JP3801677B2 - Rotary joint - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a rotary joint that is mounted in the middle of a rotary shaft such as a spindle in a machine tool and supplies high-pressure liquid in the axial direction from a hole provided on the outer peripheral surface of the rotary shaft.
[0002]
[Prior art]
When cutting workpieces while supplying coolant from the tip of the drill, coolant is supplied to the tip of the drill via the spindle of the machine tool. A rotary joint is attached to the rear end of the main motor to connect the rotation side and the piping side (fixed side), and coolant is supplied to the front end side through a hole provided through the entire shaft center of the spindle. Was provided.
[0003]
FIG. 2 shows the conventional rotary joint, in which 50 is a spindle, 51 is a rotary tube shaft fixed to the rear end of the spindle 50, 52 is a joint body on the fixed side, and 53 is the joint body 52. Floating sheet 55 is slidably mounted on the stationary coolant channel 54, 55 is a ring-shaped rotation-side seal fixed to the end surface of the rotary tube shaft 51, and 56 is fixed to the tip of the floating sheet 53. A fixed-side seal 57 having a contact surface with the rotation-side seal 55 and a spring 57 that urges the floating sheet 53 in a direction in which the fixed-side seal 56 contacts the rotation-side seal 55.
[0004]
[Problems to be solved by the invention]
By the way, the main motor conventionally mounted on this type of machine tool has a special structure in which the rotor shaft is provided integrally with the spindle in the machine tool, and if the drive system including such a motor fails, It must be replaced, and the cost will be expensive and delivery time will be increased. For this reason, there is an increasing tendency to adopt a motor that can be generally purchased.
In this case, if the rotary joint is placed at the rear end of the motor as it is, the through hole must be provided in the shaft center of the rotor shaft. In order to avoid special processing, a rotary joint must be provided in the middle of the spindle.
[0005]
However, the conventional rotary joint is inserted into the spindle 50, covers the hole for introducing the coolant provided on the outer peripheral surface of the spindle 50 into the shaft, and covers the outer peripheral surfaces on both sides of the hole. Since there is no sealing structure that seals, there is a problem that it cannot be mounted on the spindle 50 or the like.
[0006]
The present invention has been made in order to solve such a conventional problem, and the object of the present invention is to fix the rotating side seal and the fixed part in the case where machining is required for coolant that is mounted in the middle of a rotating shaft such as a spindle. To provide a rotary joint that can automatically supply the side seals in close contact with each other and protect the sealing surface without coolant by separating the fixed side seal and the rotary side seal from each other when machining is not required. It is in.
[0007]
[Means for Solving the Problems]
As a means for achieving the above object, in the rotary joint according to claim 1 of the present invention, the rotary joint is attached to a rotary shaft having a flow path from the coolant inlet opening to the shaft end to the shaft end. A cylindrical body is inserted into the rotary shaft, the cylindrical body covers the introduction port, forms an annular space portion with the rotary shaft, and communicates with the outside and the annular space portion A seal portion composed of a rotor sheet and a floating sheet arranged to face each other so that the seal rings are in contact with each other on both sides of the introduction port, with the floating sheets facing each other. The floating sheets have a boss-like piston portion whose front end faces the both sides in the annular space portion, and the boss-like piston portion is the cylindrical body. Sealed slidably; the rotor sheet is fixed in a sealed state with the rotary shaft fitting portion on the outer peripheral surface of the shaft; the cylindrical body holds the floating sheet in the axial direction and prevents rotation The holding portion and the spring that presses the floating sheet toward the side away from the rotor sheet are provided.
[0008]
In the rotary joint of the present invention, seal portions are provided on both sides of the coolant inlet port opened on the outer peripheral surface of the rotating shaft.
In the seal portion, a floating sheet is slidably held in the axial direction by a cylindrical body covering the introduction port, and a rotor sheet is fixed to the rotating shaft on both outer sides thereof. The floating sheets are urged outward by springs to bring the seal rings apart from each other. In this case, the rotor sheet side is the rotating side during rotation.
[0009]
When the coolant is supplied with pressure to the supply path of the cylindrical body in the above state, the coolant first fills the annular space, and then flows into the introduction port and faces the annular space. The tip of the piston part is pressed.
