JP4940993B2 - Rotating fluid pressure cylinder - Google Patents

Description

  The present invention relates to a rotating fluid pressure cylinder in which a shaft portion of a cylinder body is rotatably supported in a fitting hole of a housing via a bearing.

For example, as shown in FIG. 5, the rotating fluid pressure cylinder 1 is composed of a cylinder body 2 having a piston 6 and a housing 7 that rotatably supports the cylinder body 2. Bearing holes 9 a and 9 b are provided in the fitting hole 10 a of the housing 7, and the shaft portion 3 a of the cylinder body 2 is pivotally supported by the bearings 9 a and 9 b so as to be relatively rotatable with respect to the housing 7. In addition, oil seals 18a and 18b are fitted in the fitting holes 10a of the housing 7 at positions outside the bearings 9a and 9b so as to be able to slide and rotate relative to the shaft portion 3a. A piston 6 is fitted in the cylinder chamber 5 of the cylinder body 2 so as to be slidable in the direction of the rotation axis L. The cylinder chamber 5 is connected with pressure fluid supply / discharge ports 20a, 20b via flow paths 14a, 14b, 21a, 21b passing through the relative rotation part 22 between the fitting hole 10a and the shaft part 3a. Further, the housing 7 is provided with a drain recovery chamber 28 to which a drain port 27 for recovering drain leaking from the flow paths 14a, 14b, 21a, 21b of the relative rotating portion 22 to a working pressure fluid tank (not shown) is connected. ing. The thing of patent document 1 is well-known as such a rotation fluid pressure cylinder. In the rotating fluid pressure cylinder of Patent Document 1, an oil seal is fitted in the fitting hole of the housing at a position outside the bearing so as to be slidably rotatable relative to the shaft portion. In addition, a drain port is provided substantially in the middle between the bearings. The rotary fluid pressure cylinder having such a structure may be used with the rotation axis direction of the cylinder body as the vertical direction so that the cylinder body side is the upper side or the lower side. Moreover, what is shown to patent document 2 as a rotation fluid pressure cylinder is well-known, and the drain port is provided in the one bearing side. When using the thing of patent document 2 so that a rotating shaft direction may become an up-down direction, an oil seal is provided between a cylinder main body and a housing, and it uses it so that a drain may not leak.
Japanese Patent No. 3190994 (FIG. 7) Japanese Patent Laid-Open No. 62-176701 (FIG. 1)

In a rotating fluid pressure cylinder as described in Patent Document 1, for example, referring to FIG. 5, when the rotating shaft L direction of the cylinder body 2 is used as a vertical direction by attaching to a spindle 34 of a vertical lathe not shown, Since the drain port 27 is provided substantially in the middle between the upper and lower bearings 9a and 9b, the distance S between the height position H8 of the drain liquid surface 33 and the height position H2 of the lower surface 9c of the upper bearing 9b is greatly increased. Therefore, there is a problem that the bearing 9b is not immersed in the drain and the lubrication cannot be sufficiently performed. In addition, since the oil seal 18b and the shaft portion 3a are relatively slidably rotated, there is a risk of friction or wear between the oil seal 18b and the shaft portion 3a. Although it is necessary to lubricate between the parts 3a, there is a problem that drain cannot be supplied as a lubricant because the oil seal 18b is above the bearing 9b. Further, even if the drain port is provided on one bearing side as in Patent Document 2, the bottom surface of the drain port is located below the lower surface of the bearing, and the distance between the bottom surface of the drain port and the lower surface of the bearing is greatly increased. If so, there is a problem that the bearing is not immersed in the drain and cannot be sufficiently lubricated. In addition, in such a rotating fluid pressure cylinder, the drain recovery chamber can be formed by taking into consideration that the piping connected to the drain port is higher than the height of the drain port, or that the working pressure fluid tank for recovering the drain is increased. The drain can be supplied to the bearing, but it is unknown how the rotating fluid pressure cylinder, piping, and tank are arranged because it is determined by the user, and the bearing may not be lubricated by the drain. .
The present invention provides a rotating fluid pressure cylinder in which a bearing and an oil seal located on the upper side can be lubricated by a drain even when the rotation axis direction of the shaft portion of the cylinder body is set to the vertical direction.

