Abstract:
A lubricating system is adapted to supply lubricating oil to a lip portion of an oil-seal member for preventing the lubricating oil from leaking out of a case. The lubricating system includes a rotating member, a bearing, a scraping member, and a guiding section. The rotating member is configured and arranged to be rotatably housed within the case and to slidably engage the lip portion of the oil-seal member. The bearing rotatably supports the rotating member. The scraping member is configured and arranged to scrape the lubricating oil discharged from the bearing. The guiding section is configured and arranged to guide the lubricating oil scraped by the scraping member to the lip portion of the oil-seal member.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to Japanese Patent Application No. 2006-220734 filed on Aug. 11, 2006. The entire disclosure of Japanese Patent Application No. 2006-220734 is hereby incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention generally relates to a lubricating system and a lubricating method. More specifically, the present invention relates to a lubricating system and a lubricating method adapted to lubricate parts of a vehicle. 
     2. Background Information 
     Japanese Patent No. 3274916 discloses a conventional lubricating system used in a transfer case of a vehicle. An oil seal is provided so that lubricating oil does not leak from a portion of a rotating shaft rotatably supported in the transfer case via a bearing, which protrudes out of the case. The conventional lubricating system disclosed in this reference is arranged to lubricate a lip portion of the oil seal in the transfer case. In such conventional lubricating system, the lubricating oil scraped along by gears is introduced into an empty space formed between the oil seal and the bearing, and thus, a relatively large amount of the lubricating oil can be efficiently supplied to the lip portion. 
     In view of the above, it will be apparent to those skilled in the art from this disclosure that there exists a need for an improved lubricating system and lubricating method. This invention addresses this need in the art as well as other needs, which will become apparent to those skilled in the art from this disclosure. 
     SUMMARY OF THE INVENTION 
     In the conventional lubricating system disclosed in the above mentioned reference, it is necessary to provide an oil receiver in order to introduce the lubricating oil scraped along by the gears into the empty space formed between the oil seal and the bearing. Problems have arisen in that the size of an apparatus provided with such a conventional lubricating system inevitably increases in proportion to the space required for installing the oil receiver. 
     The present invention was contrived in light of the aforementioned problems in the prior art. One object of the present invention is to ensure lubricity of a lip portion of an oil seal without the size of the apparatus provided with the lubricating system being increased. Another object of the present invention is to efficiently supply lubricating oil to the lip portion of the oil seal. 
     In order to achieve the above mentioned objects of the present invention, a lubricating system is provided that is adapted to supply lubricating oil to a lip portion of an oil-seal member for preventing the lubricating oil from leaking out of a case. The lubricating system includes a rotating member, a bearing, a scraping member, and a guiding section. The rotating member is configured and arranged to be rotatably housed within the case and to slidably engage the lip portion of the oil-seal member. The bearing rotatably supports the rotating member. The scraping member is configured and arranged to scrape the lubricating oil discharged from the bearing. The guiding section is configured and arranged to guide the lubricating oil scraped by the scraping member to the lip portion of the oil-seal member. 
     These and other objects, features, aspects and advantages of the present invention will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses preferred embodiments of the present invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Referring now to the attached drawings which form a part of this original disclosure: 
         FIG. 1  is a schematic cross sectional view a vehicle transmission having a transfer device with a lubricating system in accordance with a first embodiment of the present invention; 
         FIG. 2  is an enlarged cross sectional view of the transmission at an area of an input shaft of the transfer device taken along a section line  2 - 2  in  FIG. 8  in accordance with the first embodiment of the present invention; 
         FIG. 3  is an enlarged axial cross sectional view of a driven transmission gear of the transmission in accordance with the first embodiment of the present invention; 
         FIG. 4  is an axial end elevational view of the driven transmission gear as viewed in a direction of an arrow  4  in  FIG. 3  in accordance with the first embodiment of the present invention; 
         FIG. 5  is an enlarged partial structural diagram of the driven transmission gear as viewed in a direction of an arrow  5  in  FIG. 4  in accordance with the first embodiment of the present invention; 
         FIG. 6  is an axial end elevational view of a scraping member of the lubricating system in accordance with the first embodiment of the present invention; 
         FIG. 7  is an elevational view of the scraping member as viewed in a direction of an arrow  7  in  FIG. 6  in accordance with the first embodiment of the present invention; 
         FIG. 8  is a cross sectional view of the transmission taken along a section line  8 - 8  in  FIG. 2  (with selected parts removed for purpose of illustration) in accordance with the first embodiment of the present invention; 
         FIG. 9  is an enlarged cross sectional view of a transmission provided with a lubricating system at an area of an input shaft of a transfer device in accordance with a second embodiment of the present invention; 
         FIG. 10  is an enlarged axial cross sectional view of a driven transmission gear of the transmission in accordance with the second embodiment of the present invention; 
         FIG. 11  is an enlarged cross sectional view of a transmission provided with a lubricating system at an area of an input shaft of a transfer device taken along a section line  11 - 11  in  FIG. 14  in accordance with a third embodiment of the present invention; 
         FIG. 12  is an elevational view of a scraping member of the lubricating system in accordance with the third embodiment of the present invention; 
         FIG. 13  is an axial end elevational view of a driven transmission gear of the transmission in accordance with the third embodiment of the present invention; 
         FIG. 14  is a cross sectional view of the transmission taken along a section line  14 - 14  in  FIG. 11  (with selected parts removed for purpose of illustration) in accordance with the third embodiment of the present invention; 
         FIG. 15  is an axial end elevational view of a scraping member of a lubricating system in accordance with a fourth embodiment of the present invention; 
