Smart solutions for construction machinery

22 March, 2017

Smith explains that this solution essentially uses fairly conventional technology, but adds that as a manufacturer Parker also needs the ability to respond to other demands; such as those for electro-hydraulic solutions. “In this regard, one of the areas where Parker has focused a lot of effort is based around permanent magnet servo-type liquid-cooled motors for use in hybrid vehicles,” said Smith. “These motors are around 90% smaller than conventional A/C induction air-cooled motors. The key here is flexibility; OEMs may be looking for conventional power where they want the most efficient hydraulics and the best electronic control. On the other hand, they may be looking for advanced electro-hydraulic hybrid systems. So, we must be able to respond to these requirements.”

Electro-mechanical development

Sean Kilgallen, marketing manager, Bosch Rexroth, points out that until the introduction in 2014 of the Tier 4 emissions mandate for engines used by off-highway vehicles, most construction and off-highway vehicles were fitted with mechanically injected engines, with barely any electrics on the engines other than the starter circuit. “Few electrical functions on the machine would be supplied via a fuse box and mechanical relays,” he said. “However, with Tier 4, the requirement for electronic fuel injection was required, so the engines began to have an electronic engine control unit (ECU). Then, more and more OEMs thought, now they had an electronic box on the engine and a CAN Bus system, they might as well make the whole vehicle electro-mechanical as well.”

Consequently, said Kilgallen, what started off as a revolution on the engine developed into electronics playing a bigger role on the rest of the vehicle. “Many of these vehicles are now becoming more like cars; where you can plug in and do diagnostics and run all sorts of functions electronically rather than just having a conventional fuse box and relay,” he pointed out.

The space issue

In addition, Kilgallen explains there is increasing pressure to reduce what Bosch Rexroth refers to as ‘space claim’. “There is an ever-shrinking space footprint in terms of the size of equipment and where it can be placed on construction vehicles,” he said. “Since the Tier 4 emissions mandate came into play for engines used by off-highway vehicles, OEMs have needed to add a significant amount of exhaust after-treatment equipment to meet the regulations. So, when you to have to fit a particulate filter that is four times the volume of the engine this can be a major issue, particularly on smaller vehicles.”

Fortunately, adds Kilgallen, equipment providers such as Bosch Rexroth are now offering equipment with increased efficiency and higher pressure ratings to make best use of the limited space available. He points out that Bosch Rexroth also offers a wide range of electronics and sensors; some of which have been developed from standard products offered by Bosch Automotive. “These are being used increasingly on road-going vehicles, and can be easily adapted for off-highway and construction vehicles,” he explained, adding that they are considerably more cost-effective, compact and robust than many of the industrial-type sensors that were originally designed for use in factories.

One example given by Kilgallen is using a speed sensor which is developed from a standard Bosch Automotive ABS wheel sensor. “It is far smaller, cheaper, lightweight and more robust than the large industrial screw-in metal speed sensor it replaces,” he said. “This is one example of where automotive technology with a smaller footprint is moving increasingly in the direction of construction and off-highway vehicles.”