Abstract:
The present invention provides a friction minimized bearing structure, which is operated in a same-speeded and contrary-directional manner, and actives an inner ring and an outer ring to rotate synchronously in contrary directions. Otherwise, rollers are mounted on a supporting gear module, the roller contacts with the outer ring of the bearing structure and rotate in contrary directions within the same rotation speed, therefore achieves a friction-minimized bearing structure. The bearing structure of present invention makes the relative velocity between the balls and the inner ring, and the outer ring is relatively down to zero or nearly zero. With such manner, an inner friction between the balls, inner ring and the outer ring may be relatively down to zero or nearly zero so as to achieve the objective of minimizing the friction.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to a bearing, and more particularly to a friction force minimized bearing structure. 
         [0003]    2. Description of Related Art 
         [0004]    A general mechanism operates by a reciprocating motion. A bearing is disposed at a turning point which functions as a combination element between rotation part such as a rotation shaft or a pivot shaft and a mounting base. 
         [0005]    The bearing is generally mounted on an equipment as the combination element between the rotation part such as the rotation shaft or the pivot shaft and the mounting base such that the bearing can decrease the friction resistance when the rotation part is rotating. 
         [0006]    Basically, a bearing includes an inner ring, an outer ring and multiple balls located between the inner ring and the outer ring. The outer ring is located outside the inner ring. Both of the inner ring and the outer ring include grooves. The balls are rolling in the grooves. A retainer is disposed between balls such that the balls can only roll and not slide. The balls are generally made of metal material (such as steel) and have stiffness. The balls are disposed between the inner ring and the outer ring, and two sides of each ball are contacted with the groove  104  of outer wall of the inner ring and the groove  106  of the inner wall of the outer ring. 
         [0007]    When using, the rotation part is mounted through a hole of the inner ring. The outer ring is mounted on the mounting base  124 . When the rotation part is rotating, through the rotation of the multiple balls and the lubrication of grease, the inner ring is rotated relative to the outer ring under a smaller friction. 
         [0008]    With reference to  FIG. 12  and  FIG. 13 , which show a basic structure of a bearing of the conventional art. The bearing includes an inner ring  103 , an outer ring  105  and multiple balls  108  disposed between the inner ring  103  and the outer ring  105 . The outer ring  105  is disposed outside the inner ring  103 . The inner ring  103  includes a hole for receiving a rotation part  100 . Wherein, at inner walls of the inner ring  103  and the outer ring  105 , multiple grooves  104  and  106  are formed. 
         [0009]    The multiple balls have stiffness and are separately disposed between the inner ring  103  and the outer ring  105  such that two sides of ball surface of each ball abut on the grooves  104 ,  106  at the outer wall of the inner ring  103  and the inner wall of the outer ring  105 . The above describe a ball bearing, and the rolling elements are balls. If the balls are replaced by cylindrical rollers or needle rollers, the bearing becomes a cylindrical roller bearing or a needle roller bearing. The operation principles are all the same. 
         [0010]    However, the working performance of the bearings in the conventional art depends on the status of the balls inside and the lubrication condition. Although the balls have stiffness, under friction for a long time, the balls are deformed because of abrasion. As a result, the good transmission ability of the balls is lost. 
         [0011]    Besides, in the conventional art, when the bearing is working, for the inner ring and the outer ring, one is static and the other is rotated relatively. Therefore, the balls will receive the static friction and the dynamic friction between the outer wall of the inner ring and inner wall of the outer ring at the same time. 
       SUMMARY OF THE INVENTION 
       [0012]    In order to solve the above technology problem, a technology solution utilized by the present invention is to provide A friction minimized bearing structure, comprising: a bearing including an inner ring, an outer ring and multiple balls located between the inner ring and the outer ring; and a transmission gear module transmitting a kinetic energy generated by a rotation of the inner ring to the outer ring such that the inner ring and the outer ring are rotated in opposite rotation directions; wherein, the transmission gear module includes an inner ring gear, an outer ring gear, a first transmission gear and a second transmission gear; the outer ring gear is fixed on an outer ring roller; the outer ring roller is disposed in a middle portion among multiple supporting rollers; the outer ring roller contacts with each supporting roller; an outer edge of each supporting roller is mounted with a supporting gear; the outer ring gear is engaged with the supporting gears. 
         [0013]    Wherein, the transmission gear module makes a rotation speed of the inner ring of the bearing and a rotation speed of the outer ring of the bearing to be the same. 