         FIG. 16  is a side elevational view of a driven transmission gear of a transmission in accordance with the fourth embodiment of the present invention; 
         FIG. 17  is a cross sectional view, similar to  FIG. 8 , of the transmission in accordance with the fourth embodiment of the present invention; 
         FIG. 18  is an axial end elevational view of a scraping member of a lubricating system in accordance with a fifth embodiment of the present invention; 
         FIG. 19  is a top plan view of the scraping member as viewed in a direction of an arrow  19  in  FIG. 18  in accordance with the fifth embodiment of the present invention; 
         FIG. 20  is an enlarged cross sectional view of the transmission at an area of an input shaft of the transfer device in accordance with the fifth embodiment of the present invention; 
         FIG. 21  is an enlarged axial cross sectional view of a driven transmission gear of the transmission in accordance with the fifth embodiment of the present invention; 
         FIG. 22  is an axial end elevational view of the driven transmission gear as viewed in a direction of an arrow  22  in  FIG. 21  in accordance with the fifth embodiment of the present invention; 
         FIG. 23  is an enlarged partial structural diagram of the driven transmission gear as viewed in a direction of an arrow  23  in  FIG. 22  in accordance with the fifth embodiment of the present invention; 
         FIG. 24  is an axial end elevational view of a scraping member of a lubricating system in accordance with a sixth embodiment of the present invention; 
         FIG. 25  is an elevational view of the scraping member as viewed in a direction of an arrow  25  in  FIG. 24  in accordance with the sixth embodiment of the present invention; 
         FIG. 26  is an enlarged cross sectional view of a transmission at an area of an input shaft of the transfer device taken along a section line  26 - 26  in  FIG. 28  in accordance with the sixth embodiment of the present invention; 
         FIG. 27  is an enlarged axial cross sectional view of a driven transmission gear of the transmission in accordance with the sixth embodiment of the present invention; and 
         FIG. 28  is a cross sectional view of the transmission taken along a section line  28 - 28  in  FIG. 26  (with selected parts removed for purpose of illustration) in accordance with the sixth embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Selected embodiments of the present invention will now be explained with reference to the drawings. It will be apparent to those skilled in the art from this disclosure that the following descriptions of the embodiments of the present invention are provided for illustration only and not for the purpose of limiting the invention as defined by the appended claims and their equivalents. 
     Referring initially to  FIG. 1 , a transmission  1  is illustrated that is provided with a lubricating system in accordance with a first embodiment of the present invention.  FIG. 1  is an overall schematic cross sectional view of a motive force transmitting apparatus of a vehicle including the transmission  1 . 
     As shown in  FIG. 1 , the transmission  1  includes an input shaft  1   a , an output shaft  1   b , a reverse idler shaft  1   c , an output gear  1   d  and a case  1   e . Moreover, the motive-force transmitting apparatus further includes a differential device  2  housed within a case  2   a , a forward-wheel shaft  2   b , a ring gear  4 , a transmission gear  6 , a driven transmission gear  7 , a transfer device  8  and a bearing  9 . 
     A motive force (drive force) is inputted from an engine of the vehicle to the input shaft  1   a . The output shaft  1   b  and the reverse idler shaft  1   c  are arranged to be parallel to the input shaft  1   a . The motive force from the engine is transmitted to the output shaft  1   b  using different transmission gear ratios via a plurality of gears provided to the input shaft  1   a  and the output shaft  1   b . The output gear  1   d  is provided to the output shaft  1   b . The ring gear  4  is engaged with the output gear  1   d . The ring gear  4  is screwed to the case  2   a  of the differential device  2 . The differential device  2  is rotatably provided within the case  1   e  of the transmission  1 . 
     The forward-wheel shaft  2   b  is linked to the differential device  2  and to the front wheels (not shown) of the vehicle. Thus, the motive force is transmitted to the front wheels via the differential device  2 . 
     The transmission gear  6  is screwed to the case  2   a  of the differential device  2 . The transmission gear  6  is disposed adjacent to the ring gear  4 , which is also fixed to the case  2   a . The transmission gear  6  is arranged to have a smaller diameter than the ring gear  4 . 
     The driven transmission gear  7  is positioned so as to overlap the ring gear  4  in a radial direction. The driven transmission gear  7  is configured and arranged to rotate within the transmission case  1   e  via the bearing  9 . The driven transmission gear  7  is engaged with the transmission gear  6  as shown in  FIG. 1 . 
     The transfer device  8  is coupled to an input shaft  8   a  (rotating shaft) that is connected with a spline engagement to an inner circumferential surface of the driven transmission gear  7 . Thus, the input shaft  8   a  and the driven transmission gear  7  rotate together as an integral unit. The input shaft  8   a  of the transfer device  8  is linked to an output shaft  8   c  of the transfer device  8  extending in the longitudinal direction of the vehicle at a position in the vicinity of a transverse center CC of the vehicle. The transfer device  8  is housed inside of a transfer case  8   b . In the first embodiment, the input shaft  8   a  and the driven transmission gear  7  preferably constitute a rotating member of the present invention. 
     The transfer device  8  is fixedly coupled with screw engagement to the transmission case  1   e . The transfer device  8  is configured and arranged to transmit the motive force through the output shaft  8   c  of the transfer device to a rear-wheel shaft of the vehicle. 
     The transmission  1 , the differential device  2 , and the transfer device  8  are conventional components that are well known in the art. Since the transmission  1 , the differential device  2 , and the transfer device  8  are well known in the art, these structures will not be discussed or illustrated in detail herein. 
     In the first embodiment of the present invention, the lubricating system is provided in the transmission  1  in an area in the vicinity of a connecting portion between the transfer device  8  and the driven transmission gear  7 . Referring now to  FIGS. 2 to 8 , structures of the lubricating system of the first embodiment of the present invention will be described in more detail.  FIG. 2  is an enlarged cross sectional view of the transmission  1  at an area of the input shaft  8   a  of the transfer device  8  taken along a section line  2 - 2  in  FIG. 8 . 
