Excavators are heavy equipment consisting of a boom (backhoe), bucket and cab on a rotating platform (known as a House). The House sits atop an undercarriage with tracks or wheels. All movement and functions of the excavator are accomplished through the use of hydraulic fluid, be it with Rams or Motors.
Excavators come in a wide variety of sizes. The smaller ones are called mini or compact excavators. Caterpillar's smallest mini-excavator weighs 1610 kg (3549 lb) and has 19 hp, their largest model weighs 84,980 kg (187,360 lb) and has 513 hp.
However this is far from the largest excavator available, consider the Terex RH 340, it weighs in excess of 550,000 kg, has 3000hp and has a bucket size of 34.0 m³
The primary job of the engine in an Excavator is to drive Hydraulic pumps, there are usually 3 pumps, the two Main pumps are for supplying oil at up to 5000 psi for the rams, slew motor, track motors, and accessories. The third pump is for Pilot Control, this is a lower pressure (700 psi) circuit used for the control of the spool valves, this allows for a reduced effort required when operating the controls.
The basic components of an excavator include, the Undercarriage which includes the blade (if fitted), tracks, track frame, and final drives which have a hydraulic motor and gearing providing the drive to the individual tracks. The house (including the operators cab, counterweight, engine, fuel and hydraulic oil tanks) attaches by way of a center pin to the Undercarriage, allowing the machine to slew 360° unhindered.
The main boom attaches to the house, it can be one of 3 different configurations, Most are Mono Booms, these have no movement apart from straight up and down, some others have a Knuckle Boom which can also move left and right in line with the machine, the other option is a hinge at the base of the boom allowing it to hydraulically pivot up to 180° independent to the house, however this is generally available only to compact excavators.
Attached to the end of the Boom is the Stick (or dipper arm), the stick provides the digging force required to pull the bucket through the ground, the stick length is optional depending whether reach (longer stick) or break-out power (shorter stick) is required. On the end of the stick is usually a bucket. A wide, large capacity (Mud) bucket with a straight cutting edge is used for cleanup and leveling or where the material to be dug is soft, and teeth are not required. A general purpose (GP) bucket is generally smaller, stronger, and has hardened side cutters and teeth used to break through hard ground and rocks. Buckets have numerous shapes and sizes for various applications. There are also many other attachments which are available to be attached to the excavator for boring, ripping, crushing, cutting, lifting, etc.
Prior to the 1990s, all excavators had a long, or conventional counterweight that hung off the rear of the machine to provide more digging force and lifting capacity. This became a nuisance when working in confined areas. In 1993 Yanmar launched the world's first Zero Tail Swing excavator,
1 which allows the counterweight to stay inside the width of the tracks as it slews, thus being safer and more user friendly when used in a confined space. This type of machine is now widely used throughout the world.
Michener Allen AuctionsCaterpillar
Mini Hydraulic Excavators:
Cat Mini Excavator Highlights
Mini Hydraulic Excavators
* High digging forces and fast cycle times to help you get more done, faster.
* Quiet, spacious cab and smooth ergonomic controls, with integrated auxiliary and swing boom functions keep you comfortable and reduce operator fatigue.
* Pin-Grabber Coupler and quick disconnects enables the operator to change mini excavator attachments quickly.
* Auto idle, auto two-speed and a load sensing variable pump optimize fuel efficiency.
* A compact or standard radius tail swing with a swing or fixed boom option provides a good match to any jobsite.
301.6CClick here for specifications.301.8C Click here for specifications.302.5CClick here for specifications.303C CRClick here for specifications.303.5C CRClick here for specifications.304C CRClick here for specifications.305C CR Click here for specifications.307DClick here for specifications.308D CRClick here for specifications.308D CR SBClick here for specifications.Small Hydraulic Excavators:
Cat Small Excavator Highlights
Small Hydraulic Excavators
* Improved fuel efficiency translates into more work output for your fuel cost.
* Higher digging forces, increased lifting capacity and more drawbar pull offer best in class performance creating greater revenues.
* Sleek in-cab LCD monitor is full color, user friendly and provides access to service, performance and maintenance tracking.
