Views: 18 Author: Site Editor Publish Time: 06-06-2024 Origin: Site
The hydraulic excavator has its origins in the steam shovel, which used cables and mechanical systems to operate a digging bucket at the end of a boom. In the late 19th century, an English manufacturer replaced cables with a hydraulic cylinder and used water as the hydraulic fluid. By the end of the century, steam began to power the hydraulics, and by the mid-20th century, oil became the standard for transmitting hydraulic pressure.
Early excavator models were primitive compared to today's standards. For example, a 1950s excavator lacked ergonomic design and comfort features, with operators sitting on a bench and ventilating by removing the front glass of the cab. Development was slow initially, with Caterpillar introducing its first excavator only in the 1970s. Today’s hydraulic excavators are sophisticated machines with electronic controls and are used across various industries.
Numerous manufacturers produce mid-size and full-size hydraulic excavators for the North American market. Key factors to consider include:
1. Usage: Will you be digging, demolishing, or clearing land? Ensure the model you choose has enough horsepower and hydraulic flow for the most demanding task without being oversized for other jobs.
2. Features and Configuration: Consider long booms, telescoping booms, elevated operator cabs, and rubber-tired versus crawler models based on your needs.
3. Brands and Dealerships: Research the reputation of manufacturers and the level of dealer support available.
4. Size Considerations: If operating in confined spaces, a short-tail swing model might be preferable. For height-restricted access, a lower-profile excavator is ideal. Wheeled excavators can be narrower than crawler models, potentially easing site access.
5. Transportation: Ensure your flatbed can haul the machine and attachments, and consider the regulations and permits required for transporting heavy equipment.
Renting an excavator can be a great way to evaluate a model before purchasing:
1. Fit Over Cost: Focus on finding the right machine for your project rather than the cheapest rental rate.
2. Versatility: Consider all potential tasks and ensure the rented machine is suitable for multiple uses.
When considering a used excavator, perform a visual and mechanical inspection:
1. Hydraulic Components: Check for leaks, which indicate poor condition and maintenance.
2. Undercarriage: Inspect the slewing ring for wear by looking for metal particles in the lubricant and excessive play.
3. Signs of Wear: Look for cracks in metal structures and welds, particularly on the boom and stick.
4. Attachments: Inspect any included attachments for wear and functionality but focus primarily on the base machine.
- Mid-size crawler hydraulic excavators (100-275 hp): $180,000-$300,000.
- Larger crawler excavators (300-500 hp): $350,000-$850,000.
- Mid-size crawler excavators in good condition: $100,000-$175,000.
- Full-size crawler excavators: $175,000-$250,000.
- Mid-size crawler excavator: $800-$1,500/day, $1,800-$3,100/week, $5,200-$7,000/month.
Consider leasing with an option to buy to lower initial costs or structured financing programs for outright purchase.
1. Weight and Horsepower: Match the machine’s weight and engine size to the primary tasks (e.g., excavation vs. lifting).
2. Hydraulic Flow/Pressure: Ensure hydraulic capacity matches the requirements of intended attachments.
3. Strength and Reach: Decide between different boom and stick configurations based on the required breakout force and reach.
4. Tracks or Tires: Choose between crawler excavators for rough terrain and wheeled excavators for paved surfaces.
Designed for drilling holes for fence posts, pilings, or other structural components, the auger attachment enhances the excavator's functionality. It is mounted on the end of the boom-stick, allowing access to hard-to-reach areas. Multiple holes can be drilled efficiently without needing to reposition the excavator.
The hydraulic breaker is essential for breaking through hard materials like concrete and rock. It uses a hardened bit and an internal reciprocating ram to deliver hundreds of powerful blows per minute. The downward force from the excavator enhances its ability to split or pulverize tough materials.
The bucket is the fundamental attachment for any excavator and comes in various widths, including narrow, general-purpose, and wide. Adding a movable "thumb" allows operators to grasp and handle oversized or irregularly shaped materials more easily.
The hydraulic compactor is ideal for compacting loose soil or aggregate, this flat-bottomed, box-shaped attachment delivers rapid vibratory blows. For example, a 2,000-lb model on a 15-ton excavator can deliver 2,200 vibrations per minute with a force of 16,000 pounds.
This attachment connects the excavator to various tools. Hydraulic quick couplers offer hands-free operation, while mechanical models may require manual engagement. Tilt-rotating couplers provide added dexterity, enabling wrist-like movements for precise material handling or slope-sided digs.
These crusher screener buckets combine the functions of scooping, crushing, and screening material. Hydraulic-driven churning shafts within the buckets process aggregate and debris, making them useful for handling concrete and brick.
Hydraulic excavators equipped with demolition tools can efficiently dismantle structures and manage scrap. Attachments like steel-cutting demolition shears can exert up to 280,000 pounds of cutting force, making them ideal for snatching brick, ripping welded materials, and shearing steel beams.
A versatile tool used in forestry, demolition, and construction, the hydraulic grapple features two moving jaws that function like a thumb and finger. In larger models, the jaws can resemble buckets, offering a wider grasp.
Commonly used in scrap yards, this attachment employs magnetism to move irregularly shaped steel materials. It is also useful for clean-up tasks on demolition and construction sites. A typical midsized magnet is around 40 inches in diameter.
Capable of shredding a 30-foot-tall tree down to a stump in less than a minute, the mulcher attachment is highly efficient. The tool can be up to six feet wide, with larger models requiring 70 gpm or more of hydraulic flow to operate effectively.
This pile driver/vibro hammer allows an excavator to sink and extract piles, girders, casings, and other structures. High-speed vibrations facilitate the driving of piles into the ground and aid in their extraction.
Notable manufacturers include Bobcat, Case, Caterpillar, Doosan, Gradall, JCB, John Deere, Hitachi, Hyundai, Kubota, Komatsu, Kobelco, Liebherr, Link-Belt, LiuGong, SANY, Takeuchi, and Volvo.
Hydraulic excavators are versatile machines with extensive reach, powerful hydraulics, and a swiveling base, making them indispensable for excavation, construction, material handling, demolition, and logging. They are truly multi-functional machines capable of handling a wide range of tasks.
