Patent Publication Number: US-2022213933-A1

Title: Coupling device and rotational phase adjustment method for coupling device

Description:
TECHNICAL FIELD 
     The present disclosure relates to a coupling device for transmitting a rotational force between a pair of rotational shafts and a rotational phase adjustment method for the coupling device. 
     BACKGROUND 
     A coupling device for transmitting a rotational force between a pair of rotational shafts includes a flexible coupling configured to allow misalignment (eccentricity, declination, and displacement of a distance between axial ends) between axial centers of the pair of shafts (Patent Document 1). 
     Patent Document 1 discloses the flexible coupling that includes a driving-side coupling connected to a driving shaft, a driven-side coupling connected to a driven shaft, and an intermediate member disposed between the driving shaft and the driven shaft to transmit the rotational force, and absorbing the misalignment between the axial centers of the driving shaft and the driven shaft. In addition, Patent Document 1 discloses that the above-described intermediate member includes a metal plate spring having flexibility and restorability. 
     The above-described flexible coupling may connect a driving shaft of a diesel engine and a driven shaft of a mechanical fuel injection pump. The mechanical fuel injection pump is a device which is operated by a driving force transmitted from the driving shaft, pressurizes fuel used for the diesel engine, and pumps, to the diesel engine, the fuel pressurized to have a high pressure corresponding to an injection pressure. The fuel pumped to the diesel engine is injected into a combustion chamber. In the mechanical fuel injection pump, an injection timing of the fuel is decided in accordance with a rotational phase of the driven shaft. Thus, when the driving shaft and the driven shaft are connected, a relative rotational phase of the driven shaft to the driving shaft is adjusted. Further, the injection timing may be changed in accordance with a usage of the diesel engine, that is, the relative rotational phase of the driven shaft to the driving shaft may be readjusted. 
     CITATION LIST 
     Patent Literature 
     
         
         Patent Document 1: JP2002-372068A 
       
    
     SUMMARY 
     Technical Problem 
     As a means for easily performing an adjustment operation of the relative rotational phase of the driven shaft to the driving shaft, it is considered that a fastening bolt hole (circular hole) formed in the circumferential direction of an axis of the driving-side coupling is transformed into a long hole widened in the circumferential direction by a necessary phase change amount, and a rotational phase of the driving-side coupling is shifted with respect to a rotational phase of the driven-side coupling or the metal plate spring in order to obtain a desired injection timing. However, if the fastening bolt hole is transformed into the long hole, the following problems arise. 
     The driving-side coupling is fastened to the metal plate spring (intermediate member) via a fastening bolt or nut, and a seating surface of the fastening bolt or nut is in close contact with an opening end edge of the fastening bolt hole directly or via a washer. The metal plate spring is connected not only to the driving-side coupling but also to the driven-side coupling, and is thus flexed in order to absorb misalignment between the axial centers of the driving shaft and the driven shaft. The fastening bolt for fastening the metal plate spring to the driving-side coupling receives, from the metal plate spring, a restoring force of restoring the metal plate spring to an original shape. The above-described restoring force may also act in an extension direction of the long hole. 
     If the fastening bolt hole is transformed into the long hole, the driving-side coupling has a non-uniform distribution of a contact area with the bolt or the like around the axis of the bolt inserted through the fastening bolt hole, and a fastening force is also non-uniformly transmitted. That is, the above-described fastening force does not greatly act in the extension direction of the long hole. Thus, when the fastening bolt is applied with a force from a direction along the extension direction of the long hole from the metal plate spring, the driving-side coupling having the long hole may cause slippage with respect to the fastening bolt. If the driving-side coupling slips, the coupling device may be broken. 
     In view of the above issues, an object of at least one embodiment of the present invention is to provide the coupling device capable of easily adjusting the relative rotational phase of the pair of shafts and preventing occurrence of slippage in the coupling device. 
     Solution to Problem 
     (1) A coupling device according to at least one embodiment of the present invention is a coupling device configured to transmit a rotational force between a first shaft and a second shaft, the device including a first coupling member configured to relatively non-rotatably be mounted on the above-described first shaft, a second coupling member configured to relatively non-rotatably be mounted on the above-described second shaft, and an intermediate member disposed between the above-described first coupling member and the above-described second coupling member in an extension direction of an axis of the above-described coupling device, and configured to absorb misalignment between the above-described first shaft and the above-described second shaft. The above-described second coupling member includes a base member configured to be fixed to the above-described intermediate member by a first fastening device, and a shaft mounting member configured to relatively non-rotatably be mounted on the above-described second shaft, the shaft mounting member having a long hole extending along a circumferential direction of the above-described axis and being configured to detachably be fixed to the above-described base member by a second fastening device inserted through the above-described long hole. 
     With the above configuration (1), the second coupling member includes the base member configured to be fixed to the intermediate member by the first fastening device, and the shaft mounting member which has the long hole extending along the circumferential direction of the axis and is configured to detachably be fixed to the base member by the second fastening device inserted through the long hole. That is, the second coupling member can be divided into two members, namely, the base member and the shaft mounting member, and the intermediate member is fixed to not the shaft mounting member having the long hole, but the base member. Thus, even if the intermediate member is deformed when absorbing the above-described misalignment, and a restoring force of restoring to an original shape is generated, the above-described restoring force acts on the base member via the first fastening device. That is, it is possible to prevent the above-described restoring force from acting on the shaft mounting member having the long hole, making it possible to prevent slippage of the shaft mounting member. 
     Further, with the above configuration (1), fixing of the shaft mounting member to the base member by the second fastening device is released, the shaft mounting member is relatively rotated to the base member such that a position where the second fastening device is inserted through the long hole is shifted, and then the shaft mounting member is fixed to the base member by the second fastening device, allowing the coupling device to easily adjust the relative rotational phase of the shaft mounting member to the base member. The base member is fixed to, via the intermediate member, the first coupling member relatively non-rotatably mounted on the first shaft. Further, the shaft mounting member is relatively non-rotatably mounted on the second shaft. Thus, adjusting the relative rotational phase of the shaft mounting member to the base member, it is possible to adjust the relative rotational phase of the second shaft to the first shaft. 
