Yanmar Develops Innovative 3 Star Hydraulic System

The ViO80-1B backhoe released in May, 2017 fully meets Japanese Ministry of Land, Infrastructure, Transport and Tourism fuel efficiency standards, thanks in large part to the new ViPPS2i hydraulic system. Basic research on the system began when the ministry was considering a fuel efficiency certification system for construction equipment, at a time when added importance was being placed on reducing emissions. Yanmar Construction Equipment teamed up with the Yanmar Research & Development Center and asked themselves what fuel efficiency really was, as a starting point for this project. We wanted a fuel-efficient machine that was at least as productive as its predecessors. Development commenced in 2014 on a 2 independent pump, load sensing system.

The Fuel Efficient Independent 2-Pump Load Sensing

This system has two major benefits. The first is oil flow rate control thanks to the LS (load sensing system). Previous hydraulic systems used to deliver maximum oil flow rate regardless of the task at hand, sending the unused oil back to the tank. To reduce the excessive flow rate Yanmar installed the LS system. "There are variances in pressure between the oil discharged from the pump and the cylinder that receives the oil. Unlike its predecessors, the ViPPS2i is equipped with an LS valve that regulates loads. It enables the amount of oil required to move the lever and the amount of oil that flows from the pump to be the same, reducing oil losses that arise from an excessive flow rate," said Takayuki Shirouzu, in charge of controller development. The second major benefit was having two independent oil pumps. "With the ViPPS2i's predecessors, for operations such as traveling, turning or excavating, we couldn't combine the oil discharged from multiple pumps. It used to require an amount of oil discharge that was equivalent to the maximum pressure of the cylinder that was performing the operation. With the ViPPS2i, major cylinders use separate pumps, delivering optimum pressure for each operation," said Hiroshi Matsuyama of the Development Division. When there are two operations being performed at the same time such as an arm and a boom operation, the cylinder which is most frequently used is controlled by a separate pump, allowing for optimum pressure for both operations. These two benefits still offer the same level of productivity if not more, and a 20% improvement in fuel efficiency.

Customer Feedback Leads to an Optimized Hydraulic System

This model was the first backhoe with a hydraulic system like this in the 8t class and a first for Yanmar as well. Achieving this was no easy task. In particular, evaluating the performance of the ViO80-1B was a daunting task. "Even though we have two pumps, each pump handles multiple operations. To make sure that operability wasn't compromised when performing multiple operations, flow rates needed to be optimized. Previous testing methods weren't suitable for optimizing the hydraulics, so it was a real headache," said Satoshi Kawakami, in charge of testing. For performance, strength, durability and monitor tests we got 10 companies in Japan to test ride the ViO80-1B as well as 8 international customers.

"While it was a big job, customers were extremely satisfied with the monitor. The positive feedback motivated us all the way until completion", said Hideki Seino who oversaw development. "You won't get a better backhoe in the 8t class than this. It's a shame we can't take all the credit for it. A big thanks goes out to the Research & Development Center, sales who evaluated the monitors and other departments for their help with this project," said Hideki. The ViO80-1B is sure to be a game changer.

Thoroughness Leads to Machine Efficiency

Equipped with an LS system, flow rates are optimized for each work load, minimizing the load on the engine. The 2 independent pumps only discharge enough oil to get the job done, leaving nothing to waste. Thorough technical calculations and customer feedback helped us deliver a machine that performs just as good as its predecessors and delivers a 20% improvement on fuel efficiency. The ViO80-1B is an industry first in the 8t class to be equipped with a hydraulic system like this.