Patent Publication Number: US-2010126292-A1

Title: Deflector for ball screw device

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a ball deflector for a ball screw device, and more particularly to a ball deflector including an anchoring or positioning structure or device for suitably anchoring or positioning the ball deflector to the ball screw device and for preventing the ball deflector from being tilted or deviated relative to the ball screw device and for suitably guiding the ball bearing members to smoothly move through the endless ball guiding passages of the ball screw device. 
     2. Description of the Prior Art 
     Typical ball screw devices comprise a nut threaded onto an elongated bolt or screw and rotatable and movable or adjustable along the screw, one or more endless ball guiding passages formed in the ball screw device for slidably receiving ball bearing members, and one or more ball deflectors engaged into the endless ball guiding passages of the ball screw device for guiding the ball bearing members to smoothly move through the endless ball guiding passages of the ball screw device. 
     For example, U.S. Pat. No. 3,661,030 to Gagne discloses one of the typical ball screw and nut combinations also comprising a ball deflector engaged into an endless ball guiding passage of the ball screw and nut combination for guiding the ball bearing members to smoothly move through the endless ball guiding passage of the ball screw and nut combination. 
     However, it will be difficult to precisely form and shape the ball deflector and to precisely assemble and retain the ball deflector within the endless ball guiding passage of the ball screw and nut combination during assembly and/or while working such that the ball deflector may have a good chance to be tilted or deviated relative to the ball screw and nut combination and such that the ball bearing members may not be guided to smoothly and suitably move through the endless ball guiding passage of the ball screw and nut combination after use. 
     U.S. Pat. No. 5,014,568 to Schlenker discloses another typical ball screw and nut assembly also comprising a ball deflector engaged into an endless ball guiding passage of the ball screw and nut assembly for guiding the ball bearing members to smoothly move through the endless ball guiding passage of the ball screw and nut assembly, and pairs of adjustable locator bosses situated at opposite ends of the elongated body of the ball deflector and symmetrically positioned on the upper body in adjacent quadrants of the upper body. 
     However, the pairs of adjustable locator bosses are situated at the side portions of the opposite ends of the elongated body of the ball deflector and may not precisely retain the ball deflector within the endless ball guiding passage of the ball screw and nut assembly during assembly and/or while working when the elongated body of the ball deflector is secured to the nut with an upwardly extended threaded stem. 
     U.S. Pat. No. 7,234,368 to Lin et al. of the present applicant discloses a further typical ball screw device also comprising one or more ball deflectors engaged into the endless ball guiding passage of the ball screw device for guiding the ball bearing members to smoothly move through the endless ball guiding passage of the ball screw device. 
     However, similarly, the ball deflectors also may not be precisely formed and shaped and may not be precisely assembled and retained within the endless ball guiding passage of the ball screw and nut combination during assembly and/or while working such that the ball deflector may have a good chance to be tilted or deviated relative to the ball screw device and such that the ball bearing members may not be guided to smoothly and suitably move through the endless ball guiding passage of the ball screw device after use. 
     The present invention has arisen to mitigate and/or obviate the afore-described disadvantages of the conventional ball deflectors for the ball screw devices. 
     SUMMARY OF THE INVENTION 
     The primary objective of the present invention is to provide a deflector including an anchoring or positioning structure or device for suitably anchoring or positioning the ball deflector to the ball screw device and for preventing the ball deflector from being tilted or deviated relative to the ball screw device and for suitably guiding the ball bearing members to smoothly move through the endless ball guiding passages of the ball screw device. 
     In accordance with one aspect of the invention, there is provided a ball screw device comprising a nut member including a screw hole formed therein and defined by a number of helical grooves, and including an aperture formed in the nut member and communicating with one of the helical grooves of the nut member, and including a recess formed in the nut member and communicating with the helical groove of the nut member, an elongated screw engaged into the screw hole of the nut member and including a number of helical grooves for engaging with the helical grooves of the nut member and for forming an endless ball guiding passage between the nut member and the screw, a number of ball bearing members engaged in the endless ball guiding passage of the ball screw device, and a deflector including a deflector member engaged into the helical groove of the nut member, and including a ridge extended upwardly from the deflector member and engaged with the recess of the nut member to position the deflector member to the nut member and to prevent the deflector member from deviating relative to the nut member, and including a fastener engaged through the aperture of the nut member and secured to the nut member to force the deflector member to move upwardly toward the nut member and to force the ridge of the deflector member to engage with the recess of the nut member. 
     The fastener is extended from a middle portion of the deflector member and formed integral with the deflector member, and the fastener is engaged through the aperture of the nut member and engaged with a lock nut. Alternatively, the fastener may also be threaded or engaged with a screw hole of the deflector member. 
     The ridge is preferably an elongated ridge extended upwardly from the deflector member. The recess of the nut member is preferably a curved recess, or a helical recess. 
     The nut member includes two orifices formed in the nut member and communicating with the helical groove of the nut member, and includes a ball return pipe having two ends engaged into the orifices of the nut member and having a ball return pathway formed in the ball return pipe and communicating with the helical groove of the nut member for receiving the ball bearing members. 
