Abstract:
The present disclosure discloses an active compensating hydrostatic bearing which includes a body, a mass block and a elastic member. The body includes a compensation hole and holds the mass block and the elastic member inside. The elastic member is put between the mass block and the compensation hole for generating a compensation gap near the compensation hole. By resisting the compression from the mass block, the elastic member can control the compression of the compensating gap so as to stabilize the rigidity of the bearing.

Description:
RELATED APPLICATIONS 
     This application claims priority to Taiwan Application Ser. No. 104127206, filed Aug. 20, 2015, which is herein incorporated by reference. 
     BACKGROUND 
     Technical Field 
     The present disclosure relates to a compensating hydrostatic bearing and regulator. More particularly, the present disclosure relates to an active compensating hydrostatic bearing and regulator. 
     Description of Related Art 
     Hydrostatic bearings play important roles in the precision manufacturing industry, such as automatic robotic arm, cutting machine, high speed machining tool and even astronomical telescope or wind generator. Excellent performances on mechanism locating, anti-vibration and high machining precision has made hydrostatic bearing a critical technology in the industry. 
     Hydrostatic bearings can be categorized by compensating types, such as constant pressure type or active compensating type. The constant pressure hydrostatic bearing is simpler so that can reduce the cost, but the response to an external loading is invariable since the flow resistance of the bearing is always constant, the characteristic causes the response to the external compression unfavorable. 
     The active compensating hydrostatic bearing can change the response to an external loading by adjusting the structure in short time for changing the inner pressure of the bearing, so that to overcome the disadvantage of the constant pressure hydrostatic bearing. 
     However, there are some problems need to be solved: to improve the response to an external loading, the active compensating hydrostatic bearing must adjust the inner pressure precisely and synchronously. That is, whether the inner pressure be adjusted properly or not will decide the properties of the active compensating hydrostatic bearing. 
     The active compensating hydrostatic bearing in prior art uses the external regulator to compensate the response according to an external loading, but this makes the compensation delayed because compensation liquid can&#39;t be input to or output from the bearing instantly. The asynchronous compensation causes the active compensating hydrostatic bearing in prior art poor to response to variable an external loading. 
     Another problem is that the accuracy of the active compensating hydrostatic bearing is demanding so parts in the bearing are usually combined together to avoid accumulated discrepancy. However, the manner is harmful to replace each of parts because all parts will be replaced wholly when anyone of them is fail, so the cost of the active compensating hydrostatic bearing stays high. And even so, it is still difficult to solve the problem of tolerance of each part fully. 
     Moreover, since the inner pressure of the active compensating hydrostatic bearing is changed according to an external loading, if the bearing is lack of buffer mechanism, the amplitude of compensating parts will be increased during adjusting the flow resistance. This leads the rigidity of bearing to decrease quickly with the rising loading and inferior stability. 
     SUMMARY 
     According to an embodiment of the present disclosure, an active compensating hydrostatic regulator includes a body, a mass block and at least one elastic member. The body includes a sink which has a compensation hole. The mass block is disposed in the sink. The elastic member is disposed between the mass block and the compensation hole, the mass block and the compensation hole are departed by the elastic member thereby forming a compensation gap therebetween. The elastic member withstands the mass block when the mass block is compressed to narrow the compensation gap. 
     According to another embodiment of the present disclosure, an active compensating hydrostatic bearing includes a body, a mass block, at least one elastic member and a valve. The body includes a sink which has a compensation hole. The mass block is disposed in the sink. The elastic member is disposed between the mass block and the sink, and the elastic member separates the mass block and the compensation hole by a compensation gap. The elastic member withstands the mass block when the mass block is compressed to narrow the compensation gap. The valve is adjacent to the body and having an infusion hole interconnected with the compensation hole, and the valve infuses compensation liquid into the sink via the infusion hole directly or indirectly. 
