The market of the modern excavators. Part 3

August 13th, 2008

Moving downwards on a dimensional scale, company Volvo has let out an excavator of a class 70 t. - EC700B. It is the biggest excavator which was let out ever by the company. It is intended for work in the open pit mines. Though the machine also has been already presented, nevertheless, its tests still proceed. On the worldmarket the machine leaves in the beginning of 2005. Previous model Volvo was in a class 65 t., model EC700B is completely the new machine which supports the trade mark a design providing reliable work in difficult conditions. According to Volvo, such basic knots as the main pump turning the engine, bearings and rollers of tracks have higher, than in machines of competitors, loading parameters. Thanks to its service life is maximum, and idle times on service are minimum. The chairman of Board of directors of company Volvo Construction Equipment Toni Helshem has told, that machine EC700B is created to offer production optimum corresponding A40D ADT. «To tell the truth, the excavatorEC650 mismatched ideally to our greatest tractors», he has added.
According to Volvo, machine EC700B engine D16CEAE3 is the greatest and powerful diesel engine used on the excavator of such class and it developing capacity 464 horse powers. At 1800 rpm, this engine it is very economic from the point of view of fuel consumption. Equipped with the newest system of combustion - Volvo Advanced Combustion Technology (V-ACT) the engine corresponds to rigid requirements of standards of exhausts Tier 3. In company Volvo consider, that the engine is well combined with difficult hydraulics. Access to the engine and hydraulics the good. The arrangement of served knots at ground level reduces a holding time. Thanks to the big counterbalance and long wide tracks excavator ЕС700В has high stability in difficult working conditions. For decrease in transport expenses of a track it is possible to delay. Despite a design intended for work in difficult conditions, excavator EC700B provides a productive cycle; it is economic on consumption of fuel and has the big effort of working out of a ground.
Excavator EC700B weighs 67, 5 - 70, 3 t. depending on the specification. Length of a standard arrow - 7, 7 m. Length of a standard bucket - 3, 55 m that allows digging on distance of 13, 17 m at depth of digging of 8, 4 m. Force of destruction of a ground - 301 кН. The sizes of a bucket - 2, 5 - 4, 5 m3, width of standard boots on tracks - 900 mm. In a cabin - wide windows with the good review, an armchair with numerous adjustments, ergonomic control levers. There is also a highly effective system a climate - the control, wide steps and hand-rail.
Company Liebherr offers the updated machine of a class 50 t. - R945C . Intended for high-efficiency work on mining and open pit workings out machine R945C has a reliable design and develops force of destruction of a ground to 307 кН, and force of digging - 244 кН. In model R945C checked up hydraulics Litronic, a rotary platform of the raised durability with possibility of a choice of width brake of stock 500мм, 600 mm, and 750 mm is used. The standard configuration includes an arrow «a goose neck» in the length 6, 7 m, a core in length of 2, 9 m, a set of buckets for mining works in capacity of 1 m3. As options for the machine are offered the device for fastening of hinged equipment type 77 which allows to connect quickly a tooth-ryhlitel, and a counterbalance in 10, 5 t., adding stability to the machine. The excavator is equipped by six-cylinder diesel engine Liebherr D936L with direct injection, and the subsequent cooling by capacity 240 кВ at 1800 rpm. Hydraulics Litronic provides 4 operating conditions: mode Lift and Fine - for the operations demanding accuracy. Mode Eco use for economy of fuel and midget exhausts. As well as at machines of competitors, the cabin of the excavator R945C has upholstery, the conditioner, a pendant armchair for softening of blows, double joystick managements. The liquid crystal display in real time reflects all information on a condition of systems of the machine.
The biggest hydraulic excavator of firm Caterpillar became updated model 385CL with phase-out 5000Series. This machine has replaced an excavator 385В and develops the big capacity thanks to new diesel engine Cat C18 capacity 513 horse powers. In the engine technology ACERT and the module of the control of exhausts and optimization of the expense of fuel ADEM of IV firm Cat are used. The excavator 385CL heads a lineup of machines of a class 85 t. The standard bucket of the machine has capacity 3, 8 m3, but there is 12 more various buckets in capacity from 2, 1 to 5, 93 m3. For the further optimization of use of the machine a company offers various kinds of arrows and cores of the general and a special purpose. Buyers in the USA prefer arrows and cores more lengths, than in Europe where the configuration of the general excavation is more popular. Therefore the wide choice of the forward hinged equipment allows distributors to adapt the machine for geographical features of the market better.
The big cabin of the excavator provides the good review and is conveniently organized. Operators can change an operating mode and adjustment of hydraulic system. It is very important, since hydraulic knots of different manufacturers can have various requirements to pressure; therefore possibility of its adjustment is serious improvement. In a cabin also there is a display with the full information on work of the machine and its condition. It is the original diagnostic block for works on e service.
Diesel engine C15 ACERT capacity 404 horse powers is heart of the updated model 365CL which has replaced model 365BII. The excavator has a standard bucket in capacity 3, 8 m3, 12 additional buckets and teeth of different function. The model 365CL 69 t. weighs. In a new cabin the big glasses are used, control levers are improved, the display gives the information on work of the machine which can be used at diagnostics. The wide range of the hinged equipment expands universality of the machine. The excavator is issued with the improved tracks of the increased service life which are provided by such additional means as hydraulic hammers for primary/secondary braking.
As models 385CL and 365CL, model 345CL the previous model has the big capacity and productivity, than. Diesel engine C13 of the car 245CL develops capacity 257 кВ (345 кВ), that on 7, 5 % more than in the machine 245BII though its working volume is increased by 21 % to 12, 8 l. Therefore the engine is not exposed to superfluous loading, and, hence, more reliably and is more durable. Other characteristics of diesel engine ACERT is controller ADEM IV, mechanical injection of the fuel, the increased intervals of change of oil and filters. The cabin device, control levers and model tracks 345CL is the same, as well as in the machine 356CL. In a standard configuration the excavator 345CL weighs 44, 3 t., has a bucket in capacity of 1, 82 m3, various buckets and teeth, the working tool, arrows and cores.

Source: the materials “Engineering and Mining Journal”.