Abstract:
A turning device is provided with: a casing; a drive motor provided above the casing; a drive wheel rotated by the drive motor, the drive wheel being supported on one side of a reference plane located on the drive axis of the drive motor and parallel to the vertical direction, the drive wheel being rotatable about a reference line intersecting the reference plane; a driven wheel disposed within the casing, the driven wheel being supported so as to be rotatable about an axis parallel to the reference line, the driven wheel being connected to the drive wheel through an annular member; a first gear wheel coaxially connected to the driven wheel and having a first spur gear; a second gear wheel having a second spur gear meshing with a wheel gear which is provided coaxially with a rotating shaft extending parallel to the reference line, the second spur gear also meshing with the first spur gear of the first gear wheel; an arm member for rotatably supporting the second gear wheel; a movement mechanism for moving the arm member to thereby move the second gear wheel between a meshed position at which the second gear wheel is meshed with the wheel gear and a retracted position at which the second gear wheel is not meshed with the wheel gear; and a cover adapted to mountable and removable from the casing and covering the drive wheel.

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates to a turning device which rotates a rotor such as a turbine at a low speed, and a rotary machine including the turning device. 
       BACKGROUND ART 
       [0002]    Hitherto, in a power generation plant which uses a steam turbine, a gas turbine, or a combined cycle including the steam turbine and the gas turbine, it is known that when a rotor (rotary shaft) is left while not being rotated at a high temperature during a period of time when operation is stopped, the following phenomenon occurs. That is, as the temperature of steam or gas decreases, a temperature gradient occurs in a turbine casing in a vertical direction, and thus bending occurs in the rotor due to thermal expansion, or a small degree of bending occurs during a period of time when the turbine is stopped due to the rotor&#39;s own weight. 
         [0003]    Therefore, during a period of time when the operation of the turbine is stopped or before starting-up, so-called turning, in which the rotor is rotated at a low speed for a predetermined time is performed to prevent the occurrence of bending in the rotor. 
         [0004]    For example, a turning device described in PTL 1 includes a driving motor. The shaft of the driving motor is connected to a deceleration mechanism which decelerates the rotation of the shaft. The deceleration mechanism is provided with a driving pulley (driving wheel) and is configured to transmit the rotation of the decelerated driving motor to the driving pulley. 
         [0005]    On the lower side of the deceleration mechanism, a driven pulley (driven wheel) having the same axial direction as that of the driving pulley is disposed. A V-belt (annular member) is looped over the driving pulley and the driven pulley. 
         [0006]    A first spur gear which rotates coaxially with the driving pulley is integrally attached to the driving pulley. On the lower side of the first spur gear, a second spur gear having the same axial direction as that of the first spur gear is disposed. The first spur gear and the second spur gear always engage with each other. 
         [0007]    A pair of arm members are supported by the rotary shaft of the second spur gear so as to be inclined while interposing the second spur gear therebetween in the axial direction thereof. A pinion gear (second toothed wheel) having the same axial direction as those of the second spur gear and a wheel gear is rotatably pivoted by one end portion of the arm member. The pinion gear is displaceable by the inclination of the arm member between an engagement position where the pinion gear approaches and engages with the wheel gear and a retreat position where the pinion gear is separated from the wheel gear toward a radially outer side. The wheel gear is coaxially fixed to a rotor. 
         [0008]    As described above, in the turning device described in PTL 1, gears which transmit the driving force to the wheel gear on the downstream side from the driven pulley have a three-stage configuration including the first spur gear, the second spur gear, and the pinion gear. 
         [0009]    In general, one end portion of the rotor is connected to a compressor, and the other end portion of the rotor is connected to a turbine. The connection portion of the rotor and the compressor is covered with a coupling guard for avoiding oil or the like. 
         [0010]    The driving pulley and the driven pulley are covered with a chain cover (cover), and the chain cover is detachably attached to the compressor side of the turning device. 
         [0011]    In the turning device configured as described above, the position of the pinion gear is the retreat position during an operation of a steam turbine. 
