JP3070657U - Rotary fluid coupling - Google Patents

Abstract

(57) [Problem] To provide a rotary fluid coupling capable of suppressing deterioration of rotation performance by preventing a liquid such as a cutting fluid from flowing into a bearing. SOLUTION: The rotary fluid coupling 1 is composed of a hollow coupling housing 2 and a rotating body 3 supported by bearings 27 and 28 in the coupling housing 2.
Are liquid through-holes 20, air through-holes 7, 8 and discharge through-holes 2.
2 is provided. The rotating body 3 includes a liquid feed passage 31 that connects the liquid through hole 20 and the rotary chuck, and air feed passages 32 and 33 that connect the air through holes 7 and 8 and the rotary chuck. A pressurizing means 13 is connected to the joint housing 2, and pressurized mist air is discharged through a discharge hole 22 through a bearing 23.
Sent to

Description

[Detailed description of the invention]

[0001]

[Technical field to which the invention belongs]

 The present invention relates to a rotary fluid coupling, and more particularly to a rotary fluid coupling capable of supplying air and cutting fluid to a rotary chuck used in a machine tool such as a cutting machine. .

[0002]

[Prior art]

 BACKGROUND ART Conventionally, a machine tool 40 such as a cutting machine includes an air-driven rotary chuck 41 as a means for holding a workpiece A as shown in FIG. The rotary chuck 41 is fixed to a drive shaft 42 of the machine tool 40 and rotates together with the drive shaft 42. As a specific configuration of the rotary chuck 41, for example, one disclosed in Japanese Patent Application Laid-Open No. H10-249615 is known. That is, as shown in FIG. 5, the apparatus includes a plurality of claws 43 for holding the workpiece A, a diaphragm 44 for driving the claws 43, and a piston 45 for pressing the diaphragm 44 from behind. The claw portion 43 is opened and closed by air supplied through the rotary fluid coupling 46 (see FIG. 4).

[0005] Specifically, when air is supplied to a predetermined portion of the rotary chuck 41, the rear surface of the diaphragm 44 is pressed by the piston 45, and the diaphragm 44 is elastically deformed. Thereby, the plurality of claw portions 43 are opened, and the interval between the tips of the claw portions 43 becomes larger than the outer diameter of the workpiece A. That is, the workpiece A can be inserted between the plurality of claw portions 43. When the supply of air is stopped while the workpiece A is inserted between the plurality of claws 43, the pressing state of the diaphragm 44 by the piston 45 is released, and the elastic force (restoring force) of the diaphragm 44 releases the plurality of pieces. Is closed. That is, the workpiece A is held. Further, when air is supplied to another portion of the rotary chuck 41, the rear surface of the diaphragm 44 is pulled by the piston 45, and the diaphragm 44 is elastically deformed in the opposite direction. Thereby, the plurality of claw portions 43 are urged in the closing direction, and the workpiece A is held with a stronger force.

Further, in order to cool the cut surface of the workpiece A held by the rotary chuck 41 and to remove cutting chips from the cut surface, the cutting fluid is supplied via a rotary fluid coupling 46. Has become. The cutting fluid supplied to the rotary chuck 41 is sent to the workpiece A through a cutting fluid supply hole 47 provided at the center of the rotary chuck 41. The cutting fluid sent to the workpiece A is collected, purified by a filter or the like, and then returned to the rotary fluid coupling 47 to be used again.

As shown in FIG. 6, the rotary fluid coupling 46 includes a coupling housing 48 and a rotating body 50 housed in a rotating body housing portion 48a inside the housing. The joint housing 48 is fixedly attached to the machine tool 40. The outer wall of the joint housing 48 has a cutting fluid inlet port 51 (see FIG. 4) through which cutting fluid is supplied, and an air supply means (not shown). ) Are provided with a first air port 52 and a second air port 53 to which air is supplied. Then, the cutting fluid supplied to the cutting fluid inlet port 51 flows through the liquid through hole 54 to a predetermined position of the rotating body housing part 48a, and flows to the first air port 52 and the second air port 53. The supplied air flows through the first air through hole 55 and the second air through hole 56 to a predetermined position of the rotating body housing portion 48a.

