JP6867216B2 - Rotary cylinder device - Google Patents

Description

The present invention relates to a rotary cylinder device that rotates and generates an axial driving force in the rotating body. In particular, the present invention is attached to the rear end of the spindle of a lathe and operates by receiving pressure oil from a hydraulic unit to operate the tip of the spindle. The present invention relates to a rotary cylinder device suitable for opening and closing the grasping chuck.

In the conventional rotary cylinder device, a cylinder body having a built-in piston is rotatably provided in the distributor, a lubrication part lubricated with oil is formed between the rotating cylinder body and the distributor, and pressure oil from the hydraulic unit is formed. Is supplied from the distributor into the cylinder body to operate the piston, and the piston opens and closes the grasping chuck that grasps the workpiece at the tip of the spindle. Then, the hydraulic unit is integrally provided with the distributor (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2006-226423

However, in such a conventional rotary cylinder device, the lubrication part is lubricated by using a part of the pressure oil supplied from the hydraulic unit into the cylinder body. There is a problem that it is difficult to save energy in the hydraulic unit because the hydraulic unit cannot be stopped because the pressure oil must be continuously supplied from the unit to the lubricating portion.

An object of the present invention is to provide a rotary cylinder device capable of stopping the hydraulic unit while the cylinder body is rotating to save energy in the hydraulic unit.

In order to achieve such a problem, the present invention has taken the following measures. That is,
A cylinder body with a built-in piston is rotatably provided in the distributor, a lubrication part lubricated with oil is formed between the rotating cylinder body and the distributor, and pressure oil from the hydraulic unit is supplied from the distributor into the cylinder body. In a rotary cylinder device that supplies and operates a piston, the distributor is equipped with a hydraulic pump that is rotationally driven by the rotation of the cylinder body to discharge oil, and a supply path that supplies oil discharged from the hydraulic pump to the lubrication section. It is a rotary cylinder device characterized by the provision of.

In this case, a pressure switch that outputs a signal when the pressure of the pressure oil that operates the piston reaches a set value may be provided, and the hydraulic unit may be stopped by a signal from the pressure switch. Further, the hydraulic pump includes an internal gear having internal teeth and an external gear having external teeth, the external gears are eccentrically arranged in the internal gears, and the internal teeth and the external teeth are inscribed. It may be composed of an internal gear pump that meshes and rotates the internal gear by the external gear, and the external gear may be rotationally driven by the rotation of the cylinder body. Further, the internal gear pump is provided so as to be rotatable in the forward and reverse directions, and the arcuate first port and the second port are arranged symmetrically with respect to the center in the radial direction. The oil sucked from the second port may be discharged from the second port, and the oil sucked from the second port may be discharged from the first port by the reverse rotation of the external gear.

As described in detail above, in the invention according to claim 1, the distributor is provided with a hydraulic pump that is rotationally driven by the rotation of the cylinder body to discharge oil, and supplies oil discharged from the hydraulic pump to the lubrication unit. A road was set up. Therefore, since the oil discharged from the hydraulic pump can be supplied to the lubrication part to lubricate the lubrication part, it is not necessary to supply the pressure oil from the hydraulic unit to the lubrication part, and the hydraulic unit is rotating while the cylinder body is rotating. Can be stopped, and the energy saving of the hydraulic unit can be achieved.

Further, in the invention according to claim 2, a pressure switch for outputting a signal when the pressure of the pressure oil for operating the piston reaches a set value is provided, and the hydraulic unit is stopped by a signal from the pressure switch. Therefore, when the piston operates to the operating end and is stopped, the pressure of the pressure oil supplied from the hydraulic unit reaches the set value of the pressure switch, so that the hydraulic unit can be reliably stopped by the signal from the pressure switch. , The energy saving of the hydraulic unit can be surely achieved.

Further, according to the third aspect of the present invention, the hydraulic pump includes an internal gear having internal teeth and an external gear having external teeth, and the external gear is eccentrically arranged in the internal gear. It was composed of an internal gear pump in which the teeth and the external teeth were internally meshed and the internal gear was rotated by the external gear, and the external gear was rotationally driven by the rotation of the cylinder body. Therefore, since the hydraulic pump is an internal gear pump including an external gear that is rotationally driven by the cylinder body and an internal gear that is rotated by the external gear, it can be easily manufactured with a simple configuration.