  According to the present invention, the shaft portion of the cylinder body is fitted into the fitting hole of the housing via a bearing so as to be relatively rotatable, and the piston is provided in a cylinder chamber formed in the cylinder body so as to be slidable in the axial direction of the cylinder body. Pressure that leaks from the flow path of the relative rotation part by connecting each of the cylinder chambers defined by the piston and the pressure fluid supply / discharge port provided in the housing through the flow path passing through the fitting hole and the relative rotation part of the shaft part. In a rotary fluid pressure cylinder having a drain recovery path for recovering fluid drain to the drain port in the housing, when the rotation axis direction of the shaft portion of the cylinder body is set to the vertical direction in the drain recovery path, the drain is connected to the upper side inside the housing. It is characterized by having a drain storage space that can be stored up to the height of the bearing and that can supply drain to the bearing, and that the bearing is lubricated by the drain.

  In addition, the drain collecting passage is provided with a drain storage chamber on the side of the relative rotating portion divided by the dividing wall and a drain collecting chamber on the drain port side, and a communication hole is provided in the dividing wall to communicate the drain storing chamber and the drain collecting chamber. One of the communication hole or drain port is near the upper bearing height of the housing, the other is near the lower bearing height of the housing, the drain storage chamber or drain recovery chamber is the drain storage space, and the drain is the upper bearing height. It is characterized by being able to collect up to the vicinity.

  Further, the bottom of the communication hole or drain port near the upper bearing height in the housing is positioned higher than the lower surface of the bearing inside the housing. In addition, a drain collecting hole member having a drain port is attached to the outer surface of the housing main body having a fitting hole therein to constitute a housing, and the mounting surface to the housing main body and the outer surface of the housing main body are connected to the drain collecting hole member. A drain storage chamber is provided between the drain storage chamber and the drain storage chamber and the drain port.

  According to the invention of claim 1 of the present application, when the rotation axis direction of the shaft portion of the cylinder body is set to the vertical direction in the drain recovery path, the drain is accumulated up to the vicinity of the height of the bearing which is the upper side inside the housing. Since the drain is stored in the drain storage space, the drain can be stored in the clearance of the relative rotating portion, and the upper bearing and The relative rotating part can be lubricated, drain can be reliably supplied to the fluid sealing member near the upper bearing, and the fluid sealing member can be prevented from being damaged due to poor lubrication.

  According to the second aspect of the present invention, the drain collection path includes the drain storage chamber on the side of the relative rotation section divided by the dividing wall and the drain collection chamber on the side of the drain port, and the drain storage chamber and the drain collection chamber are provided on the dividing wall. A communication hole is provided to communicate with the chamber. One of the communication hole or the drain port is set near the upper bearing height of the housing, the other is set near the lower bearing height of the housing, and the drain storage chamber or the drain recovery chamber is set as the drain. As a storage space, the drain is stored up to the vicinity of the upper bearing height. According to the invention of claim 3, the bottom surface of the communication hole or drain port near the upper bearing height in the housing is positioned higher than the lower surface of the bearing inside the housing. According to these, even if the housing is used as the upper side or the lower side and the rotation axis direction is used as the vertical direction, one of the drain port or the communication hole is the upper side and the other is the lower side. As a drain storage space, drain accumulates at a height near the bearing lower surface inside the housing, and drain also accumulates in the gap between the fitting hole and the relative rotation part of the shaft, and lubricates the upper part of the bearing and the relative rotation part. This is preferable because the drain can be reliably supplied to the fluid sealing member near the upper bearing and damage to the fluid sealing member due to poor lubrication can be prevented. In addition, since the drain storage chamber or the drain collection chamber becomes a drain storage space, there is no need to consider the height of the piping and the like, and the bearing can be lubricated by the drain. Further, if the drain storage chamber is formed in a space with a small volume, it can be filled quickly with a small amount of drain, and lubrication is immediately performed, which is more preferable.