     (2) In some embodiments, in the coupling device according to the above configuration (1), one member of the above-described base member and the above-described shaft mounting member includes a protruding shaft portion which protrudes from an end surface facing another end surface to be coaxial with the above-described axis in the extension direction of the above-described axis and is formed to have a circular cross-section orthogonal to the above-described axis, and the other member of the above-described base member and the above-described shaft mounting member includes a fitting hole portion which is disposed in the above-described another end surface and is configured to be fitted with the above-described protruding shaft portion, the other member having an inner circumferential surface formed to have a circular cross-section orthogonal to the above-described axis. 
     With the above configuration (2), the axial center of the shaft mounting member and the axial center of the base member are aligned by fitting the above-described protruding shaft portion into the above-described fitting hole portion, allowing the shaft mounting member to prevent eccentricity of the axial center of the shaft mounting member with respect to the axial center of the base member. With the configuration of preventing eccentricity of the axial center of the shaft mounting member with respect to the axial center of the base member, a worker can perform work to adjust the relative rotational phase of the shaft mounting member to the base member more easily. 
     (3) In some embodiments, in the coupling device according to the above configuration (2), the above-described end surface facing the above-described another end surface of the above-described one member includes a shaft portion-side end surface located on an outer circumferential side of the above-described protruding shaft portion and extending along a direction intersecting with the above-described axis, the above-described another end surface of the above-described other member includes a hole portion-side end surface located on an outer circumferential side of the above-described fitting hole portion and extending along the direction intersecting with the above-described axis, and the above-described one member and the above-described other member are configured such that the above-described shaft portion-side end surface and the above-described hole portion-side end surface are disposed in contact with each other. 
     With the above configuration (3), since the shaft portion-side end surface located on the outer circumferential side of the protruding shaft portion and the hole portion-side end surface located on the outer circumferential side of the fitting hole portion are disposed in contact with each other, the second coupling member (the base member and the mounting member) can increase the strength (rigidity) of the second coupling member. Further, with the above configuration (3), since the shaft portion-side end surface and the hole portion-side end surface are disposed in contact with each other, the base member and the mounting member can prevent declination of the axial center of the shaft mounting member with respect to the axial center of the base member. With the configuration of preventing declination of the axial center of the shaft mounting member with respect to the axial center of the base member, the worker can perform the work to adjust the relative rotational phase of the shaft mounting member to the base member more easily. 
     (4) In some embodiments, in the coupling device according to any one of the above configurations (1) to (3), the above-described intermediate member includes at least one plate spring member which extends along a direction intersecting with the above-described axis and is configured to be elastic flexible along the direction intersecting with the above-described axis. 
     With the above configuration (4), since the at least one plate spring member is configured to be elastic flexible along the direction intersecting with the axis, the coupling device can absorb misalignment between the axial centers of the first shaft and the second shaft by elastically flexing the plate spring member. 
     (5) In some embodiments, in the coupling device according to the above configuration (4), the above-described at least one plate spring member includes a first fastened portion configured to be fastened to the above-described first coupling member, and a second fastened portion configured to be fastened to the above-described base member. 
     With the above configuration (5), the plate spring member is fastened to the first coupling member in the first fastened portion, and is fastened to the base member in the second fastened portion. The coupling device including the above-described plate spring member is a so-called single disk type coupling. Such coupling device can have a decreased total length in the extension direction of the axis, and thus can be installed even in a narrow gap between the first shaft and the second shaft. 
     (6) In some embodiments, in the coupling device according to any one of the above configurations (1) to (5), the above-described first coupling member includes a first flange portion extending along a direction intersecting with the above-described axis, and the above-described first flange portion includes a first coupling-side fastened portion configured to be fastened to the above-described intermediate member by a third fastening device, and a first escape recess formed on an end surface on a side of the above-described intermediate member and configured to allow the above-described first fastening device to loosely be fitted into the first escape recess. 
     With the above configuration (6), the first coupling member is fastened to the intermediate member in the first coupling-side fastened portion of the first flange. Further, the first coupling member is configured to allow the first fastening device to loosely be fitted into the first escape recess formed on the end surface of the above-described first flange on the side of the intermediate member. Providing the first escape recess, it is possible to reduce an interval between the intermediate member and the first flange. Reducing the interval between the intermediate member and the first flange, it is possible to decrease the total length of the coupling device, and to improve responsiveness of the intermediate member, to which the rotational force is transmitted from the first coupling member, to the first coupling member. 
     (7) In some embodiments, in the coupling device according to the above configuration (6), the above-described base member includes a second flange portion extending along the direction intersecting with the above-described axis, and the above-described second flange portion includes a second coupling-side fastened portion configured to be fastened to the above-described intermediate member by the above-described first fastening device, and a second escape recess formed on the end surface on the side of the above-described intermediate member and configured to allow the above-described third fastening device to loosely be fitted into the second escape recess. 
     With the above configuration (7), the base member is fastened to the intermediate member in the second coupling-side fastened portion of the second flange. Further, the base member is configured to allow the third fastening device to loosely be fitted into the second escape recess formed on the end surface of the above-described second flange portion on the side of the intermediate member. Providing the second escape recess, it is possible to reduce an interval between the intermediate member and the second flange. Reducing the interval between the intermediate member and the second flange, it is possible to decrease the total length of the coupling device, and to improve responsiveness of the second coupling member, to which the rotational force is transmitted from the intermediate member, to the intermediate member. 
     (8) In some embodiments, in the coupling device according to any one of the above configurations (1) to (7), the above-described intermediate member is configured to be fixed to the above-described first coupling member and the above-described base member with a gap in the extension direction of the above-described axis. 
     With the above configuration (8), the intermediate member is fixed to the first coupling member and the base member with the gap in the extension direction of the axis. Thus, the intermediate member is not constrained by the first coupling member and the base member, it is possible to rapidly absorb misalignment between the axial centers of the first shaft and the second shaft caused when the rotational force is transmitted. 
     (9) In some embodiments, in the coupling device according to any one of the above configurations (1) to (8), one of the above-described first shaft and the above-described second shaft includes a driving shaft of a diesel engine, and the other of the above-described first shaft and the above-described second shaft includes a driven shaft of a fuel injection pump configured to pump liquid fuel to the above-described diesel engine. 
     With the above configuration (9), it is possible to easily perform work to adjust the rotational phase between the driving shaft of the diesel engine and the driven shaft of the fuel injection pump. 
