(2000-) A transport vehicle for operation in factories, hospitals and warehouses, etc. must have omni-directional properties that can move and turn freely over narrow floor space in all directions. The “VmaxCarrier” is newly developed vehicle with the following features; i) it has the omni-directional property, ii) it also has holonomic property which enables instantaneous change of the vehicle’s direction, iii) it has flat and compact shape, iv) it is very light.

The VmaxCarrier is equipped with four Omni-Discs that are the new omni-wheels. The basic principle of Omni-Disc is as follows; the vertical shafts that support the multiple small free wheels are installed in the lower disc so that they can rotate freely. The tips of the vertical shafts of the free wheels are inserted in the holes in the upper disc as shown in Figure 1. As shown in Figure 2, the two rotating discs in the Omni-Disc lie in separate planes, and are eccentrically fixed. And the two central rotating shafts of the discs have the same eccentricities as a pair of supporting shafts of a small free wheel. This ensures that individual wheels of the assembly are always aligned in the same direction, and that the Omni-Disc casters can always roll freely in that direction. The whole Omni-Disc mechanism is inclined 4 degrees with respect to its supporting plate, so only one or two small free wheels at the tip of the Omni-Disc touch the ground simultaneously. The two discs and multiple free wheels of the Omni-Disc constitute a kind of parallel mechanism as shown in Figure 3.

The overall view of the passive Omni-Disc is shown in Photo 1. The static friction coefficient of this wheel is 0.041, and its dynamic friction coefficient is 0.025. By driving the upper disc as a spur gear with a gear system, it is possible to obtain thrust in the direction perpendicular to the small wheels’ rotating direction, and a new type of omni-directional vehicle the “VmaxCarrier” can be created. The overall view of the VmaxCarrier is shown in Photo 2.

To the developer's website.