Abstract:
Supplying fluids different in pressure from one end of a revolving shaft without providing a diagonal hole in the revolving shaft for supply holes for feeding hydraulic fluid and lubricating oil. The time for manufacturing and the cost of providing a hydraulic fluid feeder to the revolving shaft is reduced. A hydraulic fluid feeder includes a central hole provided on the centerline of the revolving shaft. Hollow tubes having a smaller outside diameter than the inside diameter of the central hole are concentrically inserted into the central hole and the central hole is partitioned. Either of the passages formed by partitioning functions as a hydraulic fluid supply passage for the hydraulic equipment and the other functions as a hydraulic fluid supply passage for another piece of hydraulic equipment or a lubricating oil supply passage for a bearing provided on the revolving shaft.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application claims priority under 35 USC 119 to Japanese Patent Application No. 2001-314825 filed on Oct. 12, 2001 the entire contents thereof is hereby incorporated by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a hydraulic fluid feeder for the revolving shaft of a transmission of an internal combustion engine provided with an automatic transmission for a vehicle which is provided with hydraulic equipment such as a hydraulic clutch operated by switching oil pressure. 
     2. Description of Background Art 
     Heretofore, hydraulic fluid has been supplied to a hydraulic clutch via a central hole of a revolving shaft from one end of the revolving shaft and lubricating oil has been supplied to a lubricating location via a central hole of the revolving shaft from the other end of the revolving shaft. As hydraulic fluid and lubricating oil are different in pressure, an oil hole tilted on the basis of the central line of the shaft is required to be provided from the outside face of the revolving shaft towards the central hole to feed oil to which a predetermined pressure is applied to a predetermined location, and a complex structure is required. It requires a great deal of time to work a diagonal hole of a shaft and in addition, the cost is also high. 
     Hydraulic fluid is sometimes supplied to a hydraulic clutch via an oil supply pipe laid from the side of a crankcase cover to the inside of a central hole of a revolving shaft and the oil supply pipe is fixed to the crankcase cover. When oil is supplied to a hydraulic clutch in the center of the revolving shaft of a transmission, an oil supply pipe is required to be long. In such structure, it is difficult to attach or detach the crankcase cover, particularly in case where the crankcase cover is to be detached in an onboard state. The crankcase cover cannot be detached until the oil supply pipe is removed. Thus, the serviceability of the unit is deteriorated. In a state in which the oil supply pipe is fixed to the crankcase cover, a large depository is required. 
     SUMMARY AND OBJECTS OF THE INVENTION 
     For a supply hole for feeding hydraulic fluid and lubricating oil, no diagonal hole is required to be worked in the revolving shaft. Thus, the working time and cost are reduced. The attachment/detachment of the crankcase cover is facilitated and the serviceability is enhanced. Further, the large depository of the crankcase cover is not required. 
     The present invention is made to solve the problems wherein a hydraulic fluid feeder for a revolving shaft is provided with at least one piece of hydraulic equipment operated by switching oil pressure on the revolving shaft. A central hole is provided on the centerline of the revolving shaft with a hollow tube having a smaller outside diameter than the inside diameter of the central hole being concentrically inserted into the central hole and the central hole is partitioned. Either one of the passages formed by partitioning functions as a hydraulic fluid supply passage for the hydraulic equipment and the other passage functions as a hydraulic fluid supply passage for another piece of hydraulic equipment or a lubricating oil supply passage for a bearing provided on the revolving shaft. 
     As the invention is configured as described above, concentric outer and inner fluid passages are formed inside the central hole of the revolving shaft. Since oil that is different in pressure can be supplied from one end of the revolving shaft, the working of a diagonal hole is not required. Thus, working time and cost can be reduced. 
     The present invention includes a plurality of hollow tubes that are concentrically inserted into the central hole with the central hole being partitioned into three or more passages to provide a hydraulic fluid supply passage or a lubricating oil supply passage. Thus, even if a plurality of pieces of hydraulic equipment are provided on the revolving shaft, oil that is different in pressure can be supplied from one end of the revolving shaft, reducing working time and cost. 