     (10) A rotational phase adjustment method for a coupling device according to at least one embodiment of the present invention is a rotational phase adjustment method for a coupling device configured to transmit a rotational force between a first shaft and a second shaft, the above-described coupling device including a first coupling member configured to relatively non-rotatably be mounted on the above-described first shaft, a second coupling member configured to relatively non-rotatably be mounted on the above-described second shaft, and an intermediate member disposed between the above-described first coupling member and the above-described second coupling member in an extension direction of an axis of the above-described coupling device, and configured to allow misalignment between the above-described first shaft and the above-described second shaft, the above-described second coupling member including a base member configured to be fixed to the above-described intermediate member by a first fastening device, and a shaft mounting member configured to relatively non-rotatably be mounted on the above-described second shaft, the shaft mounting member having a long hole extending along a circumferential direction of the above-described axis and being configured to detachably be fixed to the above-described base member by a second fastening device inserted through the above-described long hole, the rotational phase adjustment method for the above-described coupling device, including a relative rotation step of relatively rotating the above-described shaft mounting member to the above-described base member, and a fixing step of fixing the above-described shaft mounting member to the above-described base member by the above-described second fastening device, after the above-described relative rotation step. 
     With the above method (10), the rotational phase adjustment method for the coupling device includes the relative rotation step of relatively rotating the shaft mounting member to the base member, and the fixing step of fixing the shaft mounting member to the base member by the second fastening device after the relative rotation step. The rotational phase adjustment method for the coupling device relatively rotates the shaft mounting member to the base member so as to shift the position where the second fastening device is inserted through the long hole in the relative rotation step, and then fixes the shaft mounting member to the base member by the second fastening device in the fixing step. Such rotational phase adjustment method for the coupling device can easily adjust the relative rotational phase of the shaft mounting member to the base member, and can easily adjust the relative rotational phase of the second shaft to the first shaft. 
     Further, with the above method (10), the intermediate member is fixed to not the shaft mounting member having the long hole, but the base member. Thus, even if the intermediate member is deformed when absorbing the above-described misalignment, and a restoring force of restoring to an original shape is generated, the above-described restoring force acts on the base member via the first fastening device. That is, it is possible to prevent the above-described restoring force from acting on the shaft mounting member having the long hole, making it possible to prevent slippage of the shaft mounting member. 
     Advantageous Effects 
     According to at least one embodiment of the present invention, provided is a coupling device capable of easily adjusting a relative rotational phase of a pair of shafts and preventing occurrence of slippage in the coupling device. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a schematic configuration view schematically showing the configuration of a diesel engine including a coupling device according to an embodiment of the present invention. 
         FIG. 2  is a schematic exploded perspective view of the coupling device according to an embodiment of the present invention. 
         FIG. 3  is a schematic view schematically showing a state where the coupling device is viewed from a side of a pump driving unit according to an embodiment of the present invention. 
         FIG. 4  is a cross-sectional view in a direction of arrow A shown in  FIG. 3 . 
         FIG. 5  is a cross-sectional view in a direction of arrow B shown in  FIG. 3 . 
         FIG. 6  is a partial cutout perspective cross-sectional view schematically showing the coupling device according to an embodiment of the present invention. 
         FIG. 7  is a schematic exploded perspective view of the coupling device according to another embodiment of the present invention. 
         FIG. 8  is a flowchart showing an example of a rotational phase adjustment method for the coupling device according to an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     Some embodiments of the present invention will be described below with reference to the accompanying drawings. It is intended, however, that unless particularly identified, dimensions, materials, shapes, relative positions and the like of components described or shown in the drawings as the embodiments shall be interpreted as illustrative only and not intended to limit the scope of the present invention. 
     For instance, an expression of relative or absolute arrangement such as “in a direction”, “along a direction”, “parallel”, “orthogonal”, “centered”, “concentric” and “coaxial” shall not be construed as indicating only the arrangement in a strict literal sense, but also includes a state where the arrangement is relatively displaced by a tolerance, or by an angle or a distance whereby it is possible to achieve the same function. 
     For instance, an expression of an equal state such as “same”, “equal”, and “uniform” shall not be construed as indicating only the state in which the feature is strictly equal, but also includes a state in which there is a tolerance or a difference that can still achieve the same function. 
     Further, for instance, an expression of a shape such as a rectangular shape or a tubular shape shall not be construed as only the geometrically strict shape, but also includes a shape with unevenness or chamfered corners within the range in which the same effect can be achieved. 
     On the other hand, the expressions “comprising”, “including” or “having” one constitutional element is not an exclusive expression that excludes the presence of other constitutional elements. 
     The same configurations are indicated by the same reference characters and may not be described again in detail. 
       FIG. 1  is a schematic configuration view schematically showing the configuration of a diesel engine including a coupling device according to an embodiment of the present invention. 
     As shown in  FIG. 1 , a coupling device  1  according to some embodiments is connected to a first shaft  11  and a second shaft  13 , and is configured to transmit a rotational force between the first shaft  11  and the second shaft  13 . 
     In the illustrated embodiment, as shown in  FIG. 1 , the coupling device  1  is mounted on a diesel engine  10 . The first shaft  11  includes a driven shaft  11 A, and the second shaft  13  includes a driving shaft  13 A. 
     As shown in  FIG. 1 , the diesel engine  10  includes a combustion chamber  103  which is defined by a cylinder  101  and a piston  102  disposed in the cylinder  101 , a fuel injection pump  12  including the driven shaft  11 A, a pump driving unit  14  including the driving shaft  13 A, and the above-described coupling device  1  which is connected to the driven shaft  11 A and the driving shaft  13 A disposed such that tip surfaces thereof are opposite to each other and is configured to transmit the rotational force between the driven shaft  11 A and the driving shaft  13 A. 
     As shown in  FIG. 1 , the coupling device  1  is connected at one end in an extension direction of an axis LA to the driven shaft  11 A, and connected at another end in the extension direction of the axis LA to the driving shaft  13 A. 
     In the illustrated embodiment, as shown in  FIG. 1 , each of an axis LB of the driven shaft  11 A and an axis LC of the driving shaft  13 A is disposed coaxially with the axis LA of the coupling device  1 . 
     The axis LB of the driven shaft  11 A and the axis LC of the driving shaft  13 A may be eccentric or declinate with respect to the axis LA as long as the driven shaft  11 A and the driving shaft  13 A fall within a range (allowable range) capable of allowing misalignment between axial centers by an intermediate member  6  to be described later, and with eccentricity or declination within the above-described allowable range, the axis LB and the axis LC are disposed coaxially with the axis LA. 