         [0012]    When the operation of the steam turbine is stopped, the arm member is inclined by a control unit of the turning device such that the pinion gear is displaced from the retreat position toward the wheel gear to the engagement position. When the driving motor is driven, the rotation power of the driving motor is transmitted to the wheel gear via the deceleration mechanism, the driving and driven pulleys, the V-belt, the first spur gear, the second spur gear, and the pinion gear. In addition, the rotor is rotated along with the wheel gear. At this time, the rotor is rotated at a lower speed than when the steam turbine is operated. 
       CITATION LIST 
     Patent Literature 
       [0013]    [PTL 1] International Publication No. WO 2013/124979 Summary of Invention 
       Technical Problem 
       [0014]    However, in the turning device described in PTL 1, when the coupling guard is attached and detached, there is concern that the coupling guard may interfere with the chain cover, and thus the gears are allowed to have the three-stage configuration. However, this causes a vertically long structure, resulting in a reduction in stiffness and an increase in the number of components. When the coupling guard interferes with the chain cover, operability during the attachment and detachment of the coupling guard is degraded. 
         [0015]    The present invention has been made taking the foregoing problems into consideration, and an object thereof is to provide a turning device which prevents a coupling guard from interfering with a cover when the coupling guard is attached and detached, and reduces the number of stages of gears, and a rotary machine including the turning device. 
       Solution to Problem 
       [0016]    In order to solve the problems, the invention proposes the following means. 
         [0017]    According to an aspect of the present invention, a turning device includes: a casing; a driving motor which is attached to be positioned higher than the casing; a driving wheel which is disposed above the casing, is supported on one side with respect to a reference plane that is parallel to a vertical direction on a driving shaft of the driving motor and, to be rotatable around a reference line that intersects the reference plane, and is rotated by the driving motor; a driven wheel which is disposed in the casing, is supported to be rotatable around an axis that is parallel to the reference line, and is connected to the driving wheel via an annular member; a first toothed wheel which is coaxially connected to the driven wheel and has first spur teeth; a second toothed wheel having second spur teeth that engage with each of a wheel gear that is provided coaxially with a rotary shaft which extends parallel to the reference line, and the first spur teeth of the first toothed wheel; an arm member which rotatably supports the second toothed wheel; a moving mechanism which moves the second toothed wheel between an engagement position where the second toothed wheel engages with the wheel gear and a retreat position where the second toothed wheel does not engage with the wheel gear, by moving the arm member; and a cover which is attachable to and detachable from the casing and covers the driving wheel, in which a compressor is connected to the rotary shaft on the other side with respect to the reference plane. 
         [0018]    In addition, it is preferable that the turning device further includes a rotating lever of which one end portion is coaxially connected to the driving wheel via a ratchet mechanism, in which the ratchet mechanism restricts rotation of one end portion of the rotating lever, with respect to an axis of the driving wheel, in one direction around the axis, while allowing the rotation thereof in the other direction around the axis, the moving mechanism includes a moving lever of which one end portion is rotatably supported by the casing, and a connection member which is connected to each of the moving lever and the arm member and is configured to move the arm member when the moving lever is rotated, and the rotating lever and the moving lever are rotated in a direction along the reference line on the same side with respect to the cover. 
         [0019]    In addition, according to another aspect of the present invention, a rotary machine includes the turning device described above. 
       Advantageous Effects of Invention 
       [0020]    According to the turning device and the rotary machine of the present invention, the number of components can be reduced by reducing the number of stages of gears, and a power transmission coefficient can be enhanced by increasing stiffness. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0021]      FIG. 1  is a sectional view illustrating the summary of the configuration of a steam turbine of a first embodiment of the present invention. 
           [0022]      FIG. 2  is a sectional view of a side of a turning device of the steam turbine. 
           [0023]      FIG. 3  is a plan view of the turning device. 
           [0024]      FIG. 4  is a block diagram of the turning device. 
           [0025]      FIG. 5  is a sectional view of a side of a turning device of a second embodiment of the present invention. 
           [0026]      FIG. 6  is a partially cutaway plan view of the turning device. 
       
    
    
     DESCRIPTION OF EMBODIMENTS 
     First Embodiment 
       [0027]    Hereinafter, a first embodiment of a rotary machine according to the present invention will be described with reference to  FIGS. 1 to 4  by exemplifying a case where the rotary machine is a steam turbine. 
