The drive system in Avant loaders consists of a variable displacement hydraulic pump, four hydraulic drive motors and some valves which are connected together with hydraulic hoses and fittings.
This system where the drive power is conveyed from engine (electric motor on Avant e series) to the wheels using hydraulic oil is often referred to as drive circuit. Instead of mechanical axles Avant uses a design where there are four separate hydraulic drive motors, one on each wheel of the loader.
Avant was the first manufacturer to design and utilize such a system in a compact loader. This system has proven to be very effective, offering lots of pushing power and yet enabling a very compact design to the loader while maintaining an extremely low center of gravity, which is an important part of the great stability of Avant loaders.
Through research & development Avant has now improved this system with an innovative way of rethinking. When hydraulic oil flows at high flow rate in the drive circuit – in hydraulic hoses, fittings, motors and valves – the resistance in these components heats up the hydraulic oil. The more there are hoses and fittings, the quicker the oil heats up, which means that all that unnecessary heat generated in the system uses a part of the engine output in vain. This also results in higher fuel consumption, and less engine power is available for the actual job.
In the new system the amount of hydraulic hoses and fittings has been radically reduced and optimized, where the name Optidrive™ derives from as well.
The principal benefits of the new Optidrive™ are:
- 10% better performance
- 60% less hydraulic connections
- 20% less hoses
- Parking brake in rear wheels
- Less heat build up
- Less engine vibrations in Avant 700 series
- Better hydraulic connector system
- Better servicing
The Optidrive™ reduces the power loss in the system by up to 1,5 kW, which is roughly 10 % of the total power used in drive circuit. This means lower fuel consumption, less heat in the hydraulic system and more power for the actual job.
Less heat build up
All of the four hydraulic drive motors in the drive circuit use flushing oil to cool the motors down when the loader is working. Especially when travelling longer distances at high travel speed the cooling is essential. On Optidrive™ the amount of flushing oil in the drive motors is 5 times bigger compared to old system, providing a far better cooling of the drive circuit.
Smaller amount of hoses and fittings
Depending on the Avant model the Optidrive™ eliminates at least three hoses from the system without losing any of the features on the loader.
This is achieved through intelligent new design with the valves (drive release valve, parking brake valve, dual speed valve) mounted together on one hydraulic block.
The amount of fittings is radically reduced. The Optidrive™ features approx. 30 fittings less (-60 %) compared to old drive circuit. There are also far less 90 degree angle fittings and T-junction fittings that are less optimal for hydraulic flow.
Parking brake in rear wheels
In order to get the best possible grip on all load and terrain situations the parking brake on the Optidrive™ is situated in the rear wheels of the loader. Rear weights, load on the boom, uphill, downhill etc. have therefore a smaller effect on the loader’s rear wheels and thus the loader stays more securely on place when parking brake is engaged.
The Optidrive™ also has an effect on the weight and balance of the engine and pump assembly on the loader. The altered weight distribution also lead to developing new engine mounts (vibration dampers) that are optimized to the new load and balance of the assembly. This optimization resulted in reducing the total vibrations of the 700 series loaders. This is especially notable in the noise level inside the cab LX and DLX. The new larger engine mounts reduce vibrations by 50 % on Avant 745 and 750, and by 37 % on Avant 755i and 760i.
The Optidrive™ has the new Parker EO3 fitting system in all of the high pressure hoses and fittings. This new system has a dial on the fitting, which shows clearly the required torque to which the fitting shall be tightened.
Also less fittings and less hoses equal to less possibility of a hydraulic leak.
Less hydraulic connections, the new fitting system and more space to work with in the engine bay and front hydraulic motors area all provide a better servicing experience.
The Optidrive™ has a centralized valve system, which collects all drive circuit valving into one valve block located in the front frame of the machine. Drive release valve, parking brake valve and dual speed valve on 750 and 760i are now all located in the same valve block.