Patent Publication Number: US-11644051-B2

Title: Cylinder device

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a National Stage application of International Patent Application No. PCT/JP2019/047152 filed on Dec. 3, 2019, which claims priority to Japanese Patent Application No. JP2018-227980 filed on Dec. 5, 2018, each of which is hereby incorporated by reference in its entirety. 
     TECHNICAL FIELD OF THE INVENTION 
     The present invention relates to a cylinder device including a rotation mechanism. 
     BACKGROUND OF THE INVENTION 
     The following Patent Literatures disclose cylinder devices including a mechanism configured to rotate a shaft member housed in a cylinder body. 
     Japanese Patent Laid-Open No. 2011-69384 discloses a rotary drive motor (brushless DC motor) configured to rotate a shaft member. 
     In Japanese Patent Laid-Open No. 2017-133593, a rotation drive portion is provided to rotate a shaft member at a predetermined angle. The rotation drive portion includes a rotary motor such as a stepping motor or a servo motor. 
     In Japanese Patent Laid-Open No. 2017-9068, a rotation drive portion is attached to a shaft member. The rotation drive portion includes a rotor and a stator surrounding a periphery of the rotor. A magnet is disposed on the rotor, and a coil is disposed on the stator. The shaft member is rotationally driven by an electromagnetic action. 
     SUMMARY OF THE INVENTION 
     However, there are problems that power consumption is increased and compactification cannot be appropriately achieved in the conventional configuration in which the shaft member is rotated by a motor or the like. In other words, heat is generated by use of the motor, and thus power consumption easily increases. Further, since the shaft member is mechanically rotated, a rotation mechanism becomes complicated, and compactification cannot be appropriately achieved. In addition, rotation unevenness is required to be prevented. 
     The present invention has been made in view of the above circumstances, and has an object to provide a cylinder device capable of preventing rotation unevenness while reducing power consumption and achieving compactification. 
     The present invention is to provide a cylinder device including: a cylinder body; and a shaft member supported in the cylinder body, the cylinder body being provided with a rotation port that communicates with an outer circumferential surface around the shaft member and rotates the shaft member based on a supply and discharge of a fluid. 
     In the present invention, preferably, the shaft member includes a rotating portion in which recessed parts and projecting parts are alternately continuous with each other along the outer circumferential surface, and the rotation port communicates with the rotating portion. 
     In the present invention, the shaft member is preferably supported to be capable of stroke. 
     In the present invention, preferably, the shaft member includes a rotating portion on the outer circumferential surface in a middle in the shaft direction, and stroke ports are provided in the cylinder body on a front side and a rear side of the rotating portion to stroke the shaft member by the supply and discharge of the fluid, the rotation port communicating with the rotating portion being provided between the stroke ports. 
     In the present invention, the rotation port is preferably formed to be plural in number. 
     In the present invention, the shaft member preferably includes a fluid bearing, the shaft member being supported in a state of floating in the cylinder body. 
     According to the cylinder device of the present invention, it is possible to prevent rotation unevenness while reducing power consumption and achieving compactification. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is an exterior perspective view of a cylinder device according to an embodiment. 
         FIG.  2    is a cross-sectional view of the cylinder device according to the present embodiment taken along a shaft direction. 
         FIG.  3    is a perspective view of a shaft member forming the cylinder device according to the present embodiment. 
         FIG.  4    is a partially enlarged cross-sectional view of the cylinder device shown in  FIG.  2   . 
         FIG.  5    is a cross-sectional view showing a state where a shaft member is stroked forward from the state of  FIG.  2   . 
         FIG.  6    is a cross-sectional view showing a state where the shaft member is stroked rearward from the state of  FIG.  2   . 
         FIG.  7    is a cross-sectional view of the cylinder device according to the present embodiment taken along a direction orthogonal to the shaft direction. 
         FIG.  8    is a cross-sectional view of a cylinder device different from that shown in  FIG.  7   . 
         FIG.  9    is a cross-sectional view of a cylinder device different from that shown in  FIG.  7   . 
         FIG.  10    is a cross-sectional view of a cylinder device different from that shown in  FIG.  7   . 
     
    
    
     DETAILED DESCRIPTION 
     An Embodiment (hereinafter, abbreviated as “embodiment”) of the present invention will be described in detail below. 
     A cylinder device  1  shown in  FIGS.  1  and  2   , and the like includes a cylinder body  2  and a shaft member  3  supported by the cylinder body  2 . 