         [0028]    As illustrated in  FIG. 1 , a steam turbine  1  of this embodiment includes an adjusting valve  11  which adjusts the amount and pressure of steam (operating fluid) that flows into the steam turbine  1 , a body side casing  12  which holds the pressure, a power generating part  13  which generates power, a rotor (rotary shaft)  14  which transmits the generated power to a machine such as a compressor  69 , a bearing device (not illustrated) which rotatably supports the rotor  14  around an axis, and a turning device  15  of the present invention for rotating the rotor  14 . 
         [0029]    A plurality of the adjusting valves  11  (only a single adjusting valve  11  is illustrated in  FIG. 1 ) are attached to the inside of the body side casing  12 , and each thereof includes an adjusting valve chamber  18  into which steam flow from a boiler (not illustrated), a valve body  19 , and a valve seat  20 . 
         [0030]    The valve seat  20  has a substantially cylindrical shape, and the axis thereof is perpendicular to the axis of the rotor  14 . The inside diameter of the valve seat  20  gradually increases toward the rotor  14 , and the tip end portion thereof communicates with a steam chamber  21 . An inner surface  20   a  of the end portion of the valve seat  20  on the opposite side of the steam chamber  21  is formed in a curved shape which is convex toward the inside. The shape of the lower portion of the valve body  19  forms a portion of a sphere and is provided to come into contact with or be separated from the inner surface  20   a  of the valve seat  20 . When the valve body  19  becomes separated from the valve seat  20 , a steam flow passage is open, and when the valve body  19  comes into contact with the valve seat  20 , the steam flow passage is closed. 
         [0031]    The adjusting valve  11  controls the flow rate of steam by opening and closing the valve body  19 . Furthermore, the output of the steam turbine is controlled by adjusting the opening and closing timings of the plurality of adjusting valves  11 . 
         [0032]    The steam chamber  21  guides the steam that is introduced from the adjusting valve  11  to the power generating part  13  and has a substantially doughnut shape. The steam flow passage of the steam chamber  21  is narrowed toward the inside and is deflected toward a direction parallel to the axis of the rotor  14 . 
         [0033]    The power generating part  13  includes nozzles  23  which are fixed to the body side casing  12 , and rotor blades  24  which are attached to the rotor  14 . A set of one of the nozzles  23  and one of the rotor blades  24  is referred to as a stage, and the steam turbine  1  of this embodiment includes six stages. 
         [0034]    The nozzle  23  has a function of generating velocity energy by allowing the steam to expand in the steam flow passage, and producing momentum in a rotational direction of a shaft by changing the direction of a flow. 
         [0035]    The rotor blade  24  has a function of converting the energy of the steam converted into the velocity energy by the nozzle  23 , into the rotational energy of the rotor  14 . 
         [0036]    A number of the nozzles  23  are radially arranged, and are held by a ring-shaped partition plate outer race  25  that is firmly fixed to the body side casing  12 , and a ring-shaped partition plate inner race  26 . A seal structure which prevents steam leakage is formed between an end portion of the partition plate inner race  26  on the rotor  14  side, and the rotor  14 . In a stage in which a high steam pressure is applied, a labyrinth structure is employed as the seal structure although not illustrated. 
         [0037]    A number of the rotor blades  24  are radially arranged, and are firmly attached to the outer peripheral portion of a disk (reference numeral thereof is omitted) provided in a cylindrical shape protruding from the rotor  14 . A shroud  29  is attached to the tip end of the rotor blade  24  in the final stage, and a fin (not illustrated) for preventing steam leakage is attached to a position on the partition plate outer race  25  side which faces the shroud  29 . 
         [0038]    The rotor  14  is formed in a bar shape, and is rotatably supported by the above-mentioned bearing device. A wheel gear  30  is fixed to the outer peripheral surface of the rotor  14  coaxially with the rotor  14 . 
         [0039]    The rotor  14  has a function of transmitting the power generated by the power generating part  13  to a machine such as the compressor  69 . A seal structure (not illustrated) for preventing leakage of steam or the like is provided between the rotor  14  and the body side casing  12 . Exhaust steam which allows the steam turbine  1  to operate and finishes its work is sent to a condenser (not illustrated) through an exhaust chamber  31 . 
