JPH0438955B2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to an air supply device for supplying control air to air-operated equipment from the outer circumferential direction of the rotating shaft through an air passage provided in the rotating shaft. The present invention relates to an air supply device suitable for equipment that does not require air supply for a long period of time.

<Prior Art and Problems> When supplying control air to air-operated equipment from the shaft end of a rotating shaft, this can generally be easily done using a rotary seal or swivel joint.

On the other hand, if air cannot be supplied from the shaft end of the rotating shaft due to the configuration of the machine, it is necessary to supply air from the outer circumferential direction of the rotating shaft.

By the way, when supplying control air from the outer circumferential direction of the rotating shaft, a sealing mechanism for the rotating shaft is required on both sides of the air passage.

However, if the diameter of the rotating shaft is large or the rotational speed is high, the circumferential speed of the rotating shaft will be large.
The sealing material that is in sliding contact with the outer periphery of the rotating shaft is subject to abrasion and heat generation due to the pressing force, resulting in a problem that the life of the sealing material is extremely shortened.

<Purpose of the Invention> The present invention has been made to solve the above-mentioned problems, and the durability of the sealing material is improved by making the sealing material and the outer circumferential surface of the rotating shaft non-contact when air supply is not required. It is an object of the present invention to provide an air supply device from the outer circumferential direction of a rotating shaft, which can significantly improve the performance.

<Means for Solving the Problems> In order to solve the above problems, the present invention forms a plurality of annular grooves side by side on the outer periphery of the rotating shaft,
The rotating shaft is provided with an air passage communicating with one annular groove, and the inside of the cylinder, which is fitted onto the rotating shaft and attached to the fixed part, is loosely fitted into the part of the rotating shaft provided with the annular groove to supply air. It incorporates an annular piston that is movable in the axial direction of the rotating shaft by evacuation, and attaches multiple inner-diameter sealing materials to the inner circumference of this piston that slide against the outer circumferential surface of the rotating shaft, matching the intervals between the annular grooves. , the piston is provided with an air supply port that communicates between the sealing materials from the outside.

<Operation> When control air is not supplied, the piston is in the retracted position and the sealing material faces the annular groove, and the sealing material is in a state of no contact with the rotating shaft, and when trying to supply control air, All you need to do is move the piston to the forward position by injecting air into the pressure chamber of the cylinder, and then supply control air from the supply port of the piston. The air passage becomes sealed and the air passage is cut off from the outside air, so the control air flows from the supply port to the air passage through the annular groove.When the control air is no longer needed, the air supply to the pressure chamber of the cylinder is stopped. Once released, the piston returns to the retracted position.

<Embodiments> Examples of the present invention will be described below based on the accompanying drawings.

As shown in FIG. 3, an air-operated device using the air supply device of the present invention will be described as an example of an air-start centrifugal clutch 1 that does not require continuous supply of control air for a long period of time.

The air start centrifugal clutch 1 is used to connect and disconnect rotational transmission between the drive shaft 2 and the driven rotating shaft 3.

Moreover, the air start centrifugal clutch 1 is connected to the drive shaft 2.
A boss 5 fixed to the end of the driven rotation shaft 3 is located inside the drum 4 fixed to the drum 4, and a centrifugal force element 7 with an outer shoe 6 facing the inner circumferential surface of the drum 4 is placed on the boss 5. element 7 to drum 4
It is constructed by attaching an air cylinder 8 that presses against the
The boss 5 is provided with a passage 9 that supplies control air to the air cylinder 8, and this passage 9 communicates with an air passage 10 provided in the rotating shaft 3 through a passage 12 of a manifold 11 fixed to the rotating shaft 3. are doing.

In order to transmit the rotation of the drive shaft 2 to the rotating shaft 3 using the air start centrifugal clutch 1, the air cylinder 8 presses the shoe 6 of the centrifugal force element 7 against the inner surface of the rotating drum 4, and The rotating shaft 3 starts rotating due to the frictional force.

It is further accelerated and the rotating shaft 3 reaches a predetermined speed,
The pressing force of the shoe 6 against the inner surface of the drum 4 is increased by centrifugal force, and power is transmitted.

At this point, it is no longer necessary to use the air cylinder 8 to press the shoe 6 against the inner surface of the drum 4, so the supply of air to the cylinder 8 is stopped.
After that, the clutch continues to transmit power using its own centrifugal force.

When the clutch is disengaged, the drive shaft 2 and the driven rotary shaft 3 slow down in response to a stop instruction from the drive machine, and when they come to a stop, the centrifugal force element 7 moves inward, and the shoe 6 is released from the inner surface of the drum 4. Even if the drive machine starts rotating again, unless the air cylinder 8 is activated, the power transmission is cut off.
The clutch remains disconnected.

In order to supply control air to the air cylinder 8 of the clutch 1, a supply device 21 for supplying control air from the outer circumferential direction of the rotating shaft 3 is located in the middle of the rotating shaft 3 and attached to a fixed part such as a bearing box 29. There is.

As shown in FIGS. 1 and 2, the supply device 21 has a plurality of annular grooves 22 and 23 formed side by side on the outer periphery of the rotating shaft 3, and one annular groove 22 and 23 formed on the rotating shaft 3.
and an air passage 24 that communicates with the passage 10 provided along the axial direction, a cylinder 25 is externally fitted into the portion of the rotating shaft 3 provided with the annular grooves 22 and 23, and a piston is inserted into the cylinder 25. It is constructed by incorporating 26.