     As shown in  FIG. 2 , a portion of the input shaft  8   a  of the transfer device  8  that protrudes into the transmission case  1   e  includes a spline-engagement part  81 , a sliding surface  82  and a sliding surface  83 . The spline-engagement part  81  has a plurality of splines formed on an outer circumference of a distal end part of the input shaft  8   a . The sliding surface  82  has a larger diameter than the spline-engagement part  81 . The sliding surface  82  is disposed with respect to the spline-engagement part  81  on a side closer to the transfer device  8  (right side in  FIG. 2 ). The sliding surface  83  has an even larger diameter than the sliding surface  82 . The sliding surface  83  is disposed with respect to the sliding surface  82  on the side closer to the transfer device  8  (right side in  FIG. 2 ). 
     The driven transmission gear  7  includes a boss part  71  having a plurality of spline bore part  73 . Thus, the spline-engagement part  81  of the input shaft  8   a  forms a spline engagement within the spline bore part  73  of the boss part  71  of the driven transmission gear  7 . 
       FIG. 3  is an enlarged axial cross sectional view of the driven transmission gear  7  of the transmission  1 .  FIG. 4  is an axial end elevational view of the driven transmission gear  7  as viewed in a direction of an arrow  4  in  FIG. 3 .  FIG. 5  is an enlarged partial structural diagram of the driven transmission gear  7  as viewed in a direction of an arrow  5  in  FIG. 4 . 
     As shown in  FIG. 3 , the driven transmission gear  7  includes the boss part  71 , a gear  72 , the spline bore part  73 , an axial end surface  74 , an annular groove  75 , a snap ring groove  76 , a radial groove  77  (guiding section), an a radial notch part  78 . 
     The gear  72  is formed on the outer circumferential surface of the boss part  71 . The spline bore part  73 , which engages with the spline-engagement part  81  of the input shaft  8   a  of the transfer device  8 , are formed on the inner circumferential surface of the boss part  71 . The annular groove  75  is formed concentrically with the spline bore part  73  on the inner circumferential surface of the boss part  71  adjacent to the axial end surface  74 . The snap ring groove  76  is formed on an outer circumferential surface of the boss part  71  at a position corresponding to the annular groove  75 . In other words, the snap ring groove  76  is formed on an outer circumferential surface of the boss part  71  at a position adjacent to the axial end surface  74  as shown in  FIG. 3 . 
     Referring back to  FIG. 2 , the bearing includes an outer race  9   a , an inner race  9   b , and a plurality of bearing balls  9   c  (smoothing member) interposed between the outer race  9   a  and the inner race  9   b . The inner race  9   b  of the bearing  9  is engaged with the outer circumferential surface of the boss part  71 , and the outer race  9   a  is engaged with the transmission case  1   e . The bearing balls  9   c  supported by a ball holder  9   d . The bearing  9  is securely attached to the driven transmission gear  7  by being inserted within the outer circumferential surface of the boss part  71  by press-fitting or the like. A snap ring  10  is provided which is fitted in the snap ring groove  76  to prevent displacement of the bearing  9  in the axial direction. 
     The input shaft  8   a  of the transfer device  8  is configured and arranged to rotate integrally with the driven transmission gear  7  via the bearing  9 . 
     As shown in  FIG. 2 , an annular sealing member  11  is provided between the input shaft  8   a  and the transfer case  8   b . The sealing member  11  is configured and arranged to slides against the sliding surface  83  of the input shaft  8   a  of the transfer device  8  and to prevent leakage of lubricating oil. Moreover, an annular oil-seal member  12  is also disposed between the input shaft  8   a  and the transfer case  8   b  on a side toward the driven transmission gear  7  with respect to the sealing member  11 . The oil-seal member  12  includes a lip portion  12   a  in a radial inner portion thereof. A radial outer portion of the oil seal member  12  (radial outer portion of the lip portion  12   a ) is rigidly formed to slide against the sliding surface  82  of the input shaft  8   a . The oil-seal member  12  further includes a fitting part  12   b  on the radial outer circumference side of the lip portion  12   a . The fitting part  12   b  abuts against the transfer case  8   b  as shown in  FIG. 2 . 
     As shown in  FIGS. 3 to 5 , the radial groove  77  is formed on the boss part  71  so that the radial groove  77  forms a recessed section on the axial end surface  74 . The radial groove  77  extends through the annular groove  75  of the boss part  71  in the radial direction as shown in  FIGS. 4 and 5 . The radial notch part  78  is formed on a portion of the radial groove  77  so that the radial notch part  78  is further indented or recessed toward the gear  72 . 
     In the lubricating system of the first embodiment, a scraping member  13  is provided that fits into the radial notch part  78 , as shown in  FIGS. 6 and 7 .  FIG. 6  is an axial end elevational view of the scraping member  13  of the lubricating system.  FIG. 7  is an elevational view of the scraping member  13  as viewed in a direction of an arrow  7  in  FIG. 6 .  FIG. 8  is a cross sectional view of the transmission  1  taken along a section line  8 - 8  in  FIG. 2  with selected parts removed for purpose of illustration. 
     The scraping member  13  includes a generally C-shaped leaf-spring part  14 , a fin part  15 , a protruding strip portion  16 , an engagement strip portion  17 . The C-shaped leaf-spring part  14  has elastic characteristics. The engagement strip portion  17  is formed to protrude outwardly in the radial direction toward a first open end portion of the leaf-spring part  14 . The fin part  15  includes an extending strip part  15   a  that extends in the radial direction. The extending strip part  15   a  is integrally formed with the engagement strip portion  17  and extends further outwardly in the radial direction from the engagement strip portion  17 . As shown in  FIG. 7 , a notch  15   b  is formed on the extending strip part  15   a  on the side facing the bearing  9  in order to bypass the snap ring  10  as shown in  FIG. 2 . In the first embodiment, the C-shaped leaf-spring part  14  and the engagement strip portion  17  preferably constitutes a fixing part of the present invention. 
