1. Field of the Invention
The present invention relates to a ball screw device, and more particularly to a ball screw device having an image sensor for viewing the balls or the rollers or the bearing members or the ball nut or the screw shaft, and for detecting or sensing whether the screw shaft has been worn out or not, and for allowing the users to view and to know whether the ball nut and/or the screw shaft has been worn out or not, and for allowing the users to change or to replace the ball nut and/or the screw shaft and/or the bearing members right away or at the best time.
2. Description of the Prior Art
Typical ball screw devices comprise a ball nut rotatably and/or moveably engaged onto a screw shaft, and normally arranged to allow the ball nut to be rotated and/or moved relative to the screw shaft in great rotational speeds. For allowing the ball nut to be smoothly rotated and moved relative to the screw shaft, a suitable bearing device or lubricating structure is further required to be provided and engaged between the ball nut and the screw shaft, for facilitating the rotational movement between the ball nut and the screw shaft.
For example, U.S. Pat. No. 4,953,419 to Schlenker, and U.S. Pat. No. 5,063,809 to Schlenker disclose two typical ball screw and nut assemblies each including a number of balls or rollers or bearing members disposed or engaged between the ball nut and the screw shaft for facilitating the rotational movement of the ball nut and the screw shaft relative to each other.
However, the balls or rollers or bearing members are engaged and shielded between the ball nut and the screw shaft, and the wear of the ball nut and/or the screw shaft and/or the bearing members may not be seen or detected or viewed by the users such that the users may not know when the balls or rollers or bearing members or the ball nut or the screw shaft has been worn out or not, and may not know the best time to change or to replace the balls or rollers or bearing members or the ball nut or the screw shaft.
U.S. Pat. No. 5,014,568 to Schlenker and U.S. Pat. No. 6,023,991 to Tabe et al. disclose two further typical ball screw and nut assemblies each also including a number of balls or rollers or bearing members disposed or engaged between the ball nut and the screw shaft for facilitating the rotational movement of the ball nut and the screw shaft relative to each other.
However, similarly, the balls or rollers or bearing members are also engaged and received and shielded between the ball nut and the screw shaft, and the wear of the ball nut and/or the screw shaft and/or the bearing members may not be seen or detected or viewed by the users such that the users may not know when the balls or rollers or bearing members or the ball nut or the screw shaft has been worn out or not, and may not know the best time to change or to replace the balls or rollers or bearing members or the ball nut or the screw shaft.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages of the conventional ball screw devices for such as machine tools or the like.
The primary objective of the present invention is to provide a ball screw device including an image sensor for viewing the balls or the rollers or the bearing members or the ball nut or the screw shaft, and for detecting or sensing whether the screw shaft has been worn out or not, and for allowing the users to view and to know whether the ball nut and/or the screw shaft has been worn out or not, and for allowing the users to change or to replace the ball nut and/or the screw shaft and/or the bearing members right away or at the best time.
In accordance with one aspect of the invention, there is provided a ball screw device comprising a screw shaft including an outer thread formed thereon, and including a number of peripheral and helical groove portions and a number of peripheral and helical ridges for forming the outer thread of the screw shaft, a ball nut including a bore formed therein for receiving the screw shaft, and including an inner thread formed therein for engaging with the outer thread of the screw shaft and for forming a helical raceway between the ball nut and the screw shaft, the inner thread of the ball nut including a number of peripheral and helical groove portions and a number of peripheral and helical ridges formed therein, a number of bearing members received in the helical raceway between the ball nut and the screw shaft for facilitating a rotating movement between the ball nut and the screw shaft, and an image device attached to the ball nut for taking an image of the screw shaft and for viewing or sensing or detecting a changing of the outer thread of the screw shaft.
The ball nut includes a cavity formed therein for receiving the image device therein, and the image device is engaged into the bore of the ball nut and directed toward the screw shaft but spaced from the screw shaft. The ball nut includes an enlarged actuator end flange formed in one side portion of the ball nut, and the cavity is formed in the actuator end flange of the ball nut and communicating with the bore of the ball nut.
A processor device may further be provided and coupled to the image device for receiving images taken by the image device and for comparing or processing the images taken by the image device and for determining the changing of the ball nut and/or the screw shaft and/or the bearing members, and for determining whether the ball nut and/or the screw shaft and/or the bearing members have been worn out or not.
A displayer may further be provided and coupled to the processor device for displaying the images taken by the image device for allowing the users to view and to know whether the ball nut and/or the screw shaft has been worn out or not, and for allowing the users to change or to replace the worn out ball nut and/or the worn out screw shaft and/or the worn out bearing members right away or at the right time or the best time.
A warning device may further be provided and coupled to the processor device for generating a warning signal when the ball nut and/or the screw shaft and/or the bearing members have been worn out.
Further objectives and advantages of the present invention will become apparent from a careful reading of the detailed description provided hereinbelow, with appropriate reference to the accompanying drawings.
Referring to the drawings, and initially to
The threading engagement and/or the rotational engagement between the ball nut 10 and the screw shaft 20 is typical and will not be described in further details. A multiple turn, helical raceway 24 will be formed between the ball nut 10 and the screw shaft 20 for rotatably and/or movably receiving one or more groups of balls or rollers or rolling or ball bearing members 80 therein (
An image device 30, such as a charge couple device (CCD), a camera, an image sensor, an image detector, an image scanner or the like is engaged with or into the cavity 17 of the ball nut 10, and engaged into the bore 11 of the ball nut 10 (
In operation, as shown in
It is to be noted that the peripheral and helical groove portions 22 and/or the peripheral and helical ridges 23 of the screw shaft 20 may be shifted longitudinally or sidewise relative to the ball nut 10 and the image device 30 when the peripheral and helical groove portions 22 and/or the peripheral and helical ridges 23 of the screw shaft 20 have been worn out, or when the peripheral and helical groove portions 13 and/or the peripheral and helical ridges 14 of the ball nut 10 have been worn out, or when the ball bearing members 80 have been worn out, or the like, such that the reference line 88 between the peripheral and helical groove portions 22 and the peripheral and helical ridges 23 of the screw shaft 20 may be taken as a reference line 88 for comparing the longitudinal or sidewise shifting between the ball nut 10 and the screw shaft 20 and may be used to determine whether the ball nut 10 and/or the screw shaft 20 have been worn out or not.
The images taken by the image device 30 as shown in
Accordingly, the ball screw device in accordance with the present invention includes an image device for viewing the balls or the rollers or the bearing members or the ball nut or the screw shaft, and for detecting or sensing whether the screw shaft has been worn out or not, and for allowing the users to view and to know whether the ball nut and/or the screw shaft has been worn out or not, and for allowing the users to change or to replace the ball nut and/or the screw shaft and/or the bearing members right away or at the best time.
Although this invention has been described with a certain degree of particularity, it is to be understood that the present disclosure has been made by way of example only and that numerous changes in the detailed construction and the combination and arrangement of parts may be resorted to without departing from the spirit and scope of the invention as hereinafter claimed.