On the other hand, the rotating body 50 is rotatably supported by two bearings 57 and 58 on the wall surface of the rotating body housing portion 48 a of the joint housing 48. The rotating body 50 includes a cylindrical rotating body 60 and a triple pipe 61 disposed in the rotating body 60. The passage 63 at the center of the triple pipe 61 functions as a cutting fluid feed passage, and the upstream end faces the outflow portion 54 a of the liquid through-hole 54 formed in the joint housing 48. The passage 64 outside the passage 63 functions as a first air feed passage, and the upstream end faces the outlet of the first air through hole 55 formed in the joint housing 48. The passage 65 outside the passage 64 functions as a second air feed passage, and the upstream end faces the outflow portion of the second air through hole 56 formed in the joint housing 48. That is, cutting fluid is sent to the rotary chuck 41 through the passage 63, and air is sent to the rotary chuck 41 through the passage 64 or the passage 65.

By the way, the cutting fluid supplied to the liquid through-hole 54 is supplied in a state where it is pressurized by a pump or the like provided outside, and is sent to the rotary chuck 41 through a passage 63. When the outflow side of the passage 63 and the cutting fluid supply hole 47 (see FIG. 5) of the rotary chuck 41 are closed, the pressure in the passage 63 increases. Therefore, the joint housing 48 is provided with a discharge through hole 69, and when the amount of the cutting fluid supplied into the passage 63 becomes excessively large, a part of the cutting fluid is discharged. The air is discharged to the outside through the hole 69.

[0008]

[Problems to be solved by the invention]

 However, in the conventional rotary fluid coupling 46, a part of the cutting fluid H may flow into the bearing 57 as shown in FIG. That is, since a small gap is formed between the wall surface of the rotating body housing portion 48a and the rotating body 50 so that the outer periphery of the rotating body 50 does not contact the wall surface of the rotating body housing portion 48a. The discharge through-hole 69 communicates with the portion where the bearing 57 is provided, and the cutting fluid H to be discharged from the discharge through-hole 69 may flow into the bearing 57.

In particular, there is a high possibility that the cutting fluid H flows into the bearing 57 when the state of air supply to the rotary chuck 41 is switched. This is because, when the supply of air to the predetermined air ports 52 and 53 is stopped, the air flow reverses for a moment, so that the cutting fluid H to be discharged from the discharge through-hole 69 follows the flow. This is because the air is sucked into the first air through hole 55 or the second air through hole 56 side.

[0010] Since fine chips and the like often remain without being removed in the cutting fluid H, when these chips and the like flow into the bearing 57 together with the cutting fluid, There is a possibility that the swarf or the like becomes an obstacle and the rotating body 50 cannot be rotated smoothly. In particular, in a machine tool that rotates the workpiece A at a high speed, even if the flow rate of the cutting fluid H flowing into the bearing 57 or the like is extremely small, there is a possibility that the rotational performance is significantly reduced.

Therefore, an object of the present invention is to provide a rotary fluid coupling capable of preventing a fluid such as a cutting fluid from flowing into a bearing, thereby suppressing a decrease in rotational performance.

[0012]

[Means for Solving the Problems]

 A rotary fluid coupling according to the invention of claim 1 is rotatably supported by a bearing on a wall of the rotary body housing of the joint housing having a hollow rotary body housing therein. A liquid through hole serving as a passage for flowing liquid supplied from liquid supply means connected to an outer wall toward the rotary body accommodating portion. An air through hole serving as a passage for flowing air supplied from an air supply means connected to an outer wall toward the rotating body housing; and an excess amount of the liquid sent to the rotating body housing. And a discharge through-hole serving as a passage for discharging the components to the outside. In addition, the rotator sends the liquid supplied through the liquid through-hole to the rotation target, and sends the air supplied through the air through-hole to the rotation target. An air feed passage. Further, the joint housing has a connecting portion for connecting a pressurizing means to an outer wall, and a connecting part for sending air supplied by the pressurizing means to the discharge through-hole via the bearing. And a pressurizing passage serving as a passage.

Therefore, according to the rotary fluid coupling according to the first aspect of the present invention, since the rotating body is supported by the bearing in the rotating body accommodating portion of the joint housing, the rotating body is rotated with respect to the joint housing. It is possible to do. That is, even when the joint housing is fixed, the rotating body can be rotated together with a rotating object (for example, a rotating chuck) connected to the end of the rotating body.

[0014] The air supplied to the joint housing by the air supply means flows to a predetermined position of the rotating body housing portion through the air through hole. Since an air feed passage is formed in the rotator housing, air supplied through the air through hole is sent to the object to be rotated through the air feed passage.

