Patent Publication Number: US-2009227405-A1

Title: Automatic adjustable apparatus

Description:
FIELD OF THE INVENTION 
     The present invention relates to an automatic adjustable apparatus, and more particularly to an automatic adjustable apparatus capable of automatically adjusting the position of the pulley of the alternator of the car. 
     BACKGROUND OF THE INVENTION 
     In the vehicle alternator system, the alternator can generate and reserve the electric power for the usage of electrical parts within the vehicle through a running engine, and a transmission mechanism in such system is constructed by using the pulley and the belt between the engine and the alternator.  FIG. 1 and 2  illustrates an exploded view and a sectional view of the one-way gearing wheel of the alternator system in prior art respectively. The one-way gearing wheel comprises a pulley  1 , a one-way bearing  21 , a ball bearing  22 , a sleeve  23  and a washer ring  24 . The pulley  1  has a step spindle hole  11  at the center, both the one-way bearing  21  and the bearing  22  are wedged in the step spindle hole  11 , and the sleeve  23  is disposed through the one-way bearing  21  and the ball bearing  22 , meanwhile, a rotor shaft connecting portion  231  which connects a rotor  25  of the alternator (not shown) is equipped at the center of sleeve  23 . When the alternator of vehicle is driven to create the electrical power, the one-way bearing  21 , ball bearing  22  and sleeve  23  are driven to rotate via a multiple groove belt  26  mounted on pulley  1 , so as to drive the rotor  25  rotating for generation of the electrical power. Since the relative position of the pulley  1  towards sleeve  23  is fixed in the conventional one-way gearing wheel, which restricts the sliding displacement along the axial direction of the sleeve  23 , hence, the multiple groove belt  26  will be compressed to squeeze the pulley  1  to slant while external force is applied thereon, this results in rapid wearing and breakdown of multiple belt  26 , and further increases the danger in driving a vehicle. 
     To overcome the foregoing drawbacks, the inventor(s) of the present invention based on years of experience in the related field to conduct extensive researches and experiments, and finally invented an automatic adjustable apparatus as a basis for resolving the foregoing drawback. 
     SUMMARY OF THE INVENTION 
     Therefore, it is one of objectives of the present invention to provide an automatic adjustable apparatus capable of automatically adjusting the position of the pulley. 
     In an aspect, the present invention provides an automatic adjustable apparatus comprising a pulley, a one-way bearing, a two-way bearing, a sleeve and a constraint component. The pulley has a spindle hole at the center and the one-way bearing is disposed in the spindle hole, and the two-way bearing is disposed in the spindle hole and located at one side of the one-way bearing. The sleeve has an axial direction and slidably disposed in one-way bearing and two-way bearing to enable the pulley sliding along at said axial direction, and a constraint portion is disposed on the sleeve. The constraint component is mounted on the constraint portion for constraining the displacement of the pulley at the axial direction of the sleeve. 
     In another aspect, the present invention provides an automatic adjustable apparatus comprising a pulley, a one-way bearing, two two-way bearings, a sleeve and two constraint components. The pulley has a spindle hole located in the center thereof in which the one-way bearing and the two-way bearings are placed, and each one of the two-way bearings is adjacently placed to the one-way bearing respectively. The sleeve has an axial direction and two constraint portions disposed at two side of said sleeve respectively. The sleeve is disposed slidably in one-way bearing and the two-way bearings for enabling the pulley to slide along at the axial direction. The constraint components are mounted on the constraint portions respectively for constraining the displacement of the pulley at the axial direction of the sleeve. As described above, followed by the automatic adjustable apparatus in accordance with the present invention, the pulley can move slidably along the axial direction of the sleeve, so the belt disposed on the pulley will not be compressed to squeeze the pulley while external force is applied thereon. This can prevent rapid wearing and breakdown of belt. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The subject matter regarded as the invention is particularly pointed out and distinctly claimed in the concluding portion of the specification. The invention, both as to system and method of operation, together with features and advantages thereof may best be understood by reference to the following detailed description with the accompanying drawings in which: 
         FIG. 1  illustrates an exploded view of the one-way gearing wheel in accordance with the prior art; 
         FIG. 2  illustrates a sectional view of the one-way gearing wheel in accordance with prior art; 
         FIG. 3  illustrates an exploded view of the embodiment of the automatic adjustable apparatus in accordance with the present invention; 
         FIG. 4  illustrates a sectional view of the embodiment of the automatic adjustable apparatus in accordance with the present invention while the pulley remains in original position without being compressed by the belt. 
         FIG. 5  illustrate a sectional view of the embodiment of the automatic adjustable apparatus in accordance with the present invention, while the pulley is compressed by the belt to move along the first direction and limited by the snap ring; and 
         FIG. 6  illustrates a sectional view of the embodiment of the automatic adjustable apparatus in accordance with the present invention, while the pulley is compressed by the belt to move along the second direction and limited by the snap ring. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     To make it easier for our examiner to understand the present invention, the following detailed description with reference to the accompanying drawings of embodiments are given for example, but such preferred embodiment is not intend to limit the scope of the present invention. For simplicity, like numerals are used for like elements as described in the specification of the present invention. 
