JPS6326609Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) The present invention relates to the improvement of a ring and its retainer used in mechanical seals, which can be disassembled and reassembled for cleaning or repair, such as in rotary pumps. It is useful as a shaft sealing device for rotating equipment that may perform

(Prior art) It has a fixed ring fixed to the casing side and a rotating ring that rotates integrally with the rotating shaft, and either the fixed ring or the rotating ring is biased by an elastic member. A mechanical seal that presses against the other ring to seal it is used as a shaft sealing device for a rotary pump or the like. If the liquid to be pumped by this rotary pump is food such as cream or juice, or medicine, the pump must be disassembled each time it is used to remove any deposits inside the pump and keep it clean. It has been cleaned and cleaned. In this case, it is natural that the mechanical seal part must be disassembled and cleaned, but in the conventional case where the retainer was simply fitted onto the seal ring, the two could easily come off and separate when disassembled. As a result, unexpected accidents often occurred in which the ring was dropped and damaged or lost. To solve this problem, for example, the ring and retainer are fixed by shrink fitting, or a snap ring or the like is attached to the retainer to prevent the ring from coming off. However, in the former case, the ring and retainer cannot be separated, making it difficult to clean them thoroughly, and in the latter case, it is necessary to create a groove for the snap spring in the retainer and fit it into the groove, which requires extra time and effort. It was hot.

(Purpose of the invention) The present invention enables elastic engagement between a ring and a retainer that is fitted onto the ring, thereby preventing the accidental accident of dropping the ring during disassembly, and easily The purpose is to provide a mechanical seal that can be disassembled and assembled and easily cleaned.

(Structure of the invention) In the present invention, a plurality of grooves for connecting rotational force and a locking groove for preventing slippage are formed along the axial direction on the outer circumferential surface of the rotating ring, and the retainer has a plurality of grooves for connecting the rotational force and a locking groove for preventing slippage. It is formed by forming a protrusion on the inner circumferential surface that fits into it, and a tongue-shaped locking piece that protrudes toward the inner circumference and elastically engages with the locking groove.

(Example) Embodiments of the present invention will be described based on the drawings.

FIG. 1 mainly shows the shaft sealing device part of a rotary pump. One end of a drive shaft 3 is inserted into a pump chamber 2 formed in a pump casing 1. A rotor 4 is coaxially fitted into the spline-shaped locking shaft portion 3a, and is tightened and fixed by a cap nut 5 screwed into the threaded portion 3b. A lid 6 is attached to the pump casing 1 with bolts or the like, and the lid 6 is formed with a bag portion 6a in which the cap nut 5 is accommodated. Further, between the rotor 4 and the cap nut 5, and between the drive shaft 3 and the rotor 4, there are gaskets 7 and 7, respectively.
It is sealed by 8.

On the other hand, an annular mating ring 9 is fitted coaxially with the drive shaft 3 in a non-contact manner and has a large-diameter portion 9a in the center.
It is held between the pump casing 1 and a tightening ring 12 with 0 and 11 interposed therebetween, and is fixed by being tightened with a bolt 13. The mating ring 9 has annular grooves 9b, 9c formed on its inner and outer circumferential surfaces, respectively, and both grooves 9b, 9c.
Communication hole 9d that communicates between 9c and groove 9 on the inner peripheral surface side
A communication hole 9e is provided that communicates the gasket 10 with the inner chamber side portion of the gasket 10. Tightening ring 12
The steam supply hole 1 is located at the position opening into the groove 9c described above.
4, and a steam supply source (not shown) is connected via piping to a port 14a communicating therewith.