Further, according to the fourth aspect of the present invention, the internal gear pump is provided so as to be rotatable forward and reverse, and the first port and the second port having an arc shape are arranged symmetrically with respect to the center in the radial direction. The oil sucked from the first port was discharged from the first port by the forward rotation of the above, and the oil sucked from the second port was discharged from the first port by the reverse rotation of the external gear. Therefore, since the inscribed gear pump can supply oil to the lubricating portion in any of forward and reverse rotations, it can satisfactorily cope with both forward and reverse rotations of the cylinder body.

It is a vertical sectional view of the rotary cylinder apparatus which showed one Embodiment of this invention. It is a hydraulic circuit diagram of one embodiment. It is sectional drawing which follows the line AA of FIG. It is sectional drawing which follows the line BB of FIG. It is sectional drawing which follows the line CC of FIG. It is sectional drawing which follows the line DD of FIG.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
In FIGS. 1 and 2, reference numeral 1 denotes a cylinder body containing a piston 2, which is rotatably provided to the distributor 3. The cylinder body 1 is formed through a sliding hole 4 for fitting the piston 2 so as to be slidable in the axial direction, and the piston 2 is rotated around the cylinder body 1. The cylinder body 1 has a lid member 5 and a shaft 6, and one end opening of the sliding hole 4 is closed by the lid member 5 to form a first hydraulic chamber 7 on one end side of the piston 2 and the sliding hole is formed. The other end opening of 4 is closed by the shaft 6 to form a second hydraulic chamber 8 on the other end side of the piston 2. Reference numeral 9 denotes a rod integrally formed on one end side of the piston 2, which penetrates the lid member 5 in a liquid-tight manner and protrudes to the outside, and the protruding end portion is attached to the main shaft 10 of the lathe. The spindle 10 of the lathe is rotationally driven by an electric motor (not shown), and a grasping chuck 11 for grasping the work W is provided so as to be openable and closable. The grasping chuck 11 closes when the rod 9 moves backward into the cylinder body 1 to grasp the work W, and opens when the rod 9 moves forward from the cylinder body 1 to release the grasping of the work W.

The distributor 3 is configured by connecting the first main body 3A, the second main body 3B, the third main body 3C, the fourth main body 3D, the fifth main body 3E, and the sixth main body 3F with bolt members (not shown). Insertion holes 9A and 9B through which the shaft 6 of the cylinder body 1 is inserted are formed through the first main body 3A and the second main body 3B. Reference numerals 10A and 10B are bearings that rotatably support the shaft 6 inserted through the insertion holes 9A and 9B to the distributor 3, and the bearing 10A is arranged at the opening end of the insertion hole 9A of the first main body 3A on the cylinder body 1 side. The bearing 10B is arranged at the opening end of the insertion hole 9B of the second main body 3B on the third main body 3C side. Reference numeral 7A is a first flow path connected to the first hydraulic chamber 7, which is formed in the shaft 6 and has one end opened on the outer peripheral surface of the shaft 6 at the insertion point with the insertion hole 9A. Reference numeral 8A is a second flow path connected to the second hydraulic chamber 8, which is formed in the shaft 6 and has one end opened on the outer peripheral surface of the shaft 6 at the insertion point with the insertion hole 9B. Reference numeral 13A is an annular groove formed by forming an annular recess in the inner peripheral surface of the insertion hole 9A, and is connected to the opening of the first flow path 7A to the outer peripheral surface of the shaft 6. Reference numeral 13B is an annular groove formed by forming an annular recess in the inner peripheral surface of the insertion hole 9B, and is connected to the opening of the second flow path 8A to the outer peripheral surface of the shaft 6. Reference numeral 14A is a first load port connected to the annular groove 13A, which is open to the outer surface of the first main body 3A. Reference numeral 14B is a second load port connected to the annular groove 13B, which is open to the outer surface of the second main body 3B. 15A and 15B are two annular sealing members provided in the first main body 3A, and are fitted to the shaft 6 with an axial gap in the front-rear direction of the opening of the first flow path 7A, and the first flow path. Prevents oil from leaking to the outside from the connection point between 7A and the annular groove 13A. 15C and 15D are two annular sealing members provided on the second main body 3B, and are fitted to the shaft 6 with an axial gap in the front-rear direction of the opening of the second flow path 8A, and the second flow path is provided. Prevents oil from leaking to the outside from the connection point between 8A and the annular groove 13B.

