Linear guide apparatus

A linear guide apparatus comprising a guide rail, a carriage block, at least two recirculating tubes, and two end covers;

• wherein the carriage block has an axial sliding channel formed at a middle portion of a bottom surface thereof, and the carriage block is slidably coupled on the guide rail through the sliding channel;
• when the carriage block is coupled on the guide rail, each of two sides of the sliding channel has at least a sliding groove formed between the carriage block and the guide rail;
• each of the sliding grooves comprises a plurality of slidable rolling balls installed therein so as to enable the carriage block to slide forward and backward on the guide rail;
• each of the sliding grooves is cooperated with a recirculating channel which axially penetrates through the carriage block and is located adjacent to and at an outer side of the sliding groove;
• wherein each of the recirculating tubes comprises a plurality of spiral threads formed on an inner surface thereof, and the number of the spiral threads is odd which enables the rolling balls to have lateral roll at a specific angle when passing therethrough;
• each of the recirculating tubes is installed in the recirculating channels;
• and
• wherein the two end covers are adapted to respectively couple with a front surface and a rear surface of the carriage block, and each of the end covers comprises a U-shaped channel embedded therein, and two ends of the U-shaped channel is formed on an inner surface of the end cover so as to enable the rolling balls to pass through therein and recirculatedly roll between the sliding groove and the recirculating tube.