     The driving shaft  13 A is configured such that a driving force generated in the combustion chamber  103  is transmitted, and is configured to be rotatable about the axis LC by the driving force transmitted from the combustion chamber  103 . As shown in  FIG. 1 , the driven shaft  11 A is configured to be rotatable about the axis LB by the driving force (rotational force) transmitted from the driving shaft  13 A via the coupling device  1 . 
     In other words, as shown in  FIG. 1 , the fuel injection pump  12  is configured such that the driving force is transmitted by the pump driving unit  14  and the driven shaft  11 A is rotated by the transmitted driving force. 
     As shown in  FIG. 1 , the fuel injection pump  12  is configured to pump high-pressure liquid fuel to the diesel engine  10 . In the illustrated embodiment, as shown in  FIG. 1 , the fuel injection pump  12  is configured to mechanically be operated by the driving force (rotational force) transmitted from the pump driving unit  14 . 
     In the embodiment shown in  FIG. 1 , the fuel injection pump  12  (mechanical fuel injection pump) is configured to internally define at least one (in  FIG. 1 , six) pumping chamber  123  defined by a cylinder  121  and a plunger  122 , as shown in  FIG. 1 . The fuel injection pump  12  (mechanical fuel injection pump) is configured to pressurize liquid fuel, which is delivered into the pumping chamber  123  by the plunger  122  lifting/lowering in conjunction with a rotation of the driven shaft  11 A and is used for the diesel engine  10 , to a high pressure corresponding to an injection pressure, and to pump the liquid fuel pressurized in the pumping chamber  123  to the combustion chamber  103 . 
     By spontaneous combustion of the liquid fuel pumped from the fuel injection pump  12  to the combustion chamber  103  and injected into the combustion chamber  103 , the diesel engine  10  generates the above-described driving force of rotating the driving shaft  13 A. 
     If the fuel injection pump  12  is the above-described mechanical fuel injection pump, an injection timing of the liquid fuel to the combustion chamber  103  is decided in accordance with a rotational phase of the driven shaft  11 A. In a certain embodiment, the fuel injection pump  12  is adjusted such that a relative rotational phase of the driving shaft  13 A to the driven shaft  11 A has a predetermined angle so the liquid fuel is injected into the combustion chamber  103 , when the piston  102  is located at a predetermined position just before the compression top dead center. 
       FIG. 2  is a schematic exploded perspective view of the coupling device according to an embodiment of the present invention. 
     The following description will be given, assuming that the extension direction of the axis LA of the coupling device  1  is an X-axis direction, one side of the X-axis direction is an X1 side, and another side of the X-axis direction is an X2 side. Further, assume that a side where the fuel injection pump  12  is located is the above-described X1 side, and a side where the pump driving unit  14  is located is the above-described X2 side. 
     As shown in  FIG. 2 , the coupling device  1  according to some embodiments includes a driven-side coupling member  2 , the intermediate member  6 , and a driving-side coupling member  3 , in order from the X1 side. The driving-side coupling member  3  includes a base member  4  and a shaft mounting member  5 , in order from the X1 side. That is, the intermediate member  6  is disposed between the driven-side coupling member  2  and the base member  4  in the X-axis direction, and the base member  4  is disposed between the intermediate member  6  and the shaft mounting member  5  in the X-axis direction. 
     As shown in  FIG. 2 , each axis of the driven-side coupling member  2 , the intermediate member  6 , the base member  4 , and the shaft mounting member  5  is disposed coaxially with the axis LA of the coupling device  1 . Further, in a mounted state, the driven-side coupling member  2 , the intermediate member  6 , the base member  4 , and the shaft mounting member  5  adjacent to each other in the X-axis direction are fixed to each other by fastening devices  7 A to  7 C, respectively. 
       FIG. 3  is a schematic view schematically showing a state where the coupling device is viewed from a side of the pump driving unit according to an embodiment of the present invention.  FIG. 4  is a cross-sectional view in a direction of arrow A shown in  FIG. 3 .  FIG. 5  is a cross-sectional view in a direction of arrow B shown in  FIG. 3 . 
     As shown in  FIG. 4 , the driven-side coupling member  2  is configured to relatively non-rotatably be mounted on the driven shaft  11 A. 
     In the illustrated embodiment, as shown in  FIG. 4 , the driven-side coupling member  2  includes a flange portion  21  extending along a direction intersecting with (orthogonal to) the X-axis direction, and a protruding portion  22  protruding from the middle of the flange portion  21  to the X2 side along the X-axis direction. In the center of the driven-side coupling member  2 , a shaft insertion hole  23  penetrating along the axis LA is formed. 
     As shown in  FIG. 4 , the shaft insertion hole  23  has a tapered surface  231  with an inner diameter gradually decreasing from the X1 side toward the X2 side. The tapered surface  231  is disposed over an entire length in the X-axis direction. 
     As shown in  FIG. 4 , a distal end portion  111  of the driven shaft  11 A has a tapered surface  112  with an outer diameter gradually decreasing from the X1 side (proximal end side) toward the X2 side (distal end side), and is configured to be fittable into the shaft insertion hole  23  from the X1 side. 
     In the illustrated embodiment, as shown in  FIG. 4 , the driven shaft  11 A has a bolt hole  115  (screwed portion) formed to be recessed from a tip surface  114  of the distal end portion  111  along the X-axis direction. The driven shaft  11 A is fixed to the driven-side coupling member  2  by screwing a shaft portion  161  (screw portion) of a fastening member  16  (bolt) to the bolt hole  115  from the X2 side, with the distal end portion  111  being inserted into the shaft insertion hole  23 . A head portion  162  of the fastening member  16  has an external dimension larger than an X2-side opening of the shaft insertion hole  23 , making it impossible to pull the distal end portion  111  of the driven shaft  11 A out of the shaft insertion hole  23 . In this case, the driven-side coupling member  2  is relatively non-rotatably mounted on the driven shaft  11 A. 
     In the illustrated embodiment, the fastening member  16  includes the bolt. However, in some other embodiments, the fastening member  16  may include a nut. That is, in some other embodiments, the driven shaft  11 A does not have the bolt hole  115 , and the driven shaft  11 A may be fixed to the driven-side coupling member  2  by screwing a female thread portion (screwed portion) of the fastening member  16  (nut) to a male thread portion (screw portion) formed on an outer peripheral surface of the protruding portion protruding to the X2 side from the shaft insertion hole  23 . The fastening member  16  (nut) is configured to have the external dimension larger than the X2-side opening of the shaft insertion hole  23 . In this case as well, the driven-side coupling member  2  is relatively non-rotatably mounted on the driven shaft  11 A. Likewise, the fastening member  16  shown in  FIG. 5  may be the bolt or the nut. 