Reference numeral 16 denotes a drive shaft coupled to the protruding end portion of the shaft 6 by a trunnion, and the tip portion is rotatably supported by the sixth main body 3F by inserting the third main body 3C to the fifth main body 3E. As shown in FIGS. 1 and 3, reference numeral 17 denotes an internal gear pump as a hydraulic pump provided in the distributor 3, which has a ring-shaped internal gear 18 having eight internal teeth 18A and one less than the internal teeth 18A. It is provided with an external gear 19 having seven external teeth 19A, and is provided so as to be rotatable forward and reverse. The internal gear 18 is rotatably housed in the fifth main body 3E. The external gear 19 is eccentrically arranged in the internal gear 18, and the internal tooth 18A and the external tooth 19A are inscribed and meshed to rotate the internal gear 18. The external gear 19 is connected to the drive shaft 16 that inserts the central portion in the radial direction in a two-sided width, and is rotationally driven via the shaft 6 and the drive shaft 16 by the rotation of the cylinder body 1. As shown in FIGS. 1 and 4, the internal gear pump 17 has an arcuate first port 20A and a second port 20B radially on the side surface of the fourth main body 3D in which the side surfaces of the gears 18 and 19 are in sliding contact with each other. It is arranged symmetrically with respect to the center C to form a depression. The first port 20A sucks oil in the forward rotation of the gears 18 and 19 in the direction of arrow A (shown in FIG. 3), and the oil is rotated in the direction opposite to the direction of arrow A of the gears 18 and 19. Is discharged. The second port 20B discharges oil in the forward rotation of the gears 18 and 19 in the direction of arrow A, and sucks oil in the reverse rotation of the gears 18 and 19 in the direction opposite to the direction of arrow A.

As shown in FIGS. 4 to 6, 21A is a first suction flow path for sucking oil, one end is opened below the first port 20A, the fourth main body 3D is axially penetrated, and the outer surface of the third main body 3C is formed. The other end is open. 21B is a second suction flow path for sucking oil, one end is opened below the second port 20B, the fourth main body 3D is axially penetrated, and the other end is opened on the outer surface of the third main body 3C. As shown in FIG. 2, the suction flow paths 21A and 21B are connected to the oil tank T. A first suction check valve 22A is provided in the first suction flow path 21A, and a second suction check valve 22B is provided in the second suction flow path 21B. The suction check valves 22A and 22B allow the flow from the oil tank T side to the ports 20A and 20B, and block the flow from the ports 20A and 20B to the oil tank T side.

As shown in FIGS. 4 and 5, 23A is a first discharge flow path for discharging oil, one end is opened above the first port 20A, and the other end is opened on the outer surface of the fourth main body 3D. Reference numeral 23B is a second discharge flow path for discharging oil, one end of which is opened above the second port 20B and the other end of which is open on the outer surface of the fourth main body 3D. A first discharge check valve 24A is provided in the first discharge flow path 23A, and a second discharge check valve 24B is provided in the second discharge flow path 23B. The discharge check valves 24A and 24B allow the flow from the ports 20A and 20B to the other end opening side of the discharge flow paths 23A and 23B, and from the other end opening side of the discharge flow paths 23A and 23B, respectively. Block the flow to the ports 20A and 20B.

Reference numeral 25 denotes a block member attached over the upper portions of the third main body 3C and the fourth main body 3D, and two flow paths 26A and 26B are bored therein. The flow path 26A connects the first discharge flow path 23A and the flow path 27A bored in the third main body 3C. The flow path 26B connects the first discharge flow path 23B and the flow path 27B formed in the third main body 3C. The flow path 27A and the flow path 27B are connected to the flow path 28 inside the third main body 3C. The flow path 28 is connected to the flow path 29 formed through the second main body 3B. The flow path 29 is connected to the flow path 30 formed in the first main body 3A, and the shaft 6 of the cylinder main body 1 is connected to the bearing 10B rotatably supported by the distributor 3. The flow path 30 is connected to another bearing 10A that rotatably supports the shaft 6 of the cylinder body 1 to the distributor 3. Then, the supply path 31 for supplying the oil discharged from the inscribed gear pump 17 to the lubricating portion is composed of the discharge flow paths 23A and 23B and the flow paths 26A, 26B, 27A, 27B, 28, 29 and 30. There is. Further, the lubricating portions 32A and 32B that are lubricated by oil between the cylinder body 1 and the distributor 3 are the bearings 10A and 10B that rotatably support the cylinder body 1 to the distributor 3.