         [0014]    Wherein, a rotation speed of the outer ring roller and a rotation speed of each supporting roller are the same or approaching to be the same, and a rotation direction of the outer ring roller and a rotation direction of each supporting roller are opposite. 
         [0015]    Wherein, the friction minimized bearing structure is mounted on a car; the car has a car body; the car body is provided with a shaft hole and a rotation shaft which is rotatable and capable of providing a kinetic energy is disposed inside the shaft hole; an outside of a car hub of the car body is mounted with the transmission gear module; an outer ring transmission seat of the transmission gear module, the outer ring gear, a secondary bearing mounted on the outer ring gear and the inner ring gear are fixed on the car hub; the transmission gear module further includes a gear connection rod; the first transmission gear, the second transmission gear, and the gear connection rod are separated from the car hub; when the car is moving, an electromagnetic movable rod engages and fixes the gear connection rod, wherein: the inner ring gear is mounted and fixed on the rotation shaft so as to rotate in a same rotation direction relative to the rotation shaft; the outer ring transmission seat is mounted and fixed on the outer ring of the bearing so as to rotate in an opposite rotation direction of the rotation shaft; the first transmission gear engages with the inner ring gear and the second transmission gear so as to rotate in an opposite rotation direction relative to the rotation shaft, and the first transmission gear also drives the second transmission gear to rotate in the same rotation direction relative to the rotation shaft; the outer ring gear is fixed to the outer ring transmission seat in order to drive the outer ring of the bearing, and the outer ring gear is engaged with the second transmission gear in order to rotate in an opposite rotation direction relative to the second transmission gear, that is, the outer ring gear is rotated in an opposite rotation direction relative to the inner ring gear and the rotation shaft. 
         [0016]    Wherein, the bearing includes a main bearing disposed in a shaft hole and a secondary bearing disposed adjacent to the main bearing; each inner ring of the main bearing and the secondary bearing are both tightly fixed with the rotation shaft. 
         [0017]    Wherein, the electromagnetic movable rod is controlled by a pneumatic way. 
         [0018]    Wherein, the electromagnetic movable rod is controlled by a spring way. 
         [0019]    Wherein, an outer wall of the inner ring and an inner wall of the outer ring are formed with concave grooves; the multiple balls are disposed between the inner ring and the outer ring such that two sides of ball surface of each ball abut between the grooves of the outer wall of the inner ring and the inner wall of the outer ring so as to be embedded between the inner ring and the outer ring. 
         [0020]    Wherein, the bearing is a ball bearing, a cylindrical roller bearing or a needle roller bearing. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0021]      FIG. 1  is a top view of a friction-minimized bearing structure according to a first embodiment of the present embodiment; 
           [0022]      FIG. 2  is a side view of a friction-minimized bearing structure according to a first embodiment of the present embodiment; 
           [0023]      FIG. 3  is top and side views of a mounting base of a friction-minimized bearing structure according to a first embodiment of the present embodiment; 
           [0024]      FIG. 4  is top and side views of a supporting gear module of a friction-minimized bearing structure according to a first embodiment of the present embodiment; 
           [0025]      FIG. 5  is top and side views of a first transmission gear module of a friction-minimized bearing structure according to a first embodiment of the present embodiment; 
           [0026]      FIG. 6  is top and side views of a second transmission gear module of a friction-minimized bearing structure according to a first embodiment of the present embodiment; 
           [0027]      FIG. 7  is top and side views of an outer ring gear module of a friction-minimized bearing structure according to a first embodiment of the present embodiment; 
           [0028]      FIG. 8  is a schematic rotation diagram of a friction-minimized bearing structure according to a second embodiment of the present embodiment; 
           [0029]      FIG. 9  is a side view of a friction-minimized bearing structure according to a second embodiment of the present embodiment; 
           [0030]      FIG. 10  is a front view of a friction-minimized bearing structure applied to a car according to a second embodiment of the present embodiment; 
           [0031]      FIG. 11  is a side view of a friction-minimized bearing structure applied to a car according to a second embodiment of the present embodiment; 
           [0032]      FIG. 12  is a schematic diagram of a bearing according to the conventional art; 
           [0033]      FIG. 13  is a side cross-sectional view of a bearing according to the conventional art; 
           [0034]      FIG. 14  is a schematic diagram for illustrating a friction force; 
           [0035]      FIG. 15  is a schematic diagram for illustrating velocities of an inner ring, an outer ring and a ball; and 
           [0036]      FIG. 16  is a schematic diagram for illustrating forces applied on a main bearing and a supporting gear bearing. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0037]    The following will combine the drawings for further description of the present invention. 
