JPH03234946A - Vibration isolating method for pump for hot water supply unit - Google Patents

Abstract

PURPOSE:To effectively isolate vibration to the utmost by supporting the neighborhood of the base section of a pump with springs, forming each rubber hose into a shape which allows the vertical movement of the pump with each rubber hose deflected, and thereby controlling the horizontal movement of the upper end of the pump by the reaction of the deflection of each hose. CONSTITUTION:When a pump main body 1 is vertically moved with vibration isolating springs 14 extended and/or contracted, both a suction side rubber hose 16 and a discharge side rubber hose 17 absorb the vertical movement of the pump main body 1 so as to allow the movement mainly by the deflection of the horizontal sections 16a and 17a of them. And when the upper end section of the pump main body 1 vibrates in the horizontal direction because of violent action at the time of starting, the reaction of the deflection of the vertical sections 16b and 17b of the rubber hoses 16 and 17 so acts as to control vibration in the horizontal direction so that it thereby functions as a vibration isolator. Since the vibration isolating springs 14 can be made small in spring constant, the vibration of the pump is hardly transmitted to frames, furthermore, resonance frequency can be made small, the occurrence of resonance can thereby be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for preventing vibration of a pump installed in a water heater.

[Conventional technology]

Regarding vibration isolation of water heater pumps installed in water heaters, it is important to prevent the vibrations generated by the pump from being transmitted to the water heater frame or casing, and to prevent the pump itself from resonating, so-called startup disturbances. It is necessary to provide vibration isolation on both sides of prevention (or mitigation) of the phenomenon.

For this reason, conventional methods have generally been used to provide vibration isolation by supporting the water heater pump on the frame or casing (hereinafter referred to as frame) of the water heater via vibration isolating rubber.

FIG. 5 is an exploded perspective view showing an example of a vibration isolation structure according to the prior art.

1 is a pump body, and 2 is a frame.

A fixing bracket 3 is fixed to the frame 2 described above. It supports the vibration-proof rubber presser foot 4 and the vibration-proof rubber 5.

A vibration isolating rubber 6 is inserted into a mounting hole 1a provided in the pump body 1, and a mounting bolt 7 is inserted into the vibration isolating rubber cylinder 6 and screwed onto the fixing bracket 3.

=2- In this way, the pump main body 1 is elastically supported by the vibration-proof rubber cylinder 6 and the vibration-proof rubber 5 with respect to the frame 2.

1b is a suction port of the pump, to which a suction side rubber hose 8 is connected. 1o is the discharge side], the discharge side rubber hose 9 is connected. 18 is a band.

In the conventional example, the rubber hoses 8 on the suction side and the discharge side,
9, no consideration has been given to providing it separately as a support member for vibration isolation.

[Problem to be solved by the invention]

The conventional vibration isolation structure shown in Fig. 5 is schematically shown in Fig. 6.
As shown in the figure, the pump body 1 is elastically supported on the frame 2 by vibration-proof rubbers 5 and 6.

k indicates a spring constant included in the anti-vibration rubber, and r also indicates mechanical resistance.

When such a vibration isolation method is used, it is difficult to obtain a large vibration isolation effect because the mechanical resistance r of the rubber is relatively large.

In order to increase the vibration-proofing effect, the spring constant k of the rubber must be made small, but if the spring constant k is made small, the elastic deformation of the vibration-proof rubber becomes excessive in the installed state.
Durability is impaired.

The present invention has been made in view of two circumstances, and has a large vibration-proofing effect and does not impair the durability of the vibration-proofing elastic member. The purpose of the present invention is to provide a vibration isolation method for a water heater pump.

[Means to solve the problem]

In order to achieve the above object, the vibration isolation method according to the present invention includes:
The pump is supported near the bottom by a spring, and a rubber hose is attached near the two ends of the pump.
And, the shape of the rubber hose is such that the pump is allowed to move in the vertical direction (movement due to the deflection of a spring) due to the bending of the rubber hose, and the upper end of the pump is moved in the horizontal direction due to the reaction force of the bending of the rubber hose. (The so-called shock when starting the pump) is braked.

[For production]

When the vicinity of the bottom of the pump is supported by the spring as described above, it is easy to obtain sufficient durability even if the spring is a member having a smaller spring constant than rubber.