Further, the liquid (for example, cutting liquid) supplied to the joint housing by the liquid supply means flows to a predetermined position of the rotating body housing through the liquid through hole. The liquid supply passage is formed in the rotator housing, so that the liquid supplied through the liquid through-hole is sent to the object to be rotated through the liquid supply passage.

By the way, if the liquid in the liquid feed passage is excessively increased due to, for example, closing of the liquid feed passage, the excess liquid is discharged outside through the discharge through-hole. A pressure means is connected to the joint housing, and air supplied by the pressure means is sent to the pressure passage. Since the pressurizing passage is formed to the discharge through-hole via the bearing, the air supplied by the pressurizing means is sent to the discharge through-hole via the bearing. That is, the internal pressure of the portion where the bearing is provided is higher than the internal pressure of the portion where the discharge through hole is formed. Therefore, the liquid (discharge liquid) to be discharged through the discharge through-hole is prevented from flowing to the bearing portion. In particular, by setting this pressure difference to be larger than the instantaneous negative pressure (negative pressure generated at the part where the bearing is provided) generated when the supply of air to the air feed passage is stopped, Can always be higher than the pressure of the part where the discharge through-hole is formed, and even when the air supply state to the rotating object is switched, the liquid (discharge liquid) ) Can be reliably prevented from flowing to the bearing portion.

A rotary fluid coupling according to a second aspect of the present invention is the rotary fluid coupling according to the first aspect, wherein the air supplied by the pressurizing means contains mist-like lubricating oil. .

Therefore, according to the rotary fluid coupling of the invention of claim 2, in addition to the operation of the rotary fluid coupling of the invention of claim 1, lubricating oil is supplied to the bearing through the pressurizing passage. The friction of the bearing is reduced, and the rotation of the rotating body with respect to the joint housing becomes smoother.

A rotary fluid coupling according to a third aspect of the present invention is the rotary fluid coupling according to the second aspect, wherein the rotating body has two or more bearings on a wall surface of the rotating body housing portion of the joint housing. And the joint housing further has a second pressurizing passage for sending the air supplied by the pressurizing means to the bearing on the side where the discharge through-hole is not provided.

Therefore, according to the rotary fluid coupling of the invention of claim 3, in addition to the action of the rotary fluid coupling of the invention of claim 2, air containing mist-like lubricating oil is passed through the bearing. As described above, the mist-like lubricating oil is also supplied to the bearing on which the discharge through-hole is not provided, that is, to all other bearings. The contained air is sent through the second pressurized passage. For this reason, the friction of all the bearings is reduced, and the rotation of the rotating body with respect to the joint housing becomes smoother.

According to a fourth aspect of the present invention, in the rotary fluid coupling according to the third aspect, an opening area of the pressurizing passage is larger than an opening area of the second pressurizing passage. It was done.

Therefore, according to the rotary fluid coupling according to the fourth aspect of the present invention, in addition to the operation of the rotary fluid coupling according to the third aspect of the present invention, a pressurizing passage (which extends through the bearing to the discharge hole). Since the opening area of the passage is larger than the opening area of the second pressurizing passage (the passage leading to the bearing on which the discharge through-hole is not provided), the air supplied from the pressurizing means cannot be supplied. It flows a lot toward.

According to a fifth aspect of the present invention, there is provided a rotary fluid coupling according to any one of the first to fourth aspects, wherein the rotating object has an air-driven claw. The liquid sent to the rotary chuck through the liquid feed passage is made of a cutting fluid.

Therefore, according to the rotary fluid coupling of the invention of claim 5, in addition to the operation of the rotary fluid coupling of the invention of any one of claims 1 to 4, the liquid feed passage and the air feed passage are provided. The rotating body rotates together with the rotating chuck. The claw portion of the rotary chuck is driven by the air sent through the air feed passage. Further, the cutting fluid is sent to the rotary chuck through the liquid feed passage, so that the workpiece held by the rotary chuck can be cooled and cutting chips attached to the workpiece can be removed.

[0025]

[Embodiment of the invention]

 Hereinafter, a rotary fluid coupling according to an embodiment of the present invention will be described with reference to FIGS. 1 is a cross-sectional view showing the configuration of the rotary fluid coupling, FIG. 2 is a cross-sectional view showing the AA cross section of the rotary fluid coupling of FIG. 1, and FIG. 3 is an explanatory diagram showing a use state of the rotary fluid coupling. is there. The rotary fluid coupling 1 is capable of supplying air and a cutting fluid to a pneumatic rotary chuck (not shown). As shown in FIGS. 3 is provided.