     The protruding strip portion  16  is integrally formed on a second open end portion of the leaf-spring part  14  as shown in  FIGS. 6 and 7 . The protruding strip portion  16  is bent toward a center of the leaf-spring part  14 . Moreover, the protruding strip portion  16  further includes a bent strip portion  16   a  (claw) formed on the inner end of the protruding strip portion  16 . The bent strip portion  16   a  is bent at about 90° toward the leaf-spring part  14  as shown in  FIG. 6 . 
     The C-shaped leaf-spring part  14  of the scraping member  13  is configured and arranged to elastically fit within the annular groove  75  of the driven transmission gear  7 . Moreover, the engagement strip portion  17  of the scraping member  13  is inserted within the radial notch part  78  of the driven transmission gear  7  as shown in  FIGS. 2 and 7 , and thus, the scraping member  13  is prevented from turning relative to the driven transmission gear  7 . As shown in  FIGS. 2 and 8 , the extending strip part  15   a  extends radially outward from the radial groove  77  so that a free end of the extending strip part  15   a  is positioned further outwardly in the radial direction than the inner race  9   b . As shown in  FIG. 2 , the radial groove  77  extends along the fin part  15  so that the lubricating oil scraped by the fin part  15  can be efficiently guided to the lip portion  12   a.    
     With this arrangement, when the lubricating oil is supplied to the bearing  9 , the lubricating oil passes between the outer race  9   a  and the inner race  9   b  as lubricating the bearing  9 . Then, the lubricating oil is discharged from a lubricating oil discharging part P ( FIG. 2 ) on the axial end surface of the bearing  9 . The discharged lubricating oil is then scraped within the radial groove  77  by the distal end of the extending strip part  15   a  of the scraping member  13  that is attached to the axial end portion of the boss part  71  of the driven transmission gear  7 . 
     The rotation of the fin part  15  (the extending strip part  15   a ) properly guides the lubricating oil, which was discharged from the discharging part P, within the radial groove  77 . The lubricating oil passes through the radial groove  77  and flows toward the radial inner side of the driven transmission gear  7 . The lubricating oil is then supplied to the lip portion  12   a  of the oil-seal member  12 , allowing a space (a contacting portion) between the lip portion  12   a  and the sliding surface  82  to be properly lubricated. In other words, the lubricating oil scraped by the extending strip part  15   a  passes through the radial groove  77  and then properly guided toward the lip portion  12   a.    
     Moreover, when the scraping member  13  is attached to the driven transmission gear  7 , the protruding strip portion  16  extends toward a center portion of the driven transmission gear  7 . Therefore, the lubricating oil that might adhere to the inner circumferential surface of the annular groove  75  of the driven transmission gear  7  due to the centrifugal force of rotation can be properly guided toward the lip portion  12   a  by the protruding strip portion  16 . 
     Therefore, the lubricating oil is prevented from adhering by the protruding strip portion  16 , and the lubricating oil can be properly supplied to the lip portion  12   a . In the first embodiment of the present invention, the leaf-spring part  14  is fitted within the annular groove  75  formed in the boss part  71  of the driven transmission gear  7 , the fin part  15  protrudes outwardly in the radial direction from the radial groove  77 , and the scraping member  13  can be easily attached to the boss part  71  of the driven transmission gear  7 . The lubricating oil discharged from the bearing  9  is properly scraped by the extending strip part  15   a  and guided radially inwardly through the radial groove  77 . The lubricating oil is prevented from adhering to the annular groove  75  by providing the protruding strip portion  16 , and the lubricating oil can be further reliably supplied to the lip portion  12   a  of the oil-seal member  12 . Moreover, the protruding strip portion  16  can also be used as a knob for detaching the scraping member  13  from the annular groove  75  of the boss part  71  during disassembly for maintenance or other purposes, thereby improving workability. 
     In the first embodiment described above, the radial notch part  78  is formed in a part of the radial groove  77 , which is formed in the axial end surface  74  of the boss part  71  of the driven transmission gear  7 . The scraping member  13  is attached to the boss part  71  in a state in which the engagement strip portion  17  is fitted within the radial notch part  78  so that a free end portion of the extending strip part  15   a  of the fin part  15  is positioned further outwardly in the radial direction than the inner race  9   b  of the bearing  9 . The lubricating oil that lubricated the bearing  9  and discharged at the lubricating oil discharging part P is therefore scraped by the fin part  15  along with the rotation of the driven transmission gear  7 . The lubricating oil passes through the radial groove  77  and is guided toward the lip portion  12   a  of the oil-seal member  12 . 
     In other words, the lubricating oil can be supplied to the lip portion  12   a  even if an oil gutter, oil receiver, or other so-called trough member is not used. As a result, the lubricity of the lip portion  12   a  of the oil-seal member  12  can be ensured without the size of the motive force transmitting apparatus being increased. The lubricating oil can be scraped by the scraping member  13 , and can be efficiently supplied to the lip portion  12   a  after the bearing  9  has been lubricated even if the amount of lubricating oil used is relatively small. 
     Moreover, the fin part  15  for scraping the lubricating oil is relatively easily fixed to the boss part  71  with the scraping member  13  having the structure as illustrated above. 
     Furthermore, the C-shaped leaf-spring part  14  of the scraping member  13  is fitted into the annular groove  75  formed in the inner circumferential surface of the boss part  71 . Therefore, displacement of the fin part  15  in the radial direction with respect to the rotating shaft (e.g., an input shaft  8   a ) can be prevented. 