         [0040]    The turning device  15  is used for continuously rotating the rotor  14  at a speed that is much lower than a speed when the steam turbine  1  is operated, during a period of time when the operation of the steam turbine  1  is stopped or during the starting-up thereof. 
         [0041]    As illustrated in  FIGS. 1 to 3 , the turning device  15  includes a casing  41 , a driving motor  42  attached to the casing  41 , a driving side sprocket (driving wheel)  43  which is specified on a driving shaft  42   a  of the driving motor  42  and is rotatably supported on one side D 1  with respect to a reference plane S parallel to the vertical direction Z, a driven side sprocket (driven wheel)  44  which is rotatably supported in the casing  41 , a toothed spur wheel (first toothed wheel)  45  which is coaxially connected to the driven side sprocket  44 , a pinion gear (second toothed wheel)  46  which engages with both of the wheel gear  30  provided in the rotor  14  and the toothed spur wheel  45 , an arm member  47  which rotatably supports the pinion gear  46 , a moving mechanism  48  for moving the arm member  47 , and a chain cover (cover)  49  which is attachable to and detachable from the casing  41 . 
         [0042]    Although the driving motor  42  is not illustrated in the section of  FIG. 2 , the driving motor  42  is illustrated by two-dot chain lines for convenience of description. 
         [0043]    The casing  41  is formed by drilling a steel plate into a predetermined shape and performing bending, welding, and the like thereon. 
         [0044]    The reference plane S is a plane which includes the driving shaft  42   a  of the driving motor  42  and is parallel to the vertical direction Z. 
         [0045]    The driving motor  42  is attached at a higher position than that of the casing  41  so that the driving shaft  42   a  is parallel to a horizontal plane. The driving motor  42  may be attached to the casing  41  by well-known fastening means such as bolts and nuts, or screws (not illustrated). 
         [0046]    As illustrated in  FIG. 4 , the turning device  15  includes a control unit  52 , and the driving motor  42  is driven by the control unit  52 . More specifically, the control unit  52  includes a motor control unit  53  which controls the energization of the driving motor  42 , a cylinder control unit  54 , which will be described later, and a main control unit  55  which collectively controls the motor control unit  53  and the cylinder control unit  54 . 
         [0047]    As illustrated in  FIGS. 1 to 3 , the driving side sprocket  43  is attached to the casing  41  to be positioned higher than the casing  41 . The driving side sprocket  43  is supported by the casing  41  to be rotatable around a reference line C that is perpendicular to the reference plane S. In addition, the above-mentioned rotor  14  extends parallel to the reference line C. 
         [0048]    A deceleration mechanism  58  is provided between the driving motor  42  and the driving side sprocket  43 . The rotation speed of the rotor shaft (not illustrated) which is rotated around the driving shaft  42   a  as the driving motor  42  is driven is decelerated by the deceleration mechanism  58 , and the driving force is transmitted to the driving side sprocket  43  via a connection shaft  58   a.    
         [0049]    That is, the driving side sprocket  43  is rotated by the driving motor  42  via the deceleration mechanism  58 . 
         [0050]    The driven side sprocket  44  is disposed lower than the driving side sprocket  43  on the same plane as that of the driving side sprocket  43 . The driven side sprocket  44  is supported by the casing  41  at a position separated from the driving side sprocket  43  to be rotatable around an axis parallel to the reference line C. The driving side sprocket  43  and the driven side sprocket  44  are connected via a chain (annular member)  59 . 
         [0051]    The toothed spur wheel  45  has first spur teeth  45   a  on the outer peripheral surface. The toothed spur wheel  45  is integrally attached to the driven side sprocket  44  via a connection shaft  60  at a position separated from the wheel gear  30 . The wheel gear  30  is disposed below the toothed spur wheel  45 . 
         [0052]    The pinion gear  46  has second spur teeth  46   a  which engage with both of the first spur teeth  45   a  of the toothed spur wheel  45  and spur teeth  30   a  of the wheel gear  30 . 
         [0053]    The arm member  47  is configured by forming a steel plate in a V-shape when viewed from a side in this example. 
         [0054]    The arm member  47  is supported to be rotatable around the connection shaft  60  at the intermediate portion of the arm member  47  in the longitudinal direction thereof. One end portion  47   a  of the arm member  47  extends downward from the intermediate portion of the arm member  47 , and the other end portion  47   b  of the arm member  47  extends from the intermediate portion of the arm member  47  substantially parallel to the horizontal plane. 