     In the present embodiment, the shaft member  3  is rotatably supported. On the other hand, a stroke of the shaft member  3  is arbitrary. In other words, the cylinder device  1  of the present embodiment may be configured to enable only rotation of the shaft member  3 , or may be configured to enable both rotation and stroke of the shaft member  3 . However, a description will be made below with respect to the cylinder device  1  which allows the shaft member  3  to be stroked in a shaft direction while rotating. 
     The term “rotation” means that the shaft member  3  rotates about a shaft center O which is the center of rotation (see  FIG.  4   ). The term “stroke” means that the shaft member  3  moves in a shaft direction (X1-X2 direction). The X1 direction indicates a front side of the cylinder device  1 , and the X2 direction indicates a rear side of the cylinder device  1 . 
     As shown in  FIG.  3   , the shaft member  3  of the present embodiment includes a piston  4  formed with a predetermined diameter and having a predetermined length dimension L 1  in the shaft direction (X1-X2 direction) and a piston rod  5  provided at a front end surface  4   a  of the piston  4  and having a diameter smaller than that of the piston  4 . 
     As shown in  FIGS.  2  and  4   , the piston  4  and the piston rod  5  are preferably formed integrally with each other. As shown in  FIG.  4   , the piston  4  and the piston rod  5  have the shaft center O aligned on a straight line. 
     As shown in  FIGS.  2  and  4   , a hole  8  is formed at a rear end surface  4   b  of the piston  4  along the shaft center O in a direction of the piston rod  5 . 
     As shown in  FIG.  3   , the piston  4  includes a front part  4   c , an intermediate part  4   d , and a rear part  4   e , and the intermediate part  4   d  forms a rotating portion (gear portion)  11  in which recessed parts  9  and projecting parts  10  are alternately continuous along an outer circumferential surface. Here, the term “intermediate” indicates a position between a front side and a rear side and does not mean a center. 
     The recessed parts  9  and the projecting parts  10  forming the rotating portion  11  are formed at regular intervals in a circumferential direction. Further, the recessed parts  9  and projecting parts  10  are formed with a predetermined width in the shaft direction (X1-X2 direction). Each of the recessed part  9  and the projecting part  10  has a width larger than a diameter of each of rotation ports  31  and  32  which will be described below. In the configuration in which the shaft member  3  strokes as in the present embodiment, a width of the rotating portion  11  in the shaft direction is set according to the stroke amount of the shaft member  3 . 
     Unlike the intermediate part  4   d , the front part  4   c  and the rear part  4   e  of the piston  4  are formed in a columnar shape. Thereby, air bearings  21  to  23 , which will be described below, are disposed on the front part  4   c  and the rear part  4   e , and the piston  4  can stably float in the cylinder body  2 . 
     The cylinder device  1  of the present embodiment is configured in which a fluid acts on the rotating portion  11  disposed on the outer circumferential surface around the shaft member  3  and thus the shaft member  3  can rotate about the shaft center O which is a center of rotation. 
     A cylinder chamber  12  is provided inside the cylinder body  2 . Further, an insertion portion  13  is provided which penetrates from the cylinder chamber  12  to a front end surface  2   a  of the cylinder body  2  and is continuous with the cylinder chamber  12 . 
     As shown in  FIGS.  2  and  4   , the piston  4  of the shaft member  3  is housed in the cylinder chamber  12 . Further, the piston rod  5  of the shaft member  3  is inserted into the insertion portion  13 . 
     The cylinder chamber  12  is a substantially cylindrical space having a diameter slightly larger than the diameter of the piston  4 . Further, the cylinder chamber  12  is formed to have a length dimension in the X1-X2 direction longer than the length dimension L 1  of the piston  4 . Therefore, the piston  4  is movably housed in the cylinder chamber  12  in the shaft direction (X1-X2 direction). 
     In the states of  FIGS.  2  and  4   , the piston  4  is housed near a center of the cylinder chamber  12  in the X1-X2 direction. For this reason, spaces are provided on the front side (X1 side) and on the rear side (X2 side) of the piston  4 , respectively. Here, the space on the front side is referred to as a first fluid chamber  14 , and the space on the rear side is referred to as a second fluid chamber  15 . The first fluid chamber  14  and the second fluid chamber  15  are divided from each other and do not interfere with each other. 