     Also, the scraping member  13  includes the protruding strip portion  16  that protrudes inwardly in the radial direction on the second open end portion of the C-shaped leaf-spring part  14 . Therefore, the lubricating oil guided inwardly in the radial direction via the radial groove  77  is prevented from adhering to the inner circumferential surface of the boss part  71  due to the centrifugal force resulting from the rotation of the driven transmission gear  7 . 
     Second Embodiment 
     Referring now to  FIGS. 9 and 10 , a lubricating system in accordance with a second embodiment will now be explained. In view of the similarity between the first and second embodiments, the parts of the second embodiment that are identical to the parts of the first embodiment will be given the same reference numerals as the parts of the first embodiment. Moreover, the descriptions of the parts of the second embodiment that are identical to the parts of the first embodiment may be omitted for the sake of brevity. 
     The lubricating system of the second embodiment is basically identical to the lubricating system of the first embodiment except for a shape of a radial groove  177  formed on the driven transmission gear  7 . 
       FIG. 9  is an enlarged cross sectional view, corresponding  FIG. 2  of the first embodiment, of the transmission provided with the lubricating system at an area of the input shaft  8   a  of the transfer device  8  in accordance with the second embodiment.  FIG. 10  is an enlarged axial cross sectional view of the driven transmission gear  7  of the transmission in accordance with the second embodiment. 
     Similarly to the first embodiment, in the second embodiment, the radial groove  177  (guiding section) is formed on the boss part  71  of the driven transmission gear  7  adjacent to the axial end surface  74 . In the second embodiment, a bottom surface of the radial groove  177  is slanted so that a radial inner end portion of the radial groove  177  is shallower than a radial outer end portion of the radial groove as shown in  FIGS. 9 and 10 . 
     In other words, the radial groove  177  is slanted toward the oil-seal member  12  in the radially inward direction as seen in  FIGS. 9 and 10 . The lubricating oil that is guided within the radial groove  177  by the extending strip part  15   a  of the scraping member  13  is directed along the slanted bottom surface of the radial groove  177  in the axial direction as shown with an arrow in  FIG. 10 . With this arrangement, the lubricating oil can be reliably supplied to the lip portion  12   a  of the oil-seal member  12 . 
     In the second embodiment, the bottom surface of the radial groove  177  is slanted so that the radial inner end portion of the radial groove  177  is shallower than the radial outer end portion of the radial groove  177 . Therefore, the lubricating oil scraped by the fin part  15  can be efficiently guided to the lip portion  12   a  even when the lip portion  12   a  is positioned toward the rear side in the axial direction (left side in  FIG. 2 ) with respect to the bearing  9 . 
     Third Embodiment 
     Referring now to  FIGS. 11 to 14 , a lubricating system in accordance with a third embodiment will now be explained. In view of the similarity between the first and third embodiments, the parts of the third embodiment that are identical to the parts of the first embodiment will be given the same reference numerals as the parts of the first embodiment. Moreover, the descriptions of the parts of the third embodiment that are identical to the parts of the first embodiment may be omitted for the sake of brevity. 
     The lubricating system of the third embodiment differs from the lubricating system of the first embodiment in that a scraping member  213  is used in the third embodiment instead of the scraping member  13  of the first embodiment. 
       FIG. 11  is an enlarged cross sectional view of a transmission provided with the lubricating system at an area of the input shaft  8   a  of the transfer device  8  taken along a section line  11 - 11  in  FIG. 14 .  FIG. 12  is an elevational view of the scraping member  213  in accordance with the third embodiment.  FIG. 13  is an axial end elevational view of the driven transmission gear  7  in accordance with the third embodiment.  FIG. 14  is a cross sectional view of the transmission taken along a section line  14 - 14  in  FIG. 11  in accordance with the third embodiment with selected parts removed for the purpose of illustration. 
     In the third embodiment, the scraping member  213  includes an axially-extending part  216   b  is that is integrally formed on a protruding strip portion  216 . The axially-extending part  216   b  is oriented in the axial direction. In other words, the axially-extending part  216   b  extends toward the lip portion  12   a  of the oil-seal member  12  when the scraping member  213  is attached to the driven transmission gear  7 . 
     Moreover, as shown in  FIG. 13 , the driven transmission gear  7  in the third embodiment includes a notch part  75   a  formed extending between the annular groove  75  and the axial end surface  74  of the boss part  71  in order to accommodate the axially-extending part  216   b  of the scraping member  213 . Thus, when the scraping member  213  is assembled with the driven transmission gear  7 , the axially-extending part  216   b  protrudes in the axial direction from the notch part  75   a  toward the lip portion  12   a  of the oil-seal member  12  as shown in  FIGS. 11 and 14 . 
     More specifically, the axially-extending part  216   b  of the scraping member  213  can be fitted and attached within the notch part  75   a , as shown in  FIG. 14 . The scraping member  213  is securely attached within the annular groove  75  of the boss part  71  and prevented from rotating since the axially-extending part  216   b  is inserted within the notch part  75   a.    
     The axially-extending part  216   b  is fitted into the notch part  75   a  in the assembled state, whereby rotation of the scraping member  213  is prevented. Therefore, the radial notch part  78  for preventing the rotation of the scraping member  13  in the first embodiment is not necessary in the third embodiment. Thus, only the radial groove  77  is formed in the axial end surface  74  of the boss part  71  of the driven transmission gear  7  so that the lubricating oil to be guided toward the annular groove  75 . 