     The present invention provides an end on the upstream side of a passage of the hollow tube that is connected to a hydraulic fluid supply passage provided on a casing via a fluid reservoir provided to the casing. Thus, even if the hydraulic fluid supply passage on the side of the casing and a revolving shaft are spaced apart, hydraulic fluid can be supplied from the side of the casing. The casing denotes a front crankcase cover in an embodiment described later. 
     The present invention includes a fluid reservoir provided on a casing that is partitioned into a plurality of small fluid reservoirs by a partitioning member, a plurality of hydraulic fluid supply passages are bored in the casing and are connected to different small fluid reservoirs with the ends on the upstream side of a plurality of fluid passages formed in concentric hollow tubes that are also connected to different small fluid reservoirs. Thus, in the case where the hydraulic fluid supply passage on the side of the casing and a revolving shaft are spaced apart and a plurality of hydraulic equipment are provided on the revolving shaft, hydraulic fluid can be also supplied from the side of the casing. 
     The present invention includes a hollow tube connected to a fluid reservoir of the casing that can be attached/detached from the outside of the casing. Thus, as the hollow tube can be attached after the casing is attached or the casing can be detached after the hollow tube is detached, the attachment/detachment of the casing is facilitated and serviceability is enhanced. As the casing can be detached, a large location for storing the casing is not required. 
     Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein: 
         FIG. 1  is a side view showing a four-wheel buggy (a saddle-type vehicle for operating on wasteland) in which an internal combustion engine according to the invention is mounted; 
         FIG. 2  is a front view showing a power unit according to the invention; 
         FIG. 3  shows a front crankcase cover viewed from the front; 
         FIG. 4  shows a front crankcase viewed from the front; 
         FIG. 5  is a longitudinal section of the inside of a crankcase showing the relationship between a crankshaft and a main shaft; 
         FIG. 6  is a longitudinal section of the inside of the crankcase showing the relationship between the main shaft, a counter shaft, an intermediate shaft and an output shaft; 
         FIG. 7  is a front view showing a valve body; 
         FIG. 8  is a side view showing the valve body viewed from the right side; 
         FIG. 9  is a rear view showing the valve body; 
         FIG. 10  is a sectional view viewed along a line X—X in  FIG. 8 ; 
         FIG. 11  is a sectional view viewed along a line XI—XI in  FIG. 8 ; 
         FIG. 12  is a schematic diagram showing a hydraulic system of control equipment of a transmission housed in the valve body; 
         FIG. 13  is a plan showing a gasket for attaching the valve body; and 
         FIG. 14  is an enlarged sectional view showing the vicinity of a fluid passage connecting part, a double tube for supplying hydraulic fluid and the counter shaft. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       FIG. 1  is a side view showing a four-wheel buggy (a saddle-type vehicle for operating on wasteland) wherein an internal combustion engine is provided with a hydraulic automatic transmission. The buggy is provided with a pair of right and left front wheels  2  and a pair of right and left rear wheels  3  in the front and in the rear of a body frame  1 . A power unit  6  in which an internal combustion engine  4  and a transmission  5  are integrated are supported in the center of the body frame  1 . The power unit  6  is arranged with a crankshaft  7  directed in a longitudinal direction of the body. The rotation of the crankshaft  7  is transmitted to an output shaft  11  via the main shaft  8  of the transmission, a counter shaft  9  and an intermediate shaft  10 , respectively, as shown in  FIG. 4 . These shafts are parallel to the crankshaft and are arranged in the longitudinal direction of the body. The front wheel  2  is driven by a front wheel driving shaft  12  connected to the front end of the output shaft  11  and the rear wheel  3  is driven by a rear wheel driving shaft  13  connected to the rear end of the output shaft  11 . On the upside of the body, a steering handlebar  14 , a fuel tank  15  and a saddle-type seat  16  are equipped in this order from the front. 
