Abstract:
The present invention relates to a roller type linear guideway which comprises the rail, the slide block, the roller-model, the recirculating-model, and the ender cap. The recirculating-model is make up of two half recirculating-models which are assembled together at a specific angle, and each of the half recirculating-models comprises two U-shaped recirculating piece which includes a return portion, a supporting portion and a reflow portion, the recirculating paths of the roller-models intersect to form a x-type turn. Therefore, there are no a lot of accessories, that can reduce time of fabrication and can save the cost of manufacture.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to a roller type linear guideway, linear guideway is widely used on machinery trade, automatic equipments, measuring machines, electronic instruments, and the likes. However, the roller type linear guideway is used on large machine. 
   2. Description of the Prior Arts 
   Linear guideway generally comprises a rail, a slide block mounted on the rail, and a plurality of rolling elements disposed between the slide block and the rail. If the rolling elements are cylindrical rollers, the guideway is called roller type linear guideway. 
   A rolling-element-circulating system of the roller type linear guideway generally comprises the rolling-element-retainer, the return path, the return unit, and etc. the circulating system of the roller type linear guideway is generally made up of a plurality of independent components or integrally formed by plastic ejection. 
   JP Patent 2002-54633 discloses a rolling-element circulating system which is made up of a plurality of independent components, wherein the rolling-element retainers  11 ,  12 ,  13 , the return path  14  and the return unit (including  15   a  and  15   b ) are independent components. The respective independent components are not integral with the slide block  4 , there are too many independent components, and thus the assembly is complicated and time-consuming. 
   JP Patent 7-317762 discloses a rolling-element circulating system that is made by integral plastic ejection, in which, the slide block  13  is used as a part of the plastic ejection mold, and then the rolling-element supporting structure (the structure  17  which is made up of  30 ,  31  and  32 ), the return path  10  and the return unit ( 16  and  19 ) are integrally formed by plastic ejection. If the slide block is big size, then the size of the corresponding mold should be large. Furthermore, the plastic ejection process needs to be controlled precisely, and the difficulties are relatively increased. In this case, the dimension tolerance of the slide block must be controlled precisely before plastic ejection, so that the slide bock can be fully fitted into the mold. In addition, the supporting structure is difficult to be produced since it has long and thin sidewalls. 
   The present invention has arisen to mitigate and/or obviate the afore-described disadvantages. 
   SUMMARY OF THE INVENTION 
   The primary object of the present invention is to provide a roller type linear guideway which can take the place of the ball type linear guideway. The contact surface (line-contact) of the roller is much larger than that of the rolling ball, the load capacity of the roller is accordingly larger than that of the rolling ball. Therefore, the roller type linear guideway is normally used on the large scale machine. 
   The roller type linear guideway in accordance with the present invention generally comprises: an elongated rail having four sliding surfaces, on the rail is mounted a slide block which is provided with four reflow passages and four sliding surfaces. Two half recirculating-models are inserted from both ends of the slide block with a specific angle so as to form a complete recirculating model. A roller mold is made up a plurality of roller and circulates in the recirculating model, and then two ender caps are assembled to both ends of the slide block. 
   In addition, the circulating mold is made up of a plurality of U-shaped half recirculating pieces, the half recirculating piece is integrally formed with a plurality of return blocks, supporting ribs and return half-tubes, each two half recirculating pieces are combined into a half recirculating-model, the half recirculating-model comprises a return portion, a supporting portion and a reflow portion, the return portion is connected between the supporting portion and the reflow portion, the return portion is provided with an outer return path and an inner return path, the recirculating-model is provided with two recirculating paths for the roller-model, the two recirculating paths intersect at the return portion to form a X-type turn, so that the roller-model will circulate in the recirculating paths and will change its direction through the X-type turn in the return portion. The inner return path of a half recirculating-model is connected with the supporting portion and the return portion of this half recirculating-model, and then is connected to the outer recirculating path of another half recirculating-model, so as to form a complete recirculating path. 
   In addition, the roller-model in accordance with the present invention can be made up of a plurality of rollers, or can be made up of a plurality of rollers and partitions, the partition can be a chain-like structure or can be a single structure. 
   The recirculating-model in accordance with the present invention is made up of a plurality of half recirculating pieces, therefore, it doesn&#39;t need a lot of accessories, so that the time of fabrication can be reduced and the manufacturing cost is saved. 