     As shown in  FIGS.  2  and  4   , the cylinder body  2  is formed with stroke ports  25  and  26  communicating with the first fluid chamber  14  and the second fluid chamber  15 . 
     Further, as shown in  FIGS.  2  and  4   , the cylinder body  2  is formed with the rotation ports  31  and  32  at positions between the stroke ports  25  and  26 . The rotation ports  31  and  32  communicate with the rotating portion  11  of the shaft member  3 . 
     The cylinder device  1  of the present embodiment is an air bearing-type cylinder device, and a plurality of air bearing spaces  16 ,  17 , and  18  are provided between the shaft member  3  and an internal space of the cylinder body  2 . As shown in  FIG.  4   , the first air bearing space  16  is formed at the position of the piston rod  5 . The second air bearing space  17  is formed at the position of the front part  4   c  of the piston  4 . The third air bearing space  18  is provided at the position of the rear part  4   e  of the piston  4 . 
     As shown in  FIGS.  2  and  4   , an air bearing  21  is disposed in the first air bearing space  16  to surround an outer circumference of the piston rod  5 . Further, an air bearing  22  is disposed in the second air bearing space  17  to surround an outer circumference of the front part  4   c  of the piston  4 . In addition, an air bearing  23  is disposed in the third air bearing space  18  to surround an outer circumference of the rear part  4   e  of the piston  4 . 
     Although not being limited, an example of each of the air bearings  21  to  23  can include an air bearing in which a porous material using sintered metal or carbon is formed in a ring shape or an orifice throttle-type air bearing. 
     As shown in  FIGS.  2  and  4   , the cylinder body  2  is provided with air bearing pressurizing ports  27 ,  28 , and  29  that communicate with the air bearing spaces  16 ,  17 , and  18 , respectively, from the outer circumferential surface of the cylinder body  2 . 
     The compressed air is supplied to each of the air bearing pressurizing ports  27  to  29 , and thus the compressed air uniformly blows onto surfaces of the piston  4  and the piston rod  5  through the each of the air bearings  21  to  23 . Thereby, each of the piston  4  and the piston rod  5  is supported in a state of floating in the cylinder chamber  12  and the insertion portion  13 . 
     In the cylinder device  1  of the present embodiment, the compressed air is supplied and discharged from the rotation ports  31  and  32  facing the rotating portion  11  of the shaft member  3 . Thus, the fluid acts on the rotating portion  11  to generate a rotational force, and the shaft member  3  can rotate about the shaft center O which is the center of rotation. In the present embodiment, the shaft member  3  can rotate in a state of floating in the cylinder body  2 . Since the shaft member  3  and the cylinder body  2  are not in contact with each other, a rotational resistance can be reduced and the rotation can be made with high accuracy. 
     The rotation port  31  shown in  FIG.  4    is, for example, a supply port for compressed air, and the rotation port  32  is an exhaust port for compressed air. In  FIG.  4   , the respective rotation ports  31  and  32  are disposed on opposite sides through the rotating portion  11 , but the preferred form of the rotation ports  31  and  32  will be described below. Thereby, it is possible to guide the compressed air from a supply position of the rotation port  31  to the rotation port  32  on the surface of the rotating portion  11  and to reduce the loss of the compressed air. 
     In the present embodiment, the piston  4  of the shaft member  3  is supported in the state of floating in the cylinder chamber  12  of the cylinder body  2  by the air bearing-type configuration, and accordingly minute gaps  30  are formed between the rotation ports  31  and  32  and the rotating portion  11  as shown in  FIG.  4   . Thereby, an air flow is formed while the compressed air passes through the gap  30 , and the rotating portion  11  can efficiently rotate. In the present embodiment, since the piston  4  of the shaft member  3  is in the floating state during the rotation and the entire shaft member  3  rotates in a non-contact manner, rotation noise can be reduced. 
     In the present embodiment, a differential pressure between the first fluid chamber  14  and the second fluid chamber  15  is generated using a supply and discharge of the compressed air from the stroke ports  25  and  26  communicating with the cylinder chamber  12  in the state where the shaft member  3  floats in the cylinder body  2 . Thereby, the piston  4  can be stroked in the shaft direction (X1-X2 direction). Although not shown, a cylinder control pressure can be appropriately adjusted by servo valves that communicate with the stroke ports  25  and  26 , respectively. 