     In the illustrated embodiment, as shown in  FIG. 4 , keyways  24 ,  113  are, respectively, formed in the shaft insertion hole  23  of the driven-side coupling member  2  and the distal end portion  111  of the driven shaft  11 A. The driven-side coupling member  2  is relatively non-rotatably connected to the driven shaft  11 A by key fastening via a key  15  fitted into both of the keyway  24  and the keyway  113 . 
     As shown in  FIG. 5 , the shaft mounting member  5  (driving-side coupling member  3 ) is configured to relatively non-rotatably be mounted on the driving shaft  13 A. 
     In the illustrated embodiment, as shown in  FIG. 5 , the shaft mounting member  5  includes a flange portion  51  extending along the direction intersecting with (orthogonal to) the X-axis direction, and a hub  52  protruding from the middle of the flange portion  51  to the X2 side along the X-axis direction. In the center of the shaft mounting member  5 , a shaft insertion hole  53  penetrating along the axis LA is formed. As shown in  FIG. 5 , a distal end portion  131  of the driving shaft  13 A is configured to be fittable into the shaft insertion hole  53  from the X2 side. 
     Further, in the illustrated embodiment, as shown in  FIG. 5 , keyways  54 ,  132  are, respectively, formed in the shaft insertion hole  53  of the shaft mounting member  5  and the distal end portion  131  of the driving shaft  13 A. The shaft mounting member  5  is relatively non-rotatably connected to the driving shaft  13 A by key fastening via a key  17  fitted into both of the keyway  54  and the keyway  132 . 
     As shown in  FIG. 3 , the distal end portion  131  of the driving shaft  13 A is fixed to be incapable of being pulled out of the shaft insertion hole  53  of the shaft mounting member  5 , by decreasing an internal dimension of the shaft insertion hole  53  with a fastening force of a bolt  18 . 
     In the illustrated embodiment, in the shaft mounting member  5 , a slot  55  extending along the radiation direction and dividing the shaft mounting member  5  in the circumferential direction is formed in the X-axis direction view as shown in  FIG. 3 . One section (right side in  FIG. 3 ) divided by the slot  55  of the shaft mounting member  5  will be referred to as a first divided section  56 , and another section (left side in  FIG. 3 ) will be referred to as a second divided section  57 . 
     As shown in  FIG. 3 , in the first divided section  56  of the hub  52 , a through hole  561 , which extends along a direction intersecting with (orthogonal to) an extension direction of the slot  55  and through which a shaft portion  181  of the bolt  18  can loosely be inserted, is formed in the X-axis direction view. Further, in the second divided section  57  of the hub  52 , a bolt hole  571  is formed which extends along a coaxial direction with the through hole  561  and to which the shaft portion  181  of the bolt  18  can be screwed. 
     As shown in  FIG. 3 , the shaft portion  181  of the bolt  18  is inserted through the through hole  561  and is screwed to the bolt hole  571 , as well as a head portion  182  of the bolt  18  is locked to a side surface  521  having an opening edge of the through hole  561  of the hub  52 , making it possible to narrow a gap formed between an end surface  562  of the first divided section  56  and an end surface  572  of the second divided section  57 . At this time, since the internal dimension of the shaft insertion hole  53  is also narrowed, the distal end portion  131  of the driving shaft  13 A is tightened and fixed to the shaft insertion hole  53 . 
     As shown in  FIG. 3 , the shaft mounting member  5  has at least one long hole  512  extending along the circumferential direction of the axis LA in a stepped surface  511  located on the X2 side of the flange portion  51 . The long hole  512  is disposed on the outer circumferential side of the shaft insertion hole  53 . The shaft mounting member  5  is configured to detachably be fixed to the base member  4  by the at least one fastening device  7 A inserted through the at least one long hole  512 . 
     In the illustrated embodiment, as shown in  FIG. 3 , the two long holes  512  are disposed symmetrically about the axis LA. 
     In the illustrated embodiment, as shown in  FIG. 5 , the fastening device  7 A includes a bolt  70 A, and a bolt hole  44  of the base member  4 . The bolt  70 A includes a shaft portion  71 A with a thread portion being formed in at least a part of the outer peripheral surface, and a head portion  72 A formed in a base end portion of the shaft portion  71 A to have a larger diameter than the shaft portion  71 A. 
     The shaft portion  71 A the bolt  70 A is inserted through the long hole  512  from the X2 side, and a tip of the shaft portion  71 A protruding from the long hole  512  to the X1 side is screwed to the bolt hole  44 , thereby fixing the shaft mounting member  5  to the base member  4 . By loosening fastening with the bolt  70 A, the shaft mounting member  5  and the base member  4  are unfixed. If the shaft mounting member  5  is not fixed to the base member  4 , it is possible to shift the shaft mounting member  5  with respect to the base member  4  in the circumferential direction until the shaft portion  71 A contacts an edge portion of the long hole  512  in the circumferential direction. That is, by loosening fastening with the bolt  70 A, it is possible to adjust the relative rotational phase of the shaft mounting member  5  to the base member  4 . 
     A washer  19  may be disposed between the head portion  72 A of the bolt  70 A and the stepped surface  511  of the shaft mounting member  5 . 
     In the illustrated embodiment, as shown in  FIG. 5 , the base member  4  is formed into a plate annular shape that includes a flange portion  40  extending along the direction intersecting with (orthogonal to) the axis LA. 
     The intermediate member  6  is configured to absorb misalignment between the first shaft  11  and the second shaft  13 . In the illustrated embodiment, the intermediate member  6  includes at least one elastic member  60  having flexibility and restorability. In the embodiments shown in  FIGS. 2 and 4 to 6 , the intermediate member  6  includes, as the elastic member  60 , a plate spring member  60 A extending along the direction intersecting with (orthogonal to) the X-axis direction. 
     As shown in  FIG. 2 , the plate spring member  60 A is formed into a plate annular shape with a through hole  65  at a center, and includes at least one driven-side bolt insertion hole  61  and at least one driving-side bolt through hole  62  on the outer circumferential side of the through hole  65 . 