         [0038]    A friction force is a force that resists contacted objects to slide each other. The formula of the friction force is f=−μN. 
         [0039]    With reference to  FIG. 14 , two contact objects A ( 128 ) and B ( 129 ); the gravitational force of the contacted object A ( 128 ) applied on the contacted object B ( 129 ) is N ( 127 ). A friction coefficient between the two contacted objects A ( 128 ) and B ( 129 ) is μ. When the friction force is generated continuously within a distance d, a work (W) done is: 
         [0000]    
       
      
       W=−μN·d;  
      
     
         [0040]    a power (P) is: 
         [0000]    
       
      
       P=−μN·d/t=−μN·v;  
      
     
         [0041]    In the above formula, v is a relative velocity between the two contacted objects A ( 128 ) and B ( 129 ). 
         [0042]    When the relative velocity v=0, the power P is also equal to 0, that is, the friction force does not act. In other words, when the relative velocity between two contacted objects A ( 128 ) and B ( 129 ) is 0, even the two contacted objects A ( 128 ) and B ( 129 ) are still moving, the contacted object A ( 128 ) and the contacted object B ( 129 ) are moving in a same velocity. A friction force between the contacted objects A ( 128 ) and B ( 129 ) will not be generated. 
         [0043]    The friction-minimized bearing structure of the present invention can minimize a friction force through a simple principle and a simple structure so as to provide a high suitability and is convenient for a practical application. The present invention can be easily and conveniently applied to existing equipment through an additional installation or modification. 
         [0044]    With reference to a supporting gear module  131  in  FIG. 4  and an outer ring gear module  134  in  FIG. 7 , the present invention adds a supporting gear  135  on a roller  118  of the supporting gear module  131 , a relationship of the number of teeth of the supporting gear  135 , a diameter of the roller  118 , the number of teeth of the outer ring gear  110 , and a diameter of the roller  117  is as following: 
         [0000]      π D 1/(the number of teeth of the outer ring gear)=π D 2/(the number of teeth of the supporting gear), wherein,
 
         [0045]    D1: the diameter of the outer ring gear roller  117 ; 
         [0046]    D2: the diameter of the supporting gear roller  118 ; 
         [0047]    Therefore, a moved curve distance of the outer ring gear roller  117  corresponds to move a tooth of the outer ring gear  110  is equal to a moved curve distance of the supporting gear roller  118 . As a result, a relative velocity between the outer ring gear roller  117  and the supporting gear roller  118  is zero or approaching to zero such that a friction force between the outer ring gear roller  117  and the supporting gear roller  118  is minimized. 
         [0048]    With reference to  FIG. 16 ,  FIG. 16  is a schematic diagram for illustrating forces applied on a main bearing and a supporting gear bearing. The diagram illustrates a force distribution of the main bearing and multiple supporting gear bearings for supporting the main bearing. In the diagram, various accessories are omitted and the force distribution of the main bearing and the supporting gear bearings is directly shown. 
         [0049]    A rotation shaft  100  passes through the middle portion of the main bearing  101 . In a general application, an outer wall of an outer ring  105  is fixed. A vertical gravitational load  151  of the rotation shaft  100  cause a friction force to be generated among the main bearing  101 , the inner ring  103 , the outer ring  105  and the balls  108 . The magnitudes of the friction forces are different according to locations of the balls. The present invention disposes the outer ring gear module  134  of the main bearing  101  among multiple supporting gear modules  131  which are used for supporting. Outer ring roller is disposed among multiple supporting rollers and the outer ring roller is contacted with every supporting rollers. An outer edge of each supporting roller is mounted with a supporting gear. The outer ring gear is engaged with every supporting gear. Through a transmission gear module which includes an inner ring gear, a first transmission gear, a second transmission gear, an outer ring gear and relative accessories, the outer ring  105  and the inner ring  103  of the main bearing  101  are rotated in a same speed and opposite directions so that a relative velocity between a ball  108  and the outer ring  105  and a relative velocity between a ball  108  and the inner ring  103  are zero or approaching to zero. Accordingly, the friction force inside the main bearing  101  is minimized. 