         [0055]    The pinion gear  46  is rotatably supported by one end portion  47   a  of the arm member  47  such that the axis of the pinion gear  46  is parallel to the reference line C. 
         [0056]    The second spur teeth  46   a  of the pinion gear  46  always engage with the first spur teeth  45   a  of the toothed spur wheel  45 . 
         [0057]    As illustrated in  FIG. 2 , a position where the second spur teeth  46   a  of the pinion gear  46  engage with the spur teeth  30   a  of the wheel gear  30  by allowing one end portion  47   a  of the arm member  47  to approach the lower side of the connection shaft  60  is an engagement position P 1  of the pinion gear  46 . On the other hand, a position to which the pinion gear  46  is moved so as not to engage with the spur teeth  30   a  of the wheel gear  30  by rotating the arm member  47  around the connection shaft  60  so as to separate one end portion  47   a  of the arm member  47  from the lower side of the connection shaft  60  (so as to push downward the other end portion  47   a  of the arm member  47 ) is a retreat position P 2  of the pinion gear  46 . 
         [0058]    As described above, in the turning device  15  of this embodiment, gears which transmit the driving force to the wheel gear  30  on the downstream side from the driven side sprocket  44  have a two-stage configuration including the toothed spur wheel  45  and the pinion gear  46 . 
         [0059]    The moving mechanism  48  includes an air cylinder  63  as a power source, a fitting and detaching lever (moving lever)  64  of which one end portion  64   a  is rotatably supported by the casing  41 , and a connection member  65  of which one end portion is rotatably connected to the other end portion  47   a  of the arm member  47  and of which the other end portion is rotatably connected to the intermediate portion of the fitting and detaching lever  64 , in the longitudinal direction thereof. 
         [0060]    An inner rod  63   a  of the air cylinder  63  extends to slide in the vertical direction Z with respect to an outer case  63   b . A lower side portion of the inner rod  63   a  is accommodated in the outer case  63   b . The outer case  63   b  of the air cylinder  63  is supported by the casing  41  via a spring bushing  66 . 
         [0061]    In the air cylinder  63 , the sliding position of the inner rod  63   a  is displaced according to a control command from the cylinder control unit  54  (see  FIG. 4 ). For example, the cylinder control unit  54  controls the opening and closing of a control valve (not illustrated) to supply and discharge air to and from the outer case  63   b , thereby controlling the position of the inner rod  63   a  in the vertical direction Z. 
         [0062]    An upper side portion of the inner rod  63   a  is rotatably connected to a portion of the fitting and detaching lever  64  closer to the other end portion  64   b  side than the portion to which the other end portion of the connection member  65  is connected. 
         [0063]    In this example, the fitting and detaching lever  64  is formed in a bar shape and is rotated on a plane parallel to the reference plane S. 
         [0064]    In the moving mechanism  48  configured as described above, in a case where the inner rod  63   a  of the air cylinder  63  slides upward with respect to the outer case  63   b , the inner rod  63   a  pushes upward the other end portion  64   b  side of the fitting and detaching lever  64  such that the fitting and detaching lever  64  is disposed at a position illustrated in  FIG. 2  in which the fitting and detaching lever  64  is rotated around one end portion  64   a . In this case, the connection member  65  connected to the fitting and detaching lever  64  moves upward and the arm member  47  is rotated around the connection shaft  60  such that the pinion gear  46  is disposed at the engagement position P 1  where the pinion gear  46  engages with the wheel gear  30 . 
         [0065]    On the other hand, in a case where the inner rod  63   a  slides downward (is lowered) from the state where the pinion gear  46  is disposed at the engagement position P 1 , the inner rod  63   a  pulls down the other end portion  64   b  side of the fitting and detaching lever  64  and the fitting and detaching lever  64  is rotated around one end portion  64   a  such that the pinion gear  46  is disposed at the retreat position P 2  where the pinion gear  46  does not engage with the wheel gear  30 . 
         [0066]    As described above, the moving mechanism  48  can move the pinion gear  46  between the engagement position P 1  and the retreat position P 2  according to the control command of the cylinder control unit  54 . 