Each member will be specifically described. The joint housing 2 is fixedly attached to a machine tool (not shown) or the like. The joint housing 2 includes a cylindrical housing main body 4 and a lid member 5 for closing one end side (the left side in FIG. 1) of the housing main body 4. Are fastened by bolts 6. The space surrounded by the housing body 4 and the cover member 5 functions as the rotating body housing 2a.

On the outer wall (surface) of the housing main body 4, two through holes penetrating to the rotating body housing portion 2 a, that is, a first air through hole 7 and a second air through hole 8 are provided side by side. ing. Female threads are formed on the peripheral surfaces of these through holes 7, 8, and air ports 7A, 8A for connecting air supply means 9 are screwed into the female threads. The air supply means 9 has a compressor or the like and supplies compressed air as needed. The air supplied from the air supply means 9 to the air port 7A or the air port 8A is sent to a predetermined position of the rotating body housing portion 2a through the first air through hole 7 or the second air through hole 8. In addition, annular guide grooves 7B, 8B communicating with the first air through hole 7 and the second air through hole 8, respectively, are formed on the wall surface of the rotating body housing 2a (the inner peripheral surface of the housing 4). I have.

A screw hole 11 is provided on the outer wall (surface) of the housing body 4 at a position substantially opposed to the first air through hole 7 and the second air through hole 8. A mist air port 12 for connecting a pressurizing means 13 is screwed into 11. Here, the combination of the screw hole 11 and the mist air port 12 corresponds to the connecting portion of the present invention. In the vicinity of the bottom of the screw hole 11, a pressure passage 14 formed from the screw hole 11 to one end of the housing body 4, and a second pressure hole formed from the screw hole 11 to the other end of the housing body 4. A pressure passage 15 is provided along the longitudinal direction of the housing body 4. Each of the pressurizing passage 14 and the second pressurizing passage 15 is a hole having a circular cross section, and the opening area of the pressurizing passage 14 is larger than that of the second pressurizing passage 15. For example, the diameter of the pressure passage 14 is 2 mm, and the diameter of the second pressure passage 15 is 1 mm.

The pressurizing means 13 connected to the mist air port 12 pressurizes and supplies air containing mist-like lubricating oil (hereinafter referred to as “mist air”), and generates compressed air. It has a compressor to make it work, a tank to store lubricating oil, and a nozzle to spray lubricating oil.

The lid member 5 includes a disc-shaped base 16, a cylindrical protrusion 17 protruding outward from the center of the base 16, and an annular wall 18 protruding from the periphery of the base 16 toward the housing body 4. And a cylindrical insertion portion 19 protruding from the center of the base portion 16 toward the rotating body accommodating portion 2a. When the lid member 5 is fastened to the housing main body 4 by the bolt 6, the tip of the annular wall portion 18 is pressed against the end face 4a of the housing main body 4. Further, the projecting portion 17, the base portion 16, and the insertion portion 19 are provided with a liquid through-hole 20 penetrating to the rotating body accommodating portion 2 a. A cutting fluid inlet port 20A for connecting the liquid supply means 21 is screwed into a portion corresponding to the surface. The liquid supply means 21 is for recirculating the used cutting fluid and supplying it to the liquid through-hole 20, and has a pump, a filter, and the like. The cutting fluid supplied from the liquid supply means 21 to the cutting fluid inlet port 20A is sent to a predetermined position of the rotating body housing 2a through the liquid through hole 20.

The outer wall (surface) of the lid member 5 is provided with a discharge through hole 22 penetrating to the rotating body housing portion 2a. A female screw portion is formed on the peripheral surface of the discharge through hole 22, and a drain port 22A for connecting a drain hose (not shown) is screwed into the female screw portion.