The cylinder 25 is made up of a cylinder body 27 and a cylinder cover 28, and is fixed with bolts to a bearing box 29 that supports the rotating shaft 3. It's in tiers.

The piston 26 is inserted into the large diameter hole 3 of the cylinder body 27.
0 through a sealing material 32, and a small diameter part 34 that fits into the small diameter part 31, and is movable in the axial direction of the rotating shaft 3, and is connected to the guide pin 35 of the cylinder cover 28 and the large diameter part 34. The fit of the horizontal hole 36 provided in the portion 33 prevents rotation, and the return spring 37 compressed between the cylinder cover 28 provides elasticity to return to the retracted position shown in FIG. has been done.

The inner diameter of the piston 26 fits loosely around the outer periphery of the rotating shaft 3, and sealing material 3 is attached to both ends of the inner diameter.
8 and 39 are fixed to seal holders 40 and 41 using bolts.

The sealing materials 38 and 39 have an inner diameter that fits over the outer diameter of the rotating shaft 3, and are fixed at an interval equal to the annular grooves 22 and 23, so that when the piston 26 is in the retracted position, Both sealing materials 38 and 39 face the annular grooves 22 and 23 as shown in FIG.
In contrast, both sealing materials 38 and 39 are in a non-contact state, and the air passage 24 is in communication with the outside air.

The cylinder body 27 is provided with a passage 43 for supplying air to a pressure chamber 42 formed between the inner periphery of the large diameter hole 30 and the piston 26. When air is supplied to the pressure chamber 42, the piston 26 moves as shown in FIG. As shown, the return spring 37 is compressed and moved to the forward position.

In the forward position, both the sealing materials 38 and 39 come into sliding contact with the outer periphery of the rotary shaft 3 across the annular groove 22 that communicates with the air passage 24, thereby blocking the air passage 24 from the outside air.

Further, an annular air circuit 4 is formed between both seal members 38 and 39 on the inner periphery of the small diameter portion 34 of the piston 26.
4 is formed, and the piston 26 is provided with an air supply port 45 that communicates with this air circuit 44 from the outside.
When the piston 26 is in the forward position, the air circuit 4
4 communicates with the annular groove 22, so that control air to the air start centrifugal clutch 1 can be supplied to the air passage 24 from an air supply port 45.

The air supply device of the present invention has the above-described configuration, and when there is no need to supply control air to the air start centrifugal clutch 1, the piston 26 is in the first position.
The seals 38 and 39 are in the retracted position as shown.
are located at positions corresponding to the annular grooves 22 and 23 and are in a non-contact state with the rotating shaft 3.

When trying to supply control air, pressure air is supplied to the passage 43 of the cylinder 25, and the piston 2
6 to the forward position as shown in FIG. At this time, both sealing materials 38 and 39 are in sliding contact with the outer periphery of the rotating shaft 3 on both sides of the annular groove 22, and the air passage 24
is isolated from the outside air.

When control air is supplied from the air supply port 45 of the piston 26 in this state, the air circuit 44 and the annular groove 2
Air flows through the air cylinder 8 of the air start centrifugal clutch 1 through the air passage 2 and the air passage 24, and the clutch 1 is coupled so that the rotation of the drive shaft 2 is transmitted to the rotating shaft 3.

When the supply of control air to the clutch 1 is no longer necessary, the supply of control air and air to the passage 43 of the cylinder 25 can be stopped, and the piston 26
is returned to the retracted position as shown in FIG. 1 by the return spring 37, and both sealing materials 38 and 39 come out of contact with the rotating shaft 3, thereby preventing generation of heat and wear.

<Effect> As described above, according to the present invention, when supplying control air into the shaft from the outer circumferential direction of the rotating shaft, the sealing material is brought into contact with the rotating shaft only when air supply is necessary. The contact of the sealing material with the shaft can be kept to a minimum, reducing heat generation and abrasion of the sealing material, and significantly improving the life of the sealing material.

[Brief explanation of drawings]

Fig. 1 is a partially cutaway front view showing the state of the air supply device according to the present invention before air is supplied, Fig. 2 is a partially cutaway front view showing the same as above when air is being supplied, and Fig. 3 is the air supply device. FIG. 2 is an explanatory diagram showing how the device is used. 21... Supply device, 22, 23... Annular groove, 2
4... Air passage, 25... Cylinder, 26... Piston, 27... Cylinder body, 37... Return spring, 38, 39... Seal material, 42...
...Pressure chamber, 43...Passway, 44...Air circuit, 4
5...Air supply port.

Claims (1)

[Claims] 1 A plurality of annular grooves are arranged and formed on the outer periphery of a rotating shaft, an air passage communicating with one of the annular grooves is provided on the rotating shaft, and the rotating shaft is placed inside a cylinder that is fitted onto the rotating shaft and attached to a fixed part. Incorporating an annular piston that loosely fits into the annular groove and can move freely in the axial direction of the rotating shaft by supplying and discharging air.
A plurality of inner-diameter sealing materials that slide into contact with the outer peripheral surface of the rotating shaft are attached to the inner periphery of the piston according to the intervals between the annular grooves, and an air supply port that communicates between the sealing materials from the outside is provided on the piston. Air supply device from the direction.