     As shown in  FIG. 12 , the scraping member  213  of the third embodiment includes a leaf-spring part  214 , a fin part  215 , the protruding strip portion  216  and an engagement strip portion  217 . The structures of the leaf-spring part  214 , the fin part  215  and the engagement strip portion  217  are basically identical to the leaf-spring part  14 , the fin part  15  and the engagement strip portion  17  of the scarping member  13  in the first embodiment. As in the first embodiment, the scraping member  213  is tightly fixed to the annular groove  75  by the elasticity of the leaf-spring part  214  of the scraping member  213 , and an extending strip part  215   a  of the scraping member  213  protrudes outwardly in the radial direction along the radial groove  77  in the third embodiment. The scraping member  213  rotates integrally with the driven transmission gear  7 . Therefore, the lubricating oil discharged from the lubricating oil discharging part P on the axial end surface of the bearing  9  is scraped by the extending strip part  215   a  and properly guided within the radial groove  77 . The lubricating oil is also prevented from adhering to the annular groove  75  by the protruding strip portion  216 . The lubricating oil is properly supplied to the lip portion  12   a  of the oil-seal member  12  along the axially-extending part  216   b  that extends in the axial direction. The lubricating oil can be more reliably supplied to the lip portion  12   a  even if the amount of lubricating oil is relatively small. 
     In the third embodiment, the protruding strip portion  216  includes the axially-extending part  216   b  that is oriented toward the lip portion  12   a . Therefore, the lubricating oil is further prevented from adhering to the inner circumferential surface of the boss part  71  due to the centrifugal force resulting from the rotation of the driven transmission gear  7 , and the non-adhering lubricating oil can be efficiently guided to the lip portion  12   a.    
     Fourth Embodiment 
     Referring now to  FIGS. 15 to 17 , a lubricating system in accordance with a fourth embodiment will now be explained. In view of the similarity between the first and fourth embodiments, the parts of the fourth embodiment that are identical to the parts of the first embodiment will be given the same reference numerals as the parts of the first embodiment. Moreover, the descriptions of the parts of the fourth embodiment that are identical to the parts of the first embodiment may be omitted for the sake of brevity. 
       FIG. 15  is an axial end elevational view of a scraping member  313  in accordance with the fourth embodiment.  FIG. 16  is an axial end elevational view of the driven transmission gear  7  in accordance with the fourth embodiment.  FIG. 17  is a cross sectional view, similar to  FIG. 8  in the first embodiment, of the transmission in accordance with the fourth embodiment. 
     The lubricating system of the fourth embodiment differs from the lubricating system of the first embodiment in that, in the fourth embodiment, the scraping member  313  includes an extending strip part  315   a  and an engagement strip portion  317  formed on a first open end portion of a C-shaped leaf-spring part  314 , which are slanted with respect to the radial direction in a rotation direction of the driven transmission gear  7  as shown in  FIG. 17 . In other words, the extending strip part  351   a  (the fin part  351 ) is slanted such that a distal end portion of the extending strip part  351   a  is oriented toward the rotation direction of the driven transmission gear  7  with respect to a base end portion of the extending strip part  351   a  where it connects to the engagement strip portion  317 . The scraping member  313  further includes a protruding strip portion  316  is integrally formed on a second open end portion of the leaf-spring part  314 . The structures of the leaf-spring part  314  and the protruding strip portion  316  of the scraping member  313  are basically the same as the structures of the leaf-spring part  14  and the protruding strip portion  16  of the scraping member  13  in the first embodiment. 
     In the fourth embodiment, the driven transmission gear  7  includes a radial groove  377  (guiding section) that extends through the annular groove  75  formed on the boss part  71  of the driven transmission gear  7  adjacent to the axial end surface  74 . The radial groove  377  is slanted with respect to the radial direction of the driven transmission gear  7  in the rotation direction in order to receive the extending strip part  351   a  of the scraping member  313 . Moreover, a deep radial notch part  378  is further indented in the axial direction from the bottom surface of the radial groove  377  and the radial notch part  378  is also slanted in the rotation direction as shown in  FIG. 16 . As shown in  FIG. 17 , the engagement strip portion  317  of the scraping member  313  is fitted within the radial notch part  378  so that the scraping member  313  is prevented from rotating with respect to the driven transmission gear  7 . Thus, the scraping member  313  can be fitted and secured within the annular groove  75  of the driven transmission gear  7 . 
     As shown in  FIG. 17 , when the driven transmission gear  7  rotates in the rotation direction shown by an arrow with the scraping member  313  in an assembled state, the lubricating oil discharged from the lubricating oil discharging part P on the axial end surface of the bearing  9  is scraped within the radial groove  377  by the extending strip part  315   a  that extends slantwise in the rotation direction. Since the radial groove  377  and the extending strip part  315   a  are slanted in the rotation direction, the lubricating oil can be efficiently introduced into the annular groove  75 . Moreover, similarly to the first embodiment, the protruding strip portion  316  prevents the lubricating oil from adhering to the annular groove  75 , and the lubricating oil can be reliably supplied to the lip portion  12   a  of the oil-seal member  12 . 
     Fifth Embodiment 
     Referring now to  FIGS. 18 to 23 , a lubricating system in accordance with a fifth embodiment will now be explained. In view of the similarity between the first and fifth embodiments, the parts of the fifth embodiment that are identical to the parts of the first embodiment will be given the same reference numerals as the parts of the first embodiment. Moreover, the descriptions of the parts of the fifth embodiment that are identical to the parts of the first embodiment may be omitted for the sake of brevity. 
       FIG. 18  is an axial end elevational view of a scraping member  413  of the lubricating system in accordance with the fifth embodiment.  FIG. 19  is a top plan view of the scraping member  413  as viewed in a direction of an arrow  19  in  FIG. 18 .  FIG. 20  is an enlarged cross sectional view, corresponding to  FIG. 2  of the first embodiment, of the transmission at an area of the input shaft  8   a  of the transfer device  8  in accordance with the fifth embodiment.  FIG. 21  is an enlarged axial cross sectional view of the driven transmission gear  7  in accordance with the fifth embodiment.  FIG. 22  is an axial end elevational view of the driven transmission gear  7  as viewed in a direction of an arrow  22  in  FIG. 21  in accordance with the fifth embodiment.  FIG. 23  is an enlarged partial structural diagram of the driven transmission gear  7  as viewed in a direction of an arrow  23  in  FIG. 22 . 
