An excavator is an engineering vehicle consisting of an articulated arm (boom, stick), bucket and cab mounted on a pivot (a rotating platform, like a Lazy Susan) atop an undercarriage with tracks or wheels. Their design is a natural progression from the steam shovel.
Excavators are used in many roles:
Though many companies produce Hydraulic excavators today. Komatsu is the top producer of Hydraulic Excavators world wide, for every one competitive model there are three Komatsu Excavators
Excavators come in a wide variety of sizes. The smaller ones are called a mini-excavator or compact excavator
. One manufacturer's largest model weighs 84,980 kg
) and has a maximum bucket size of 4.5 m³
). The same manufacturer's smallest mini-excavator weighs 1470 kg (3240 lb), has a maximum bucket size of 0.036 m³ (0.048 yd³) and the width of its tracks can be adjusted to 89 cm
). Another company makes a mini excavator that will fit through a doorway with tracks that can be adjusted to only 70 cm (28 inches) wide.
In recent years, hydraulic excavator capabilities have expanded far beyond excavation tasks with buckets
. With the advent of hydraulic powered attachments such as a breaker
, a grapple
or an auger
, the excavator is frequently used in many applications other than excavation. Many excavators feature quick-attach mounting systems for simplified attachment mounting, dramatically increasing the machine's utilization on the jobsite. Excavators are usually employed together with loaders
. Most wheeled versions, and smaller, compact excavators
have a small backfill (or dozer-) blade. This is a horizontal bulldozer-like blade attached to the undercarriage and is used for pushing removed material back into a hole. Prior to the 1990s, all excavators had a hang over, or "conventional" counterweight that hung off the rear of the machine to provide more digging force and lifting capacity. This became a nuisance in tight turn areas - the machine could not swing the second half of its cycle due to restricted turn radius. In the early 1990s The Komatsu Engineering Company launched a new concept excavator line that did away with the "conventional" counterweight design, and so started building the world's first tight tail swing excavators (PC128.PC138,PC228,PC308). These machines are now widely used though out the world.
Excavators are also called diggers
and 360-degree excavators
, sometimes abbreviated simply to a 360
. Tracked excavators are sometimes called trackhoes
by analogy to the backhoe
Even though the 'back' in backhoe refers to the action of the bucket (which pulls "back" toward the machine) and not the location of the shovel, excavators are also occasionally referred to as fronthoes
or even just "hoes".
In Japan, alias is more popular than concerning association named. French company SICAM produced the excavator and modeled Yumbo S25 after patent right obtained from Italy in 1954. SICAM licensed technologies to many countries, such as Drott in United States, Priestman in UK, Mitsubishi in Japan and other countries from early 1960s. First excavator from Mitsubishi was named Yumbo Y35 in aiming international market in 1961. Yumbo had been becoming popular name and de facto standard among Japanese through Classified ad, not formal naming though.
The National Association of Heavy Equipment Training Schools
(NAHETS), established 2002, uses excavator training schools and circuilum as a method to test and train users in the ability of excavator use.
The excavating technology of Mars rovers
The Phoenix spacecraft has a robotic excavating arm, controlled by an on-board computer system and/or by the terrestrial command center, equipped with a bucket, drill, special sensors and camera.
Because of the extreme climatic conditions of Mars there were several malfunctioning problems with Phoenix's "excavator".
Types of excavator
Reference and foot notes