         [0050]    With reference to  FIG. 16 , a distribution position of the multiple supporting bearings can be different according to the practical application. For illustration, a vertical supporting gear bearing  148 , a left side supporting bearing  149  and a right side supporting gear bearing  150  are shown. The vertical supporting gear bearing  148  is located right above the vertical gravitational load  151  of the rotation shaft  100 . Because the vertical supporting gear bearing  148  is not affected by the vertical gravitational load  151 , the internal friction force is very small. The main friction force is generated from the left side supporting gear bearing  149  and the right side supporting gear bearing  150 . 
         [0051]    Action forces are respectively a left side supporting gear bearing action force  152  and a right side supporting gear bearing action force  153 . The left side supporting gear bearing action force  152  is along a center line of the rotation shaft  100  and a left side supporting gear shaft  149  and the action force  152  is denoted as F8. The right side supporting gear bearing action force  153  is along a center line of the rotation shaft  100  and a right side supporting gear shaft  150  and the action force  153  is denoted as F9. The left side supporting gear bearing action force  152  is composed of a left side horizontal component force  154  and a left side vertical component force  156 , and an included angle  158  between the left side horizontal component force  154  and the left side vertical component force  156  is θ1. The right side supporting gear bearing action force  153  is composed of a right side horizontal component force  155  and a right side vertical component force  157 , and an included angle  159  between the right side horizontal component force  155  and the right side vertical component force  157  is θ2. 
         [0052]    Assuming that: 
         [0053]    The left side vertical component force  156  is F1; the included angle is θ1; F1=F8·Sin θ1; 
         [0054]    The right side vertical component force  157  is F2; the included angle is θ2; F2=F9·Sin θ2; 
         [0055]    The vertical gravitational load  151  of the rotation shaft  100  is F3; 
         [0056]    The left side horizontal component force  154  is F4; F4=F8·Cos 1; 
         [0057]    The right side horizontal component force  155  is F5; F5=F9·Cos θ2; 
         [0058]    When θ1 and θ2 are appropriately selected, a sum of the left side vertical component force  156  and the right side vertical component force  157  is equal to the vertical gravitational load  151  of the rotation shaft  100 . 
         [0059]    That is, F1+F2=F3 
         [0060]    At this time, θ1+θ2=θ3; 
         [0061]    A sum of horizontal component forces is F6; 
         [0000]        F 4 +F 5 =F 6; 
         [0062]    When θ1+θ2&lt;θ3, a sum of the left side vertical component force  156  and the right side vertical component force  157  is smaller than F3. 
         [0063]    That is, F1+F2&lt;F3; and 
         [0000]      F4 +F 5 &gt;F 6; 
         [0064]    When gradually moving to reduce the left side included angle  158  and the right side included angle  159 , and maintaining the system ability at the same time, that is: 
         [0000]      θ1+θ2&lt;&lt;θ3;
 
         [0065]    Then, F1+F2&lt;&lt;3; 
         [0066]    And, F4+F5&gt;&gt;F6; 
         [0067]    However, directions of the left horizontal component force  154  and the right horizontal component force  155  are opposite so that the two forces are canceled with each other. When the included angles θ1 and θ2 are equal, a resultant force of the two horizontal component forces is zero. Accordingly, appropriately selecting the included angles θ1 and θ2 can reduce external forces act on the supporting bearing, the vertical gravitational load  151  (F3) is reduced so as to achieve the purpose of minimizing the system friction force. 
         [0068]    Assuming that: 
         [0069]    When θ1 and θ2 are moving upward such that each of the included angles is 15°, that is, θ1=θ2=15°; 
         [0000]        F 1 =F 2=½ F 3·Sin 15°;
 
         [0000]        F 1 +F 2 =F 3·Sin 15°=0.259  F 3;
 
         [0070]    For the left side horizontal component force and the right side horizontal component force, 
         [0000]        F 4 =−F 5=½ F 3·Cos 15°;
 
         [0071]    Accordingly, the vertical gravitational load sustained by the system is also reduced to 25.9% of the original value. The friction force is proportional to the vertical gravitational load of the system so that the friction force is also reduced to 25.9% of the original value and the friction energy inside the bearing is also reduced about 74%. 
         [0072]    The present invention is not limited to the above angles. The present invention can be applied to various angles. The present invention is also not limited to θ1=θ2, and also can be applied to various angles. 
         [0073]    The above is a first embodiment of a friction minimized bearing of the present invention. 
