Drive shaft with improved shaft lubrication

A drive shaft comprising:

• a telescopic shaft comprising an axis, an outer tubular shaft and an inner tubular shaft inserted slidable into the outer shaft, the outer tubular shaft comprising an inner surface, wherein the outer shaft and the inner shaft are torsionally coupled through grooved profiles, the inner tubular shaft and the outer tubular shaft defining a gap;
• a lubrication system comprising a lubricant receiving chamber housed in the inner shaft, a lubricant distribution block housed in the inner shaft, lubricant supply ports for supplying lubricant from the lubricant distribution block and at least a lubricant transferring duct extending from the receiving chamber to the distribution block, each of the lubricant supply ports extending through a tubular wall of the inner shaft towards the gap between the inner shaft and the outer shaft, wherein a first one of the lubricant supply ports is arranged in a first position, a second one of the lubricant supply ports is arranged in a second position, a third one of the lubricant supply ports is arranged in a third position and a fourth one of the lubricant supply ports is arranged in a fourth position, the first position, the second position, the third position and the fourth position being offset from each other in a direction of the axis of the telescopic shaft, the tubular wall of the inner tubular shaft having a plurality of outer longitudinal projections extending parallel to the axis of the telescopic shaft, the inner surface of the outer tubular shaft comprising a plurality of grooves, each of the outer longitudinal projections slidably engaging one of the plurality of the grooves, the distribution block comprising a plurality of lubricating ducts, each of the lubricating ducts being defined by a longitudinal extension of the telescopic shaft, one of the lubricating ducts being fluidly coupled to at least two of said first one of the lubricant supply ports, the second one of the lubricant supply ports, the third one of the lubricant supply ports and the fourth one of the lubricant supply ports, another one of the lubricating ducts being fluidly coupled to at least another two of said first one of the lubricant supply ports, the second one of the lubricant supply ports, the third one of the lubricant supply ports and the fourth one of the lubricant supply ports.

A drive shaft comprising:

• a telescopic shaft comprising an axis, an outer tubular shaft and an inner tubular shaft inserted slidable into the outer shaft, the outer tubular shaft comprising an inner surface, the outer shaft and the inner shaft being torsionally coupled through grooved profiles, the inner tubular shaft and the outer tubular shaft defining a gap;
• a lubrication system comprising a lubricant receiving chamber housed in the inner shaft, a lubricant distribution block housed in the inner shaft, lubricant supply ports for supplying lubricant from the lubricant distribution block and at least a lubricant transferring duct extending from the receiving chamber to the distribution block, each of the lubricant supply ports extending through a tubular wall of the inner shaft towards the gap between the inner shaft and the outer shaft, the lubricant supply ports comprising a first lubricant supply port, a second lubricant supply port, a third lubricant supply port and a fourth lubricant supply port, each of the first lubricant supply port, the second lubricant supply port, the third lubricant supply port and the fourth lubricant supply port being offset from each other in a direction of the axis of the telescopic shaft, the tubular wall of the inner tubular shaft having a plurality of outer longitudinal projections extending parallel to the axis of the telescopic shaft, the inner surface of the outer tubular shaft comprising a plurality of grooves, each of the outer longitudinal projections slidably engaging one of the plurality of the grooves, the distribution block comprising a plurality of lubricating ducts, each of the lubricating ducts being defined by a longitudinal extension of the telescopic shaft, one of the lubricating ducts being fluidly coupled to at least the first lubricant supply port and the second lubricant supply port, another one of the lubricating ducts being fluidly coupled to at least the third lubricant supply port and the fourth lubricant supply port.