  According to the invention of claim 4, the housing is constructed by attaching the drain collection hole member having the drain port to the outer surface of the housing body having the fitting hole therein, and the housing body is attached to the drain collection hole member. Since the drain storage chamber is provided between the mounting surface of the housing and the outer surface of the housing main body, and the drain storage chamber and the drain port are communicated with each other through the communication hole, manufacture is facilitated. Further, a conventional rotating fluid pressure cylinder in which a drain recovery hole member having a drain port is attached to a housing main body is preferable because a drain storage chamber can be provided only by exchanging the drain recovery hole member.

  Embodiments of the present invention will be described with reference to FIGS. In FIG. 1, a rotating fluid pressure cylinder 1 is attached to the other end of a main shaft 34 having a chuck attached to one end of a vertical lathe (not shown), and the rotation axis L direction of the rotating fluid pressure cylinder 1 is the vertical direction. The cylinder body 2 of the rotating fluid pressure cylinder 1 is configured by closing the front end surface of the distributor shaft 3 with a rod-shaped rod cover 4, forming a cylinder chamber 5 inside thereof, and a piston 6 in the cylinder chamber 5. Are slidable in the direction of the rotation axis L. The cylinder chamber 5 is divided into front and rear cylinder chambers 5 a and 5 b by a piston 6. 1 to 3, for the sake of convenience, the cylinder chamber 5 side, that is, the lower side is the front side, and the housing 7 side, that is, the upper side, which will be described later, is the rear side. A restriction pin 8 that restricts relative rotation with the cylinder body 2 is fixed to the piston 6. The shaft portion of the cylinder body 2, that is, the thin shaft portion 3a of the distributor shaft 3 is rotatable relative to a fitting hole 10a of the distributor 10 of the housing 7 described later via a pair of front and rear bearings 9a and 9b. It is mated.

  An end cap 11 for fixing the rear bearing 9 b to the distributor 10 is integrally provided at the rear portion of the shaft portion 3 a of the distributor shaft 3. In addition, a ring 12 that abuts the distributor shaft front rear surface 3b and restricts relative rotation is integrally provided at the front portion of the shaft portion 3a of the distributor shaft 3, and the ring 12 is provided between the distributor 10 and the front bearing. 9a is fixed. Further, annular grooves 13a and 13b are formed on the outer peripheral surface 3c of the shaft portion 3a of the distributor shaft 3, and the annular grooves 13a and 13b form part of the flow paths 14a and 14b provided in the cylinder body 2, respectively. The flow paths 14a and 14b communicate with the front and rear cylinder chambers 5a and 5b, respectively.

  The housing 7 is configured by attaching a drain collection hole member 16 to the outer surface 15 a of the housing body 15. The housing main body 15 is fitted in the fitting hole 15b, and the distributor 10 fixed integrally with a screw and the annular member 17 are screwed together. Fluid sealing members 18a and 18b are provided on the front and rear sides of the housing body 15, respectively. The fluid sealing members 18a and 18b are oil seals, and end caps 11 and a ring 12 integrated with the shaft portion 3a of the distributor shaft 3 are fitted to the oil seals 18a and 18b so as to be relatively slidable and rotatable. It is.

  On the outer peripheral surface of the distributor 10, annular grooves 19a and 19b are formed. Each of the annular grooves 19a and 19b communicates with a pair of supply / discharge ports 20a and 20b provided on the outer peripheral surface 15c of the housing main body so as to have different phases in the circumferential direction and the axial direction so as not to interfere with each other. The supply / discharge ports 20a and 20b are connected to a pressurized fluid supply source (not shown). These annular grooves 19a and 19b form part of flow paths 21a and 21b provided in the distributor 10, respectively. The flow path 21a communicates with the flow path 14a, the flow path 21b communicates with the flow path 14b, the fitting hole 15b of the housing main body 15, and the relative rotation portion 22 of the shaft portion 3a of the distributor shaft 3. The shaft portion 3a of the distributor shaft 3 and the distributor 10 constitute a rotary joint. Further, the distributor 10 is provided with drain channels 24 a and 24 b that open to the fitting hole 10 a of the distributor 10 and the relative rotating portion 22 of the shaft portion 3 a of the distributor shaft 3.