On the other hand, the rotating body 3 is rotatably supported by the first bearing 23 and the second bearing 24 on the inner peripheral surface of the housing body 4, that is, the wall surface of the rotating body housing 2 a. The rotating body 3 includes a cylindrical rotating body 25 and three pipes 26, 27 and 28 adhered to the inner surface of the rotating body 25. About half of the length of the rotating body 25 in the longitudinal direction is housed in the rotating body housing part 2 a, and the other half protrudes from the housing body 4. Also, the outer diameter of the rotating body 25 is different between the portion housed in the rotating body housing portion 2a and the portion protruding from the housing body 4, and the former is slightly smaller than the diameter of the rotating body housing portion 2a, The latter is considerably larger than the diameter of the rotator housing 2a. A male screw portion 25a for screwing the bearing support screw 29 is formed on the outer periphery of one end of the rotating main body 25, and the insertion portion 19 of the lid member 5 is inserted therein. The inner diameter of one end of the rotating main body 25 is slightly larger than the outer diameter of the insertion portion 19, and a gap S1 for discharging cutting fluid is provided between the inner diameter and the outer diameter. In addition, a step is formed on the inner peripheral surface of the rotating main body 25 in order to mount three pipes 26, 27, and 28.

Each of the three pipes 26, 27, 28 is a pipe having a cross section of a perfect circle and different diameters arranged concentrically. One end of the innermost first tube 26 extends to near the distal end of the insertion portion 19, and one end of a second tube 27 arranged outside the first tube 26. Extend to the vicinity of the guide groove 7B. Further, one end side of the outermost third tubular body 28 is located outside the rotator housing 2a. On the other hand, the other ends of the three tubes 26, 27, 28 are all connected to a rotary chuck (not shown). The first passage 31 (cutting fluid feed passage) formed inside the first tube 26 corresponds to the liquid feed passage of the present invention, and is formed between the first tube 26 and the second tube 27. The second passage 32 (first air passage) that is formed and the third passage 33 (second air passage) that is formed between the second tube 27 and the third tube 28 are connected to the air supply of the present invention. Corresponds to a passage.

That is, the one end opening portion of the first passage 31 (cutting fluid feed passage) faces the tip of the insertion portion 19, that is, the outflow side of the liquid through hole 20, and is supplied through the liquid through hole 20. The cut fluid is sent to the rotary chuck through the first passage 31. In addition, one end opening of the second passage 32 (first air passage) faces the outflow side of the first air through hole 7, and the air supplied through the first air through hole 7 is It is sent to the rotating chuck through the passage 32. Similarly, one end opening of the third passage 33 (second air passage) faces the outflow side of the second air through hole 8, and the air supplied through the second air through hole 8 is It is sent to the rotary chuck through the third passage 33.

A receiving hole communicating with the second passage 32 and the third passage 33 is provided on the outer wall of the rotating main body 25 at a position facing the inner grooves 7 B and 8 B formed on the inner surface of the housing main body 4. 34 and 35 are formed at predetermined intervals. For this reason, even while the rotating body 3 is rotating with respect to the joint housing 2, the receiving hole 34 and the guide groove 7B and the receiving hole 35 and the guide groove 8B face each other and communicate with each other. The air supplied from the one air through hole 7 and the second air through hole 8 can be reliably sent to the second passage 32 and the third passage 33.

The bearing support screw 29 has a female screw portion formed on the inner peripheral surface, and a through hole 29 a having the same size as the inner diameter of one end of the rotating main body 25 is provided at the center. That is, the inner diameter of the through hole 29a is larger than the outer diameter of the insertion portion 19, and a gap S1 for discharging the cutting fluid is extended between the two. Further, the outer diameter of the bearing support screw 29 is smaller than the inner diameter of the annular wall portion 18, and a gap S2 for flowing mist air is provided between the two. The end of the bearing support screw 29 is pressed against the inner ring of the first bearing 23.

An annular bearing fixing member 36 that rotates together with the rotating main body 25 is provided substantially at the center in the longitudinal direction of the rotating main body 25. The bearing fixing member 36 is disposed with a gap S3 provided between the bearing main body 4 and the end of the housing main body 4, and the inner peripheral portion of the surface facing the housing main body 4 serves as the inner ring of the second bearing 24. We are in pressure contact.

The first bearing 23 and the second bearing 24 are bearings (rolling bearings), each having a plurality of balls between the outer ring and the inner ring, and having the outer ring and the inner ring in rolling contact with each other. , To reduce friction. In addition, a gap is provided between the balls in the first bearing 23 and the second bearing 24 so that mist air can pass through. The first bearing 23 is fitted into a concave portion 4b formed on one end side of the housing body 4 so as to face the outflow side of the pressurizing passage 14, and the end of the outer ring (the right end in FIG. 1) is fitted. The inner ring is fixed in contact with the bottom surface of the recess 4b, with the end of the inner ring (the left end in FIG. 1) in contact with the tip of the bearing support screw 29. The second bearing 24 is fitted into a recess 4c formed on the other end of the housing body 4 so as to face the outflow side of the second pressurizing passage 15, and the end of the outer ring (the left side in FIG. 1). The end of the inner ring is in contact with the bottom surface of the concave portion 4c via a lip washer (not shown), and the end of the inner ring (the right end in FIG. 1) is in contact with the bearing fixing member 36. .