       FIG. 2  is a front view showing the front of the power unit  6 . The body of the power unit  6  is roughly composed of four parts of a cylinder head cover  20 , a cylinder head  21 , a cylinder block  22  and a crankcase  23  in that order from the head. The crankcase  23  is divided into four parts on a face perpendicular to the crankshaft  7  and includes a front crankcase cover  24 , a front crankcase  25 , a rear crankcase  26  and a rear crankcase cover  27  in that order from the front (these are partially shown in  FIGS. 5 and 6 ). In  FIG. 2 , the front crankcase cover  24  is illustrated and the front crankcase  25  is slightly shown in the periphery. Various equipment and piping are mounted on the front of the front crankcase cover  24 . A valve body  60  of a hydraulic control unit is provided with an orifice of a fluid passage and an orifice clogging preventing mechanism according to the present invention.  FIG. 3  illustrates the front crankcase cover  24  viewed from the front in a state in which the various equipment is not mounted and  FIG. 4  shows the front crankcase  25  viewed from the front. 
     In  FIG. 4 , each position of the crankshaft  7 , the main shaft  8  of the transmission, the counter shaft  9 , the intermediate shaft  10  and the output shaft  11  are shown.  FIGS. 5 and 6  are longitudinal sections showing the inside of the crankcase including primary shafts in the crankcase,  FIG. 5  shows the relationship between the crankshaft  7  and the main shaft  8  and  FIG. 6  shows the relationship between the main shaft  8 , the counter shaft  9 , the intermediate shaft  10  and the output shaft  11 . In  FIG. 5 , an arrow F indicates the front. 
       FIG. 5  shows a power transmission mechanism between the crankshaft  7  and the main shaft  8 . The crankshaft  7  is supported by the front and rear crankcases  25  and  26  via a bearing. A front extended part of the crankshaft  7  is supported by the front crankcase cover  24  via a bearing. A driving gear  29  is provided on the crankshaft  7  via a torque converter  28 . The driving gear  29  is held by the crankshaft  7  via a needle bearing  30  so that the driving gear can revolve. The torque converter  28  is provided with a pump impeller  28   a  fixed to the crankshaft  7 , a turbine runner  28   b  opposite to the pump impeller and a stator  28   c . The driving gear  29  is revolvable around the crankshaft  7  and is connected to the turbine runner  28   b . When the torque converter  28  is connected, power from the crankshaft  7  can be transmitted. An oil filter  31  is provided on the front crankcase cover  24  that supports the front end of the crankshaft  7 . A driven gear  32  is always engaged with the driving gear  29  and is fixed to the front end of the main shaft  8  of the transmission. When the torque converter  28  is connected, the revolution of the crankshaft  7  is transmitted to the main shaft  8  via the driving gear  29  and the driven gear  32 . 
       FIG. 6  shows the power transmission mechanism between the main shaft  8  of the transmission, the counter shaft  9 , the intermediate shaft  10  and the output shaft  11 . The main shaft  8  of the transmission is supported by the front and rear crankcases  25  and  26  via a bearing. A first-speed driving gear  40 , a second-speed driving gear  41  and a third-speed driving gear  42 , respectively, are provided on the main shaft  8  that are different in the number of gear teeth according to a gear ratio. The second-speed driving gear  41  and the third-speed driving gear  42  are fixed gears fixed to the main shaft  8 . However, the first-speed driving gear  40  is supported by the main shaft  8  via a needle bearing so that the first-speed driving gear can be rotated. In the following description, an idle gear is described which is a gear held by a needle bearing so that the gear can be rotated around a rotation axis. A hydraulic multiple disc clutch for first speed  43  is provided between the main shaft  8  and the first-speed driving gear  40 . For this clutch, a clutch outer  43   a  is fixed to the main shaft and a clutch inner  43   b  is connected to the first-speed driving gear  40  which is the idle gear. When hydraulic fluid is supplied between the clutch outer  43   a  and a pressure plate  43   c  respectively of this clutch and is pressurized, the pressure plate  43   c  is moved and connects the clutch, the first-speed driving gear  40  is fixed to the main shaft  8 . 