     In the illustrated embodiment, as shown in  FIG. 2 , the plurality of driven-side bolt insertion holes  61  and the plurality of driving-side bolt insertion holes  62  are uniformly disposed on the same circumference in the circumferential direction. 
       FIG. 6  is a partial cutout perspective cross-sectional view schematically showing the coupling device according to an embodiment of the present invention. In  FIG. 6 , the shaft mounting member  5  is not depicted. 
     As shown in  FIG. 6 , the driven-side coupling member  2  is configured to be fixed to the plate spring member  60 A (intermediate member  6 ) by the at least one fastening device  7 B. As shown in  FIG. 6 , the base member  4  is configured to be fixed to the plate spring member  60 A (intermediate member  6 ) by the at least one fastening device  7 C. 
     In the illustrated embodiment, as shown in  FIG. 6 , the fastening device  7 B includes a bolt  70 B including a shaft portion  71 B and a head portion  72 B as with the bolt  70 A, and a bolt hole  211  of the driven-side coupling member  2 . The shaft portion  71 B of the bolt  70 B is inserted through a driven-side bolt insertion hole  61  of the plate spring member  60 A and is screwed to the bolt hole  211  of the driven-side coupling member  2 , thereby fixing the driven-side coupling member  2  to the plate spring member  60 A. 
     In the illustrated embodiment, as shown in  FIG. 6 , the fastening device  7 C includes a bolt  70 C including a shaft portion  71 C and a head portion  72 C as with the bolt  70 A, and a bolt hole  41  of the base member  4 . The shaft portion  71 C of the bolt  70 C is inserted through a driving-side bolt insertion hole  62  of the plate spring member  60 A and is screwed to the bolt hole  41  of the base member  4 , thereby fixing the base member  4  to the plate spring member  60 A. 
     The plate spring member  60 A has lower rigidity than the driven-side coupling member  2  and the base member  4 , and is flexed or twisted in order to absorb misalignment between the first shaft  11  and the second shaft  13 . 
     For example, as shown in  FIG. 2 , the coupling device  1  according to some embodiments includes the above-described driven-side coupling member  2  (first coupling member), the above-described intermediate member  6 , and the above-described driving-side coupling member  3  (second coupling member). The above-described driving-side coupling member  3  includes the above-described base member  4  and the above-described shaft mounting member  5 . 
     With the above configuration, the driving-side coupling member  3  (second coupling member) includes the base member  4  configured to be fixed to the intermediate member  6  by the fastening device  7 C (first fastening device), and the shaft mounting member  5  which has the long hole  512  extending along the circumferential direction of the axis LA and is configured to detachably be fixed to the base member  4  by the fastening device  7 A (second fastening device) inserted through the long hole  512 . That is, the driving-side coupling member  3  can be divided into two members, namely, the base member  4  and the shaft mounting member  5 , and the intermediate member  6  is fixed to not the shaft mounting member  5  having the long hole  512 , but the base member  4 . Thus, even if the intermediate member  6  is deformed when absorbing the above-described misalignment, and a restoring force of restoring to an original shape is generated, the above-described restoring force acts on the base member  4  via the fastening device  7 C. That is, it is possible to prevent the above-described restoring force from acting on the shaft mounting member  5  having the long hole  512 , making it possible to prevent slippage of the shaft mounting member  5 . 
     Further, with the above configuration, fixing of the shaft mounting member  5  to the base member  4  by is released, the shaft mounting member  5  is relatively rotated to the base member  4  such that a position where the shaft portion  71 A of the bolt  70 A (fastening device  7 A) is inserted through the long hole  512  is shifted, and then the shaft mounting member  5  is fixed to the base member  4  by the fastening device  7 A, allowing the coupling device  1  to easily adjust the relative rotational phase of the shaft mounting member  5  to the base member  4 . The base member  4  is fixed to, via the intermediate member  6 , the driven-side coupling member  2  relatively non-rotatably mounted on the driven shaft  11 A. Further, the shaft mounting member  5  is relatively non-rotatably mounted on the driving shaft  13 A. Thus, adjusting the relative rotational phase of the shaft mounting member  5  to the base member  4 , it is possible to adjust the relative rotational phase of the driving shaft  13 A to the driven shaft  11 A. 
     In some embodiments described above, the driven-side coupling member  2  is the first coupling member, and the driving-side coupling member  3  is the second coupling member. However, the driving-side coupling member  3  may be the first coupling member, and the driven-side coupling member  2  may be the second coupling member. Further, in some embodiments described above, the driving-side coupling member  3  includes the above-described base member  4  and the above-described shaft mounting member  5 . However, the driven-side coupling member  2  may include the above-described base member  4  and the above-described shaft mounting member  5 . 
     In some embodiments, as shown in  FIG. 5 , the above-described shaft mounting member  5  includes a protruding shaft portion  58  which protrudes coaxially with the axis LA from an end surface  513  opposite to an end surface  45  located on the X2 side of the base member  4  in the X-axis direction. The above-described base member  4  includes a fitting hole portion  46  disposed coaxially with the axis LA in the above-described end surface  45  and configured to be fitted with the protruding shaft portion  58 . Each of an outer circumferential surface  581  of the protruding shaft portion  58  and an inner circumferential surface  461  of the fitting hole portion  46  is formed such that a cross-sectional shape (side cross-sectional shape) orthogonal to the axis LA has a circular shape. 
     In the illustrated embodiment, as shown in  FIG. 5 , the protruding shaft portion  58  is inserted into the fitting hole portion  46  and is configured to slidingly be rotatable in a state where the outer circumferential surface  581  is in contact with the inner circumferential surface  461  of the fitting hole portion  46 . 
     With the above configuration, the axial center of the shaft mounting member  5  and the axial center of the base member  4  are aligned by fitting the protruding shaft portion  58  into the fitting hole portion  46 , allowing the shaft mounting member  5  to prevent eccentricity of the axial center of the shaft mounting member  5  with respect to the axial center of the base member  4 . With the configuration of preventing eccentricity of the axial center of the shaft mounting member  5  with respect to the axial center of the base member  4 , a worker can perform work to adjust the relative rotational phase of the shaft mounting member  5  to the base member  4  more easily. 
     In some embodiments described above, the above-described shaft mounting member  5  includes the above-described protruding shaft portion  58 , and the above-described base member  4  includes the above-described fitting hole portion  46 . However, tin some other embodiments, the above-described shaft mounting member  5  may include the above-described fitting hole portion  46 , and the above-described base member  4  may include the above-described protruding shaft portion  58 . 