     From the states of  FIGS.  2  and  4   , the compressed air in the first fluid chamber  14  is sucked through the stroke port  25  by the servo valve. On the other hand, the compressed air is supplied into the second fluid chamber  15  through the stroke port  26  by the servo valve. Thus, the differential pressure is generated between the first fluid chamber  14  and the second fluid chamber  15 , and the piston  4  can move to the front side (X1) as shown in  FIG.  5   . Thus, the piston rod  5  can be protruded forward from the front end surface  2   a  of the cylinder body  2 . 
     A front wall  40  is provided between the cylinder chamber  12  and the insertion portion  13 , and the piston  4  is regulated so as not to move forward from the front wall  40 . Further, as shown in  FIG.  4   , the front wall  40  is preferably provided with an elastic ring  41 . The elastic ring  41  acts as a buffer material when the piston  4  comes into contact with the front wall  40 . 
     Alternatively, from the states of  FIGS.  2  and  4   , the compressed air in the second fluid chamber  15  is sucked through the stroke port  26  by the servo valve. On the other hand, the compressed air is supplied into the first fluid chamber  14  through the stroke port  25  by the servo valve. Thus, the differential pressure is generated between the first fluid chamber  14  and the second fluid chamber  15 , and the piston  4  can move to the rear side (X2) as shown in  FIG.  6   . Thus, the piston rod  5  can be retracted rearward from the front end surface  2   a  of the cylinder body  2 . 
     A rear wall  42  of the cylinder chamber  12  is a regulatory surface that regulates the movement of the piston  4  to the rear side (X2), and the piston  4  can hardly move rearward from the rear wall  42 . Further, as shown in  FIG.  4   , the rear wall  42  is preferably provided with an elastic ring  43 . The elastic ring  43  acts as a buffer material when the piston  4  comes into contact with the rear wall  42 . 
     As shown in  FIGS.  1 ,  2 , and  4   , and the like, a sensor (stroke sensor)  50  is provided in the hole  8  formed in the rear end surface  4   b  of the piston  4  in a non-contact manner with the piston  4 . The sensor  50  is fixedly supported on the rear end side of the cylinder body  2 . 
     In the present embodiment, a position of the piston  4  can be measured by the sensor  50  disposed in the hole  8 . An example of the sensor  50  can include an existing sensor such as a magnetic sensor, an eddy-current sensor, or an optical sensor. 
     Position information measured by the sensor  50  is transmitted to a control unit (not shown) through a cable  51  (see  FIG.  4   ). Based on the position information measured by the sensor  50 , the cylinder control pressures of the first fluid chamber  14  and the second fluid chamber  15  can be adjusted to control the amount of protrusion of the piston rod  5 . 
     Further, the sensor  50  can also measure a rotational frequency of the shaft member  3 . Based on rotation information measured by the sensor  50 , a rotation pressure can be adjusted to control a rotational frequency of the rotating portion  11 . 
     Hereinafter, a description will be made with respect to the form of the rotation ports  31  and  32  for facilitating the rotation of the rotating portion  11 . All the drawings described below are partial cross-sectional views taken in a direction orthogonal to the shaft direction (X1-X2 direction). 
     For example, as shown in  FIG.  7   , the rotation port  31  and the rotation port  32  are provided on opposite sides through the shaft member  3 , but it is preferable that one or both of the rotation ports  31  and  32  be changed in angle such that penetration directions of the respective rotation ports  31  and  32  are not aligned in a straight line through the shaft center O of the shaft member  3 . In  FIG.  7   , the penetration direction of the rotation port  31  is provided to be inclined from a straight direction S passing through the shaft center O. An arrow A indicates a direction of the flow of the compressed air, and the compressed air enters the cylinder body  2  diagonally from the rotation port  31  and easily flows in one side direction of the rotating portion  11 . As a result, the rotating portion  11  can appropriately rotate. 
     In  FIG.  8   , the rotation port  31  is disposed at a position deviated from the straight direction S passing through the shaft center O. In other words, the rotation ports  31  and  32  are disposed to be shifted from each other without being aligned on a straight line passing through the shaft center O. At this time, the rotation port  31 , which is the supply side, is preferably disposed to be shifted. Thus, the compressed air supplied from the rotation port  31  easily flows in one side direction of the rotating portion  11  as indicated by the arrow A. As a result, the rotating portion  11  can appropriately rotates. 