     The counter shaft  9  is an integrated counter shaft acquired by connecting a front  9   a  and a rear  9   b . The counter shaft  9  is supported by the front crankcase  25 , the rear crankcase  26  and the rear crankcase cover  27  via a bearing. A first-speed driven gear  44 , a second-speed driven gear  45  and a third-speed driven gear  46 , respectively, are always engaged with the first-speed driving gear  40 , the second-speed driving gear  41  and the third-speed driving gear  42 , respectively, of the main shaft  8  are provided on the front  9   a  of the counter shaft  9 . The first-speed driven gear  44  is a fixed gear fixed to the counter shaft. However, the second-speed driven gear  45  and the third-speed driven gear  46  are idle gears. A hydraulic multiple disc clutch for a second speed  47  and a hydraulic multiple disc clutch for a third speed  48  are provided between the counter shaft  9  and either of these idle gears. The respective clutch outers of these clutches are fixed to the counter shaft  9  and the respective clutch inners are connected to the idle gears. When hydraulic fluid is supplied between the clutch outer and a pressure plate, respectively, of this clutch and is pressurized, the pressure plate is moved and connects the clutch. The idle gears are fixed to the counter shaft  9  and power transmission at second or third speed is enabled. 
     A driving gear for normal rotation  49  and a driving gear for reverse rotation  50  are provided to the rear  9   b  of the counter shaft  9 . These are both idle gears. The gear with a manual dog clutch  51  provided in a medium is engaged and is fixed to the rear counter shaft. 
     An intermediate shaft  10  is supported by the rear crankcase  26  and the rear crankcase cover  27 . A first intermediate gear  52  is always engaged with the driving gear for reverse rotation  50  and a second intermediate gear  53  is connected to the first intermediate gear  52  via a long sleeve  53   a  are held by the intermediate shaft  10  so that they can be turned. 
     The output shaft  11  is supported via a bearing by the front crankcase cover  24 , the rear crankcase  26  and the rear crankcase cover  27 . The output shaft  11  pierces the front crankcase  25  without being touched to the front crankcase  25 . A driven gear  54  is always engaged with the driving gear for normal rotation  49  and the second intermediate gear  53  is fixed to the output shaft  11 . The driven gear  54  is normally rotated or reversibly rotated via the gear with which the dog clutch  51  is engaged and rotates the output shaft  11  in a direction suitable for the forward or backward travel of the vehicle. Reverse rotation is controlled so that it occurs only when the counter shaft is rotated at the first speed. 
     The gears in the transmission are all constant-mesh gears. Depending upon which clutch of the hydraulic multiple disc clutches  43 ,  47 ,  48  is to be connected it is determined that any transmission gear ratio is executed. It is a valve body  60  built by a cut-off poppet valve and a solenoid for driving it as an integrated hydraulic control unit that controls oil pressure. The valve body is attached to the front of the front crankcase cover  24  as shown in  FIG. 2 . The valve body  60  is mounted on a mounting concave portion  61  of the front crankcase cover  24  as shown in  FIG. 3  and is fixed on a mounting face  62  on the periphery of the mounting concave portion via a gasket. In a state in which the valve body is mounted, a front half of the valve body  60  is exposed to the outside of the front crankcase cover  24  and a rear half is buried in the mounting concave portion  61  of the front crankcase cover  24 . The mounting face  62  is formed in parallel with a divided face of the crankcase. 
     As shown in  FIGS. 8 ,  10  and  11 , an arrow F indicates the front. This unit is composed of four layers as a whole, is detailedly composed of a first layer  63 , a second layer  64 , a third layer  65  and a fourth layer  66  in this order from the front. The rear face of the second layer, that is, a face shown by a line A—A in  FIGS. 8 ,  10  and  11  is in contact with the mounting face  62  of the front crankcase cover and is fixed by a bolt via the gasket. The third layer  65  and the fourth layer  66  of the valve body  60  are housed in the mounting concave portion  61  of the front crankcase cover. 
     A linear solenoid valve  67  and an emergency valve  68  are provided on the first layer  63  of the valve body  60 . An electric wire connecting terminal  67  is provided on the solenoid. A solenoid valve for switching first speed and second speed  69  and a solenoid valve for switching second speed and third speed  70  are provided on the second layer  64 . Electric wire connecting terminals  69   a  and  70   a  are provided on each solenoid. A spool valve for switching first speed and second speed  71  and a spool valve for switching second speed and third speed  72 , the respective spools of which are driven by oil pressure according to the on-off action of each solenoid valve, are provided on the third layer  65 . The spool valves are valves for controlling the supply of hydraulic fluid to the hydraulic multiple disc clutches  43 ,  47  and  48 . Hydraulic control valves  73  and  74  are provided on the fourth layer  66 . The control valves are valves for controlling the discharge of hydraulic fluid from the hydraulic multiple disc clutches  43 ,  47  and  48 . 