     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. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a cross sectional view of a ball screw device including a ball deflector in accordance with the present invention; 
         FIG. 2  is an enlarged partial cross sectional view of the ball screw device; 
         FIG. 3  is a perspective view of the ball deflector; 
         FIG. 4  is a cross sectional view illustrating the other arrangement of the ball deflector and the ball screw device; and 
         FIG. 5  is a perspective view illustrating the ball deflector for the ball screw device as shown in  FIG. 4 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to the drawings, and initially to  FIGS. 1-3 , a ball screw device  1  in accordance with the present invention comprises a nut member  10  including a screw hole  11  formed therein and formed or defined by a number of helical threaded portions or grooves  12 , and an elongated bolt or screw  20  engaged into the screw hole  11  of the nut member  10  and including a number of helical threaded portions or grooves  21  for threading or engaging with the helical threaded portions or grooves  12  of the nut member  10  and for allowing the nut member  10  to be rotated and moved or adjusted along the screw  20 , and for forming one or more endless ball guiding passages  22  in the ball screw device  1  or between the nut member  10  and the screw  20  and for slidably receiving a number of ball bearing members  80 . 
     The nut member  10  includes one or more pairs of orifices  14  formed in the nut member  10  and communicating with the helical grooves  12  of the nut member  10 , and includes one or more apertures  15  formed in the nut member  10  and also communicating with the helical grooves  12  of the nut member  10 , and includes a curved or helical recess  16  formed in the nut member  10  and communicating with either of the helical grooves  12  of the nut member  10 . One or more ball return pipes  30  each include two ends  31  engaged into the orifices  14  of the nut member  10 , and each include a ball return pathway  32  formed therein and communicating with the helical grooves  12  of the nut member  10  and/or communicating with the endless ball guiding passages  22  of the ball screw device  1 . The coupling structure of the ball return pipes  30  to the nut member  10  and the screw  20  is typical and will not be described in further details. 
     The ball screw device  1  further includes one or more ball deflectors  4  each having an elongated body or deflector member  40  engaged into the endless ball guiding passages  22  of the ball screw device  1  for guiding the ball bearing members  80  to smoothly move through the endless ball guiding passages  22  of the ball screw device  1 , the deflector member  40  includes a curved depression  41  formed in each of the two end portions  42  thereof for engaging with and for guiding the ball bearing members  80  to smoothly move into the endless ball guiding passages  22  of the ball screw device  1 , and includes a curved or elongated ridge  43  extended upwardly from the deflector member  40  for engaging with the helical recess  16  of the nut member  10  ( FIG. 2 ) and for suitably anchoring or positioning the deflector member  40  to the nut member  10  of the ball screw device  1  and for preventing the deflector member  40  from being tilted or deviated relative to the nut member  10  of the ball screw device  1 . 
     The deflector  4  further includes a fastener  44  attached or secured to the middle portion  45  of the deflector member  40 , or extended from the middle portion  45  of the deflector member  40  and formed integral with the deflector member  40 , and engaged through the aperture  15  of the nut member  10  and engaged with a lock nut  46  for solidly securing the deflector member  40  of the deflector  4  to the nut member  10 . As shown in  FIG. 1 , when the deflector member  40  is secured to the nut member  10 , the deflector member  40  may be forced to move upwardly relative to the nut member  10 , and the ridge  43  of the deflector member  40  may also be moved upwardly to solidly engage with the helical recess  16  of the nut member  10  ( FIG. 2 ) and to suitably anchor or position the deflector member  40  to the nut member  10  and to prevent the deflector member  40  from being tilted or deviated relative to the nut member  10  of the ball screw device  1 . 
     Alternatively, as shown in  FIGS. 4-5 , the deflector  4  may include a screw hole  48  formed in the middle portion  45  of the deflector member  40 , and a fastener  441  may be engaged through the aperture  15  of the nut member  10  and threaded or engaged with the screw hole  48  of the deflector member  40  for solidly securing the deflector member  40  of the deflector  401  to the nut member  10  and for preventing the deflector member  40  of the deflector  401  from being tilted or deviated relative to the nut member  10  of the ball screw device  1 . It is to be noted that the ridge  43  of the deflector member  40  may be forced to move upwardly and to solidly engage with the helical recess  16  of the nut member  10  and to suitably anchor or position the deflector member  40  to the nut member  10  when the deflector member  40  is forced to move upwardly relative to the nut member  10  and when the deflector member  40  is secured to the nut member  10  with the fastener  44 ,  441 , best shown in  FIGS. 1 and 4 . 
     Accordingly, the deflector in accordance with the present invention includes an anchoring or positioning structure or device for suitably anchoring or positioning the ball deflector to the ball screw device and for preventing the ball deflector from being tilted or deviated relative to the ball screw device and for suitably guiding the ball bearing members to smoothly move through the endless ball guiding passages of the ball screw device. 
     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.