     The respective rotation ports  31  and  32  are disposed on the substantially opposite sides through the shaft member  3  in  FIGS.  7  and  8   , but the respective rotation ports  31  and  32  may be disposed on the same side as viewed from the shaft member  3  as shown in  FIG.  9   . As shown in  FIG.  9   , the respective rotation ports  31  and  32  may be preferably disposed to be shifted to left and right with respect to the straight direction S passing through the shaft center O. Thereby, as indicated by the arrow A, the compressed air supplied from the rotation port  31  flows in one side direction of the rotating portion  11 , rotates more than a half of the circumference, and is discharged to the outside from the rotation port  32 . In  FIG.  9   , since the respective rotation ports  31  and  32  are disposed at positions close to each other, in order to prevent the flow of the compressed air from occurring as much as possible at a short distance between the respective rotation ports  31  and  32 , a body thickness t 1  of the cylinder body  2  on a side of a short distance is preferably thicker than a body thickness t 2  of the cylinder body  2  on a side of a long distance between the respective rotation ports  31  and  32 . Thereby, a space between the cylinder body  2  and the rotating portion  11  can be made narrower at the position of the body thickness t 1  compared with the position of the body thickness t 2 , and the compressed air can be controlled so as not to flow through the short distance between the respective rotation ports  31  and  32  as much as possible. Therefore, the compressed air supplied from the rotation port  31  can be discharged from the rotation port  32  by passing through the side of the long distance from the rotating portion  11 . As a result, the rotating portion  11  can appropriately rotate. 
     In  FIG.  10   , the penetration directions of the rotation ports  31  and  32  is provided along the straight direction S passing through the shaft center O, but a body thickness t 3  of the cylinder body  2  on one side of the rotation ports  31  and  32  is set to be thicker than a body thickness t 4  of cylinder body  2  on the other side. Thereby, a space between the cylinder body  2  and the rotating portion  11  can be made narrower at the position of the body thickness t 3  compared with the position of the body thickness t 4 , and the compressed air can be controlled so as not to flow through a portion of the body thickness t 3  as much as possible. Therefore, the compressed air supplied from the rotation port  31  can easily flow to only one side where the space between the rotating portion  11  and the cylinder body  2  is wide as indicated by the arrow A, and as a result, the rotating portion  11  can appropriately rotate. 
     Features of the present embodiment will be described. 
     The present embodiment is to provide the cylinder device  1  including the cylinder body  2  and the shaft member  3  supported in the cylinder body  2 , the cylinder body  2  being provided with the rotation ports  31  and  32  that communicate with the outer circumferential surface around the shaft member  3  and rotate the shaft member  3  based on the supply and discharge of the fluid. 
     In the present embodiment, as described above, the cylinder body  2  is provided with the rotation ports  31  and  32  communicating with the outer circumferential surface of the shaft member  3  such that the fluid acts on the outer circumferential surface of the shaft member  3  to rotate the shaft member  3 . According to such a configuration, it is possible to reduce power consumption and achieve compactification as compared with the conventional configuration using a rotary motor such as a stepping motor or a servo motor. 
     In the present embodiment, prevention of rotation unevenness can be made. The “prevention of rotation unevenness” will be described in detail. In the present embodiment, the rotating portion  11  is configured on the outer circumferential surface of the shaft member  3  that coincides with the rotating direction. Therefore, the distances from the rotating portion  11  to the rotation ports  31  and  32  can always be substantially constant without being changed depending on the rotation of the rotating portion  11  or the stroke of the shaft member  3 . For example, in a configuration in which the distances from the rotating portion to the rotation ports change depending on the stroke of the shaft member  3 , a rotation pressure changes, resulting in uneven rotation. On the other hand, according to the present embodiment, since the distances from the rotating portion  11  to the rotation ports  31  and  32  can be kept substantially constant, the rotation pressure does not change and rotation unevenness can be prevented. 
     In the present embodiment, since the rotating portion  11  is configured on the outer circumferential surface of the shaft member  3  that coincides with the rotating direction, it is possible to prevent the generation of thrust in the shaft direction (X1-X2 direction) for the shaft member  3  based on the rotation of the rotating portion  11 . Therefore, the shaft member  3  can be prevented from freely moving in the shaft direction or the stroke amount of the shaft member  3  can be prevented from being varied, so that no special means for controlling the stroke amount due to the rotation is required. 