     According to still another embodiment of the present disclosure, an active compensating hydrostatic regulator applying for an active compensating hydrostatic bearing includes a compensation hole, a valve and a damping means. The compensation hole is disposed on the active compensating hydrostatic regulator. The valve includes an infusion hole and a compensation channel. The damping means withstands the external force applied to the active compensating hydrostatic regulator. The valve includes an infusion hole and a compensation channel. The infusion hole is interconnected with the compensation hole. The compensation channel is interconnected with the infusion hole. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The disclosure can be more fully understood by reading the following detailed description of the embodiment, with reference made to the accompanying drawings as follows: 
         FIG. 1  is an exploded view of an active compensating hydrostatic bearing according to one embodiment of the present disclosure; 
         FIG. 2  is a cross-sectional view of front of the active compensating hydrostatic bearing of  FIG. 1 ; 
         FIG. 3A  is a cross-sectional perspective view of the active compensating hydrostatic bearing of  FIG. 1 ; 
         FIG. 3B  is a schematic view of the elastic member of the active compensating hydrostatic bearing of  FIG. 1 ; 
         FIG. 4A  is a schematic view of the groove of the active compensating hydrostatic bearing of  FIG. 1 ; 
         FIG. 4B  is a schematic view of the groove of the active compensating hydrostatic bearing of  FIG. 1 ; 
         FIG. 4C  is a schematic view of one embodiment of the body of the active compensating hydrostatic bearing of  FIG. 1 ; 
         FIG. 4D  is a schematic view of another embodiment of the body of the active compensating hydrostatic bearing of  FIG. 1 ; 
         FIG. 5  is a top view of the sink of the active compensating hydrostatic bearing of  FIG. 1 ; 
         FIG. 6  is a schematic view of the compensation channel of the active compensating hydrostatic bearing of  FIG. 1 ; 
         FIG. 7  is a schematic view of the bottom of the body of the active compensating hydrostatic bearing of  FIG. 1 ; 
         FIG. 8  is a cross-sectional perspective view of the pad of the active compensating hydrostatic bearing of  FIG. 1 ; 
         FIG. 9A  is a schematic view of the flow path of the compensation channel of the active compensating hydrostatic bearing of  FIG. 1 ; and 
         FIG. 9B  is a schematic view of the flow path of the infusion hole of the active compensating hydrostatic bearing of  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  is an exploded view of an active compensating hydrostatic bearing according to one embodiment of the present disclosure.  FIG. 2  is a cross-sectional view of front of the active compensating hydrostatic bearing of  FIG. 1 . In  FIG. 1 , the active compensating hydrostatic bearing includes an active compensating hydrostatic regulator  100 , a valve  800  and a pad  900  concatenated from top to bottom sequentially. 
     The active compensating hydrostatic regulator  100  includes an adjusting member  200 , a lid  300 , a load member  400 , a mass block  500 , two elastic members  600  and a body  700 . The lid  300  covers on the body  700  and includes a through hole for passing through the adjusting member  200 . The load member  400  and the mass block  500  are accommodated in a sink  710  of the body  700  and the adjusting member  200  passes through the through hole and abuts the load member  400 . 
     In  FIG. 2 , center of the elastic members  600  are hollow, and the elastic members  600  sleeve on the mass block  500  which is cross-shaped in section. The two elastic members  600  are disposed between the load member  400  and the mass block  500 , and between the mass block  500  and the sink  710  respectively. 
     The load member  400  can include a ring  410  disposed therethrough. In one example, the ring  410  can be an O-ring made of rubber, and the O-ring is bound on the outer edge of the load member  400 . In  FIG. 2 , normally, a passageway on the left side of the body  700  is controlled to be closed. Sensors that capable of measuring temperature and pressure of the sink  710  can be disposed in the passageway, or a capillary restriction can be disposed in the passageway when the flow rate of the active compensating hydrostatic regulator  100  is lower than normal condition. 
     To explain the structure of the body  700  in detail, please refer to  FIG. 6 ,  FIG. 7  and  FIG. 8 . In  FIG. 7 , a compensation hole  711  and an infusion channel  712  are disposed at the bottom of the body  700 . The compensation hole  711  and the infusion channel  712  are interconnected with each other in the form of Y-shape. The shorter branch interconnects with the mentioned passageway so that temperature and pressure of the sink  710  can be measured. 