Next, the operation of the rotary fluid coupling 1 of the present embodiment and the flow of fluid will be described with reference to FIGS. Since a rotating chuck is connected to the tip of the rotating body 3, when power is given to the rotating chuck by the drive shaft of the machine tool, the rotating body 3 rotates together with the rotating chuck. Since the rotating body 3 is supported by the rotating body accommodating portion 2a of the joint housing 2 by the two bearings 23, 24, the rotating body 3 is rotated with little friction with respect to the fixed joint housing 2. Can be.

The air supply means 9 supplies air to the joint housing 2 by the air supply means 9 in order to supply air for driving to the rotary chuck, that is, to drive the claw portion of the rotary chuck. The air supplied to one of the two flows through the first air through hole 7 or the second air through hole 8 and flows to a predetermined position of the rotating body housing 2a. The air supplied through the first air passage 7 is sent to the rotary chuck through the second passage 32, and the air supplied through the second air passage 8 is passed through the third passage 33. It is sent to the rotating chuck. In the rotary chuck, the claw portion is driven to open and close by the air sent from these passages 32 and 33.

Specifically, when air is supplied from the second passage 32 to the rotary chuck, a rear surface of the diaphragm is pressed by a piston provided in the rotary chuck, and the diaphragm is elastically deformed. As a result, the plurality of claws attached to the diaphragm are expanded, and a state in which a workpiece can be attached and detached between the plurality of claws is established. When the supply of the air from the second passage 32 is stopped and the air is supplied from the third passage 33, the rear surface of the diaphragm is pulled by the piston, and the diaphragm is elastically deformed in the opposite direction. As a result, the plurality of claws are urged in the closing direction, and the workpiece can be held.

Further, in order to supply the cutting fluid to the rotary chuck, the cutting fluid supplied to the joint housing 2 by the liquid supply means 21 passes through the liquid through hole 20 and reaches a predetermined position in the rotating body housing part 2 a. Flows to The cutting fluid is sent to the rotary chuck through the first passage 31. The rotating chuck allows the supplied cutting fluid to flow through the workpiece held by the rotating chuck, thereby cooling the workpiece and washing away the cutting debris attached to the workpiece. Can be.

When the outflow side of the first passage 31 is closed and the amount of the cutting fluid in the first passage 31 is excessively increased, as shown in FIG. Flows through the clearance S1 outside the insertion portion 19 to the discharge through hole 22, and is discharged outside through the drainage port 22A and the drainage hose.

On the other hand, a part of the mist air M supplied by the pressurizing means 13 flows to the first bearing 23 through the pressurizing passage 14, further passes between the balls of the first bearing 23, and The liquid is discharged to the discharge through-hole 22 through the gap S2 outside the screw 29. Here, the combination of the pressure passage 14 and the gap S2 corresponds to the pressure passage of the present invention. The internal pressure of the portion where the first bearing 23 is disposed becomes higher than the internal pressure of the discharge through hole 22 due to the pressurized mist air M. Therefore, this pressure difference prevents the cutting fluid E to be discharged through the discharge through hole 22 from flowing to the first bearing 23 side, and impurities such as cutting chips contained in the cutting fluid E are removed. It does not flow into the first bearing 23. In particular, by setting this pressure difference to be greater than the instantaneous negative pressure (negative pressure generated in the portion where the first bearing 23 is provided) generated when the supply of air is stopped, The pressure at the portion where the bearings 23 are disposed can always be higher than the pressure at the portion where the discharge through-holes 22 are formed, so that even when the state of air supply to the rotary chuck is switched, cutting is performed. It is possible to reliably prevent the liquid E from flowing to the first bearing 23 side. In addition, since the cutting fluid E does not flow to the first bearing 23 side, the cutting fluid E does not naturally flow into the gap between the housing main body 4 and the rotating main body 25.