Reference numeral 33 denotes a discharge path for discharging the oil supplied to the lubrication portions 32A and 32B to the tank T (shown in FIG. 2), which is composed of flow paths 34, 35, 36, 37, 38 and 39. The flow path 34 is bored in the first main body 3A and is connected to the bearing 10A on the side opposite to the connection point of the flow path 30 in the radial direction. The flow path 35 is formed through the second main body 3B and is connected to the flow path 34 bored in the first main body 3A, and is connected to the bearing 10B on the side opposite to the connection point of the flow path 29 in the radial direction. The flow path 36 is formed through the third main body 3C and is connected to the flow path 35 of the second main body 3B. The flow path 37 is formed through the fourth main body 3D and is connected to the flow path 36 of the third main body 3C. The flow path 38 is formed through the fifth main body 3E and is connected to the flow path 37 of the fourth main body 3D. The flow path 39 is formed through the 6th main body 3F and is connected to the flow path 38 of the 5th main body 3E.

As shown in FIG. 2, reference numeral 40 denotes a hydraulic unit, which supplies pressure oil from the distributor 3 into the cylinder body 1 to operate the piston 2. The flood control unit 40 includes a pump 41, an electric motor 42, a relief valve 43, an electromagnetic switching valve 44, a pilot-operated check valve 45, a variable throttle valve 46 with a check valve, a pressure switch 47, and a tank T. The pump 41 is rotationally driven by the electric motor 42, sucks the oil stored in the tank T, and discharges the pressure oil. The relief valve 43 sets the pressure of the pressure oil discharged from the pump 41 to a set value. The electromagnetic switching valve 44 has three positions and four ports, and has three positions, a neutral position X, a first switching position Y, and a second switching position Z, which can be switched between energized and non-energized. The neutral position X cuts off the supply flow path P for supplying the pressure oil discharged from the pump 41, and connects the first load flow path A to the first hydraulic chamber 7 of the cylinder body 1 and the second hydraulic chamber 8 of the cylinder body 1. The second load flow path B connected to the tank T is communicated with the discharge flow path R connected to the tank T. At the first switching position Y, the first load flow path A is switched and communicated with the supply flow path P, and the second load flow path B is switched and communicated with the discharge flow path R. At the second switching position Z, the first load flow path A is switched and communicated with the discharge flow path R, and the second load flow path B is switched and communicated with the supply flow path P.

In the pilot-operated check valve 45, the first check valve body 45A is arranged in the first load flow path A, and the second check valve body 45B is arranged in the second load flow path B, respectively. The check valve bodies 45A and 45B allow the flow from the electromagnetic switching valve 44 side to the hydraulic chambers 7 and 8 side, and block the flow from the hydraulic chambers 7 and 8 side to the electromagnetic switching valve 44 side. Then, the check valve bodies 45A and 45B flow through the other load flow path B or A in which they are not arranged, in a state where the flow from the hydraulic chambers 7 and 8 side to the electromagnetic switching valve 44 side is blocked. A part of the pressure oil is acted as a pilot pressure oil to open the operation, and the flow from each of the flood control chambers 7 and 8 to the electromagnetic switching valve 44 side is allowed.

In the variable throttle valve 46 with a check valve, the first variable throttle valve body 46A is arranged in the first load flow path A, and the second variable throttle valve body 46B is arranged in the second load flow path B, respectively. The variable throttle valve bodies 46A and 46B throttle the oil discharged from the hydraulic chambers 7 and 8 to the electromagnetic switching valve 44 side to control the flow rate. The pressure switch 47 is branched and arranged in the first load flow path A, discharged from the pump 41, flows through the electromagnetic switching valve 44, the pilot-operated check valve 45, and the variable throttle valve 46 with the check valve, and flows through the cylinder body 1. A signal is output when the pressure of the pressure oil supplied to the first hydraulic chamber 7 reaches a set value. The electric motor 42 stops the rotary drive by the signal output from the pressure switch 47.

Next, the operation of such a configuration will be described.
The state of FIG. 2 shows the stopped state of the hydraulic unit 40, the electric motor 42 and the pump 41 are stopped, and the electromagnetic switching valve 44 is located at the neutral position X. The piston 2 of the cylinder body 1 is located at the forward end, and the grip chuck 11 is not opened to grip the work W. Further, the spindle 10 has stopped rotating.