         [0067]    The chain cover  49  illustrated in  FIGS. 1 to 3  is attachable to and detachable from the casing  41  by the above-mentioned fastening means on one side D 1  of the reference plane S. When the chain cover  49  is attached to the casing  41 , the chain cover  49  covers the driving side sprocket  43 . The chain cover  49  is used to prevent an operator or the like from coming into contact with the driving side sprocket  43  or the chain  59 . 
         [0068]    As illustrated in  FIG. 1 , the above-mentioned compressor  69  is connected to the rotor  14  on the other side D 2  of the reference plane S. In order to cover the connection portion of the rotor  14  and the compressor  69 , a cylindrical coupling guard  70  is detachably attached. 
         [0069]    Next, an operation of the above-described turning device  15 , and particularly, an operation of the steam turbine  1  immediately after the stop of the operation will be described. 
         [0070]    First, during the operation of the steam turbine  1 , the control unit  52  of the turning device  15  allows the inner rod  63   a  of the air cylinder  63  to be held at a position where the inner rod  63   a  is lowered to the outer case  63   b . At this time, the driving motor  42  is in a stopped state, and the pinion gear  46  is disposed at the retreat position P 2 . 
         [0071]    Thereafter, when the control unit  52  receives a signal indicating that the operation of the steam turbine  1  is stopped from the outside, first, the control unit  52  allows the inner rod  63   a  of the air cylinder  63  to slide upward via the cylinder control unit  54 . Therefore, the arm member  47  is rotated around the connection shaft  60  via the fitting and detaching lever  64  and the connection member  65  and the pinion gear  46  is moved from the retreat position P 2  to the engagement position P 1 . 
         [0072]    When the pinion gear  46  engages with the wheel gear  30 , the driving of the driving motor  42  is started. Accordingly, the rotation power of the driving motor  42  is transmitted to the wheel gear  30  via the deceleration mechanism  58 , the sprockets  43  and  44 , the chain  59 , the toothed spur wheel  45 , and the pinion gear  46 . In addition, the rotor  14  is rotated along with the wheel gear  30 . At this time, the rotor  14  is rotated at a lower speed than when the steam turbine  1  is operated. 
         [0073]    The coupling guard  70  may be removed during the maintenance, inspection, or the like of the compressor  69 . Even in this case, since the coupling guard  70  is attached on the other side D 2  of the reference plane S and the chain cover  49  is attached on one side D 1  of the reference plane S, the chain cover  49  does not cause inconvenience during the attachment and detachment of the coupling guard  70 . 
         [0074]    In addition, when the control unit  52  is not operated or the like, by raising or lowering the other end portion  64   b  side of the fitting and detaching lever  64  by the operator, the position of the pinion gear  46  can be manually controlled to be the engagement position P 1  or the retreat position P 2 . 
         [0075]    As described above, in the turning device  15  of this embodiment and the steam turbine  1 , since the compressor  69  is connected to the rotor  14  on the other side D 2  of the reference plane S, the coupling guard  70  is attached to the connection portion of the rotor  14  and the compressor  69 . Even in this case, since the chain cover  49  is attached on one side D 1  of the reference plane S, the interference of the coupling guard  70  with the chain cover  49  during attachment and detachment can be prevented. 
         [0076]    Since the gears which transmit the driving force of the driving motor  42  have the two-stage configuration including the toothed spur wheel  45  and the pinion gear  46 , compared to the case of the three-stage configuration of the gears according to the related art, the number of components is reduced, rigidity is increased, and a reduction in the size can be achieved by suppressing the length of the turning device  15  in the vertical direction Z. The transmission efficiency of the driving force of the driving motor  42  can be enhanced. 
       Second Embodiment 
       [0077]    Next, a second embodiment of the present invention will be described with reference to  FIGS. 5 and 6 . Like elements similar to those of the above-described embodiment are denoted by like reference numerals, the description thereof will not be repeated, and only differences will be described. 
         [0078]    As illustrated in  FIGS. 5 and 6 , a turning device  80  of this embodiment further includes, in addition to each configuration of the turning device  15  of the first embodiment, a rotating lever  82  of which one end portion  82   a  is coaxially connected to the driving side sprocket  43  via a ratchet mechanism  81 . 
