产品的过程。在 1995 年 3D CAD 绘图系统介绍后跟固体建模和 1999 年的内部数控仿形切割。歌赋工程是能够提供标准和定制设计及其历史和制造系统的后盾卡特彼勒机械产品。产品现在涵盖了广泛的应用和机器。 附录二：外文资料原文
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Wheel Loader Prototypes
In the 1920s, small agricultural tractors were outfitted with a loader bucket for re-handling of light materials. This contraption served as the earliest prototype for the modern wheel loader. The earliest versions of the wheel loader were nothing more than a pivoting bucket and lift arms mounted on a farm-type tractor. A bucket was mounted on a tractor using wire ropes through a clutch-operated winch, and then dumped by gravity through a trip release mechanism. By the 1930s, a number of manufacturers were developing small wheel loaders by fastening buckets onto tractors. E.Boydell & Co., in Manchester England, was one of the first recorded makers of a bucket-mounted tractor with their Muir-Hill loader, a 0.5-cubic yard (0.4 m3) cable-controlled bucket mounted on a 28 horsepower Fordson Tractor. Rigid Frame Wheel Loaders
In 1939, an engineer from Chicago by the name of Frank G. Hough developed the first self contained, two-wheel drive, rubber tired, loader called the Hough Model HS. The machine had a bucket capacity of 1/3 cubic yard (0.25 m3). The bucket was dumped by gravity through a latch mechanism.
Other manufacturers began to produce integrated four-wheel drive wheel loaders. Many of the first wheel loaders had rigid frames. Though these machines were integrated, their rigid frames limited maneuverability resulting in the machines to turn in large circles rendering them useless to operate in tight places.The first three wheel loaders developed by Caterpillar, for example, had rigid frames. Other manufacturers like Euclid/ Terex entered the wheel loader market in 1957, rather late, with a small rigid frame wheel loader unit known as the L-7. Furukawa FL35I 4x4 Articulated Wheel Loader
Perhaps one of the most significant milestones in the evolution of the wheel loader was the introduction of the articulated frame. Mixermobile Manufacturers
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in Portland, Oregon first pioneered this technology in 1953 with the Scoopmobile Model LD-5, In 1944, Hough went on to manufacture a loader with the first hydraulically actuated bucket tilt. This gave the machine the ability to control dumping and the operator could approach a bank in low gear and scoop a full bucket by tilting the bucket back during loading. In 1947, Hough would advance wheel loader development once again when the company developed the world's first four-wheel drive hydraulic wheel loader the HM Model. The model is still considered the forerunner for the modern wheel loader.
Mixermobile Manufacturing can be credited with introducing the first wheel loaders with hydraulic motors when it developed the Model H wheel loader in 1952 and the Model HP wheel loader in 1957. These loaders had a single centrally mounted bucket arm.
The Tractomotive Corp., founded by Van Dobeus, was another company to introduce the hydraulic wheel loader to the U.S. market. This involved fastening a hydraulic wheel mechanism with hydraulic power to the bucket crowd. This development transformed the wheel loader virtually from a re-handling machine to a digging machine. Front Pivot Arm
As wheel loaders increased in size through the 1950s, concern for safety arose, particularly in the positioning of the loader arm pivot. Positioned behind the operator, the loader arms, as they moved up and down, were in close proximity to the operator. This posed problems. First, the moving arms presented an accident just waiting to happen. Second, the moving parts limited the operators' side visibility, particularly when in a raised position. In the late 1950s, a number of American wheel loader manufacturers were working in collaboration with the National Safety Council to reposition the arm pivot to be in front of the operator rather than behind. Hough was one of the first manufacturers to come up with a new, safer design with the production of their Model HO wheel loader.Other manufacturers quickly followed suit in adopting the front mounted pivot including Caterpillar in 1958, Case in 1959, Allis-Chalmers in 1961 and
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Michigan in 1962. Large-sized Wheel Loaders
As the 1960s arrived, the trend in wheel loader production focused on larger machines with greater payload capacity. After Caterpillar launched their six-cubic yard (4.6-m3) Model 998 in 1963, a number of industry surveys revealed a need for loaders to be much larger than the standard size of five to six cubic yards (3.8 to 4.6 m3). The market was demanding more rugged mobility from loading tools and larger wheel loaders were deemed the solution. Manufacturers began to flood the market with larger sized wheel loaders. Hough Division of International Harvester built the H-400, a wheel loader with a 10-cubic yard (7.6-m3) bucket. Other manufacturers responded by producing loaders with 10-cubic yard (7.6-m3) buckets including Caterpillar's 992, the Scoopmobile 1200 and Michigan's 475.
Over the years, the industry has continued to push the boundaries in terms of payload capacity. In the 1970s, a number of wheel loaders were showcased at 1975 CONEXPO with increased payload capacity not otherwise seen before in the industry including Hough's 21-cubic yard (16-m3) 580 Payloader and Clark-Michigan's massive 675 wheel loader with a 24-cubic yard (18.3-m3) capacity.[15] In 1986, the record in payload capacity was broken when Kawasaki Heavy Industries Ltd., developed the largest wheel loader with a 25-cubic yard (19-m3) capacity for Japan's Surface Mining Equipment for Coal Technology Research Association. Eventually, other manufacturers including Caterpillar, Komatsu, and LeTourneau would delve into making loaders with capacities of 20 cubic yards (15.3 m3). LeTourneau's Legacy
1988 Komatsu WA600-1L Wheel LoaderLeTourneau is a manufacturer that has a reputation of building record-breaking heavy equipment. The company developed and still manufacturers the largest wheel loader in the world, the L-2350.This loader is primarily used in surface mining and boasts a 2300 horsepower machine and an 80-ton, 53-cubic yard (40.5-m3) capacity rock bucket and a breakout force of 266,000 pounds. The height, to the top of the cab and bucket fully raised,
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is a staggering 43 feet and nine inches (13.23 m). The machine was designed to load 300- to 400-ton plus mining trucks in four to five passes.
Le Tourneau's wheel loaders feature diesel-electric drive with DC electric motors in each wheel, a concept developed by LeTourneau himself. In the 1960s, the company started producing very large electric loaders with power to the hoist and bucket tilt transmitted through a rack-and-pinion drive. At first, these huge rack-and-pinion motors were not very commercially successful because the advantage of articulated steering was diminished due to the loader's industrial strength. As a result, few were actually built. One such model was the SL-40 model nicknamed the Monster and measuring 52 feet (16 m) long.
The present day line of LeTourneau wheel loaders is derived from the L-700 series electrical drive model first produced in 1968. The L-700 was the forerunner to a series of successful loaders produced in large amounts to this day. The machines have departed from the rack-and-pinion motors but retain the electric drive wheels. Though the rack-and-pinion motor wheel loaders where not big sellers, they did prove to work hard and had a life cycle of more than 20 years. New Developments
Today, electrical loaders exist on the market and function with much the same capacity and versatility as diesel engine or gasoline engine wheel loaders. Wheel loaders also come with a range of attachments such as grapples, forks, and buckets in varying sizes that expand their tasking to include light demolition and tunneling.[21] Some wheel loaders come equipped with ride control, which allows for greater operating speeds on bumpy surfaces.
New breakthroughs in adopting hybrid technology to reduce fuel transmissions are underway. In March 2008, Volvo unveiled at CONEXPO, a pre-production prototype of its L220F Hybrid wheel loader. The loader will offer a 10 percent reduction in fuel consumption. The technology has been developed within the Volvo Group and remains confidential and subject to patents. Slated for production in late 2009, the L220F will be the industry's first commercially available hybrid wheel loader.
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