  The drain collecting hole member 16 attached to the outer surface 15a of the housing main body 15 has a groove 25 formed in the attaching surface 16a to the housing main body 15, and the drain collecting hole member 16 is fixed to the housing main body 15, A drain storage chamber 26 is formed between the groove 25 of the mounting surface 16 a and the outer surface 15 a of the housing body 15. Drain passages 24 a and 24 b communicate with the drain storage chamber 26. Further, the drain recovery hole member 16 is provided with a drain recovery chamber 28 to which a drain port 27 is communicated. The drain storage chamber 26 and the drain recovery chamber 28 are communicated with each other through a communication hole 30 formed in a dividing wall 29 that divides the drain storage chamber 26 and the drain recovery chamber 28. A drain recovery path 31 is constituted by the drain channels 24 a and 24 b, the drain storage chamber 26, the communication hole 30, and the drain recovery chamber 28. As shown in FIG. 3, the bottom surface 30 a of the communication hole 30 has the cylinder chamber 5 on the lower side of the housing 7, and the rotation axis direction of the rotating fluid pressure cylinder 1, that is, the rotation axis L direction of the cylinder body 2 is vertical. The height position H1 is higher than the height position H2 of the lower surface (front surface) 9c of the rear bearing 9b on the upper side of the housing 7. In addition, when the cylinder chamber 5 is positioned above the housing 7 with the cylinder chamber 5 positioned above the housing 7 and the rotation axis L direction of the cylinder body 2 is defined as the vertical direction, the bottom surface 27a of the drain port 27 is at the top inside the housing 7 at this time. The height is higher than the height position of the lower surface (rear surface) 9d of the front bearing 9a. That is, in FIG. 3, the height position H3 of the bottom surface 27a of the drain port 27 is a position lower than the height position H4 of the rear surface 9d of the front bearing 9a on the lower side inside the housing 7.

  Next, the operation will be described. In the rotating fluid pressure cylinder 1, pressurized fluid is supplied to the front cylinder chamber 5a via the flow paths 21a and 14a, and the piston 6 moves upward in FIG. The pressurized fluid in the rear cylinder chamber 5b is recovered through the flow paths 14b and 21b. When the pressurized fluid is supplied to the rear cylinder chamber 5b via the flow paths 21b and 14b and the piston 6 moves downward, the pressurized fluid in the front cylinder chamber 5a is recovered via the flow paths 14a and 21a. By moving the piston 5 up and down, for example, a chuck claw (not shown) is held and released. At this time, the drain of the pressurized fluid leaking from the relative rotation part 22 where the flow paths 14a, 14b and the flow paths 21a, 21b communicate with each other passes through the slight gap 32 of the relative rotation part 22 shown in FIG. 24b flows into the drain storage chamber 26. Here, the gap 32 shown in FIG. 3 is enlarged for explanation. As a result, the drain is stored in the drain storage chamber 26, and the drain liquid level 33 is stored up to a height position H <b> 1 reaching the communication hole 30, so that the drain storage chamber 26 becomes a drain storage space.

  When drain accumulates in the drain storage chamber 26, the drain liquid level 33 a also accumulates in the gap 32 of the relative rotating portion 22 up to a height position H 1 where the drain liquid level 33 a reaches the communication hole 30. Further, the drain leaked from the relative rotation part 22 flows into the drain storage chamber 26 through the drain flow paths 24a and 24b, and passes through a communication hole 30 to a drain pipe (not shown) connected from the drain recovery chamber 28 to the drain port 27. To the working pressure fluid tank. In the drain storage chamber 26, the drain liquid level 33 is accumulated up to the height position H1 of the communication hole 30, so that the drain liquid level 33a accumulated in the slight gap 32 of the relative rotating portion 22 is the height of the front surface 9c of the rear bearing 9b. The position is above the position H2, and the drain is supplied to the rear bearing 9b as a lubricant. In a state where the drain is supplied to the rear bearing 9b, the rear bearing 9b is rotated by the rotation of the distributor shaft 3 by the rotation of the main shaft 34, and the drain is scattered by the rear bearing 9b. The scattered drain wets the rear oil seal 18b and oozes between the rear oil seal 18b and the end cap 11 to act as a lubricant, and lubricates between the rear oil seal 18b and the end cap 11 to prevent poor lubrication. It is possible to reduce friction and suppress generation of wear and sound.