* Unparalleled Tool Control System offers preset Cat tools and pre-programmable pressure and flow for up to 10 hydraulic work tools.
* Unmatched dealer support for your small excavator from the undercarriage to your auxiliary hydraulics and work tools.
311D LRRClick here for specifications.312D/312D L Click here for specifications.314D CR/314D LCRClick here for specifications.315D LClick here for specifications.319D L/319D LNClick here for specifications.
Medium Hydraulic Excavators:
Cat Medium Excavator Highlights
* Cat hydraulic excavators are known for swing torque, hydraulic power, controllability, faster cycle times, reliability, lower owning & operating costs, and the best tons per hour productivity in the industry.
* Exclusive upper frame swing bearings are designed for more surface contact for longer life, improved stability, and reduction of machine pitching.
* Cat is the only manufacturer to offer a compact radius, reduced radius, and a standard radius in the medium hydraulic excavator size class.
* Hydraulic excavators are equipped with Product Link, which allows the customer to monitor the machine from a remote location by keeping track of hours of use, location, security, and machine health.
336D LClick here for specifications.320D L Click here for specifications.320D LRRClick here for specifications.321D LCRClick here for specifications.324D LClick here for specifications.329D LClick here for specifications.328D LCRClick here for specifications.
Large Hydraulic excavators:
Cat Large Excavator Highlights
* Cat ACERT™ technology works at the point of combustion to optimize engine performance and provide low exhaust emissions.
* The optimized hydraulic system has been designed to provide reliability and outstanding controllability.
* The operator station provides maximum space, wider visibility, and easy access to switches. All of this ensures the most comfortable working environment for the operator.
* Many boom and stick options are available, offering a large range of configurations suitable for a wide variety of applications.
* Cat designed excavator undercarriage is stable, durable, and low maintenance.
* Caterpillar offers a wide variety of factory-installed auxiliary hydraulic and work tool options. This best-in-class versatility enhances performance and job site management.
* Fast, easy service has been designed in with extended service intervals, advanced filtration, convenient filter access and user-friendly electronic diagnostics for increased productivity and reduced maintenance costs.
345D L Click here for specifications.365C LClick here for specifications.385C LClick here for specifications.Hitachi
Compact Excavators:
Hitachi mini excavators are known for their efficiency and innovation. Used mainly in densely populated urban areas, they have been designed to function efficiently and safely in narrow jobsites.
ZX17U-2Click here for specifications.ZX27U-3Click here for specifications.ZX35U-3Click here for specifications.ZX50U-3Click here for specifications.ZX60USB-3Click here for specifications.Excavators:
Hitachi excavators have earned a reputation for quality and cutting-edge technology. People love them because they can count on them, and that didn't happen by accident.
ZX75US-3Click here for specifications.ZX85USB-3Click here for specifications.ZX120-3Click here for specifications.ZX135US-3Click here for specifications.ZX160LC-3Click here for specifications.ZX200LC-3Click here for specifications.ZX225USLC-3Click here for specifications.ZX240LC-3Click here for specifications.ZX270LC-3Click here for specifications.ZX350LC-3Click here for specifications.ZX450LC-3Click here for specifications.ZX650LC-3Click here for specifications.ZX850LC-3Click here for specifications.Wheeled Excavators:
ZX190W-3Click here for specifications.ZX220W-3Click here for specifications.John Deere
0-6 Metric Tons:
Some work requires a smaller machine to achieve bigger results. For those kinds of jobs, turn to a John Deere compact excavator. Their small stature, independent-swing boom, and zero-tail-swing design enable these highly maneuverable machines to put more work within reach.
17DClick here for specifications.27D Click here for specifications.35DClick here for specifications.50DClick here for specifications.60DClick here for specifications.
6-40 Metric Tons:
'75D
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85D
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120D
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135D
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160D LC
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190D W Wheeled
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200D/200D LC
Click here for specifications.
220D W Wheeled
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225D LC
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240D LC
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270D LC
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350D LC
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40-85 Metric Tons:
450D LC
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650D LC
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850D LC''
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