JP4426392B2 - Rotary joint - Google Patents

Description

  The present invention relates to a rotary joint particularly suitable for supplying a liquid such as a chemical having a metal corrosive action to a rotating shaft side.

  Conventionally, when supplying coolant for cutting to a rotating tool or the like attached to the spindle end of a machine tool, a rotary joint is directly connected to the rear end of the main spindle or the rotor shaft rear end of the direct-coupled spindle motor. The coolant liquid is pumped from the rotary joint through a flow path provided at the shaft center.

  In this type of rotary joint, a seal ring is installed between the fixed shaft side flow path and the rotary shaft side flow path, and when the machine tool is driven, the floating ring side seal ring provided on the fixed shaft side is replaced by a coil spring. The rotary seal portion is configured by sliding in the seal ring direction on the rotating shaft side by the urging force and bringing the annular seal surfaces of both seal rings into close contact with each other.

  Normally, the annular seal surfaces of the seal ring on the fixed side of the seal part and the seal ring on the rotating shaft side are finished to be smooth on the whole surface, so that the liquid flowing in the internal flow path does not leak and comes into close contact with each other. (For example, refer to Patent Document 1).

Japanese Patent Laid-Open No. 9-152077 (Specification page 1, FIG. 2)

  However, in the rotary joint of the conventional example (Patent Document 1), a main body that is a fixed member, a rotating shaft that is a rotating member, a bearing for rotatably supporting the rotating shaft with respect to the main body, and the like Since most of the parts are made of metal, there is a problem that the liquid supplied via the rotary joint cannot be used when the liquid is a chemical such as acid or alkali that corrodes the metal.

  Therefore, as a solution to this problem, there is one in which only the inner surface of the flow path in the rotary joint is coated with PTFE resin, but in the case of resin coating, the occurrence of pinholes is inevitable, so completely metal Corrosion of manufactured parts cannot be prevented.

  In addition, the seal ring is generally made of ceramic having excellent wear resistance, and as a means for fixing the ceramic seal ring to the rotary shaft side, an adhesive that is conventionally not preferable in terms of chemical resistance. Therefore, it cannot be used when the fluid is a chemical.

  The present invention has been made in order to solve the above-described conventional problems, and its object is to provide a rotary joint that has corrosion resistance and can be used even when the fluid is a chemical. Is to provide.

  In order to solve the above-mentioned problems, a rotary joint according to claim 1 of the present invention is a body-side supply port provided at the bottom of a space chamber provided by opening one end side of the body body and the outer surface of the body body. And a flange portion integrally provided at one end of a boss portion that is slidably mounted in the body side supply passage via an annular sliding seal member. The floating sheet provided with a flow path penetrating in the axial direction from the boss portion to the front end sliding surface of the flange portion and the sliding surface of the rear end seal ring portion are brought into close contact with the front end sliding surface and the front end portion is A rotating shaft side supply path that is rotatably supported through a rotating shaft support means in the state of protruding from the space chamber of the body body and penetrates from the center of the rear end sliding surface to the front end portion. Formed times A rotation preventing means for preventing the rotation of the floating sheet while allowing the shaft to slide in the axial direction by engaging the shaft and the bottom of the space chamber in the body main body and the flange portion of the floating sheet; And provided at the bottom of the space chamber in the body main body so as to urge the floating sheet in the direction of the rotation axis so as to urge the sliding surface of the front end to be in close contact with the sliding surface of the seal ring portion. In the rotary joint provided with an urging means that acts on the flange portion, the fixed body, the rotating shaft and the floating sheet are made of chemical-resistant synthetic resin, and the seal ring portion is made of ceramic And a ring on which the seal ring portion can be mounted on a rear end opening end surface of the rotary shaft provided with the seal ring portion. A groove is formed, and a rubber ring having a large coefficient of friction is accommodated between the bottom of the annular groove and the seal ring part so as to prevent relative rotation between the rotary shaft and the seal ring part. The means is characterized by being configured.

  According to a second aspect of the present invention, there is provided a rotary joint according to the first aspect, wherein the floating sheet is made of PTFE including a sliding surface of the tip.