       FIG. 6  shows an adjacent surface of the valve  800  and the body  700 , the valve  800  includes a seal surface  801  and an infusion hole  810  near the mentioned adjacent surface. As shown in  FIG. 7 , the infusion hole  810  aligns the infusion channel  712  of the body  700  to make compensation liquid be infused into the sink  710  of the body  700  via the infusion hole  810  and the infusion channel  712 . 
     In  FIG. 8 , the pad  900  under the valve  800  can infuse compensation liquid into the valve  800  via the path, and the pad  900  has a chamber  910  for interconnecting with the external compensation liquid system via an interstice I at the bottom. 
     In detail, compensation liquid is infused into the pad  900  form the broadside, and then flows through the infusion hole  810 , the infusion channel  712  and the sink  710 . 
     In  FIG. 2 , since the compensation hole  711  of the sink  710  interconnects with the chamber  910 , and the sink  710  is closed at the lid  300  by the load member  400  and the ring  410 , compensation liquid will be discharged downward to the interstice I of the chamber  910  when the inner pressure of the sink  710  raises. 
       FIG. 3A  is a cross-sectional perspective view of the active compensating hydrostatic bearing of  FIG. 1 . In  FIG. 3A , because the elastic member  600  on top withstands the load member  400  and the mass block  500 , the mass block  500  can be controlled only by the elastic member  600  and without moving caused by the pressure from the load member  400 . 
     The elastic member  600  is disk-shaped and made of S45C steel. Each of the elastic members  600  includes a disk surface  610 , and the two disk surfaces  610  face forward the load member  400  and the compensation hole  711  respectively for deforming to respond to the external pressure. 
       FIG. 3B  is a schematic view of the elastic member  600  of the active compensating hydrostatic bearing of  FIG. 1 . In  FIG. 3B , each of the elastic members  600  has an initial compression C which can be adjusted by the adjusting member  200  to change the rigidity of the elastic members  600 , such as using the socket set screws. Moreover, the initial compression C can be smaller than 0.2 mm, in the range of the compression, the deformation of the elastic members  600  are proportional to the loading, that is, the rigidity of the elastic members  600  are constant. For demand to the variable rigidity of bearing, the initial compression C can be adjusted out of the mentioned range. 
     Besides, two of the elastic members  600  can be different sizes to change its characteristic of rigidity. The detail of technique for variable rigidity is related to mechanical knowledge and analysis method, so will not state herein. 
     The compensation principle of the active compensating hydrostatic regulator  100  is as follows: the mass block  500  and the seal surface  801  are separated by a compensation gap h, when the bearing is influenced by an external loading, the elastic members  600  deform and cause the compensation gap h narrowed to rise flow resistance of compensation liquid goes through the compensation hole  711 . Therefore, the bearing can against an external loading with the mentioned flow resistance grows proportionally under the fixed flow rate of compensation liquid. The abovementioned principle is basic knowledge of active compensating hydrostatic bearing, and will not describe in detail herein. 
     Because the inner pressure of the sink  710  rise, the mass block  500  will be pushed up, this makes the compensation gap h and the initial compression C greater than the beginning. After that that the inner pressure of the sink  710  decreases with the dropping flow resistance, thereby adjusting the compensation gap h repeatedly to balance an external loading. 
     For the active compensating hydrostatic regulator  100 , the elastic members  600  in disk-shaped can be regarded as a heavy damping system. The presence of the initial compression C coupled with isolation between the mass block  500  and the load member  400 , members in the sink  710  will not collide each other. Moreover, the disposition is helpful to stabilize the response to an external loading. 
       FIG. 4A  is a schematic view of the groove  510  of the active compensating hydrostatic bearing of  FIG. 1 .  FIG. 4B  is a schematic view of the groove  510  of the active compensating hydrostatic bearing of  FIG. 1 .  FIG. 4C  is a schematic view of one embodiment of the body  700  of the active compensating hydrostatic bearing of  FIG. 1 .  FIG. 4D  is a schematic view of another embodiment of the body  700  of the active compensating hydrostatic bearing of  FIG. 1 .  FIG. 5  is a top view of the sink  710  of the active compensating hydrostatic bearing of  FIG. 1 . 
