JPS6017298A - Circulating pump - Google Patents

Abstract

PURPOSE:To reduce the squeak due to the sliding between a floating seat and a seal ring, abrasion of the both, and the roughening of the surfaces, by forming a seal box by fitting a cylindrical ring having water passing windows at the same position to a mechanical slidable surface, onto a shock absorbing rubber. CONSTITUTION:When a pump is driven, a portion of circulating water passes through the rear surface of a vane wheel 23 and two water passing windows 18 of a cylindrical ring 19 which are arranged in the opposite directions at the same position to a mechanical slidable surface 17 and beats the mechanical slidable surface 17, and enters into the cylindrical ring 19 and further enters into a seal box 16 constituted by fitting a floating seat 15 onto a buffer rubber 14 installed water-tightly, and is introduced into a suction passage, passing through the water passing hole 25 of the vane wheel 23. In this case, since the circulating water supplied from the above-discribed circulating-water passage beats the mechanical slidable surface 17 from the vicinity, air foams are collapsed and discharged into the suction passage of the vane wheel 23, and the heat due to the sliding of the mechanical seal is perfectly radiated by the circulating water. Therefore, the abrasion between the floating seat 15 and a seal ring 20 can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a circulation pump for hot water heating systems, hot water supply systems, etc.

Structure of a conventional example and its problems The mechanical seal portion of a conventional circulation pump is configured as shown in FIG. 1, for example.

That is, the bottom of the seal box 1 is watertightly fitted to the four-stage part of the bracket 2, and the end of the folded part 1' of the opening of the seal box 1 is connected to the pump casing 3 of the bracket 2 with the hook 2. ' to form a donut-shaped passage between the peripheral wall 1' of the seal box 1 and the cylindrical part 2' of the bracket 2, and located outside the folded part of the seal box of the pump casing 3. The folded part 1 of the seal box 1 is aligned with the groove 4 and the water inlet 5.
'' is provided with a water passage hole 〇, and a water passage window 7 is formed in the peripheral wall 1' of the seal box 1.

By the way, in this configuration, a circulation path is provided by the water passage hole ○ provided in the seal box 1 and the water passage window 7, and the circulating water prevents air from stagnation in the seal box 1. Since the water passage window 7 of the seal box 1 is not located near the mechanical seal sliding surface 8, most of the air accumulated in the seal box 1 can be removed, but the seal ring 9 When the floating sheet 10 slides, the rotation of the seal ring 9 causes air bubbles 11, which have a smaller specific gravity than water, to accumulate on the mechanical seal sliding surface 8.

This means that even if the air bubbles 11 are small, the seal ring 9 is surrounded by air, the mechanical seal sliding surface 8 is in a criss-cross state, the sliding heat increases, and the seal ring 9 and the 70-ting sheet The film of the 1Q liquid, which has the effect of lubricating oil, broke, causing abnormal sliding noise and causing noise. Furthermore, due to the increase in sliding heat, wear of the seal ring 9 and the floating seat 10 increases, resulting in a shortened service life.

Purpose of the Invention In view of the above-mentioned conventional problems, the present invention aims to improve the seal box, reduce the abnormal sliding noise between the floating seat and the seal ring, and reduce the wear and surface roughness of both. That is.

Structure of the Invention In order to achieve the above-mentioned object, the present invention forms a seal box by attaching a cylindrical ring to a buffer rubber that watertightly fits a 70-ding sheet into a bracket, and a water-permeable window of the ring is formed. A cylindrical part is provided in the rear shroud of the impeller, and a water passage hole is provided in the cylindrical part of the impeller to communicate the seal box with the inside of the impeller. The cylindrical portion of the impeller is fitted with one end of the ring.

Description of examples An embodiment of the present invention will be described below with reference to FIG.

A floating sheet 15 is watertightly fitted to the portion of the bracket 12 through which the pump shaft 13 passes through, via a buffer rubber 14, and two water passage windows 18 are provided in opposite directions at the same position as the mechanical seal sliding surface 17. The cylindrical ring 19 is attached to the buffer rubber 14, and the seal box 1 is closed.
On the other hand, a seal ring 2o is formed on the pump shaft 13.
and packing 21, coil spring 22, impeller 2
3 is attached, and this seal ring 2o is brought into pressure contact with the floating seat 16.