       FIG. 12  is a schematic diagram of hydraulic fluid for connecting the equipment. As shown in  FIG. 12 , all of the equipment is built in the valve body  60  except the hydraulic multiple disc clutches  43 ,  47  and  48 . A part of the fluid fed under pressure through a filter from an oil pump (not shown) is provided in the crankcase  23  and is driven by the internal combustion engine  4  and is supplied to the system from a direction shown by an arrow P in a lower part of  FIG. 12  as hydraulic fluid for operating the hydraulic multiple disc clutch. A discharge port shown by X in  FIG. 12  is a discharge port for fluid and used hydraulic fluid discharged from the discharge port is collected in an oil tank not shown. The other part of the fluid through the filter is fed to each part as hydraulic fluid for the torque converter or lubricating oil for the transmission and a valve cam though its path is not shown in the schematic diagram. 
     As shown in  FIG. 12 , hydraulic fluid is supplied to the clutch further via each spool valve for switching through the linear solenoid valve  67 . The linear solenoid valve  67  is a valve for slacking the rise of oil pressure when the supply of hydraulic fluid is initiated. The hydraulic fluid through the linear solenoid valve  67  is fed to the spool valve for switching via the emergency valve  68 . The emergency valve  68  normally fulfills only a role of providing a passage of hydraulic fluid, however, when the linear solenoid valve  67  fails, the emergency valve provides a new path for making hydraulic fluid flow without passing the linear solenoid valve  67  and is manually operated when the linear solenoid valve fails. 
     The solenoid valve for switching first speed and second speed  69  and the solenoid valve for switching second speed and third speed  70  have the on-off control of oil pressure for driving each spool of the spool valve for switching first speed and second speed  71  and the spool valve for switching second speed and third speed  72 , and the supply destination of hydraulic fluid of each spool valve  71 ,  72  is determined depending upon the position of the spool. When hydraulic fluid is supplied to any of the hydraulic multiple disc clutches  43 ,  47  and  48 , the clutch is connected, the idle gear connected to the clutch is fixed to the shaft and a shift is made according to the transmission gear ratio defined for the gear. At this time, hydraulic fluid is required to be discharged from the connected hydraulic multiple disc clutch before the shift. Discharged fluid is discharged via a hydraulic control valve  73  or  74  the oil pressure is controlled and inside the hydraulic control valves  73  and  74  a suitable fluid passage is formed. 
     As shown in  FIGS. 10 and 11 , on an opposite face of each layer of the valve body  60  to the adjacent layer, multiple fluid passages  75  in the hydraulic system shown in  FIG. 12  are formed. In a part wherein fluid passages on the surface and the rear surface are required to be connected in each layer, a fluid passage perpendicular to the opposite face is provided with the fluid passage piercing the inside of the layer. O-ring  76  is installed in a communicating part of the fluid passages of both layers on the opposite faces of the first and second layers so as to prevent fluid from leaking. Steel plates  77  and  78  are inserted between the opposite faces of the second layer and the third layer and the opposite faces of the third layer and the fourth layer. A fluid passage hole is provided in locations of this plate required to connect a groove type fluid passage provided on the surface of each layer. 
     As shown in  FIG. 9 , an inlet  80  is provided for hydraulic fluid to the valve body  60 . An outlet  81  is provided for hydraulic fluid to flow towards the hydraulic multiple disc clutch for first speed. An outlet  82  is provided for hydraulic fluid to flow towards the hydraulic multiple disc clutch for the second speed. An output  83  is provided for hydraulic fluid to flow towards the hydraulic multiple disc clutch for the third speed. The inlet  80  of hydraulic fluid is also shown in  FIGS. 10 and 11 . 
     Openings on the side of the front crankcase cover  24  corresponding to the inlet  80  and the outlets  81 ,  82  and  83  of hydraulic fluid shown in  FIG. 9  are equivalent to a supply port  85  of hydraulic fluid to the valve body  60  provided to the valve body mounting face  62  shown in  FIG. 3 , an inlet  86  of hydraulic fluid towards the hydraulic multiple disc clutch for the first speed, an inlet  87  of hydraulic fluid towards the hydraulic multiple disc clutch for the second speed and an inlet  88  of hydraulic fluid towards the hydraulic multiple disc clutch for the third speed. When the valve body  60  is mounted on the valve body mounting face  62 , a gasket  89  shown in  FIG. 13  is inserted. A small-diameter hole  89   a  provided on the gasket is a mounting bolt inserting hole and a large-diameter hole  89   b  is a hydraulic fluid passage hole. 