By reducing the spring constant, the vibration of the pump is less likely to be transmitted to the frame, and the resonant frequency can be reduced, so resonance can be avoided.

Furthermore, since springs have lower mechanical resistance than rubber, the sharpness of resonance can be increased.

If the sharpness of the resonance increases, the vibration transmissibility at a vibration transmissibility of 1 or less can be reduced (that is, the vibration damping effect can be increased).

〔Example〕

FIG. 1 is an explanatory diagram of the method of the present invention, and is an exploded perspective view of an example in which the vibration isolating method according to the present invention is implemented by improving the conventional vibration isolating structure shown in FIG.

The method of the present invention uses springs to support the pump near the bottom. In this example, the upper pump mounting plate 11 is fixed to the pump body 1 with pump mounting bolts 12, and the lower pump mounting plate 13 is fixed to a frame (not shown), and - The pump mounting plate/upper 11 was supported by the vibration isolation spring 14 relative to the lower 13. 15 is a spring restraining plate constructed using a speed nut.

In the method of the present invention, the vicinity of the upper end of the pump is supported by a rubber hose. In this example, the suction side rubber hose 16 is connected to the suction port 1b provided at the upper end of the pump body 1, and the discharge port 1 is connected to the suction side rubber hose 16.
The discharge-side rubber hoses 17 were fitted onto the outsides of the tubes, respectively, and tightened with bands 18.

The rubber hoses 1, 6, and 17 of this example each have an L-shaped bent portion. When the pump body 1 moves up and down due to the expansion and contraction of the anti-vibration spring 4, the suction side rubber hose 16 absorbs and allows the up and down movement mainly through the flexure of its horizontal portion 16a. Similarly, the discharge side rubber hose 17 mainly causes the pump main body 1 to bend due to the bending of its horizontal portion 17a.
Absorbs and tolerates the vertical movement of

Furthermore, when the upper end of the pump body 1 vibrates in the horizontal direction due to cracks during startup, the reaction force due to the bending of the suction side rubber hose vertical portion 16b and the reaction force due to the bending of the discharge side rubber hose vertical portion 17b are It functions to dampen vibrations in different directions.

FIG. 2(A) is an explanatory diagram to help understand the state in which the rubber hoses 16 and 17 allow the pump body 1 to move up and down (movement in the direction of expansion and contraction of the spring 14) by bending.

FIG. 2(B) is an explanatory diagram to help understand the state in which the horizontal movement of the upper end of the pump body 1 is braked by the reaction force of the bending of the rubber hoses 16 and 17.

The vibration isolating spring 14 can have a smaller spring constant k than the vibration isolating rubber used in the prior art (even if the spring constant k is made smaller, durability will not be impaired).

The frequency of vibration caused by the rotation of the pump in the rated state is f, and the system consisting of the mass of the pump and the anti-vibration rubber is 0.
Assuming that the resonant frequency is fO, the relationship between the frequency and the vibration transmissibility in the conventional example is as shown by the solid line curve a in FIG. 4, and the vibration transmissibility curve a peaks at the resonant frequency f.

The illustrated dimension A represents the vibration damping effect in the prior art.

The above resonant frequency fO is given by the following equation.

fo = (1/2π) to 1 year old - However, m is the mass of the pump.

If fo' is the resonance frequency when the vibration isolating rubber in the prior art is replaced with a vibration isolating spring and the spring constant k is reduced, then fo'<fo.

In this way (see FIG. 4), in this embodiment the resonant frequency fo' deviates from the frequency f (the frequency of vibrations caused by the rotation of the pump).

Furthermore, springs have a lower mechanical resistance r than rubber.

Then, the resonance sharpness Q is given by the following equation.

Q=2π fo m/r 7- Therefore, as the mechanical resistance r becomes smaller, Q becomes larger.

In FIG. 4, curve a in the prior art changes to curve b shown by a two-dot chain line in the embodiment of the present invention.

That is, by decreasing the spring constant, the resonant frequency t'o becomes f
o', and the sharpness of the resonance increases as the mechanical resistance r decreases.

Therefore, the resonance peak point P1 in the prior art moves to the resonance peak point P2 in this embodiment.

As a result of the sharpness of the resonance, the vibration transmissibility (vertical axis) of the curve b of this example rapidly decreases as it goes to the right beyond the frequency fo'. The effect is represented by dimension B. It can be seen that this is significantly improved compared to the vibration damping effect A in the conventional example.

