain a given mode, the ACS contains feedback, which provides a corrective effect on the magnetic amplifiers and further on the current in the generator excitation circuit.
A more progressive scheme is considered to be one in which the excitation winding of the generator (motor) is powered by a thyristor converter. With this scheme, there is no need to use an auxiliary generator designed to power the excitation windings of electric machines and low-power drives (opening the bottom of the bucket). The main advantages of thyristor exciters are low inertia and higher efficiency. compared to power magnetic amplifiers. The thyristor converts alternating current into direct current with regulation of the rectified voltage. The thyristor control current is regulated by a synchronous command device.
The second method is to use a thyristor converter (TP-D) instead of a generator. However, the use of power thyristor converters for the electric drive of main drives leads to a decrease in the power factor of the excavator power plant, the appearance of additional harmonics and voltage fluctuations in the network, which reduces the quality of power supply to the quarry. To reduce the negative impact of transformer substations on the network, filter compensating devices are used on excavators. In the former USSR, the TP-D scheme was tested on ECG-20.
Another promising direction is the use of a pulse method for changing any motor parameter - voltage, resistance in the stator or rotor circuits. By changing the pulse duration, a change in the average rotation speed is achieved.
Asynchronous motors powered by adjustable static frequency converters (FC-AS) have been used in electric drives since the 1970s. Due to their ease of production and reliability in operation, asynchronous electric motors are widely used in unregulated electric drives. Their main disadvantages are a limited range of rotation speed control and significant consumption of reactive power.
Frequency converters have become widespread primarily in soft start systems. Nowadays, frequency converters are also being introduced as regulators in powerful drives (up to 10 MW mine lifts, ventilation systems, drainage, conveyor transport, traction drive of rolling stock in railway transport, etc.). The use of frequency converters allows you to: smoothly regulate the rotation speed of an asynchronous electric motor while maintaining torque on the shaft; reduce energy consumption by 30...50% due to optimal control of the electric motor depending on the load;
carry out a soft start of the electric motor with a current not exceeding the rated value for the electric motor; eliminate peak loads on the electrical network and voltage sags in it at the time of starting the electric drive.
Frequency converters create certain electromagnetic interference, to reduce which it is necessary to use additional filters. Effective forced cooling is required to operate at low frequencies. Another aspect is the difficulty of ensuring excavator mechanical performance. During the operation of an excavator, load moments can vary significantly over short periods of time from maximum moments that can “overturn” the engine to minimum ones. Therefore, automatic simultaneous adjustment of the frequency and supply voltage supplied to the stator winding is required.
Despite the high promise of the IF-AS system, it has not yet received mass and rapid implementation on excavators in Russia. This reflects both a certain general failure of the 1990s in industry and the need to introduce new solutions in automatic control systems. The performance of the IF-AS system has been repeatedly proven, including during the operation of the modernized ESh-20.90 excavator at the Safronovsky open-pit mine (Irkutsk region).
Many questions arise when using an IF-AS system; a brief review of them will require a separate publication.
Today, world leaders in the production of electric excavators, such as Bucyrus International Inc. with its members Marion and Ransomes-Rapier, as well as P&H, they offer excavators with electric drives made according to different schemes - FC-AS, G-D, TP-D. The choice of system remains with the customer.
Source https://www.os1.ru/article/service/2009_01_A_2010_05_18-11_42_22/
volamper.ru