Due to the pressure of this coolant, the floating sheet slides against the urging force of the spring toward the rotor sheet side and presses its own seal ring against the seal ring of the rotor sheet. The flow path is connected in a sealed state.
[0010]
Therefore, when the coolant is rotated without being supplied, the hydraulic pressure does not act on the boss-like piston portion, so that the seal rings are separated from each other, thereby causing troubles such as seizure of the seal rings. Will prevent.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments according to the present invention will be described in detail with reference to the drawings.
FIG. 1 shows a rotary joint A according to the present embodiment.
In FIG. 1, 1 is a machine frame of a machine tool such as a machining center, 2 is a spindle as a rotating shaft supported by the machine frame 1, 3 is an inlet for coolant provided on the outer peripheral surface 2a of the spindle, This is a supply path that is drilled in the axial center from the inlet 3 to the end.
[0012]
In the figure, reference numeral 5 denotes a cylindrical body, and reference numeral 6 denotes a cylindrical body 5 that is inserted into the spindle 2 and mounted on the machine frame 1 so that the same cover is provided on the left and right with the rotational position of the inlet 3 of the spindle 2 as the center. An annular stepped portion having a width for providing the coolant, 7 is a coolant supply passage penetrating from the outer peripheral surface 5a to the inner peripheral surface 6a in the center of the annular stepped portion 6, 7a is a supply port opened to the outer peripheral surface 5a, Reference numeral 8 denotes an annular space formed between the inner peripheral surface 6a of the annular stepped portion and the spindle outer peripheral surface 2a. Reference numeral 9 denotes both side surfaces of the annular stepped portion 6, each of which is appropriately arranged on the same circumference. Pins 10 are provided with the same amount and projecting, and 10 are both side surfaces of the annular stepped portion 6, and are headed pins that are provided with an appropriate number of components arranged on the same circumference.
Further, 11 is a flange portion for mounting the machine frame of the cylindrical body 5, 12 is its mounting bolt, and 12a is a positioning pin.
[0013]
Next, 13 is a floating seat, 13a is a bush, 14 is a boss-like piston portion slidably extended from the floating seat body to the inner peripheral surface 6a of the cylindrical body 5, 14a is a tip portion thereof, and 15 is a tip portion. A seal portion 16a for sealing between the portion 14a and the inner peripheral surface 6a, 16a is a seal ring disposed at the end opposite to the boss-like piston portion 14. The seal ring can be formed of, for example, ceramics, metal, cermet, silicon carbide or the like.
[0014]
17 is a flange portion provided between the seal ring 16a and the boss-like piston portion 14, and 17a is a through hole that is equally distributed on the same circumference as the headed pin 10 and through which the headed pin 10 is inserted. , 18 is a spring that is inserted between the side surface of the annular stepped portion 6 and the head of the headed pin 10 in a compressed state and presses the flange portion 17 to the side away from the seal ring 16a, and 19 is the annular stepped portion. It is a hole that is slidably inserted into the pin 9 protruding from the side surface of the attaching portion 6, and is equally arranged on the side surface of the flange portion 17 on the same circumference as the pin 9.
The floating sheet 13 is disposed symmetrically on both sides of the annular stepped portion 6 as the structure.
[0015]
A rotor sheet 20 is provided so as to face the floating sheets 13 and 13 respectively. A seal ring 16b is fixed to the rotor seat body so as to face the seal ring 16a, 21 is a seal portion for sealing between the fitting portion 22 and the spindle 2, and 23 is a key portion for preventing rotation. In this embodiment, since the terminal end side (right end side in FIG. 1) of the spindle 2 is a screw shaft, the fitting portion 22 of the rotor sheet 20 is screwed and fixed with a set screw 24. I am letting.
[0016]
Next, the operation of the rotary joint A will be described.
When no coolant is supplied, the rotary joint A presses the floating sheet 13 away from the rotor sheet 20 by the urging force of the spring 18, and the seal ring 16a is separated from the seal ring 16b and is always released. Yes.