When starting the pump, its frequency starts from O and gradually increases to f when steady operation is reached. During its increase, it passes through a resonant frequency, and at this time, the resonance causes the pump to fray. The force that causes the flailing phenomenon is generated by the action 9 reaction between the pump housing and the rotating body. The flailing direction is mainly the rotational direction of the pump as indicated by the reciprocating arc arrow R (see FIG. 2(B)).

Therefore, in the event of a breakout, the upper end of the pump body 1 reciprocates in the horizontal direction as shown by the reciprocating arc arrow 1'. At this time, in this embodiment, the rubber hoses 1, 6, and 17 are bent, and the reaction force of the bending acts to brake the reciprocating movement of the reciprocating arc arrow R', thereby suppressing the flailing phenomenon.

As can be understood from the above principle of operation, in the present invention, braking the horizontal movement of the upper end of the pump does not mean braking only purely horizontal movement, but braking movement that has a horizontal component. I intend to do so.

As mentioned above, the method of the present invention uses a vibration-proofing spring instead of a vibration-proofing rubber to elastically support the pump body, thereby improving the vibration-proofing effect without any risk of impairing durability. If the spring constant of the elastic support member is reduced (supported flexibly), there is a risk that the pump body will jump significantly and be damaged when subjected to impact during transportation. For this reason,
The upper pump mounting plate 11 (see Fig. 1) used in the above embodiment is provided with a stopper Ila extending downward, and the lower pump mounting plate 13 is provided with a stopper Ila extending upward. Do it! 〜Providing a collar 13a, ``S 1 ~ Collar 1 of both of the above
10° 13a were made to face each other in the vertical direction. Figure 3 (A)
is an explanatory diagram schematically depicting the state.

When transporting, use the fixing screw 19 for transportation, insert the fixing screw 19 into the through hole 13b drilled in the lower mounting plate 13, and insert it into the female screw hole 11b provided in the upper mounting plate 11 as shown by arrow C. Screw in and tighten, anti-vibration spring 14
Compress and tighten as shown in Figure 3 (B). As a result, the stopper lla and the spring 13a come into contact with each other, and the pump body 1 is rigidly supported. When installing the water heater after transportation, remove the transportation fixing screw 19 and
The state is shown in Figure (A).

〔Effect of the invention〕

As explained above, according to the vibration isolating method for a water heater pump according to the present invention, a large vibration isolating effect can be obtained, and there is no risk of impairing the durability of the vibration isolating elastic member.

[Brief explanation of drawings]

FIG. 1 is an exploded perspective view of a vibration-isolating structure in one example of implementing the vibration-isolating method for a water heater pump according to the present invention. FIGS. 2(A) and 2(n) are explanatory diagrams schematically depicting the vibration isolation structure. FIGS. 3(A) and 3(B) are explanatory diagrams of a method of transporting a pump provided with the above-mentioned vibration isolation structure. FIG. 4 shows the operation in one embodiment of the method of the present invention. This is a chart for explaining the effect. FIG. 5 is an exploded perspective view showing a vibration isolation structure of a water heater pump in the prior art. FIG. 6 is a schematic diagram for explaining the vibration isolation structure in the above-mentioned prior art. DESCRIPTION OF SYMBOLS 1... Pump body, 1a... Mounting hole, 1b... Suction port, 1c... Discharge port, 2... Frame, 11...
・Pump mounting plate・Top, lla...stopper, 12...
・Pump mounting bolt, 1311- ... Pump mounting plate, bottom, 14 ... Anti-vibration spring,
15...Spring holding plate, 16...Suction side rubber hose, 16a...Horizontal part, 16b...Vertical part, ]7
...Suction side rubber hose, 17a...Horizontal part, 17b
...Vertical part, 18...Band, 19...Fixing screw for transportation. 12-

Claims (1)

[Claims] 1. When the pump is attached to the frame of the water heater, the bottom of the pump is supported by a spring, a rubber hose is attached to the top of the pump, and the shape of the rubber hose is Vibration isolation for a water heater pump, characterized in that the pump has a shape that allows vertical movement of the pump by the bending of the rubber hose, and the horizontal movement of the upper end of the pump is damped by the reaction force of the bending of the rubber hose. Method.