     As shown in  FIG. 3 , an extended position  90  of the centerline of a pump shaft of an oil pump is provided. Note that the oil pump is not shown. The oil pump is provided between the front crankcase cover  24  and the front crankcase  25 . Oil fed from the oil pump is fed to the oil filter  31  via an oil passage  91  from inside the wall of the front crankcase cover  24 . After the oil filter filters out foreign matter from the oil, the oil is fed via an oil passage  92  and a part of the oil is fed to the valve body  60  from the hydraulic fluid supply port  85 . The other part of the oil is fed to locations requiring lubrication via an oil passage  93 . An oil passage  94  is perpendicular to the oil passage  93  and extends in a direction of the front crankcase  25 . 
     The oil passages provided on the front crankcase cover  24  are all made from the outside face of the front crankcase cover  24 , the linear short oil passages mutually communicate inside and form a long bent oil passage. The open ends made during manufacture are directed outside the front crankcase cover of the oil passages and are blocked by a blocking bolt. As illustrated in  FIG. 3  blocking bolts  92   a  and  93   b  are provided. A similar oil passage is also formed in the front and rear crankcases and the rear crankcase cover and is utilized as a supply path for lubricating oil. 
     As shown in  FIG. 3 , an extended position  8   a  of the centerline of the main shaft  8  of the transmission is provided. Note that the transmission is not shown. Hydraulic fluid fed from the valve body  60  to the inlet  86  of hydraulic fluid towards the hydraulic multiple disc clutch for the first speed is fed from the rear face of the front crankcase cover  24  to the central hole  8   b  of the main shaft via a pipe for supplying hydraulic fluid  95  (shown in  FIGS. 5 and 6 ) and is supplied to the hydraulic multiple disc clutch for the first speed  43 . 
     As shown in  FIG. 3 , an extended position  9   c  of the centerline of the counter shaft  9  is provided. A fluid passage connecting part  96  is provided in this part of the front crankcase cover  24  and fluid passages  97  and  98  are formed from the inlet  87  of hydraulic fluid towards the hydraulic multiple disc clutch for the second speed and the inlet  88  of hydraulic fluid towards the hydraulic multiple disc clutch for the third speed to the fluid passage connecting part  96 . Hydraulic fluid fed from the valve body  60  to the inlet  87  or the inlet  88  of hydraulic fluid is supplied to the hydraulic multiple disc clutch for second speed  47  or the hydraulic multiple disc clutch for the third speed  48  via either an inner or outer passage of a double pipe  99  (shown in  FIG. 6 ) for supplying hydraulic fluid supplied from the fluid passage connecting part  96  to the central hole  9   d  of the counter shaft  9 . 
       FIG. 14  is an enlarged sectional view showing the vicinity of the fluid passage connecting part  96 , the double tube for supplying hydraulic fluid  99  and the counter shaft  9 . The fluid passage connecting part  96  with a front opening  100   d  is provided on the front crankcase cover  24 . In the fluid passage connecting part  96 , the fluid passages  97  and  98  are bored in a thick part formed in the front crankcase cover  24  downwardly as view in  FIG. 14 . A fluid reservoir  100 , like a container, is bored from the front. A small hole  101  is formed at the bottom of the fluid reservoir  100 . An outer tube  99   a  of the double tube for supplying hydraulic fluid  99  is inserted into the small hole  101  via an o-ring. Further, a partitioning member  102  is installed in each intermediate part of the openings of the fluid passages  97  and  98  in the fluid reservoir  100  like a container via an o-ring. An inner tube  99   b  of the double tube for supplying hydraulic fluid  99  is inserted into a small hole  103  made in the center of the partitioning member  102  via an o-ring. A lid  104 , for preventing fluid from leaking, is fixed to a front the front opening  100   d  and front wall  100   w  of the fluid passage conneting part  96  via an o-ring by a screw. In addition, openings  100   e,    100   f  at the lower ends of the fluid passages  97  and  98  of the fluid passage connecting part  96  are blocked by blocking bolts  97   a  and  98   a . A first fitting part  99   a   1  is provided between the front crankcase cover  24  and the outer tube  99   a  and a second fitting part  99   a   2  is provided between the partitioning member  102  and the inner tube  99   b . The fitting parts prevent the outer tube  99   a  and the inner tube  99   b  from rotating. The revolution of the partitioning member  102  itself is prevented by the friction of the o-ring. 