     The lubricating system of the fifth embodiment differs from the lubricating system of the first embodiment in that an extending strip part  415   a  that constitutes a fin part  415  protruding from a leaf-spring part  414  of the scraping member  413  is slanted with respect to the axial end surface  74  of the driven transmission gear  7 . In other words, the extending strip part  415   a  of the scraping member  413  includes a scraping surface  415   a ′ that faces toward the lip portion  12   a  when the scraping member  413  is attached to the driven transmission gear  7 . The scraping surface  415   a ′ is configured and arranged to scrape the lubricating oil. With such arrangement, the lubricating oil discharged from the axial end surface of the bearing  9  is guided in the axial direction, i.e., toward the lip portion  12   a  of the oil-seal member  12 , at the same time as the lubricating oil is scraped away by rotation. 
     Since the extending strip part  415   a  is slanted so that the scraping surface  415   a ′ faces toward the lip portion  12   a , the driven transmission gear  7  includes a radial notch part  478  (guiding section) that is deeply indented in the axial direction formed on the outer circumferential surface of the annular groove  75  of the boss part  71  so that the extending strip part  415   a  is fitted within the radial notch part  478  as shown in  FIG. 23 . The scraping member  413  is fitted and attached within the radial notch part  478 . In the fifth embodiment, a groove that corresponds to the radial groove  77  of the first embodiment is not provided in the driven transmission gear  7 . The extending strip part  415   a  of the scraping member  413  is held in position and the scraping member  413  is prevented from rotating with respect to the driven transmission gear  7  since the extending strip part  415   a  is fitted within the radial notch part  478  of the boss part  71 . 
     As in the first embodiment, the leaf-spring part  414  of the scraping member  413  of the fifth embodiment is elastically fixed within the annular groove  75  of the boss part  71 . The protruding strip portion  416  is formed on the opposite side from the extending strip part  415   a  of the scraping member  13 , as in the first embodiment. The structures of the leaf-spring part  414  and the protruding strip portion  416  of the scraping member  413  are basically identical to the structures of the leaf-spring part  14  and the protruding strip portion  16  of the scraping member  13  in the first embodiment. 
     The scraping surface  415   a ′ of the extending strip part  415   a  faces in the direction of the lip portion  12   a  and is configured and arranged to scrape the lubricating oil when the driven transmission gear  7  rotates in the state in which the scraping member  413  is non-rotatably (with respect to the driven transmission gear  7 ) assembled in the annular groove  75  of the boss part  71 . Therefore, the lubricating oil discharged from the axial end surface of the bearing  9  is scraped away by the extending strip part  415   a , the scraped lubricating oil flows in the axial direction, i.e., toward the lip portion  12   a  of the oil-seal member  12 , and the lubricating oil can be properly supplied to the lip portion  12   a.    
     Sixth Embodiment 
     Referring now to  FIGS. 24 to 28 , a lubricating system in accordance with a sixth embodiment will now be explained. In view of the similarity between the first and sixth embodiments, the parts of the sixth embodiment that are identical to the parts of the first embodiment will be given the same reference numerals as the parts of the first embodiment. Moreover, the descriptions of the parts of the sixth embodiment that are identical to the parts of the first embodiment may be omitted for the sake of brevity. 
       FIG. 24  is an axial end elevational view of a scraping member  513  of the lubricating system in accordance with the sixth embodiment.  FIG. 25  is an elevational view of the scraping member  513  as viewed in a direction of an arrow  25  in  FIG. 24 .  FIG. 26  is an enlarged cross sectional view of the transmission at an area of the input shaft  8   a  of the transfer device  8  taken along a section line  26 - 26  in  FIG. 28  in accordance with the sixth embodiment.  FIG. 27  is an enlarged axial cross sectional view of the driven transmission gear  7  of the transmission in accordance with the sixth embodiment.  FIG. 28  is a cross sectional view of the transmission taken along a section line  28 - 28  in  FIG. 26  with selected parts removed for purpose of illustration. 
     The lubricating system of the sixth embodiment differs from the lubricating system of the first embodiment in the structure of the scarping member  513 . More specifically, the scraping member  513  of the sixth embodiment has similar configuration as the scraping member  13  of the first embodiment, except that the thickness and width of the scraping member  13  in the first embodiment are reversed to form the scarping member  513  of the sixth embodiment. 
     As shown in  FIGS. 24 and 25 , the scraping member  513  includes a snap-ring part  514 , a fin part  515 , a protruding strip portion  516  and an engagement strip portion  517 . The snap-ring part  514  is arranged as a conventional generally C-shaped snap ring. The engagement strip portion  517  of the scraping member  513  of the sixth embodiment is formed to protrude outwardly in the radial direction from a first open end of the C-shaped snap-ring part  514 . The fin part  515  includes an extending strip part  515   a  that is integrally formed with the engagement strip portion  517  to extend further outward in the radial direction from the engagement strip portion  517 . The protruding strip portion  516  is integrally formed on a second open end portion of the C-shaped snap-ring part  514  and bent toward a radial center portion of the snap-ring part  514 . The protruding strip portion  516  further includes a bent strip portion  516   a  formed on the radial inner end (free end) of the protruding strip portion  516 , which is bent at about 90° toward the snap-ring part  514 . 