         [0079]    In addition, although the ratchet mechanism  81  and the rotating lever  82  are not illustrated in the section of  FIG. 5 , the ratchet mechanism  81  and the rotating lever  82  are illustrated by two-dot chain lines for convenience of description. 
         [0080]    The ratchet mechanism  81  is not illustrated in detail and has a well-known configuration. The ratchet mechanism  81  is attached to the end portion of the connection shaft  58   a  on the opposite side of the driving side sprocket  43 , that is, the end portion on the other side D 2  of the reference plane S via a spacer  84 . 
         [0081]    The ratchet mechanism  81  restricts the rotation of one end portion  82   a  of the rotating lever  82  in one direction around the reference line C with respect to the reference line C which is the axis of the driving side sprocket  43 , that is, the spacer  84 , while allowing the rotation in the other direction around the reference line C. That is, by rotating the other end portion  82   b  of the rotating lever  82  around the reference line C to reciprocate several times in one direction, the other direction, one direction, and the like, the driving side sprocket  43  can be rotated in only one direction around the reference line C. Accordingly, the rotation of the driving side sprocket  43  is transmitted and the rotor  14  is rotated to match the phase of the rotor  14 . 
         [0082]    In this example, the rotating lever  82  is formed in a bar shape and is rotated on a plane parallel to the reference plane S. 
         [0083]    The rotating lever  82  and the above-mentioned fitting and detaching lever  64  are rotated in a direction along the reference line C on the same side with respect to the chain cover  49 . 
         [0084]    In the turning device  80  configured as described above, when the operation of the steam turbine is stopped and the control unit  52  is not operated or the like, an operator Q can operate the rotating lever  82  to rotate the rotor  14  or can operate the fitting and detaching lever  64  to control the position of the pinion gear  46 . 
         [0085]    As described above, according to the turning device  80  of this embodiment, the coupling guard  70  is prevented from interfering with the chain cover  49  when the coupling guard  70  is attached and detached. 
         [0086]    Since the rotating lever  82  and the fitting and detaching lever  64  are rotated in the direction along the reference line C on the same side with respect to the chain cover  49 , one operator Q can easily operate both the levers  64  and  82  on one side of the turning device  80  without the interruption of the chain cover  49 . 
         [0087]    While the first and second embodiments of the present invention have been described in detail with reference to the drawings, the specific configurations are not limited to the embodiments, and include changes, combinations, omissions, and the like of the configurations without departing from the gist of the present invention. Furthermore, it is needless to say that the configurations described in each of the embodiments can be appropriately combined for use. 
         [0088]    For example, in the first and second embodiments, a driving wheel is the driving side sprocket  43 , a driven wheel is the driven side sprocket  44 , and an annular member is the chain  59 . However, a configuration in which the driving wheel is a driving pulley, the driven wheel is a driven pulley, and the annular member is a V-belt looped over both the pulleys may also be employed. 
         [0089]    In the description, the rotary machine is the steam turbine. However, the rotary machine is not limited thereto and may also be a gas turbine or the like. 
       INDUSTRIAL APPLICABILITY 
       [0090]    The present invention can be applied to a turning device for rotating a rotor at a low speed. 
       REFERENCE SIGNS LIST 
       [0000]    
       
         
           
               1  steam turbine (rotary machine) 
               14  rotor (rotary shaft) 
               15 ,  80  turning device 
               30  wheel gear 
               41  casing 
               42  driving motor 
               42   a  driving shaft 
               43  driving side sprocket (driving wheel) 
               44  driven side sprocket (driven wheel) 
               45  toothed spur wheel (first toothed wheel) 
               45   a  first spur teeth 
               46  pinion gear (second toothed wheel) 
               46   a  second spur teeth 
               47  arm member 
               48  moving mechanism 
               49  chain cover (cover) 
               59  chain (annular member) 
               64  fitting and detaching lever (moving lever) 
               65  connection member 
               69  compressor 
               81  ratchet mechanism 
               82  rotating lever 
               82   a  one end portion 
             C reference line 
             D 1  one side 
             D 2  the other side 
             P 1  engagement position 
             P 2  retreat position 
             S reference plane 
             Z vertical direction