     The fluid reservoir  100  is partitioned into a first small fluid reservoir  100   a  on the side of the bottom and a second small fluid reservoir  100   b  on the side of the lid  104  by the partitioning member  102 . The first small fluid reservoir  100   a  is connected to a fluid passage between the outer tube  99   a  and the inner tube  99   b . The second small fluid reservoir  100   b  is connected to a fluid passage in the inner tube  99   b.    
     The first-speed driven gear  44 , the second-speed driven gear  45  and the third-speed driven gear  46  are provided on the front counter shaft  9   a  as described above. The second-speed driven gear  45  and the third-speed driven gear  46  are idle gears supported by the front counter shaft  9   a  via needle bearings  105  and  106 . The hydraulic multiple disc clutch for the second speed  47  and the hydraulic multiple disc clutch for the third speed  48  are inserted between the driven gears  45  and  46  and the counter shaft  9 . 
     The hydraulic multiple disc clutch for the second speed  47  is composed of a clutch outer  107  like a container fixed to the counter shaft  9 , a circular stopper  108  fixed to an open end of the clutch outer  107 , an outer clutch plate  109  held by the inside face of the clutch outer via a spline so that the outside clutch plate can be axially displaced A pressure plate  110  is provided adjacent to the bottom wall  107   a  of the clutch outer  107  and is fitted like a piston. A coil spring  112  is provided between a fitting part  111  provided on the clutch outer  107  and the pressure plate  110  for pressing the pressure plate I  10  towards the bottom wall  107   a  of the clutch outer  107 . A clutch inner  113  is integrated with the second-speed driven gear  45 . An inner clutch plate  114  is held by the outside face of the clutch inner  113  via a spline so that the inner clutch plate can be axially displaced and alternated with the outer clutch plate  109 . A hydraulic fluid supply hole  115  IS provided for connecting the counter shaft  9  and the clutch outer  107  of the hydraulic multiple disc clutch for the second speed  47 . A lubricating oil supply hole  116  is provided for the needle bearing  105  of the second-speed driven gear  45 . 
     When hydraulic fluid is supplied from the hydraulic fluid supply hole  115 , it enters between the bottom wall  107   a  of the clutch outer  107  and the pressure plate  110 . The pressure plate  110  is moved against the pressure of the coil spring  112  by oil pressure. The inner and outer clutch plates are axially pressed and the outer clutch plate  109  restrains the movement of the inner clutch plate  114 . Thus, the clutch inner  113  is integrated with the clutch outer  107  and the second-speed driven gear  45  is fixed to the counter shaft  9 . 
     The third-speed driven gear  46  and the hydraulic multiple disc clutch for the third speed  48  are also similarly configured. When hydraulic fluid is supplied to a hydraulic fluid supply hole  117  provided in the counter shaft  9 , the third-speed driven gear  46  is fixed to the counter shaft  9 . A lubricating oil supply hole  118  is provided towards the needle bearing  106  of the third-speed driven gear  46  and is also bored in the counter shaft  9 . 
     The hydraulic fluid supply holes  115  and  117  and the lubricating oil supply holes  116  and  118  are all bored in the front counter shaft  9   a  and are in communication with the central hole  9   d  provided on the centerline of the front counter shaft  9   a . The central hole  9   d  includes inside diameters that become smaller by degrees and is partitioned into a front central hole  120  and a rear central hole  121  by a steel ball  119  press-fitted into the narrowest part. The rear central hole  121  communicates with a central hole of a rear counter shaft  9   b . The hydraulic fluid supply holes  115  and  117  and the lubricating oil supply hole  116  are in communication with the front central hole  120 . The lubricating oil supply hole  118  are in communication with the rear central hole  121 . 