  Further, even when the cylinder chamber 5 is used upside down from the state shown in FIG. 1, the flow paths 14 a and 14 b and the flow paths 21 a and 21 b leak from the relative rotation portion 22 that communicates with each other in substantially the same manner as described above. The drainage of the pressurized fluid flows through the slight gap 32 of the relative rotating portion 22 to the drain storage chamber 26 via the drain passages 24a and 24b. The drain in the drain storage chamber 26 flows into the drain recovery chamber 28 through the communication hole 30. In the drain collection chamber 28, the drain liquid level is accumulated up to the height position H3 of the bottom surface 27a of the drain port 27, and this time the drain collection chamber 28 becomes a drain accumulation space. The liquid level of the drain also accumulates in the gap 32 of the relative rotation part 22 up to the height position H3 of the bottom surface 27a of the drain port 27, and the drain is supplied to the front bearing 9a as a lubricant. As a result, the drain is scattered and spreads and lubricated between the front oil seal 18a and the ring 12, and the oil seal is prevented from being damaged due to poor lubrication as described above. Further, the drain exceeding the drain port 27 is collected in the working pressure fluid tank.

  In the present embodiment, even if the rotating fluid pressure cylinder 1 is used in the vertical direction so that the cylinder chamber 5 is on the upper side or the lower side, the drain storage chamber 26 or the drain recovery chamber 28 serves as a drain storage space, and drainage is collected. As a result, drainage also accumulates in the gap 32 of the relative rotating portion 22, and the oil seals 18a, 18b and the bearings 9a, 9b on the upper side can be lubricated, so that the oil seal on the upper side can be prevented from being damaged due to poor lubrication.

  FIG. 4 shows the second embodiment, and the same parts as those in the first embodiment are denoted by the same reference numerals and the description thereof is omitted. A drain storage chamber 26A in which the drain passages 24a and 24b communicate with each other to serve as a drain storage space and a drain recovery chamber 28 for recovering drain from a drain port 27 provided in the housing main body 15A are provided in the housing main body 15A. The drain storage chamber 26A and the drain recovery chamber 28 are communicated with each other through a communication hole 30A. The height position H5 of the bottom surface 30Aa of the communication hole 30A is lower than the height position H2 of the front surface 9c of the rear bearing 9b, which is the upper side inside the housing 7, and the drain that has flowed into and accumulated in the drain storage chamber 26A. When passing through the communication hole 30A and flowing into the drain collecting chamber 28, the height position H6 of the drain liquid surface 33 is set to be higher than the height position H2 of the front surface 9c of the rear bearing 9b. Further, the height position H3 of the bottom surface 27a of the drain port 27 is a height position above the height position H4 of the rear surface 9d of the front bearing 9a which is the lower inside of the housing 7 in FIG. When the housing 7 is turned upside down and the housing 7 is placed on the lower side, when the drain accumulated in the drain collection chamber 28 passes through the drain port 27 and is collected in the working pressure fluid tank, the drain liquid level indicated by a two-dot chain line The height position H7 of 33b is provided to be higher than the rear surface 9d of the front bearing 9a. As shown in FIG. 4, when the rotation axis L is used in the vertical direction with the housing 7 facing upward, when the drain passes through the communication hole 30 </ b> A, the drain liquid level 33 a is in the communication hole even in the gap 32 of the relative rotation portion 22. The level of the drain liquid surface 33 at 30A becomes substantially the same level as that supplied to the rear bearing 9b, the rear bearing 9b is lubricated by the drain, and the rear bearing 9b rotates as the cylinder body 2 rotates. Thus, the drain is scattered and the oil seal 18b is lubricated, so that the oil seal 18b can be prevented from being damaged due to poor lubrication. 4, the drain liquid level 33b overflowing from the drain port 27 and the drain liquid level in the gap 32 are also different even when the rotation axis L is used in the vertical direction with the housing 7 facing down from the state shown in FIG. The front bearing 9a and the oil seal 18a are lubricated at substantially the same height, and poor lubrication is prevented.