  The rotary joint according to claim 3 is the rotary joint according to claim 1 or 2, wherein a sliding hole is provided in a bottom portion of the space chamber in the body main body, and a flange portion of the floating seat is provided in the sliding hole. A pressing piston formed in a projecting manner is slidably mounted through an annular sliding seal member, and is made of a metal that presses and urges the floating sheet in the direction of the rotation axis through the pressing piston in the sliding hole. The coil spring is accommodated.

  A rotary joint according to a fourth aspect is the rotary joint according to the first or second aspect, wherein a sliding hole is provided in a bottom portion of the space chamber in the body main body, and a flange portion of the floating seat is provided in the sliding hole. An integrally projecting press piston is slidably mounted via an annular sliding seal member, and the floating seat is pressed and urged toward the rotation axis via the press piston at the bottom of the slide hole. A pressure generating source such as air or liquid is connected.

  The rotary joint according to claim 5 is the rotary joint according to any one of claims 1 to 4, wherein the inner peripheral surface of the space chamber and the outer peripheral surface of the rotary shaft of the body main body are an inner ring and an outer ring of the bearing. The rotating shaft support means is configured by forming a plurality of resin balls between the inner ring and the outer ring.

  The rotary joint according to claim 6 is the rotary joint according to claim 5, wherein the body main body constituting the inner ring and the outer ring in the rotary shaft support means and the material of the rotary shaft are more resistant to wear than the material constituting the ball. The means is characterized by being composed of an excellent resin.

  The rotary joint according to claim 7 is the rotary joint according to any one of claims 1 to 6, wherein a sliding seal member is mounted in an annular groove formed in an inner peripheral surface of the body-side supply port in the body body. The external connection pipe is configured to be connectable in a slidable state.

  In the rotary joint according to claim 1, as described above, the stationary body, the rotating shaft, and the floating sheet are made of a synthetic resin having chemical resistance, and the seal ring portion is made of ceramic, so that at least the flow is achieved. The entire inner surface of the road has corrosion resistance, and an annular groove to which the seal ring portion can be attached is formed on the rear end opening end surface of the rotary shaft provided with the seal ring portion, and the bottom of the annular groove, the seal ring portion, A rubber ring with a large coefficient of friction is accommodated between the shaft and the seal ring portion, so that relative rotation between the rotating shaft and the seal ring portion is prevented without using an adhesive. By this, the effect that it can be used even when the fluid is a chemical is obtained.

  In the rotary joint according to claim 2, as described above, the floating sheet is made of PTFE including its tip sliding surface, so that the cost is lower than the case where the ceramic seal ring is attached to the floating sheet side. Can be reduced, and the rotational sliding resistance with the seal ring portion on the rotary shaft side can be reduced.

  In the rotary joint according to claim 3, as described above, a sliding piston is provided at the bottom of the space chamber in the body main body, and the pressing piston is integrally projected from the flange portion of the floating seat in the sliding hole. Is slidably mounted via an annular sliding seal member, and a metal coil spring that presses and biases the floating sheet in the direction of the rotation axis via the pressing piston is accommodated in the sliding hole. By doing so, corrosion of the metal coil spring can be prevented.

  In the rotary joint according to claim 4, as described above, a slide hole is provided at the bottom of the space chamber in the body body, and the press formed integrally and protrudes from the flange portion of the floating seat in the slide hole. A piston is slidably mounted via an annular sliding seal member, and a pressure source such as air or liquid that presses and urges the floating sheet in the direction of the rotation axis is connected to the bottom of the sliding hole via the pressing piston. By adopting such a configuration, it is possible to eliminate metals that may corrode.

  In the rotary joint according to claim 5, as described above, the inner peripheral surface of the space chamber and the outer peripheral surface of the rotary shaft in the body main body are formed in the shape of an inner ring and an outer ring of the bearing, and between the inner ring and the outer ring. Rotating shaft support means is configured by accommodating multiple resin balls, so that it has superior chemical resistance compared to metal bearings, and can be reduced in cost and size and weight. Become.