In this state, when the hydraulic unit 40 is put into operation, the pump 41 is rotationally driven by the electric motor 42, and the electromagnetic switching valve 44 is energized to switch to the first switching position Y, the pump 41 discharges the pump 41 to the supply flow path P. The pressure oil flows from the electromagnetic switching valve 44 through the first load flow path A via the pilot-operated check valve 45 and the variable throttle valve 46 with the check valve, and is supplied to the first hydraulic chamber 7 of the cylinder body 1. The piston 2 retracts to the left in FIG. 2 to close the grasping chuck 11 to grasp the work W. As the piston 2 retracts to the left in FIG. 2, the oil in the second hydraulic chamber 8 is throttle-controlled by the variable throttle valve 46 with a check valve from the second load flow path B, and the pilot-operated check valve 45, It flows through the discharge flow path R via the electromagnetic switching valve 44 and is discharged to the tank T.

Then, when the piston 2 operates to the retracted end and the pressure of the pressure oil supplied to the first hydraulic chamber 7 reaches the set value of the pressure switch 47, the electric motor 42 is stopped by the signal from the pressure switch 47. Further, the electromagnetic switching valve 44 is de-energized and returned to the neutral position X. In this state, the pressure oil supplied to the first hydraulic chamber 7 is blocked from flowing to the electromagnetic switching valve 44 side by the first check valve body 45A of the pilot-operated check valve 45, and the first hydraulic chamber 7 The grasping chuck 11 keeps the closed state and keeps grasping the work W without the pressure decreasing.

With the work W grasped by the grasping chuck 11, the spindle 10 of the lathe is rotationally driven to process the work W. At this time, the cylinder body 1, the shaft 6, and the drive shaft 16 are rotationally driven along with the rotational drive of the spindle 10. The internal gear pump 17 rotationally drives the external gear 19 on the drive shaft 16 in the positive direction of the arrow A (shown in FIG. 3), and the external gear 19 rotates the internal gear 18 in the same direction. The oil sucked from the suction flow path 21A through the first suction check valve 22A is discharged from the second discharge flow path 23B through the second discharge check valve 24B. The discharged oil flows through the supply path 31 and is supplied to the lubrication sections 32A and 32B to lubricate the lubrication sections 32A and 32B, and the lubricated oil flows through the discharge path 33 and is discharged to the tank T.

When the machining of the work W is completed, the rotation of the spindle 10 is stopped. The internal gear pump 17 stops the rotation of both gears 18 and 19 as the spindle 10 stops rotating, and stops the supply of oil to the lubricating portions 32A and 32B.

When the pump 41 is rotationally driven by the electric motor 42 and the electromagnetic switching valve 44 is energized to switch to the second switching position Z while the rotation of the spindle 10 is stopped, the pressure oil discharged from the pump 41 to the supply flow path P. Flows from the electromagnetic switching valve 44 via the pilot-operated check valve 45 and the variable throttle valve 46 with the check valve through the second load flow path B, and is supplied to the second hydraulic chamber 8 of the cylinder body 1. The piston 2 moves forward to the right in FIG. 2 to open the grasping chuck 11 to release the grasping of the work W. As the piston 2 moves forward to the right in FIG. 2, the oil in the first hydraulic chamber 7 is throttle-controlled by the variable throttle valve 46 with a check valve from the first load flow path A, and the pilot-operated check valve 45, It flows through the discharge flow path R via the electromagnetic switching valve 44 and is discharged to the tank T. Then, when the piston 2 operates to the forward end, the electric motor 42 is stopped, the electromagnetic switching valve 44 is de-energized, and the piston 2 returns to the neutral position X.

With this operation, the distributor 3 is provided with a hydraulic pump 17 that is rotationally driven by the rotation of the cylinder body 1 to discharge oil, and is provided with a supply path 31 that supplies the oil discharged from the hydraulic pump 17 to the lubricating portions 32A and 32B. .. Therefore, the oil discharged from the hydraulic pump 17 can be supplied to the lubrication portions 32A and 32B to lubricate the lubrication portions 32A and 32B, so that the pressure oil from the pump 41 of the hydraulic unit 40 is not supplied to the lubrication portions 32A and 32B. The pump 41 and the electric motor 42 of the hydraulic unit 40 can be stopped while the cylinder body 1 is rotating, and the hydraulic unit 40 can be energy-saving.