Now, at both ends of the mating ring 9, fixing rings 15a made of carbide or ceramic, etc.
15b is fitted and integrally fixed, and a rotary ring 17 into which retainers 16a and 16b are fitted is attached to the end surface of each fixed ring 15a and 15b.
a and 17b are urged by compression springs 18a and 18b and are pressed into contact with each other. Each pressure contact surface is rotatable in sliding contact and has sealing properties, forming a mechanical seal. The rotating ring 17 is made of carbon, and has an annular convex portion 18a for pressure sealing on one end surface and a packing groove 18b on the inner peripheral surface, as shown in FIGS. 2 and 3, and rotates in the axial direction of the outer peripheral surface. It has four concave grooves 18c for force connection and two locking grooves 19 for preventing slippage. On the other hand, retainer 16
are made of stainless steel and are shown in Figures 2 to 4.
As shown in the figure, a tubular large-diameter portion 20a and a small-diameter portion 2
0b connected by a collar-shaped ring plate 20c, forming a two-stage cylinder shape. On the inner circumferential surface of the large-diameter portion 20a, there are four protrusions 20 shaped to fit into the aforementioned grooves 18c.
d, and a portion of the large diameter portion 20a is cut out in the axial direction to form two tongue-shaped locking pieces 21, respectively.

The locking piece 21 is flexible, and the vicinity of its tip protrudes smoothly toward the inner circumference, and is fitted into the locking groove 19 described above. Due to its own elasticity, the locking piece 21 generates a resistance force against the rotating ring 17 coming out of the retainer 16 in the axial direction. Therefore, this locking piece 21
This prevents the rotary ring 17 from freely coming out of the retainer 16 during disassembly and assembly of the mechanical seal, prevents the rotary ring 17 from falling accidentally, and also prevents the rotary ring 17 and the retainer 16 from being attached or detached. , which can be easily performed by simply inserting and withdrawing. Note that the notch 20e provided in the small diameter portion 20b is for engagement with a locking pin 22 provided to rotate integrally with the drive shaft 3. In FIG. 1, reference numeral 23 is a collar, and reference numeral 24 is a collar that also serves as a spring holder for the drive shaft 3.
26, 27, 28, 29 are gaskets such as O-rings. Further, the drive shaft 3 is rotatably supported by a bearing (not shown) fixedly attached to the pump casing 1 on the right side of FIG.

In the shaft sealing device portion of the rotary pump configured as described above, a mechanical seal consisting of two sets of fixed rings 15a, 15b and rotating rings 17a, 17b is interposed between the pump chamber 2 and the outside air to provide airtight sealing. Furthermore, by supplying steam from the steam supply hole 14, the space between both mechanical seals is filled with steam, thereby completely preventing bacteria from entering from the outside air. When disassembling the mechanical seal to clean it or to replace parts, the retainer 16 and rotary ring 17 are taken out as a unit, and then the rotary ring 17 is pulled out from the retainer 16. You can clean it, etc., and then do the reverse when reassembling it.

In the above embodiment, two locking grooves 19 were provided on the outer peripheral surface of the rotating ring 17, but the number of locking grooves 19 was reduced to one.
or three or more.

(Effect of the invention) Since the locking portion of the rotating ring and the locking piece of the retainer are elastically engaged, it is possible to prevent an unexpected accident such as the rotating ring falling off from the retainer when disassembling the mechanical seal. Since both can be easily attached and detached, the mechanical seal can be easily disassembled and assembled, and can be easily cleaned.

[Brief explanation of the drawing]

The drawings show embodiments of the present invention; Fig. 1 is a sectional view showing an example in which the present invention is applied to a shaft sealing device of a rotary pump, and Fig. 2 shows a rotating ring and a retainer of the mechanical seal of the present invention. 3 is a front view of FIG. 2, and FIG. 4 is a plan view of the same. 1...Pump casing (casing), 3...
...Drive shaft (rotating shaft), 15a, 15b...Fixing ring, 16, 16a, 16b...Retainer, 1
7, 17a, 17b...Rotating ring, 18a, 1
8b...compression spring (elastic member), 19...locking part,
21...Latching piece.

Claims (1)

[Scope of utility model registration request] It has a fixed ring fixed to the casing side and a rotating ring that rotates integrally with the rotating shaft, and either the fixed ring or the rotating ring is biased by an elastic member to the other ring. A mechanical seal that presses and seals and has a retainer fitted onto the rotary ring, the rotary ring having a plurality of concave grooves for connecting the rotational force and a retaining engagement along the axial direction on the outer circumferential surface of the rotary ring. A locking groove is formed, and the retainer is formed with a protrusion on an inner circumferential surface that fits into the groove, and a tongue-shaped locking piece that protrudes toward the inner circumference and elastically engages with the locking groove. A mechanical seal that is characterized by the ability to