Linear motion transmission apparatus with a chain

A linear motion transmission apparatus comprising:

• an elongated shaft provided on its outer surface with a rolling groove;
• a slide block slidably mounted on the elongated shaft and formed with a rolling groove for cooperating with the rolling groove of the elongated shaft to form a load path, both ends of the load path are connected to both ends of a return path to form an endless circulation path;
• a plurality of rolling elements movably received in the endless circulation path to enable the slide block to slide along the elongated shaft, the rolling elements don't contact the rolling groove of the elongated shaft and the rolling groove of the slide block when within the return path, and when in the load path, the rolling elements being in contact with the rolling groove of the elongated shaft and the rolling groove of the slide block to take load, when the rolling elements roll between the rolling groove of the elongated shaft and the rolling groove of the slide block, a rolling contact track formed on each of the rolling elements when the rolling elements are rolling with respect to the rolling grooves is annular-shaped and defined as a load area;
• a chain received in the endless circulation path and comprising at least one flexible link and a plurality of spacers, the spacers being equidistantly spaced apart and connected by the link, each two neighboring spacers defining a holding space for holding the rolling elements, each of the spacers having two separated arcuate contact areas for contacting the rolling elements.