If no coolant is required for processing, the spindle 2 is rotated in this state. In this case, since the floating sheet 13 is prevented from rotating toward the cylindrical body 5 by the pins 9 and the rotor sheet 20 rotates together with the spindle 2, the seal ring 16b rotates while the seal rings 16a and 16b are disconnected. .
When the coolant is supplied from the supply port 7 a, the coolant first flows into the introduction port 3 of the spindle 2 while filling the annular space portion 8 and is supplied to the tool side via the supply path 4. When the hydraulic pressure increases and the front end of the boss-like piston portion is pressed, the floating sheet 13 slides toward the rotor sheet 20 and the seal rings are brought into close contact with each other. At the same time, the coolant also flows between the floating sheet 13 and the spindle 2 and reaches the contact portion between the seal rings 16a and 16b. While the spindle is rotating, the coolant cools the seal rings and is slightly wound between the contact surfaces to lubricate the contact surfaces.
[0017]
Further, in this case, the coolant filling the annular space 8 is a seal portion 15 between the cylindrical body 5 and the floating seat 13, and seal rings 16 a and 16 b between the floating seat 13 and the rotor seat 20. A leakage between the sheet 20 and the spindle 2 is prevented by a seal portion 21.
[0018]
Although the embodiment of the present invention has been described above, the specific configuration of the present invention is not limited to this embodiment, and even if there is a design change or the like within a scope that does not depart from the gist of the present invention. Included in the invention.
[0019]
For example, the spindle of the machine tool has been described as the rotating shaft, but the rotating shaft that can be applied is not limited to this, and includes a rotating shaft of a wind turbine generator.
[0020]
【The invention's effect】
As described above, since the rotary joint of the present invention has the above-described configuration, it can be supplied into the rotary shaft without leaking coolant from the outside that is mounted and fixed in the middle of the rotary shaft. .
Further, since the seal portion has a mechanical seal structure, it can be used for a high-speed rotating shaft. In addition, the seal ring is kept open when processing that does not require coolant between seal rings, so seizure is prevented, and when processing that requires coolant, the seal is automatically sealed by supplying the coolant. As a result, it is possible to obtain effects such as eliminating the need for control pipes and the like and being very easy to handle.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a rotary joint A in an embodiment of the present invention.
FIG. 2 is a cross-sectional view showing a conventional rotary joint.
[Explanation of symbols]
A Rotary joint 1 Machine frame 2 Spindle 2a Spindle outer peripheral surface 3 Coolant inlet 4 in the spindle Coolant supply path 5 in the spindle Tubular body 5a Tubular body outer peripheral surface 6 Cylindrical body annular stepped portion 7 Tubular body The supply path 7a of the cylindrical body The annular space 9 of the cylindrical body 9 The pin for locking and sliding the cylindrical body 13 The floating seat 14 The boss-like piston part 14a The tip part 15 of the boss-like piston part The seal part 16a Floating sheet side seal ring 16b Rotor seal side seal ring 18 Spring 19 Pin 9 insertion hole 20 Rotor sheet 21 Rotor sheet seal part 22 Rotor sheet fitting part 23 Rotor sheet key part (adhesion)
24 Rotor seat set screw (adhesion)

Claims (1)

A rotary joint attached to a rotary shaft having a flow path at the shaft center from an inlet of coolant opening to an outer peripheral surface of the shaft to a shaft end;
A cylindrical body is inserted into the rotating shaft, the cylindrical body covers the introduction port, forms an annular space portion with the rotating shaft, and has a supply path communicating with the outside and the annular space portion. Fixed to the machine frame side;
Seal portions composed of a rotor sheet and a floating sheet arranged to face each other so that the seal rings are in contact with each other are arranged on both sides of the introduction port with the floating sheets facing each other;
The floating sheets have a boss-like piston portion with front ends facing the annular space portion from both sides, and the boss-like piston portion is slidably sealed to the cylindrical body;
The rotor sheet is fixed in a sealed state with a rotating shaft fitting portion on a shaft outer peripheral surface;
A rotary joint characterized in that the cylindrical body has a holding portion for holding and preventing rotation of the floating sheet in the axial direction and a spring for pressing the floating sheet toward a side away from the rotor sheet.

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