Since the mist air M contains mist-like lubricating oil, the mist air M is supplied to the first bearing 23, so that the friction in the first bearing 23 is reduced. The mist air M is supplied not only to the first bearing 23 but also to the second bearing 24 through the second pressure passage 15. The mist air M passes between the balls of the second bearing 24, flows into the gap S3 between the housing body 4 and the bearing fixing member 36, and is discharged to the outside. By supplying the mist air M to all the bearings 23 and 24 in this manner, the friction in all the bearings 23 and 24 is reduced, and the rotation of the rotating body 3 with respect to the joint housing 2 is always smooth. It can be maintained in a state. It is also possible to cope with high-speed rotation. In the rotary fluid coupling 1 of the present embodiment, since the diameter of the pressurizing passage 14 connected to the first bearing 23 is larger than the diameter of the second pressurizing passage 15 connected to the second bearing 24, The mist air M supplied by the pressure means 13 flows to the pressurizing passage 14 side more than the second pressurizing passage 15. For this reason, even if the capacity of the pressurizing means 13 is relatively small, it is possible to sufficiently flow the mist air M from the first bearing 23 to the discharge through hole 22.

As described above, in the rotary fluid coupling 1 described above, the air M supplied by the pressurizing means 13 reduces the pressure of the portion where the first bearing 23 is disposed to form the discharge through hole 22. The cutting fluid to be discharged through the discharge through-hole 22 is prevented from flowing to the first bearing 23 side, and the cutting fluid and the like contained in the cutting fluid E can be prevented from flowing to the first bearing 23 side. Is prevented from flowing into the first bearing 23. For this reason, it is possible to prevent the rotation performance from being degraded due to impurities such as chips. In particular, since the air M supplied to the first bearing 23 contains mist-like lubricating oil, the first bearing 23 can be provided with lubricity, and the friction in the first bearing 23 can be reduced. Can be. Moreover, since the mist air M is also supplied to the second bearing 24 on the side where the discharge through-hole 22 is not provided, the rotating body 3 can be always smoothly rotated with respect to the joint housing 2.

As described above, the present invention has been described with reference to the preferred embodiments. However, the present invention is not limited to these embodiments, and as described below, within the scope not departing from the gist of the present invention. Various improvements and design changes are possible.

That is, in the rotary fluid coupling 1 of the above-described embodiment, the passage provided with the two passages 32 and 33 as the passage for supplying the air to the rotary chuck is shown, but one or three or more air passages are provided. The present invention may be applied to those provided. For example, when a rotary chuck that closes the claw by the restoring force of the diaphragm is used, air needs to be supplied only when the workpiece is attached to or detached from the claw, so that only one air passage is required. Good. Also, when making the claw portion of the rotary chuck move complicatedly or when supplying air to the workpiece, three or more air passages may be required. The present invention has the above-described excellent effects even in such a rotary fluid coupling. When two or more air passages are provided, a plurality of pipes having different diameters may be arranged concentrically to form a passage between the pipes as in the above embodiment. Alternatively, a plurality of pipes may be arranged side by side without overlapping, and the inside of each pipe may be used as an air passage. Further, a plurality of through holes may be formed in the rod-shaped member, and the inside of the through hole may be used as an air passage.

In the rotary fluid coupling 1 of the above embodiment, the mist air M is supplied to the two bearings 23 and 24, but the mist air is supplied only to the first bearing 23. Is also good. In the rotary fluid coupling 1 of the above embodiment, the diameter of the pressurizing passage 14 for supplying the mist air to the first bearing 23 is set to the second pressure for supplying the mist air to the second bearing 24. Although the case where the diameter is made larger than the diameter of the passage 15 is shown, both may be made the same size. However, by making the opening areas of the diameters different from each other as in the above embodiment, even if the capacity of the pressurizing means 13 is small, it is possible to flow a sufficient amount of mist air from the first bearing 23 to the discharge through hole 22. Can be.

Further, in the rotary fluid coupling 1 of the above embodiment, the rotary chuck for holding the workpiece is shown as the object to be rotated. However, the present invention is not particularly limited to the rotary chuck. A rotary spray gun for spraying a liquid may be used. In this case, the liquid can be sprayed by blowing out the supplied liquid (for example, paint) from the supplied compressed air using a nozzle or the like.