         [0074]    With reference to  FIG. 8 ,  FIG. 9 ,  FIG. 10  and  FIG. 11 , which illustrates a second embodiment of a friction minimized bearing structure of the present invention. The friction minimized bearing structure of the present invention utilizes a car for the mounting base, and includes: 
         [0075]    Bearings, which includes a main bearing  101  disposed in a shaft hole and a secondary bearing  102  disposed adjacent to the main bearing  101 . Each of the main bearing  101  and the secondary bearing  102  includes an inner ring  103 , an outer ring  105  and multiple balls  108  disposed between the inner ring  103  and the outer ring  105  for transmission. The inner rings  103  of the main bearing  101  and the secondary ring  102  are tightly fixed with the rotation shaft  100 . An outer wall of the inner ring  103  and the inner wall of the outer ring  105  are formed with concave grooves  104 ,  106 . 
         [0076]    Every ball  108  has a stiffness, and the multiple balls  108  are separately disposed between the inner ring  103  and the outer ring  105 . Two sides of each ball surface abut on the grooves  104 ,  106  of the outer wall of the inner ring  103  and inner wall of the outer ring  105  so that the balls  108  are fixed between the inner ring  103  and the outer ring  105 . 
         [0077]    Transmission gear module includes an inner ring gear  109 , an outer ring transmission seat  115 , a first transmission gear  111 , a second transmission gear  112  and an outer ring gear  110 . Wherein, the inner ring gear  109  is mounted and fixed at the rotation shaft  100  so that the inner ring gear  109  has the same rotation speed as the rotation shaft  100 . 
         [0078]    The outer ring transmission seat  115  is disposed and fixed on the outer ring  105  of the main bearing  101 . The first transmission gear  111  and the second transmission gear  112  are pivotally mounted on a gear connection rod  116  so that the first transmission gear  111 , the second transmission gear  112  and the gear connection rod  116  are connected with each other. Wherein, the first transmission gear  111  and the second transmission gear  112  can rotate relatively. A radius and the number of teeth of each first transmission gear  111 , the second transmission gear  112  and the inner ring gear  109  are the same. Wherein, the first transmission gear  111  is engaged with the inner ring gear  109  and the second transmission gear  112 . Besides, when the inner ring  103  is rotated, the inner ring gear  109  drives the second transmission gear  112  such that the second transmission gear  112  and the rotation shaft  100  are both rotated in a same rotation direction. 
         [0079]    The outer ring gear  110  is fixed on the outer ring transmission seat  115  so as to drive the outer ring  105  of the secondary bearing  102 . Besides, the outer ring gear  110  is engaged with the second transmission gear  112  such that the outer ring gear  110  is rotated in an opposite rotation direction relative to the second transmission gear  112 . That is, the outer ring gear  110  is rotated in the same rotation speed and an opposite rotation direction relative to the inner ring gear  109  and the rotation shaft  100 . 
         [0080]    Furthermore, a ratio of the number of teeth of the inner ring gear  109  to the outer ring gear  110  is equal to a ratio of the radius of the inner ring  103  to the radius of the outer ring  105 , and is also equal to a ratio of the rotation speed of the outer ring gear  110  to the rotation speed of inner ring gear  109 . 
         [0081]    When the rotation shaft  100  is rotated, the secondary bearing  102  is rotated synchronously, the inner ring  103  and the outer ring  105  of the secondary bearing  102  are rotated in the opposite rotation directions. In this condition, with reference to  FIG. 15 , at a contact point of a side of the ball  108  of the secondary bearing  102  and the inner ring  103 , the ball  108  and the inner ring  103  are moved in a tangential velocity having the same direction so that a relative velocity of the ball  108  and the inner ring  103  is a subtraction of the velocity of the ball  108  and the velocity of the inner ring  103 . If the velocities of the ball  108  and the inner ring  103  are equal or almost equal, the relative velocity of the ball  108  and the inner ring  103  is zero or approaching to zero. 