     Please refer to  FIG. 4A ,  FIG. 4B ,  FIG. 4C ,  FIG. 4D  and  FIG. 5 , the mass block  500  can include a plurality of grooves, and the body  700  can have different shapes according to the grooves. 
     The groove  510  and the body  700  can be straight as in  FIGS. 4A and 4C , or can be spiral in  FIG. 4B  and  FIG. 4D . The groove  510  can be disposed on the mass  500  symmetrically, but the shape and position are not limited herein. 
     In  FIG. 5 , the grooves  510  disposed on the mass block  500  speed up the compensation because compensation liquid will be infused into the sink  710  faster, so avoid decrease of rigidity of the active compensating hydrostatic regulator  100  when an external loading is changed. In addition, the symmetrical groove  510  can keep balance and without vibration caused by high pressure compensation liquid. 
       FIG. 6  is a schematic view of the compensation channel  820  of the active compensating hydrostatic bearing of  FIG. 1 .  FIG. 7  is a schematic view of the bottom of the body  700  of the active compensating hydrostatic bearing of  FIG. 1 . In  FIG. 6 , the valve  800  includes a compensation channel  820  and a registration channel  830 , and the compensation channel  820  passes through the registration channel  830 . 
     In  FIG. 7 , the infusion channel  712  is disposed diagonally at the bottom of the body  700 , and divided into two parts in the middle by the compensation hole  711 . Therefore, the infusion hole  810  can align with the infusion channel  712  at two positions. In detail, when the valve  800  combines with the body  700 , the compensation channel  820  is back to the infusion channel  712 , so only the infusion hole  810  interconnects the infusion channel  712 . In brief, the infusion hole  810  is disposed between the compensation hole  711  and the compensation channel  820 . 
       FIG. 8  is a cross-sectional perspective view of the pad  900  of the active compensating hydrostatic bearing of  FIG. 1 . In  FIG. 8 , the body  700 , the valve  800  and the pad  900  are penetrated at the centers, so compensation liquid in the sink  710  can be infused into the chamber  910 . 
       FIG. 9A  is a schematic view of the flow path of the compensation channel  820  of the active compensating hydrostatic bearing of  FIG. 1 .  FIG. 9B  is a schematic view of the flow path of the infusion hole  810  of the active compensating hydrostatic bearing of  FIG. 1 . Please refer to  FIG. 9A  and  FIG. 9B , the infusion hole  810  and the infusion channel  712  keep alignment with each other, and the flow path of compensation liquid can be switched by the valve  800 . More specifically, the valve  800  can select the registration channel  830  or the infusion hole  810  to align with the pad  900  for receiving compensation liquid, and the selection will decide whether the compensation channel  820  is used or not. 
     In  FIG. 9A , the registration channel  830  is controlled to align with the source of compensation liquid of pad  900 , and the infusion hole  810  at the other side is closed by the pad  900  (the valve  800  and the pad  900  are substantially combined). In this case, compensation liquid will be infused into the sink  710  through the registration channel  830 , the compensation channel  820 , the infusion hole  810  and the infusion channel  712  sequentially. 
     Conversely, in  FIG. 9B , the body  700  and the valve  800  rotate  180  degrees, the infusion hole  810  is switched to align with the source of compensation liquid. A little compensation liquid will fill the compensation channel  820  and mostly be infused into the infusion channel  712  directly via the infusion hole  810 . 
     The present disclosure utilizes resistance network method to monitor and compensate the mentioned routes of compensation liquid. Resistance network method controls inner pressure of active compensating hydrostatic bearing by viewing fluid as circuit. Controlling inner pressure by resistance network method is commonly used, so the details will not be described herein. 
     In brief, the flow resistances of compensation liquid at the compensation channel  820 , the compensation gap h and the chamber  910  can be viewed as three electric resistances connected in series. 
     Hence, using the compensation channel  820  may be thought of connecting an electric resistance. In view of the principle of active compensating hydrostatic bearing, the rigidity of the bearing can be adjusted by the height of the compensation gap h. That is, the quality of controlling the compensation gap h can be considered as an indicator for stability of bearing. 