Further, a pressure switch 47 for outputting a signal when the pressure of the pressure oil operating the piston 2 reaches a set value is provided, and the electric motor 42 for rotationally driving the pump 41 of the hydraulic unit 40 is stopped by the signal from the pressure switch 47. Therefore, when the work W is grasped by the grasping chuck 11, that is, when the piston 2 operates to the retracted end and is stopped, the pressure of the pressure oil supplied from the pump 41 of the hydraulic unit 40 is the pressure switch. Since the set value of 47 is reached, the electric motor 42 that rotationally drives the pump 41 of the hydraulic unit 40 can be reliably stopped by the signal from the pressure switch 47, and the energy saving of the hydraulic unit 40 can be reliably achieved.

Further, the hydraulic pump 17 includes an internal gear 18 having internal teeth 18A and an external gear 19 having external teeth 19A, and the external gear 19 is eccentrically arranged in the internal gear 18 so that the internal gear 18A is arranged. The external gear 19A and the external gear 19A are internally meshed to form an internal gear pump that rotates the internal gear 18 by the external gear 19, and the external gear 19 is rotationally driven by the rotation of the cylinder body 1. Therefore, since the hydraulic pump 17 is an internal gear pump including an external gear 19 that is rotationally driven by the cylinder body 1 and an internal gear 18 that is rotated by the external gear 19, it can be easily manufactured with a simple configuration. can do.

Further, the internal gear pump 17 is provided so as to be rotatable in the forward and reverse directions, and the arcuate first port 20A and the second port 20B are arranged symmetrically with respect to the center C in the radial direction, and the external gear 19 is oriented in the arrow A direction. The oil sucked from the first port 20A is discharged from the second port 20B by the forward rotation to the first port, and the oil sucked from the second port 20B by the reverse rotation in the direction opposite to the arrow A direction of the external gear 19 is discharged from the second port 20B. Discharged from 20A. Therefore, since the inscribed gear pump 17 can supply oil to the lubricating portions 32A and 32B in any of forward and reverse rotations, it can satisfactorily cope with both forward and reverse rotations of the cylinder body 1.

In one embodiment, the hydraulic pump 17 is an inscribed gear pump including an external gear 19 and an internal gear 18, but a vane pump including a rotor and a vane may be used. Further, although it was applied to a lathe, it is needless to say that it may be applied to an inner diameter grinding machine or an outer diameter grinding machine.

1: Cylinder body 2: Piston 3: Distributor 17: Internal gear pump (hydraulic pump)
18: Internal gear 18A: Internal tooth 19: External gear 19A: External tooth 20A: First port 20B: Second port 31: Supply path 32A, 32B: Lubrication unit 40: Hydraulic unit

Claims (4)

A cylinder body with a built-in piston is rotatably provided in the distributor, a lubrication part lubricated with oil is formed between the rotating cylinder body and the distributor, and pressure oil from the hydraulic unit is supplied from the distributor into the cylinder body. In a rotary cylinder device that supplies and operates a piston, the distributor is equipped with a hydraulic pump that is rotationally driven by the rotation of the cylinder body to discharge oil, and a supply path that supplies oil discharged from the hydraulic pump to the lubrication section. A rotary cylinder device characterized by being provided with. The rotary cylinder device according to claim 1, wherein a pressure switch for outputting a signal when the pressure of the pressure oil for operating the piston reaches a set value is provided, and the hydraulic unit is stopped by a signal from the pressure switch. .. The hydraulic pump includes an internal gear having internal teeth and an external gear having external teeth, the external gear is eccentrically arranged in the internal gear, and the internal teeth and the external teeth are internally meshed with each other. The rotary cylinder device according to claim 1 or 2, wherein the rotary cylinder device comprises an internal gear pump that rotates the internal gear by the external gear, and the external gear is rotationally driven by the rotation of the cylinder body. The internal gear pump is provided so as to be rotatable in the forward and reverse directions, and the arcuate first port and the second port are arranged symmetrically with respect to the center in the radial direction, and suction is performed from the first port by the forward rotation of the external gear. The rotary cylinder device according to claim 3, wherein the oil is discharged from the second port, and the oil sucked from the second port is discharged from the first port by the reverse rotation of the external gear.

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