  In the rotary joint according to claim 6, as described above, the body main body constituting the inner ring and the outer ring of the rotating shaft support means and the material of the rotating shaft are made of a resin having higher wear resistance than the material constituting the ball. By adopting such a configuration, only the balls need to be replaced due to wear, so that the cost for replacing the components can be reduced.

  In the rotary joint according to claim 7, as described above, the sliding seal member is mounted in the annular groove formed in the inner peripheral surface of the body-side supply port in the body main body, and the external connection pipe is slidable. By being configured to be connectable in a state, expansion and contraction due to heat of the external connection pipe can be absorbed in the body side supply port.

  Embodiments of the present invention will be described below with reference to the drawings.

The rotary joint of Example 1 corresponds to the inventions described in claims 1 to 3 and 5 to 7.
1 is a longitudinal sectional view showing a rotary joint of Embodiment 1, FIG. 2 is a longitudinal sectional view taken along line II-II of FIG. 1, and FIG. 3 is a left side view showing the rotary joint of Embodiment of the present invention.
The rotary joint according to the first embodiment includes a fixed body 1, a floating seat 2, a rotating shaft 3, a rotation preventing unit 5, a biasing unit 6, and a rotating shaft support unit 7 as main components. ing.

  More specifically, the fixed-side body 1 has a bottom portion 11a of a space chamber 12a provided by opening one end side of the body main body 11, and a body-side supply port 11b opened on the outer surface of the body main body 11. The body side supply path 11c communicates. In the first embodiment, the cylindrical portion 12 constituting the space chamber 12a portion is formed separately from the disc-shaped main body portion 13 in which the body side supply passage 11c is formed, and both are fastened and fixed by bolts 14. However, it may be formed integrally.

  In the floating sheet 2, a flange portion 22 is integrally formed at one end of a boss portion 21 that is slidably mounted in the body side supply passage 11 c via a fluorine rubber O-ring (annular sliding seal member) 2 a. A flow path 23 is provided in the axial direction from the boss portion 21 to the tip sliding surface 24 of the flange portion 22, and the tip sliding surface 24 projects annularly from the tip surface of the flange portion 22. It is provided in the state.

  Further, the bolt 2b is screwed into the bottom 11a of the space chamber 12a in the body main body 11, and the head of the bolt 2b is inserted and locked into the sliding through hole 25 formed in the flange portion 22, whereby the floating seat 2 The rotation preventing means 5 is configured to prevent the rotation of the shaft while allowing the shaft to slide in the axial direction.

A sliding hole 11d is provided at the bottom of the space chamber 12a in the body main body 11, and a pressing piston 22a is inserted into the sliding hole 11d via an O-ring (annular sliding seal member) 2c made of fluoro rubber. A metal coil spring (biasing means) 6 that presses and biases the floating sheet 2 in the direction of the rotary shaft 3 via the pressing piston 22a is accommodated in the sliding hole 11d. As a result, the floating sheet 2 is pressed in the direction of the rotation shaft 3 via the pressing piston 22a, and the sliding surface 24, which will be described later, provided on the rear end portion of the rotation shaft 3 with its tip sliding surface 24 is slid. It is urged in a direction to always adhere to the surface. The pressing piston 22a may be integrally formed so as to protrude from the flange portion 22 of the floating seat 2.
The entire floating sheet 2 including the tip sliding surface 24 is made of PTFE having a low frictional resistance.

  The rotary shaft 3 has the rear end sliding surface 31a of the rear end seal ring portion 31 in close contact with the front end sliding surface 24 of the floating sheet 2 and the front end portion protrudes from the space chamber 12a of the body main body 11. Thus, the rotary shaft side supply path 3a that is rotatably supported in the space chamber 12a via two sets of rotary shaft support means 7 and penetrates from the center of the rear end sliding surface 31a to the front end portion is provided. Is formed.

  The seal ring portion 31 is formed in a ceramic ring shape separately from the rotary shaft 3, and the seal ring portion 31 is provided on the rear end opening end surface of the rotary shaft 3 provided with the seal ring portion 31. An attachable annular groove 32 is formed, and a rubber ring 33 made of fluororubber having a high coefficient of friction is accommodated between the bottom of the annular groove 32 and the seal ring part 31, thereby using an adhesive. Without this, the relative rotation between the rotary shaft 3 and the seal ring portion 31 is prevented.