     To understand as electricity, using the compensation channel  820  means the influence of the flow resistance of the compensation gap h declined in the whole system, so can reduce the amount of adjustment of the flow resistance in accordance with variable an external loading. The feature moderates the amplitude of the compensation gap h, especially when an external loading is increased, the decrease of the rigidity of active compensating hydrostatic bearing will be smoothed to ensure stability. 
     In contrast, for faster compensation in the condition of under loading, switch to the infusion hole  810  is considerable. In view of the foregoing, infusing via the infusion hole  810  can speed up the compensation and gain the greater rigidity under low variation of loading. 
     As mentioned previously, the present disclosure uses double buffering mechanisms. Firstly, using the elastic members  600  to withstand an external loading and avoid decreasing of rigidity caused by sudden compression of the compensation gap h. Moreover, the elastic members  600  will reset continuously during the compression, so that to take the mass block  500  to the balanced position quickly. For the second, the valve  800  can smooth the compensation of the active compensating hydrostatic bearing, and be optional to the faster mode for different conditions. 
     According to another embodiment of the present disclosure, an active compensating hydrostatic regulator  100  is applied to an active compensating hydrostatic bearing, and includes a body  700 , a valve  800  and a damping means, wherein the body  700  includes a compensation hole  711 . 
     In  FIG. 6  and  FIG. 7 , the valve  800  connects to the active compensating hydrostatic regulator  100 , and includes an infusion hole  810  and a compensation channel  820 . The infusion hole  810  and the compensation hole  711  are interconnected with each other, and the compensation channel  820  interconnects the infusion hole  810 , wherein the infusion hole  810  can be disposed between the compensation hole  711  and the compensation channel  820 . The valve  800  can rotate itself to switch to the infusion hole  810  or the compensation channel  820  for receiving compensation liquid and infuse into the active compensating hydrostatic regulator  100 . 
     As shown in  FIG. 6 , the valve  800  can include a registration channel  830  disposed on the valve  800 , and the infusion hole  810  and the registration channel  830  can be symmetric with respect to the rotating axis of the valve  800 . That is, the infusion hole  810  and the registration channel  830  are  180  degrees of azimuth apart for easy to align with the source of compensation liquid. 
     The damping means withstands an external loading applied to the active compensating hydrostatic regulator  100 . The damping means can be a elastic member  600  disposed in the active compensating hydrostatic regulator  100 , such as a disk-shaped subject, a spring with high coefficient of elasticity, or an ebonite, but are not limited to the foregoing items. 
     By such arrangement, the active compensating hydrostatic regulator  100  can be modularized and applied to the active compensating hydrostatic bearing by adjusting the shape of the valve  800  or other members. Besides, each of the members can be replaced separately, this features is helpful to overcome the tolerance since the size of each member can be adjusted and match with each other. 
     According to the foregoing embodiments, the advantages of the present disclosure are described as follows. 1. By using the elastic member disposed in the body, the compensation gap can be controlled via the deformation of the elastic member. Thus, the inner pressure of the active compensating hydrostatic bearing can be adjusted automatically, so that the performance of rigidity of the hydrostatic bearing becomes more stable. Besides, the elastic member can support the mass block to avoid polarization or impaction. 2. The active compensating hydrostatic bearing is modularized that all of the parts can be replaced separately, the feature is helpful to overcome the problem of tolerance and convenient for maintenance. 3. By using the regulator, the user can switch the active compensating hydrostatic bearing to the compensation channel, so that can improve the stability and efficiency of machining. 4. The active compensating hydrostatic bearing, the pad and the regulator are integrated together so easy to install on difference machines. And, all of the interfaces between the mentioned members are kept sealed to avoid leakage. Moreover, the active compensating hydrostatic regulator of the present disclosure needn&#39;t use the external regulator, this makes the compensation mechanism response more quickly and solve the problem of delay. 
     It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the present disclosure without departing from the scope or spirit of the present disclosure. In view of the foregoing, it is intended that the present disclosure cover modifications and variations of this present disclosure provided they fall within the scope of the following claims.