Bearing failure monitoring device for ball screw

A linear motion guide device comprising:

• an elongated member including a helical threaded groove formed on an outer peripheral surface thereof,
• a movable member including a bore formed therein for receiving said elongated member and for movably attaching onto said elongated member, and including a helical threaded groove formed therein and aligned with said helical threaded groove of said elongated member for forming a ball guiding passage between said elongated member and said movable member, said movable member including a depression formed therein and communicating with said helical threaded groove and said ball guiding passage of said movable member, and said movable member including a compartment formed therein and communicating with said depression of said movable member,
• a deflecting device attached to said depression of said movable member and including a deflecting pathway formed therein and communicating with said ball guiding passage and said helical threaded groove of said movable member for forming an endless multiple-turn, helical raceway between said elongated member and said movable member,
• a plurality of ball bearing members disposed in said endless multiple-turn, helical raceway that is formed between said elongated member and said movable member for facilitating a sliding movement between said elongated member and said movable member, and
• a detecting device including a magnetic member and an integrated circuit disposed and secured into said compartment of said movable member, and arranged close to said endless multiple-turn, helical raceway of said linear motion guide device for detecting a moving frequency of said ball bearing members through said endless multiple-turn, helical raceway of said linear motion guide device, and said integrated circuit of said detecting device being disposed for a spacing distance smaller than 15 mm from said ball bearing members, and including a first terminal and a second terminal coupled to a power supply, and a third terminal coupled to a processing device.