     In the present embodiment, the shaft member  3  includes the rotating portion  11  in which the recessed parts  9  and the projecting parts  10  are alternately continuous with each other along the outer circumferential surface. Then, the rotation ports  31  and  32  are formed to communicate with the rotating portion  11 . The rotation ports  31  and  32  preferably face the rotating portion  11 . 
     With such a configuration, it is not necessary to provide the rotating portion  11  separately from the shaft member  3 , and the rotating portion  11  can be formed in a simple shape. Accordingly, the cylinder device  1  can be made compact and manufacturing cost can be reduced. 
     In the present embodiment, the shaft member  3  is preferably supported to be capable of stroke. Thereby, the shaft member  3  can be stroked while rotating. 
     In the present embodiment, the shaft member  3  includes the rotating portion  11  on the outer circumferential surface in the middle in the shaft direction (X1-X2 direction). The stroke ports  25  and  26  are provided in the cylinder body  2  on the front side (X1 side) and the rear side (X2 side) of the rotating portion  11  to stroke the shaft member  3  by the supply and discharge of the fluid. Then, the rotation ports  31  and  32  communicating with the rotating portion  11  are preferably provided between the stroke ports  25  and  26 . 
     As described above, according to the present embodiment, since the rotating portion  11  is provided in the middle of the shaft member  3 , a rotation mechanism needs not to be separately provided, and the device can be made compact. Further, the cylinder body  2  is provided with the rotation ports  31  and  32  communicating with the rotating portion  11 , and the stroke ports  25  and  26  are provided in front of and behind the rotation ports  31  and  32 . Thereby, it is possible to manufacture the cylinder device  1  in which the shaft member  3  can be stroked while rotating with a simple structure. 
     In the present embodiment, one rotation port may be provided. However, in such a case, the fluid is supplied and discharged by the one rotation port, and thus it is necessary to divide a supply time and a discharge time from each other, make the rotation port large or the like. In order to easily control the fluid and realize a smooth fluid flow, a plurality of rotation ports  31  and  32  are preferably provided. 
     In the present embodiment, the shaft member  3  preferably includes a fluid bearing, and the shaft member  3  is preferably supported in the state of floating in the cylinder body  2 . Thereby, the stroke and rotation can be performed with high accuracy. The air bearing is preferably used as the fluid bearing. Thus, sliding resistance during the stroke and rotation can be effectively reduced. 
     The present invention is not limited to the above embodiment, and can be modified in various ways. In the above embodiment, the size and shape shown in the accompanying drawings can be appropriately changed within the range, in which the effects of the present invention are exhibited, without limitation. In addition, the above embodiment can be appropriately modified and implemented without deviating from the scope of the object of the present invention. 
     For example, the sensor  50  is not disposed as shown in  FIGS.  2  and  4   , and the like, and the sensor  50  may be disposed such that the position of the piston rod  5  can be directly measured. 
     However, as shown in  FIGS.  2  and  4   , and the like, when the sensor  50  is disposed in the hole  8  formed at the rear end surface  4   b  of the piston  4 , the sensor  50  can be disposed, without any difficulty, on the piston  4  in a non-contact manner, compactification can be promoted, and the accuracy of position and rotation measurement can be improved. 
     The cylinder body  2  may be formed in such a manner that a plurality of divided cylinder bodies are assembled or integrated. 
     The cylinder body  2  and the shaft member  3  are made of, for example, an aluminum alloy and the like, but the material can be variously changed depending on the intended use, installation locations and the like without limitation. 
     As described above, according to the present embodiment, since the cylinder device  1  can be driven by the action of a fluid other than air, for example, a hydraulic cylinder can be exemplified in addition to the air bearing-type cylinder, as the cylinder device. 
     According to the present invention, it is possible to realize a cylinder device capable of preventing rotation unevenness while reducing power consumption and promoting compactification. The present invention may be either of a cylinder device capable of only rotation or a cylinder device capable of both rotation and stroke. According to the present invention, it is possible to obtain excellent rotation accuracy and rotational stroke accuracy. In this way, when the cylinder device of the present invention is applied to a use that requires high rotational accuracy and rotational stroke accuracy or the like, it is possible to reduce power consumption and promote compactification in addition to high accuracy. 
     While the present disclosure has been illustrated and described with respect to a particular embodiment thereof, it should be appreciated by those of ordinary skill in the art that various modifications to this disclosure may be made without departing from the spirit and scope of the present disclosure.