     The scraping member  513  of the sixth embodiment can be manufactured by punching out using a press or other method a plate that has the snap-ring part  514  and the fin part  515  (shown by the alternating double-dotted line in  FIG. 24 ) on the same plane as shown in  FIG. 24 . The fin part  515  is then formed by bending at about 90° in the axial direction of the snap-ring part  514  relative to the snap-ring part  514 . The scraping member  513  as shown in  FIGS. 24 and 25  is thereby manufactured more efficiently. 
     As shown in  FIGS. 26 ,  27  and  28 , the driven transmission gear  7  of the sixth embodiment includes the radial notch part  78  within which the engagement strip portion  517  is fitted so that a free end portion of the extending strip part  515   a  is positioned further outwardly in the radial direction than the inner race  9   b  of the bearing  9 . Moreover, the drive transmission gear  7  includes an annular groove  575  having an axial length arranged to hold the snap-ring part  514  therebetween. Thus, the snap-ring part  514  is elastically fitted within the annular groove  575  of the driven transmission gear  7  as shown in FIG.  26 . The protruding strip portion  516  can be used as a knob for detaching the scraping member  13  from the annular groove  575  of the boss part  71  during disassembly for maintenance or other purposes, allowing for improved workability. 
     When the driven transmission gear  7  rotates in the state in which the scraping member  513  is non-rotatably (with respect to the driven transmission gear  7 ) assembled in the annular groove  575  of the boss part  71 , the lubricating oil discharged from the axial end surface of the bearing  9  is scraped away by the extending strip part  515   a . Then, the scraped lubricating oil flows through the radial groove  77  in the axial direction, i.e., toward the lip portion  12   a  of the oil-seal member  12 . Therefore, the lubricating oil can be properly supplied to the lip portion  12   a , as in the first embodiment. 
     In the first through sixth embodiments, the scraping member  13 ,  213 ,  313 ,  413  or  513  is attached to the driven transmission gear  7  by the elasticity of the leaf-spring part  14 ,  214 ,  314  or  413 , or the snap-ring part  514  However, the structures of the scraping member  13 ,  213 ,  313 ,  413  or  513  are not limited to the illustrated embodiments as long as the fin part  15 ,  215 ,  315 ,  415  or  515  of the scraping member  13 ,  213 ,  313 ,  413  or  513  is configured and arranged to rotate integrally with the driven transmission gear  7 . For example, the scraping member  13 ,  213 ,  313 ,  413  or  513  can include only the fin part  15   215 ,  315 ,  415  or  515  and be welded or otherwise anchored directly to the axial end surface  74  of the boss part  71  of the driven transmission gear  7 , the inner race  9   b  of the bearing  9 , or other members. 
     In the first through sixth embodiments, the rotation of the scraping member  13 ,  213 ,  313 ,  413  or  513  relative to the driven transmission gear  7  is prevented by fitting the engagement strip portion  17 ,  317 ,  417  or  517  into the radial notch part  78 ,  378 ,  478 , or by fitting the axially-extending part  216   b  of the protruding strip portion  216  within the notch part  75   a . Alternatively, the scraping member  13 ,  213 ,  313 ,  413  or  513  can be welded or otherwise anchored to the driven transmission gear  7 , thereby preventing the rotation of the scraping member  13 ,  213 ,  313 ,  413  or  513  relative to the driven transmission gear  7 . 
     In the first through sixth embodiments, the extending strip part  15   a ,  215   a ,  315   a ,  415   a  or  515   a  is formed to have a substantially flat surface extending radially outwardly from the engagement strip portion  17 ,  217 ,  317 ,  417  or  517 . However, the extending strip part  15   a ,  215   a ,  315   a ,  415   a  or  515   a  is not limited to the illustrated embodiments. For example, the extending strip part  15   a ,  215   a ,  315   a ,  415   a  or  515   a  can be arranged so that a side surface of the extending strip part  15   a ,  215   a ,  315   a ,  415   a  or  515   a  that faces the rotation direction of the driven transmission gear  7  is in the shape of a recessed curve. 
     In the first through fourth and sixth embodiment, the radial groove  77  or  177  is formed on the axial end surface  74 , but the radial groove  77  or  177  need not necessarily be provided. In the first, second, fourth, fifth and sixth embodiments, the protruding strip portion  16 ,  316 ,  416 , or  516  is formed on the scraping member  13 ,  313 ,  413  or  513 , but the protruding strip portion  16  need not necessarily be provided. 
     GENERAL INTERPRETATION OF TERMS 
     In understanding the scope of the present invention, the term “comprising” and its derivatives, as used herein, are intended to be open ended terms that specify the presence of the stated features, elements, components, groups, integers, and/or steps, but do not exclude the presence of other unstated features, elements, components, groups, integers and/or steps. The foregoing also applies to words having similar meanings such as the terms, “including”, “having” and their derivatives. Also, the terms “part,” “section,” “portion,” “member” or “element” when used in the singular can have the dual meaning of a single part or a plurality of parts. 
     While only selected embodiments have been chosen to illustrate the present invention, it will be apparent to those skilled in the art from this disclosure that various changes and modifications can be made herein without departing from the scope of the invention as defined in the appended claims. For example, the size, shape, location or orientation of the various components can be changed as needed and/or desired. Components that are shown directly connected or contacting each other can have intermediate structures disposed between them. The functions of one element can be performed by two, and vice versa. The structures and functions of one embodiment can be adopted in another embodiment. It is not necessary for all advantages to be present in a particular embodiment at the same time. Every feature which is unique from the prior art, alone or in combination with other features, also should be considered a separate description of further inventions by the applicant, including the structural and/or functional concepts embodied by such feature(s). Thus, the foregoing descriptions of the embodiments according to the present invention are provided for illustration only, and not for the purpose of limiting the invention as defined by the appended claims and their equivalents.