Here, the rear shroud of the impeller 23 has a water hole 25 that communicates with the seal box 16 and the inside 24 of the impeller, and a cylindrical portion 26 provided on the rear shroud of the impeller 23 fits into the ring 19. has been done. 2 in the diagram
7 is a spring receiver, 28 is a nut, and 29 is a Carter spring.

Note that the area of the water passage window 18 of the ring 19 is made smaller than that of the water passage hole 26 of the impeller 23.

In the above configuration, when the pump is driven, circulating water is sucked in from the suction port 30 by the pumping action of the impeller 23, pressurized by the rotation of the impeller 23, and discharged from the discharge port 31 and circulated. A part of the water passes through the rear surface 32 of the impeller 23 and the water passage window 18 of the IJ'ing 19, hits the mechanical seal sliding surface 17, enters the seal box 16, and further flows through the impeller 23. It passes through the hole 25 and reaches the suction path.

By having this circulation waterway, in the conventional method of seal boxes for mechanical seals, the water passage window of the seal box was not located close to the sliding surface of the mechanical seal, so air bubbles were prevented from forming on the sliding surface of the mechanical seal. However, when the circulating water from the circulation path hits the sliding surface of the mechanical seal from the vicinity, the bubbles are destroyed, and the circulating water and the impeller 23
The sliding heat of the mechanical seal is completely dissipated by the circulating water, and the mechanical seal slides smoothly. Further, since the circulating water hits the mechanical seal sliding surface 17, it is not affected by the direction of the circulation pump, and even if the direction of the circulation pump changes by 90', for example, bubbles can be discharged without any problem. Since the water passage window area 18 of the ring 19 is smaller than the area of the water passage hole 25 of the impeller 23, the pressure inside the seal box 16 is equal to the pressure P2 of the suction port 3o rather than the pressure P1 of the pump discharge port 31. The sliding surface pressure of a mechanical seal is not affected by the pump's discharge pressure, and can be lowered by the amount equal to the pump's discharge than before, which prevents noise and reduces wear on the sliding parts.

・Effects of the Invention As is clear from the above explanation, the circulation pump of the present invention has a seal formed by attaching a ring forming a cylindrical wall to the buffer rubber near the sliding surface of the floating seat and fitting the ring to the impeller. The structure of the box is simple, and even air bubbles inside the seal box can be quickly and completely discharged without being affected by the pump's position.Also, the sliding surface pressure of mechanical seals is lower than before, which is equal to the pump discharge. only,
This has the effect that the mechanical seal can slide smoothly and its life can be extended.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view showing a conventional example of a mechanical seal installed in a pump, and FIG. 2 is a vertical cross-sectional view of a mechanical seal according to an embodiment of the present invention. 12 ・ Bracket, 13... Pump shaft, 14...
-Buffer com, 16... Floating sheet, 16...
・Seal box, 17 ・Mechanical seal sliding surface, 18... Water window, 19-・Ring, '2o...
・Seal ring, 25 ・ Water hole, 26 ・ Impeller cylindrical part, Pl ・Pump discharge side pressure, P2 ・
・Pump suction side pressure. Name of agent: Patent attorney Toshio Nakao and one other person.

Claims (2)

[Claims] (1) A cylindrical ring is attached to the cushioning rubber of the mechanical seal to form a seal box, and the water passage window formed on the side of the ring is placed opposite the sliding surface of the mechanical seal, and the impeller A cylindrical portion is provided in the rear shroud, a water hole is provided in the cylindrical portion of the impeller to communicate the inside of the seal box and the inside of the impeller, and the cylindrical portion of the impeller is configured to fit with one end of the ring. A circulation pump featuring: (2) The circulation pump according to claim 1, wherein the area of the water passage window of the ring is smaller than the area of the water passage hole of the rear shroud of the impeller.