  In the present invention, as in the first and second embodiments, the vicinity of the bearing height on the upper side inside the housing is the height at which the drain in the drain storage space reaches the bearing, and the drain storage chamber is the drain storage space. When the bottom of the communication hole near the upper bearing height in the housing, the drain near the height of the upper bearing accumulated in the drain storage chamber overflows from the communication hole and is collected in the drain recovery chamber. The drain liquid level is set so that the liquid level of the drain is higher than the lower surface of the upper bearing, or upside down with the cylinder chamber facing upward and the rotation axis as the vertical direction. When the drain port near the upper bearing height in the housing is recovered from the drain port overflowing from the drain port near the upper bearing height accumulated in the drain recovery chamber. The liquid surface of the drain is the height position becomes higher than the lower surface of the upper bearing.

It is a longitudinal cross-sectional view of the rotating fluid pressure cylinder of this invention. FIG. 2 is a II view of FIG. 1. It is explanatory drawing which expanded the principal part. It is explanatory drawing which shows 2nd Embodiment. It is a figure which shows the prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Rotating fluid pressure cylinder 2 Cylinder main body 3a Shaft part 5 Cylinder chamber 6 Piston 7 Housing 9a, 9b Bearing 9c, 9d Lower surface of bearing 10a Fitting hole 14a, 14b Flow path 15a Outer surface of housing main body 16 Drain collection hole member 16a Mounting surface 20a, 20b Supply / discharge port 22 Relative rotating part 26, 26A Drain storage chamber 27 Drain port 27a Drain port bottom surface 28 Drain recovery chamber 29 Partition wall 30, 30A Communication hole 30a, 30Aa Communication hole bottom surface 31 Drain recovery path L Rotation axis

Claims (4)

The shaft part of the cylinder body is fitted to the fitting hole of the housing via a bearing so as to be relatively rotatable, and a piston is provided in a cylinder chamber formed in the cylinder body so as to be slidable in the axial direction of the cylinder body. Each of the cylinder chambers is connected to a pressure fluid supply / discharge port provided in the housing through a flow path passing through the relative rotation portion of the fitting hole and the shaft portion, and a drain of pressure fluid leaking from the flow path of the relative rotation portion is connected. In a rotating fluid pressure cylinder equipped with a drain recovery path to be recovered in the drain port in the housing, when the axis of rotation of the shaft portion of the cylinder body is in the vertical direction in the drain recovery path, A rotary fluid pressure cylinder comprising a drain storage space in which the drain can be supplied to the bearing and supplied to the bearing, and the bearing is lubricated by the drain. The drain collection path is provided with a drain storage chamber on the side of the relative rotation section divided by the partition wall and a drain collection chamber on the drain port side, and a communication hole is provided in the partition wall for communicating the drain storage chamber and the drain collection chamber. One of the hole or drain port is near the upper bearing height in the housing, the other is near the lower bearing height in the housing, the drain storage chamber or drain recovery chamber is the drain storage space, and the drain is near the upper bearing height 2. The rotating fluid pressure cylinder according to claim 1, wherein 3. The rotary fluid pressure cylinder according to claim 2, wherein the bottom surface of the communication hole or drain port near the upper bearing height in the housing is positioned higher than the lower surface of the bearing inside the housing. A drain collecting hole member having a drain port is attached to the outer surface of the housing main body having a fitting hole therein, and the housing is configured. The drain collecting hole member has a mounting surface to the housing main body and an outer surface of the housing main body. The rotary fluid pressure cylinder according to claim 2 or 3, wherein a drain storage chamber is provided between the drain storage chamber and the drain port.

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