  The inner peripheral surface of the cylindrical portion 12 constituting the space chamber 12a and the outer peripheral surface of the rotary shaft 3 are formed in the shape of bearing inner rings 71, 71 and outer rings 72, 72, and the inner rings 71, 71 and outer rings 72, 72 The rotating shaft support means 7 is configured by accommodating a plurality (8 by 8) of resin balls 73, 73 respectively. That is, the inner rings 71 and 71 are brought into contact with the outer arc portions of the balls 73 and 73, respectively, while the outer rings 72 and 72 are brought into contact with the inner arc surfaces of the balls 73 and 73, respectively. 73 is prevented from moving in the axial direction. In addition, holes 12b and 12b through which the balls 73 and 73 can be taken in and out are formed in the upper part of the cylindrical portion 12, and the holes 12b and 12b are closed by the lids 16 and 16 so as to be freely opened and closed. ing.

  Further, an O-ring (sliding seal member) 15 made of fluororubber is mounted in an annular groove 11e formed on the inner peripheral surface of the body-side supply port 11b in the body main body 11, and the body-side supply port The fixed-side external connection pipe P1 is configured to be slidable with respect to 11b.

And the said fixed side body 1, the rotating shaft 3, the volt | bolts 2b and 14, and the cover body 16 are comprised with the vinyl chloride (synthetic resin) which has chemical resistance.
The balls 73, 73 are made of polypropylene. That is, the material of the inner ring 71, 71 and the outer ring 72, 72 of the rotating shaft support means 7 and the material of the rotating shaft 3 is made of vinyl chloride having higher wear resistance than the material of the balls 73, 73. As a result, the cylindrical portion 12 and the rotating shaft 3 side are less likely to wear.

Further, on both side surfaces of the cylindrical portion 12, two-surface widths 12 c and 12 c are formed for fixing in a state in which the rotation of the fixed-side body 1 is prevented.
A drain hole 12 d is formed at the bottom of the cylindrical portion 12.

In addition, a male thread portion 34 capable of union-connecting the rotation-side external connection pipe P2 is formed at the distal end portion of the rotating shaft 3, and an annular groove 36 in which an O-ring 35 is mounted is formed at the opening end surface.
Further, a flange 37 that integrally closes the tip opening of the space chamber 12a in a non-contact state is formed on the outer periphery of the rotary shaft 3 protruding from the space chamber 12a.

Next, operations and effects of the first embodiment will be described.
In the rotary joint of the first embodiment, as described above, the stationary body 1 and the rotating shaft 3 are made of vinyl chloride (synthetic resin) having chemical resistance, the floating sheet 2 is made of PTFE, and The seal ring portion 31 is made of ceramic, so that at least the entire inner surface of the flow channel that is in contact with the fluid has corrosion resistance, and the seal ring is provided on the end surface of the rear end opening of the rotary shaft 3 provided with the seal ring portion 31. An annular groove 32 into which the portion 31 can be mounted is formed, and a rubber ring 33 made of fluororubber having a large friction coefficient is accommodated between the bottom of the annular groove 32 and the seal ring portion 31, thereby It is configured to prevent relative rotation between the rotary shaft 3 and the seal ring part 31 without using an adhesive for attaching the ring part 31. Therefore, the effect is obtained that it becomes possible to use even when the fluid is chemicals.

  Further, since the floating sheet 2 is made of PTFE including the tip sliding surface 24, the cost can be reduced as compared with the case where a ceramic seal ring is attached to the floating sheet 2 side. At the same time, the rotational sliding resistance with the seal ring portion 31 on the rotating shaft 3 side can be reduced.

  A sliding hole 11d is provided at the bottom of the space chamber 12a in the body main body 11, and a pressing piston 22a is slidably mounted in the sliding hole 11d through an O-ring 2c made of fluoro rubber. Corrosion of the metal coil spring 6 is achieved by accommodating the metal coil spring 6 that presses and urges the floating sheet 2 in the direction of the rotation axis via the pressing piston in the sliding hole 11d. Can be prevented.