     In some embodiments, as shown in  FIG. 5 , the end surface  513  of the shaft mounting member  5  described above includes a shaft portion-side end surface  513 A located on the outer circumferential side of the protruding shaft portion  58  and extending along the direction intersecting with the axis LA. The end surface  45  of the base member  4  described above includes a hole portion-side end surface  45 A located on the outer circumferential side of the fitting hole portion  46  and extending along the direction intersecting with the axis LA. The base member  4  and the shaft mounting member  5  are configured such that the hole portion-side end surface  45 A and the shaft portion-side end surface  513 A are disposed in contact with each other. 
     In the illustrated embodiment, as shown in  FIG. 5 , the shaft portion-side end surface  513 A includes a portion in the vicinity of the inner circumferential edge adjacent to a proximal end-side edge portion on the outer circumferential surface  581  of the protruding shaft portion  58 . The hole portion-side end surface  45 A includes a portion in the vicinity of the inner circumferential edge adjacent to an opening edge of the fitting hole portion  46 . 
     With the above configuration, since the shaft portion-side end surface  513 A located on the outer circumferential side of the protruding shaft portion  58  and the hole portion-side end surface  45 A located on the outer circumferential side of the fitting hole portion  46  are disposed in contact with each other, the driving-side coupling member  3  (base member  4  and the shaft mounting member  5 ) can increase the strength (rigidity) of the driving-side coupling member  3 . Further, with the above configuration, since the shaft portion-side end surface  513 A and the hole portion-side end surface  45 A are disposed in contact with each other, the base member  4  and the shaft mounting member  5  can prevent declination of the axial center of the shaft mounting member  5  with respect to the axial center of the base member  4 . With the configuration of preventing declination of the axial center of the shaft mounting member  5  with respect to the axial center of the base member  4 , the worker can perform the work to adjust the relative rotational phase of the shaft mounting member  5  to the base member  4  more easily. 
     In some embodiments, the above-described intermediate member  6  includes the at least one plate spring member  60 A which extends along the direction intersecting with the axis LA and is configured to be elastic flexible at least along the direction intersecting with the axis LA. In the illustrated embodiment, the plate spring member  60 A is configured to be elastic flexible along the X-axis direction and along the circumferential direction of the axis LA as well. Further, the at least one plate spring member  60 A may include a plurality of plate springs which extend along the direction intersecting with the axis LA and are laminated in the X-axis direction. 
     With the above configuration, since the at least one plate spring member  60 A is configured to be elastic flexible along the direction intersecting with the axis LA, the coupling device  1  can absorb misalignment between the axial centers of the driven shaft  11 A and the driving shaft  13 A by elastically flexing the plate spring member  60 A. 
     In some embodiments, the above-described driven-side coupling member  2  includes the above-described flange portion  21  (first flange portion) extending along the direction intersecting with (orthogonal to) the axis LA. As shown in  FIG. 4 , the above-described flange portion  21  includes the bolt hole  211  (first coupling-side fastened portion) configured to be fastened to the intermediate member  6  by the fastening device  7 B. Further, as shown in  FIG. 5 , the above-described flange portion  21  includes a first escape recess  212  formed on an end surface  213  on the side of the intermediate member  6  and configured to allow the bolt  70 C (first fastening device) to loosely be fitted into the first escape recess  212 . 
     In the illustrated embodiment, as shown in  FIG. 5 , the first escape recess  212  defines a cylindrical interior space and internally houses the head portion  72 C of the bolt  70 C. 
     With the above configuration, the driven-side coupling member  2  is fastened to the intermediate member  6  in the bolt hole  211  (first coupling-side fastened portion) of the flange portion  21 . Further, the driven-side coupling member  2  is configured such that the bolt  70 C (first fastening device) can loosely be fitted into the first escape recess  212  formed on the end surface  213  of the flange portion  21  on the side of the intermediate member  6 . Providing the first escape recess  212 , it is possible to reduce an interval between the intermediate member  6  and the flange portion  21 . Reducing the interval between the intermediate member  6  and the flange portion  21 , it is possible to decrease the total length of the coupling device  1 , and to improve responsiveness of the intermediate member  6 , to which the rotational force is transmitted from the driven-side coupling member  2 , to the driven-side coupling member  2 . 
     In some embodiments, the above-described base member  4  includes the above-described flange portion  40  (second flange portion) extending along the direction intersecting with (orthogonal to) the axis LA. As shown in  FIG. 5 , the above-described flange portion  40  includes the bolt hole  41  (second coupling-side fastened portion) configured to be fastened to the intermediate member  6  by the fastening device  7 C. Further, as shown in  FIG. 4 , the above-described flange portion  40  includes a second escape recess  42  formed on an end surface  47  on the side of the intermediate member  6  and configured to allow the bolt  70 B (third fastening device) to loosely be fitted into the second escape recess  42 . 
     In the illustrated embodiment, as shown in  FIG. 4 , the second escape recess  42  defines a cylindrical interior space and internally houses the head portion  72 B of the bolt  70 B. Further, the second escape recess  42  communicates with a hole  43  for inserting a bolt fastening jig that penetrates toward the end surface  45 . 
     With the above configuration, the base member  4  is fastened to the intermediate member  6  in the bolt hole  41  (second coupling-side fastened portion) of the flange portion  40 . Further, the base member  4  is configured such that the bolt  70 B (third fastening device) can loosely be fitted into the second escape recess  42  formed on the end surface  47  of the flange portion  40  on the side of the intermediate member  6 . Providing the second escape recess  42 , it is possible to reduce an interval between the intermediate member  6  and the flange portion  40 . Reducing the interval between the intermediate member  6  and the flange portion  40 , it is possible to decrease the total length of the coupling device  1 , and to improve responsiveness of the base member  4  (driving-side coupling member  3 ), to which the rotational force is transmitted from the intermediate member  6 , to the intermediate member  6 . 
     In some embodiments, the above-described intermediate member  6  is configured to be fixed to the driven-side coupling member  2  and the base member  4  with the gap in the X-axis direction. In other words, the coupling device  1  provides a spacer  8  between the intermediate member  6  and the driven-side coupling member  2  in the X-axis direction, and provides the spacer  8  between the intermediate member  6  and the base member  4  in the X-axis direction. 