     The rear end of the double tube  99  for supplying hydraulic fluid the front end of which is connected to the fluid passage connecting part  96  of the front crankcase cover  24  is inserted into the front central hole  120  of the front counter shaft  9   a . The rear end of the outer tube  99   a  is supported via a bushing  122  provided between the lubricating oil supply hole  116 , the hydraulic fluid supply hole  115  and an opening in the central hole. An oil seal  125  is inserted between the front crankcase  25  and the outer tube  99   a . The rear end of the inner tube  99   b  is supported via a bushing  123  provided between the hydraulic fluid supply hole  115 , the hydraulic fluid supply hole  117  and an opening in the central hole. As the outer tube  99   a  and the inner tube  99   b  are not rotated though the counter shaft  9  is rotated, each outside face of the tubes is slid on each inside face of the bushings  122  and  123  supported by the inside face of the counter shaft  9 . 
     The outer tube  99   a  and the inner tube  99   b  are installed from the front of the front crankcase cover  24  after the front crankcase cover  24  is attached to the transmission. The revolution of the outer tube  99   a  and the inner tube  99   b  is prevented by a fitting part, however, work for attaching/detaching by axial movement can be executed in a state in which the lid  104  of the fluid passage connecting part  96  is detached. 
     Hydraulic fluid supplied to the hydraulic multiple disc clutch for the second speed  47  is fed from the outlet  82  of hydraulic fluid of the valve body  60  shown in  FIG. 9  towards the hydraulic multiple disc clutch for the second speed and is injected from the hydraulic fluid supply hole  115  via the fluid passage  97  shown in  FIG. 3 , the first small fluid reservoir  100   a  of the fluid passage connecting part  96  shown in  FIG. 14  and a fluid passage between the outer tube  99   a  and the inner tube  99   b . Hydraulic fluid supplied to the hydraulic multiple disc clutch for the third speed  48  is fed from the outlet  83  of the hydraulic fluid of the valve body  60  shown in  FIG. 9  towards the hydraulic multiple disc clutch for the third speed and is injected from the hydraulic fluid supply hole  117  via the fluid passage  98  shown in  FIG. 3 , the second small fluid reservoir  100   b  of the fluid passage connecting part  96  shown in  FIG. 14  and a fluid passage in the inner tube  99   b . Fluid is discharged via a path reverse to the parts. 
     Lubricating oil supplied to the needle bearing  105  of the second-speed driven gear  45  enters the front central hole  120  of the counter shaft  9  via the oil passages  93  and  94  shown in  FIG. 3  and an oil passage  124  bored in the front crankcase  25 , shown in  FIG. 14 , and is injected from the lubricating oil supply hole  116 . Lubricating oil supplied to the needle bearing  106  of the third-speed driven gear  46  is injected from the lubricating oil supply hole  118  via an oil passage not shown connected to the oil passages  93  and  94  shown in  FIG. 3  of the rear crankcase cover  27  and the rear counter shaft  9   b.    
     As described in detail above, in this embodiment, even if a plurality of pieces of hydraulic equipment are provided on the revolving shaft, fluid that is different in pressure can be supplied from one end of the revolving shaft. Therefore, as the hydraulic fluid supply hole and the lubricating oil supply hole are respectively provided on the revolving shaft both have only to be bored so that they are perpendicular to the centerline of the revolving shaft. The conventional type working of a diagonal hole is not required to be applied to the revolving shaft. Thus, working time and the cost can be reduced. Even if the hydraulic fluid supply passage on the side of the front crankcase cover and the revolving shaft are spaced apart, hydraulic fluid or other fluids can be supplied from the side of the front crankcase cover towards the plurality of pieces of hydraulic equipment via the double tube for supplying hydraulic fluid. 
     Also, as the double tube for supplying hydraulic fluid can be attached after the front crankcase cover is attached or the front crankcase cover can be detached after the double tube for supplying hydraulic fluid is detached, the attachment/detachment of the front crankcase cover is facilitated and serviceability can be enhanced. As the double tube for supplying hydraulic fluid can be detached, a large location for storing the front crankcase cover is not required. 
     The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.