  In addition, the inner peripheral surface of the space chamber 12a and the outer peripheral surface of the rotary shaft 3 in the body main body 11 are formed in the shape of bearing inner rings 71, 71 and outer rings 72, 72, and the inner rings 71, 71 and outer rings 72, 72 Since the rotary shaft support means 7 is configured by accommodating a plurality of resin balls 73 between the two, the cost can be reduced and the size and weight can be reduced.

  Further, the material of the body main body 11 and the rotating shaft 3 constituting the inner rings 71 and 71 and the outer rings 72 and 72 in the rotating shaft support means 7 is made of a resin having higher wear resistance than the material constituting the balls 73 and 73. By adopting such a configuration, only the balls 73 and 73 are required to replace the parts due to wear, so that the cost for replacing the parts can be reduced.

  Further, an O-ring 15 made of fluororubber is mounted in an annular groove 11e formed in the inner peripheral surface of the body side supply port 11b in the body main body 11, and fixed side external connection is made with respect to the body side supply port 11b. Since the pipe P1 is configured to be connectable in a slidable state, expansion and contraction due to heat of the fixed-side external connection pipe P1 can be absorbed in the body-side supply port 11b.

  Next, another embodiment of the present invention will be described. In addition, about the other Example, illustration and description of the component similar to the said Example are abbreviate | omitted, attaches | subjects the same code | symbol, the description is abbreviate | omitted, and only a different point is demonstrated.

The rotary joint of the second embodiment corresponds to the invention described in claims 1, 2, 4 to 7.
As shown in the longitudinal sectional view of FIG. 4, the rotary joint of the second embodiment is provided with a sliding hole 11d at the bottom of the space chamber 12a in the body body 11, and the floating seat is formed in the sliding hole 11d. The press piston 22a formed integrally and projecting from the flange portion 22 is slidably mounted via a fluororubber O-ring 2c, but the slide hole is similar to the first embodiment. 11d is different from the first embodiment in that a pressure generating source 8 such as air or liquid that presses and urges the floating sheet 2 in the direction of the rotary shaft 3 is connected to the bottom of the 11d through a pressing piston 22a. It is.

  Therefore, in the second embodiment, an additional effect that the metal that can be corroded can be completely eliminated is obtained.

The embodiment of the present invention has been described above, but the specific configuration of the present invention is not limited to this embodiment, and the present invention can be applied even if there is a design change or the like without departing from the gist of the present invention. include.
For example, in the embodiment, the stationary body 1 and the rotating shaft 3 are made of vinyl chloride (synthetic resin) having chemical resistance, but other resins can be used.

  In the embodiment, as the rotation preventing means 5, a bolt 2 b is screwed into the bottom portion 11 a of the space chamber 12 a in the body main body 11, and a sliding through hole 25 in which the head portion of the bolt 2 b is formed in the flange portion 22. Although the rotation of the floating sheet 2 is prevented while allowing the sliding of the floating sheet 2 in the axial direction, the pin protruding from the flange portion 22 is attached to the bottom portion 11a of the space chamber 12a in the body body 11. The floating sheet 2 may be prevented from rotating by inserting and locking the formed sliding locking holes so as to be axially slidable.

Moreover, in the Example, although the floating sheet 2 showed the example which comprised the whole including the front-end | tip sliding surface 24 with PTFE with small frictional resistance, it can be comprised with resin other than PTFE.
Further, in the embodiment, an example in which the O-rings 2a, 2c, 15, 35 and the rubber ring 33 are made of fluororubber is shown, but other rubbers can be used.

It is a longitudinal cross-sectional view which shows the rotary joint of an Example. It is a longitudinal cross-sectional view in the II-II line of FIG. It is a left view which shows the rotary joint of this invention Example. 6 is a longitudinal sectional view showing a rotary joint of Example 2. FIG.

