Utility Contractor

SEP-OCT 2018

As the official magazine of NUCA, Utility Contractor presents the latest information affecting every aspect of the utility construction industry, including technological advancements, safety issues, legislative developments and instructional advice.

Issue link: http://digital.utilitycontractoronline.com/i/1031723

Contents of this Issue


Page 24 of 43

3. Simple to maintain Convenient service checkpoints, quality components and extended service intervals can help keep maintenance costs low and daily production schedules moving for smaller- sized wheel loaders. To improve machine uptime and reduce unexpected machine issues down the road, operators should follow daily, monthly and hourly maintenance schedules, based on the manufacturer's recommended guidelines outlined in the Operation & Maintenance manual. Operators should complete a daily walk-around, checking for obvious machine damage or wear. Inspecting fluids, oils and filters, as well as tire pressure, is also crucial in construction and infrastructure applications. New wheel loaders have been designed with engine after- treatment systems designed to clean diesel engine exhaust and meet the Environmental Protection Agency's emission standards for Tier 4-compliant engines. While each equipment manufacturer has a slightly different emission strategy, it is more important than ever to follow their guidelines for maintenance and service. 4. Additional safety features Since smaller-sized wheel loaders work on congested jobsites or in confined spaces, many manufacturers equip their machines with helpful safety features such as a rearview camera, backup alarms and optimal visibility from the cab. Options include machine lighting for operators who work early in the morning and continue late into the night. Other wheel loader options may include hydraulic locking differentials, heated mirrors and emergency steering. 5. Equipped with hydrostatic transmissions Instead of using a traditional transmission, some manufacturers now offer a hydrostatic transmission for the smaller-sized wheel loader class, which provides excellent means of power when variable output speed is required. This type of transmission allows operators to fine- tune the travel speed and can obtain full engine rpm to run hydraulically powered attachments at their optimal efficiency. A hydrostatic transmission consists of an entire hydraulic system: It contains a pump, two hydraulic motors and a gearbox. Power is generated and transmitted by fluid flowing through a specialized system. This type of wheel loader is equipped with a constant velocity (mechanical) gearbox that is connected to two hydraulic motors — a low-speed and a high-speed motor. A variable displacement pump attaches directly to the engine and provides the hydraulic flow to accelerate or decelerate the machine. If more torque is needed, especially in heavy digging applications, both the low- and high-speed motors will receive flow. This provides low-speed, high-torque output from the motors. When the demand for higher torque decreases and speed increases, the system automatically transfers the flow to the higher-speed motor. This provides higher speed output with lower torque for improved machine performance. Hydrostatic wheel loaders have several benefits including improved fuel efficiency because of improved performance at lower engine rpms; enhanced machine position control to increase productivity, especially when climbing a pile to fill the wheel loader's bucket; and low heat development in the digging range. In addition, they have fewer moving parts compared to torque converter transmission-style wheel loaders, which makes servicing the machine easier. Smaller-sized wheel loaders have a variety of advantages, especially when working in construction and infrastructure applications where a larger wheel loader may be too big. By looking at overall performance, versatility, serviceability and safety features, equipment owners can do away with a "bigger is better" mentality and be open to the idea of utilizing smaller wheel loaders. Allison Grettenberg is a writer for Two Rivers Marketing, Des Moines, Iowa. The article was written on behalf of Doosan Infracore North America, LLC, Suwanee, Georgia. July/August 2018 | Utility Contractor 25

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