       FIG. 3  illustrates an exploded view of the embodiment of the automatic adjustable apparatus in accordance with the present invention. The automatic adjustable apparatus comprises a pulley  4 , two two-way bearings, a one-way bearing, a sleeve  7  and two constraint components. In this embodiment, the one-way bearing is implemented by a one-way needle bearing  6 , the two-way bearing is implemented by the ball bearing  5 , and the constraint component is implemented by a snap ring  74 . Preferably, the two-way bearing also can be selected from a group including a self lubricating bearing, a thrust cone ball bearing, a thrust ball bearing, a two-way needle bearing, and the bearing which can sustain the two-way axial loading. 
     The pulley  4  has a step spindle hole  44  at the center which has an one-way bearing section  441  and two two-way bearing section  442  located at two side of the one-way bearing  441 , and the one-way needle bearing  6  and the ball bearings  5  are disposed in the one-way bearing section  441  and two two-way bearing sections  442  respectively. A plural V shape belt grooves  43  are disposed at the outer surface of wall of the pulley  4 . 
     The one-way needle bearing  6  has an outer surface of the wall  61  which contacts against the one-way bearing section  441  tightly for preventing the pulley  4  and the ball bearings  5  from occurring relative displacement with each other. The inner side of the one-way needle bearing  6  is disposed plural one-way needle rollers  63  for driving the one-way needle bearing  6  to rotate clockwise only. While the one-way needle roller  63  is rotated counterclockwise, the one-way needle roller  63  will be in a running idle state and can not drive the one-way needle bearing  61  to rotate counterclockwise. The ball bearings  5  are tightly disposed in the corresponding two-way bearing section  42  respectively for preventing the relative displacement between the pulley  4  and the ball bearing. 
     The sleeve  7  has an axial direction  73 , and is formed a shape of hollow cylinder and slidably disposed in the one-way needle bearing  6  and ball bearings  5 , so that the pulley  4  can slidably move back and forth along the axial direction  73 . The one side of the sleeve  7  is formed a rotor shaft connecting portion  72  having a shape of tapped hole, and the other side is formed a hexagonal hole as a grabbing portion for assembly (not shown). The constraint portions  71  are further disposed at two side of the outer surface of the sleeve  7  respectively. Each of the constraint portions  71  is the shape of circular constraint groove, which are concaved from the outer surface of the sleeve  7  towards the axis of the sleeve  7 . The distance between two constraint portions  71  is larger than the distance between the inner radiuses of the two ball bearings  5  which are disposed in the two-way bearing sections  442 . 
       FIG. 4 ,  FIG. 5  and  FIG. 6  illustrate the sectional view of the embodiment of the embodiment of the automatic adjustable apparatus in accordance with the present invention while the pulley is at different location respectively. After the sleeve  7  is disposed in the spindle hole  44  of the one-way needle bearing  6  and the ball bearing  5 , the two snap rings  74  are then mounted tightly on corresponding constraint portions  71 . The radius of the snap ring  74  is larger than the inner radius of ball bearings  5 , and the distance between the two constraint portions  71  is larger than the distance between two ball bearings  5  disposed in the pulley  4 , so the snap rings  74  can contact against one of the ball bearing  5  and limit the displacement range of the pulley  4  while pulley  4  moves along the axial direction  73  of the sleeve  7 . Therefore, the pulley  4  is only able to move back and forth between two constraint portions  7  land this can prevent the pulley  4  disengaging from sleeve  7 . 
     For generating electricity by using the alternator, the rotor  8  of the alternator is connected with the rotor shaft connecting portion  72 , and the belt  9  disposed on the belt groove  43  is used for driving the pulley  4  to rotate clockwise. The rotation of the pulley  4  further drives the one-way needle  6 , the sleeve  7 , the rotor shaft connecting portion  72 , and the rotor  8  to rotate synchronously, so as to cause the alternator generate electricity. While the pulley  4  rotates, only the outer ring of ball bearing  5  is rotated by the pulley  4 , the inner ring of ball bearing  5  will not be rotate by the pulley  4 , so that the ball bearing  5  can improve the axial loading and thrusting loading of the pulley  4 . 
     While receiving an external force parallel to axial direction  73 , the belt  9  will compress the pulley  4  which then is forced to glide towards the first direction  200  or the second direction  300 , and the compressing pressure received by the belt  9  can be released, this can prevent the belt  9  becoming deformation or separating from belt groove  43 , and the rapid abrasion and breakdown of the belt  9  due to abnormal operating location will not occurred. While the pulley  4  glides towards the first direction  200  or the second direction  300 , the ball bearing  5  will contacts against the snap ring  74  and its displacement range is limited by the snap ring  74 , this can prevent over-displacement of the pulley  4 , and further prevent the pulley  4  from disengaging from the automatic adjustable apparatus  3 . 
     By using the snap ring  74  and the constraint portion  71 , the pulley  4  can glide in a predefined displacement range while being compressed by the pulley  9 , and the relative position between the belt  9  and the pulley  4  can be hold, this can prevents over abrasion of the belt  9  due to deviation from original disposed position while belt  9  compresses the pulley  4  at high speed. The designer can determine the distance between two constraints portions  71  based on width of the belt  9  or rotation speed of the pulley  4 , so the goal of present invention can be achieved. 
     While the invention has been described by way of example and in terms of a preferred embodiment, it is to be understood that the invention is not limited thereto. To the contrary, it is intended to cover various modifications and similar arrangements and procedures, and the scope of the appended claims therefore should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements and procedures.