   The present invention will become more obvious from the following description when taken in connection with the accompanying drawings, which show, for purpose of illustrations only, the preferred embodiments in accordance with the present invention. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is an exploded view of a roller type guideway in accordance with the present invention; 
       FIG. 2  shows an end surface of a roller type guideway in accordance with the present invention; 
       FIG. 3  is an exploded view for showing the half recirculating-model of the roller type linear guideway in accordance with the present invention; 
       FIG. 4  is another exploded view for showing the half recirculating-model of the roller type linear guideway in accordance with the present invention; 
       FIG. 5  is a partial amplified view of  FIG. 4 ; 
       FIG. 6  is a perspective assembly view of a complete recirculating-model of  FIG. 4 ; 
       FIG. 7  is a cross sectional view taken along the line of A—A of  FIG. 7 ; 
       FIG. 8  is a cross sectional view taken along the line of B—B of  FIG. 6 ; 
       FIG. 9  is a cross sectional view taken along the line of C—C of  FIG. 6 ; 
       FIG. 10  is a cross sectional view of the end cap of  FIG. 1 ; 
       FIG. 11  is a roller-model in accordance with another embodiment of the present invention; 
       FIG. 12  is a partition of the roller-model of  FIG. 11 . 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1  is an exploded view of a roller type guideway in accordance with the present invention.  FIG. 2  shows an end surface of a roller type guideway in accordance with the present invention, wherein the roller type guideway is not equipped with end cap. The roller type guideway comprises: a rail  10  which is an elongated structure having four sliding surfaces  11  and  12 , a slide block  20  having four reflow passages  21 ,  22  and four sliding surfaces  23 ,  24 , a pair of half recirculating-models  30 , two ender caps  40 , a roller-model  50  which is made up of a plurality of rollers, a dust-proof plate  60  and two end seals  70 . The slide block  20  is mounted on the rail  10  and slides thereon, the sliding surfaces  11 ,  12  abut against the sliding surfaces  23 ,  24  of the slide block, and the roller-model  50  is disposed in the space defined by slide surfaces  11 ,  12  of the rail  10  and the slide surfaces  23 ,  24  of the slide block  20 . The half recirculating-models  30  are inserted in the reflow passages  21 ,  22  of the slide block  20 . The end caps  40  are assembled at both ends of the slide block  20 , the dust-proof pieces  60  are installed in the clearances at the lower part of the slide block for preventing dust. The end seals  70  are disposed at the outer side of the ender caps  40  for stopping the dirty oil or dust on the rail  10  from entering into the slide block  20 . 
     FIG. 3  is an exploded view for showing the half recirculating-model of the roller type linear guideway in accordance with the present invention.  FIG. 4  is another exploded view for showing the half recirculating model of the roller type linear guideway in accordance with the present invention.  FIG. 5  is a partial amplified view of  FIG. 4 . Each of the half recirculating-models  30  is made up of a pair of U-shaped half recirculating pieces  30   a ,  30   b  which are integrally formed with return blocks  33   a ,  33   b , supporting ribs  31   a ,  31   b  and return half-tubes  32   a ,  32   b . The return block  33   a  of the U-shaped half recirculating piece  30   a  is connected between the supporting rib  31   a  and the reflow half-tube  32   a , and the return block  33   b  of the U-shaped half recirculating piece  30   b  is connected between the supporting rib  31   b  and the reflow half-tube  32   b . The return blocks  33   a  and  33   b  are provided with inner return surfaces  333   b  and outer return surfaces  332   a . The half recirculating model is provided with a groove  322  along the recirculating path of the roller type linear guideway for guiding the motion of the roller-model (not shown). The width of the groove  322  is larger than one third the diameter of the roller, and the half recirculating-model is further provided with an oiling groove  34   b  and oil scuppers  341   b ,  342   b . An end of the supporting ribs  31   a ,  31   b  that is not connected to the return blocks  33   a ,  33   b  is provided with a fixing pin  311   a ,  311   b , respectively. After the two half recirculating pieces  30   a  and  30   b  are combined together through the positing pins  321   b ,  331   b  and the locating holes (not shown), the supporting ribs  31   a ,  31   b  will be combined into a supporting portion  31 , the reflow half-tubes  32   a  and  32   b  will be combined into a reflow portion  32 , and the return blocks  33   a  and  33   b  will be combined into a return portion  33 . On the outer surface of the reflow portion  32  are provided a plurality of projections  35   a  which are to be inserted in the reflow passages  21 ,  22  of the slide block  20  and serve as a positioning means. A recirculating space  323  is defined in the reflow portion  32  for circulation of the roller-model (not shown). The return portion  33  is provided with an inner return path (not shown) that is made up of inner return surfaces  333   b , an outer return path  332  that is made up of outer return surfaces  333   a , an oiling entrance  34  made up of the oiling grooves, an outer drainage port  341  made up of the oil currages  341   b , and an inner drainage port (not shown) made up of oil scuppers  342   b . The lubricant oil, after entering the oiling entrance  34 , will flow via the outer drainage port  341  to the inner and the outer return path so as to lubricate the roller-model. In addition, the two half recirculating-models  30  are inserted from both ends of the slide block  20  with a specific angle of 90 degrees so as to form a complete recirculating-model. 