     With the above configuration, the intermediate member  6  is fixed to the driven-side coupling member  2  and the base member  4  with the gap in the extension direction of the axis LA. Thus, the intermediate member  6  is not constrained by the driven-side coupling member  2  and the base member  4 , making it possible to rapidly absorb misalignment between the axial centers of the first shaft  11  and the second shaft  13  caused when the rotational force is transmitted. 
     As described above, in some embodiments, as shown in  FIG. 1 , one of the above-described first shaft  11  and the above-described second shaft  13  includes the driving shaft  13 A of the pump driving unit  14  (diesel engine  10 ). The other of the above-described first shaft  11  and the above-described second shaft  13  includes the driven shaft  11 A of the fuel injection pump  12  configured to pump the liquid fuel to the combustion chamber  103  (diesel engine  10 ). In this case, it is possible to easily perform work to adjust the rotational phase between the driving shaft  13 A of the pump driving unit  14  (diesel engine  10 ) and the driven shaft  11 A of the fuel injection pump  12 . 
     As described above, in some embodiments, as shown in  FIG. 6 , the at least one plate spring member  60 A includes a first fastened portion  63  configured to be fastened to the above-described driven-side coupling member  2 , and a second fastened portion  64  configured to be fastened to the above-described base member  4 . 
     In the illustrated embodiment, the first fastened portion  63  includes the driven-side bolt insertion hole  61 , and the second fastened portion  64  includes the driving-side bolt insertion hole  62 . 
     With the above configuration, the plate spring member  60 A is fastened to the driven-side coupling member  2  in the first fastened portion  63 , and is fastened to the base member  4  in the second fastened portion  64 . That is, the coupling device  1  that includes the plate spring member  60 A including the first fastened portion  63  and the second fastened portion  64  is a so-called single disk type coupling. Such coupling device  1  can have a decreased total length in the extension direction of the axis LA, and thus can be installed even in a narrow gap between the first shaft  11  and the second shaft  13 . 
       FIG. 7  is a schematic exploded perspective view of the coupling device according to another embodiment of the present invention. 
     In some embodiments, as shown in  FIG. 7 , the intermediate member  6  includes, in order from the X1 side, a first plate spring member  60 B configured to be fixed to the driven-side coupling member  2  via the fastening device  7 B, a connecting member  9  configured to be fixed to the first plate spring member  60 B via the fastening device  7 D, and a second plate spring member  60 C configured to be fixed to the connecting member  9  via the fastening device  7 E, as well as configured to be fixed to the base member  4  via the fastening device  7 C. That is, the coupling device  1  shown in  FIG. 7  is a so-called double disk type coupling. The fastening device  7 D and the fastening device  7 E have the same configuration as the fastening devices  7 B and  7 C. 
       FIG. 8  is a flowchart showing an example of a rotational phase adjustment method for the coupling device according to an embodiment of the present invention. 
     A rotational phase adjustment method  100  for the coupling device according to some embodiments is a method for adjusting the relative rotational phase of the shaft mounting member  5  to the base member  4  in the coupling device  1  described above. As shown in  FIG. 8 , the rotational phase adjustment method  100  for the coupling device includes a relative rotation step S 101  of relatively rotating the shaft mounting member  5  to the base member  4 , and a fixing step S 102  of fixing the shaft mounting member  5  to the base member  4  by the fastening device  7 A after the relative rotation step S 101 . 
     In the illustrated embodiment, as shown in  FIG. 8 , the rotational phase adjustment method  100  further includes a fixing release step S 201  of releasing fixing of the shaft mounting member  5  to the base member  4  by the fastening device  7 A, before the relative rotation step S 101 . The fixing release step S 201  includes loosening the bolt  70 A of the fastening device  7 A for fixing the shaft mounting member  5  to the base member  4 , before the fixing release step S 201 . By loosening the bolt  70 A, the shaft mounting member  5  can be relatively rotatable to the base member  4 . 
     With the above method, the rotational phase adjustment method  100  for the coupling device includes the relative rotation step S 101  of relatively rotating the shaft mounting member  5  to the base member  4 , and the fixing step S 102  of fixing the shaft mounting member  5  to the base member  4  by the fastening device  7 A after the relative rotation step S 101 . The rotational phase adjustment method  100  for the coupling device relatively rotates the shaft mounting member  5  to the base member  4  so as to shift the position where the shaft portion  71 A of the bolt  70 A (fastening device  7 A) is inserted through the long hole  512  in the relative rotation step S 101 , and then fixes the shaft mounting member  5  to the base member  4  by the fastening device  7 A in the fixing step S 102 . Such rotational phase adjustment method  100  for the coupling device can easily adjust the relative rotational phase of the shaft mounting member  5  to the base member  4 , and can easily adjust the relative rotational phase of the second shaft  13  to the first shaft  11 . 
     Further, with the above method, the intermediate member  6  is fixed to not the shaft mounting member  5  having the long hole  512 , but the base member  4 . Thus, even if the intermediate member  6  is deformed when absorbing the above-described misalignment, and the restoring force of restoring to the original shape is generated, the above-described restoring force acts on the base member via the fastening device  7 C. That is, it is possible to prevent the above-described restoring force from acting on the shaft mounting member  5  having the long hole  512 , making it possible to prevent slippage of the shaft mounting member  5 . 
     The present invention is not limited to the above-described embodiments, and also includes an embodiment obtained by modifying the above-described embodiments and an embodiment obtained by combining these embodiments as appropriate. 
     REFERENCE SIGNS LIST 
     
         
           1  Coupling device 
           2  Driven-side coupling member 
           21  Flange portion 
           22  Protruding portion 
           23  Shaft insertion hole 
           24  Keyway 
           3  Driving-side coupling member 
           4  Base member 
           5  Shaft mounting member 
           51  Flange portion 
           52  Hub 
           53  Shaft insertion hole 
           54  Keyway 
           55  Slot 
           56  First divided section 
           57  Second divided section 
           6  Intermediate member 
           60  Elastic member 
           60 A Plate spring 
           7 A to  7 E Fastening device 
           8  Spacer 
           9  Connecting member 
           10  Diesel engine 
           11  First shaft 
           11 A Driven shaft 
           12  Fuel injection pump 
           13  Second shaft 
           13 A Driving shaft 
           14  Pump driving unit 
           15 ,  17  Key 
           16  Fastening member 
           18  Bolt 
           101  Cylinder 
           102  Piston 
           103  Combustion chamber 
           121  Cylinder 
           122  Plunger 
           123  Pumping chamber