         [0082]    Similarly, at a contact point of another side of the ball  108  and the outer ring  105 , the another side of the ball  108  and the outer ring  105  are moved in a tangential velocity having the same direction so that a relative velocity of the another side of the ball  108  and the outer ring  105  is a subtraction of the velocity of the another side of the ball  108  and the velocity of the outer ring  105 . If the velocities of the another side of the ball  108  and the outer ring  105  are equal or almost equal, the relative velocity of the another side of the ball  108  and the outer ring  105  is zero or approaching to zero. In the above situation, because a relative velocity of each ball  108  inside the secondary bearing  102  and the inner ring  103 , and a relative velocity of each ball  108  inside the secondary bearing  102  and the outer ring  105  are both zero or approaching to zero, so that a friction force of each ball  108  inside the secondary bearing  102  and the inner ring  103  and a friction force of each ball  108  inside the secondary bearing  102  and the outer ring  105  are both zero or approaching to zero. 
         [0083]    Accordingly, when the car is operating, the main bearing  101  can generate the same effect so that the friction force generated by the car load can be minimized. 
         [0084]    With reference to  FIG. 11 , the car includes a suspension system  125 , the suspension system  125  is connected with a car body support  126 . A side of the suspension system  125  is provided with a car hub  120  and a tire  123  disposed on the car hub  120 . Inside the car hub  120 , the main bearing  101  is provided. The rotation shaft  100  passes through the main bearing  101 . The rotation shaft  100  is connected with an engine crankshaft component, which can rotate and provide a kinetic energy. 
         [0085]    An outside of the car hub of the car body is mounted with a transmission gear module. The outer ring transmission seat of the transmission gear module and the outer ring gear are fixed on the car hub. The remaining parts of the transmission gear module includes a secondary bearing and an inner ring gear mounted on the secondary bearing, an outer ring transmission seat, a first transmission gear, a second transmission gear, an outer ring gear, a gear connection rod and so on, which are separated from the car hub. Wherein, the first transmission gear, the second transmission gear are fixed with the gear connection rod. When the car is moving, the electromagnetic movable rod mounted on the car body engages and fixes the gear connection rod. Wherein: 
         [0086]    The inner ring gear is mounted and fixed on the rotation shaft, and the inner ring gear is rotated in the same rotation direction as the rotation shaft. The outer ring transmission seat is mounted and fixed on the outer ring of the bearing so as to rotate in an opposite rotation direction relative to the car body shaft. The first transmission gear engages with the inner ring gear and the second transmission gear so as to rotate in an opposite rotation direction relative to the rotation shaft. At the same time, the first transmission gear drives the second transmission gear to rotate in the same rotation direction as the rotation shaft. The outer ring gear is fixed on the outer ring transmission seat, and the outer ring gear engages with the second transmission gear so that the outer ring gear is rotated in an opposite rotation direction relative to the second transmission gear. That is, the inner ring gear and the rotation shaft are rotated in opposite rotation directions. 
         [0087]    When braking, the electromagnetic movable rod is released and separated from the gear connection rod. The second transmission gear does not drive the outer ring gear anymore. The outer ring of the second bearing is idling. The outer ring of the main bearing does not affect by the transmission gear module. 
         [0088]    The electromagnetic movable rod and the accessory utilize the electromagnetic property to control the activity rod and the accessory. A pneumatic driving way can replace the electromagnetic way to control the activity rod and the accessory. When braking, the pneumatic driving rod is released and separated from the gear connection rod. When the car is moving, the pneumatic activity rod engages and fixes the gear connection rod. 
         [0089]    Through above structure and transmission way of the transmission gear module, the outer ring of the bearing is driven through the outer ring transmission seat by the outer ring gear such that the outer ring of the bearing is rotated in an opposite rotation direction relative to the inner ring of the bearing. 
         [0090]    Accordingly, the friction force inside the secondary bearing  102  and the main bearing  101  is minimized. The above is a second embodiment of the friction minimized bearing structure, which can be applied on the wheel of the car so as to minimize the friction force of the bearings inside the wheel. 
         [0091]    With reference to  FIG. 11  and  FIG. 12 , the present invention further includes an electromagnetic movable rod  122 . The electromagnetic movable rod  122  can lock the gear connection rod  116  when the car is moving so that every gear is rotated normally. When the car is braking, the electromagnetic movable rod  122  released from the gear connection rod  116  such that the second transmission gear does not drive the outer ring gear anymore. The purpose is to eliminate the friction force of the bearing inside the car hub of the car when driving, and when braking, the internal stress of the gear is decreased. 
         [0092]    The above embodiments of the present invention are not used to limit the claims of this invention. Any use of the content in the specification or in the drawings of the present invention which produces equivalent structures or equivalent processes, or directly or indirectly used in other related technical fields is still covered by the claims in the present invention.