     FIG. 6  is a perspective assembly view of a complete recirculating-model of  FIG. 4 .  FIG. 7  is a cross sectional view taken along the line of A—A of  FIG. 7 .  FIG. 8  is a cross sectional view taken along the line of B—B of  FIG. 6 .  FIG. 9  is a cross sectional view taken along the line of C—C of  FIG. 6 . The roller mold  50  comprises a plurality of rollers and chain-like partition, the recirculating-model is provided with two recirculating paths for the reception of the roller-model  50 , wherein one of the recirculating paths is accommodated with a roller-model  50  and the other of the recirculating paths is not accommodated with the roller-model  50 . The reflow space  325  is made up of the two half reflow tubes  32   a  and  32   b , the slide space  312  is made up of the two supporting ribs  31   a  and  31   b , and the groove  322  serves for guiding the partitions among the roller-model  50  (not shown). As shown in  FIG. 7 , which is a cross sectional view of showing the right side of the return portion of the recirculating-model, the recirculating path accommodated with the roller-model  50  extends from the inner return path (not shown) of the right side of the recirculating-model, and changes from load condition (or circulating condition) to circulating condition (or load condition). However, the recirculating path without the roller-model  50  is the outer return path  332  of another half recirculating-model which is located at the right side of the recirculating-model. The two lines of recirculating paths intersect at the return portion  33  to form a X-type turn, so that the roller-model  50  is able to circulate in the recirculating path and to change its direction through the X-type turn of the return portion. With reference to  FIG. 9 , which is a cross sectional view of showing the left side of the return portion of the recirculating-model, the recirculating path accommodated with the roller-model  50  extends from the inner return path (not shown) of the left side of the recirculating-model, and changes from load condition (or circulating condition) to circulating condition (or load condition). However, the recirculating path without the roller-model  50  is the outer return path  332  of another half recirculating-model which is located at the left side of the recirculating-model. The two lines of recirculating paths intersect at the return portion  33  to form a X-type turn, so that the roller-model  50  is able to circulate in the recirculating path and to change its direction through the X-type turn of the return portion. 
     FIG. 10  is a cross sectional view of the ender cap of  FIG. 1 . The ender caps  40  are assembled to both ends of the slide block  20  of  FIG. 1 , each of the ender caps  40  is provided with a return curve-surface  47  which is used to cooperate with the outer return path  332  of the half recirculating-model  30  in  FIG. 5 , so as to prevent the roller-model  50  from being fallen off the recirculating path when passing through the outer return path  332 . The ender caps  40  are further provided with a plurality of fixing holes  43 ,  44  which are employed to position the supporting ribs  31   a ,  31   b  by cooperating with the fixing pins  311   a ,  311   b . A plurality of grooves  46  are formed on the ender caps  40  for cooperating with the reflow portion  32  of the half recirculating-model  30 . To improve the lubricating effect, an oiling aperture  41  is formed on each of the ender caps  40  and connected to both sides of the ender caps  40  via oilways  42 . At the end of the oilways  42  are provided oil spaces  45  for cooperating the oiling entrance  34  on the return portion  33  of the half recirculating-model  30 , so that the lubrication can be poured into oiling aperture  41  and flows to the oil spaces  45  via the oilways  42 , and then flows to the oiling entrance  34  of the half recirculating-model  30  for lubricating the roller-model (not shown). 
     FIG. 11  is a roller-model in accordance with another embodiment of the present invention.  FIG. 12  is a partition of the roller-model of  FIG. 11 . The roller-model  50  comprises a plurality of rollers  51  and the partitions  52 ,  53 . The partition  52  is a chain-like structure which is made up of a plurality of spacing portions  521  and a chain  522 , the rollers  51  are separated from one another by the spacing portions  521  and linked together by the chain  522 . A plurality of troughs  523  are formed on the chain structure for enabling the roller mold to change moving direction during circulation. Another type partition  53  is a one-piece structure comprised of a spacing portion  531  and a pin portion  532  and serves to separate the rollers  51 . 
   While we have shown and described various embodiments in accordance with the present invention, it should be clear to those skilled in the art that further embodiments may be made without departing from the scope of the present invention.