Explanation of symbols

P1 Fixed side external connection pipe P2 Rotation side external connection pipe 1 Fixed side body 11 Body main body 11a Bottom 11b Body side supply port 11c Body side supply path 11d Sliding hole 11e Annular groove 12 Cylindrical portion 12a Space chamber 12b Hole 12c 2 side width 12d Drain hole 13 Disc-shaped body part 14 Bolt 15 O-ring (sliding seal member)
16 Lid 2 Floating sheet 2a O-ring 2b Bolt 2c O-ring 21 Boss part 22 Flange part 22a Pressing piston 23 Flow path 24 Tip sliding surface 25 Sliding through hole 3 Rotating shaft 3a Rotating shaft side supply path 31 Seal ring part 31a Rear end sliding surface 32 Annular groove 33 Rubber ring 34 Male thread part 35 O-ring 36 Annular groove 37 Flange 5 Rotation prevention means 6 Coil spring (biasing means)
7 Rotating shaft support means 71 Inner ring 72 Outer ring 73 Ball

Claims (7)

A fixed-side body in which a bottom portion of a space chamber provided by opening one end side of the body body and a body-side supply port opened on the outer surface of the body body are communicated with each other through a body-side supply path;
A flange portion is integrally provided at one end of a boss portion that is slidably mounted in the body-side supply path via an annular sliding seal member, and the axial direction extends from the boss portion to the tip sliding surface of the flange portion. A floating sheet provided with a flow path penetrating into
The sliding surface of the rear end seal ring portion is in close contact with the tip sliding surface, and the tip end portion protrudes from the space chamber of the body body so as to be rotatably supported via the rotating shaft support means in the space chamber. A rotary shaft formed with a rotary shaft side supply path that penetrates from the center of the rear end sliding surface to the tip portion;
Rotation preventing means for preventing the rotation of the floating sheet while allowing the sliding of the floating sheet in the axial direction by engaging with each other between the bottom portion of the space chamber in the body body and the flange portion of the floating sheet;
It is provided at the bottom of the space chamber in the body body, and presses the floating sheet in the direction of the rotation axis so as to urge the sliding surface of the front end thereof in a direction that always keeps in close contact with the sliding surface of the seal ring portion. Urging means for acting on the flange portion;
In a rotary joint with
The fixed side body, the rotating shaft and the floating sheet are made of a synthetic resin having chemical resistance,
The seal ring portion is made of ceramic;
An annular groove on which the seal ring part can be mounted is formed on the rear end opening end surface of the rotary shaft provided with the seal ring part, and a friction coefficient is large between the bottom part of the annular groove and the seal ring part. A rotary joint configured to prevent relative rotation between the rotating shaft and the seal ring portion by accommodating a rubber ring.   The rotary joint according to claim 1, wherein the floating sheet is made of PTFE including a tip sliding surface thereof. 3. The rotary joint according to claim 1, wherein a sliding hole is provided in a bottom portion of the space chamber in the body body, and a pressing piston formed integrally and projecting from the flange portion of the floating seat is formed in the sliding hole. It is slidably mounted via an annular sliding seal member,
A rotary joint in which a metal coil spring that presses and biases the floating sheet in the direction of the rotation axis via the pressing piston is accommodated in the sliding hole. 3. The rotary joint according to claim 1, wherein a sliding hole is provided in a bottom portion of the space chamber in the body body, and a pressing piston formed integrally and projecting from the flange portion of the floating seat is formed in the sliding hole. It is slidably mounted via an annular sliding seal member,
A rotary joint, characterized in that a pressure source such as air or liquid that presses and urges the floating sheet in the direction of the rotation axis is connected to the bottom of the sliding hole via the pressing piston.   5. The rotary joint according to claim 1, wherein an inner peripheral surface of the space chamber and an outer peripheral surface of the rotary shaft in the body main body are formed in a shape of an inner ring and an outer ring of a bearing, and the inner ring and the outer ring are formed. The rotary joint is configured by accommodating a plurality of resin balls between the rotary joint and the rotary joint.   6. The rotary joint according to claim 5, wherein a material of the body main body and the rotating shaft constituting the inner ring and the outer ring in the rotating shaft support means is made of a resin having higher wear resistance than a material forming the ball. Rotary joint characterized by   The rotary joint according to any one of claims 1 to 6, wherein a sliding seal member is mounted in an annular groove formed in an inner peripheral surface of the body-side supply port in the body body, and the external connection pipe is slid. A rotary joint characterized in that it can be connected in a movable state.

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