[0051]

[Effect of the invention]

 As described above, in the rotary fluid coupling according to the present invention, the pressure of the portion where the bearing is disposed is determined by the air supplied by the pressurizing means from the pressure of the portion where the through hole for discharge is formed. Since the height can be increased, the cutting fluid to be discharged through the discharge through-hole is prevented from flowing toward the bearing, and impurities contained in the liquid are prevented from flowing into the bearing. For this reason, it is possible to suppress a decrease in rotational performance of the rotating body.

In the rotary fluid coupling according to the second aspect of the present invention, in addition to the effect of the rotary fluid coupling according to the first aspect, the air supplied to the bearing contains mist-like lubricating oil. Therefore, lubrication can be given to the bearing, and friction in the bearing can be reduced.

In the rotary fluid coupling according to the third aspect of the present invention, in addition to the effect of the rotary fluid coupling according to the second aspect, air containing mist-like lubricating oil is supplied to all bearings. In addition, the rotating body can be smoothly rotated with respect to the joint housing.

The rotary fluid coupling according to the fourth aspect of the present invention has the same effects as those of the rotary fluid coupling according to the third aspect. The air can be sufficiently flowed toward the outlet, and the pressure at the portion where the bearing is provided can be reliably increased to be higher than the pressure at the portion where the discharge through hole is formed.

The rotary fluid coupling according to the fifth aspect of the present invention has the same effect as the rotary fluid coupling according to any one of the first to fourth aspects. The cutting fluid can be sent, and even if the used cutting fluid is recirculated, chips and the like contained in the cutting fluid do not flow into the bearing.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a configuration of a rotary fluid coupling according to an embodiment of the present invention.

FIG. 2 is a sectional view showing an AA section of the rotary fluid coupling of FIG. 1;

FIG. 3 is an explanatory view showing a use state of the rotary fluid coupling according to the embodiment of the present invention;

FIG. 4 is an explanatory view showing a partial configuration of a processing machine including a conventional rotary fluid coupling.

FIG. 5 is a schematic sectional view showing a configuration of a rotary chuck connected to a rotary fluid coupling.

FIG. 6 is an explanatory diagram for explaining a configuration of a conventional rotary fluid coupling.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rotary fluid coupling 2 Joint housing 2a Rotary body accommodating part 3 Rotary body 7 First air through-hole (air through-hole) 8 Second air through-hole (air through-hole) 9 Air supply means 11 Screw hole ( Connection part) 12 mist air port (connection part) 13 pressurizing means 14 pressurizing passage 15 second pressurizing passage 20 liquid through hole 21 liquid supply means 22 discharge through hole 23 first bearing (bearing) 24 second bearing (Bearing) 31 First passage (liquid supply passage) 32 Second passage (air supply passage) 33 Third passage (air supply passage)

Claims (5)

[Utility model registration claims] 1. A liquid through-hole, which has a hollow rotating body housing portion therein and serves as a passage for flowing liquid supplied from liquid supply means connected to an outer wall toward the rotating body housing portion. An air through hole serving as a passage for flowing air supplied from an air supply means connected to the outer wall toward the rotating body housing, and an excess amount of the liquid sent to the rotating body housing. A joint housing having a discharge through-hole serving as a passage for discharging to the outside, and a rotatably supported by a bearing on a wall surface of the rotating body accommodating portion of the joint housing, and passing through the liquid through-hole. A rotary type including a rotating body having a liquid feed passage for sending the supplied liquid to the rotating object and an air sending passage for sending the air supplied through the air through hole to the rotating object. In the fluid coupling, the coupling housing A connecting portion for connecting the pressurizing means to the outer wall, and a pressurizing passage serving as a passage for sending air supplied by the pressurizing means to the discharge through-hole via the bearing. A rotary fluid coupling comprising: 2. The rotary fluid coupling according to claim 1, wherein the air supplied by said pressurizing means contains mist-like lubricating oil. 3. The rotating body is supported by two or more bearings on a wall surface of the rotating body accommodating portion of the joint housing. The joint housing discharges air supplied by the pressurizing means for discharging the air. 3. The rotary fluid coupling according to claim 2, further comprising a second pressure passage that feeds the bearing on the side where the through hole is not provided. 4. 4. The rotary fluid coupling according to claim 3, wherein an opening area of the pressure passage is larger than an opening area of the second pressure passage. 5. The rotary object comprises a rotary chuck having an air-driven claw, and the liquid sent to the rotary chuck through the liquid feed passage comprises a cutting fluid. The rotary fluid coupling according to any one of claims 1 to 4.