CN2239516Y

CN2239516Y - Pump axial force balancing device

Info

Publication number: CN2239516Y
Application number: CN 95239006
Authority: CN
Inventors: 关醒凡; 陆伟刚; 张庆平
Original assignee: Individual
Current assignee: Individual
Priority date: 1995-01-06
Filing date: 1995-01-06
Publication date: 1996-11-06
Anticipated expiration: 2005-01-06

Abstract

A pump axial force balancing device for a pump, particularly for a segmented multi-stage pump. The device is characterized in that a group of mechanical seals and a group of thrust bearings are arranged on a rear cover plate of a final-stage impeller of the pump, so that one part of the rear cover plate of the final-stage impeller is separated from high-pressure liquid in a final-stage pump cavity and communicated with a low-pressure area outside the pump body, and the purpose of reducing axial force is achieved. The thrust bearing integrated with the mechanical seal makes the sealing end face less susceptible to wear, so that cheap materials can be used and the device is low in cost. The device replaces the traditional axial force balancing method, and can improve the efficiency of the water pump by more than 2-8%. The device can also improve the stress condition of the pump shaft and prolong the service life of the pump.

Description

Balance unit for pump axial force

The utility model is a kind of balance unit for pump axial force.This device is mainly used in pump, especially for various sectional type multistage pumps such as deep well submerged pump, oil-immersed pump and multistage centrifugal pumps.

Traditional pump shaft mainly contains three kinds of equalizing orifice, balancing drum and Balance discs to the equilibrium of forces method.The structure of equalizing orifice and balancing drum is all very simple, but leakage loss is big, and sealing surface weares and teares easily, and can not compensate automatically after the wearing and tearing, thus leakage loss with increasing, simultaneously the ability of balancing axial thrust also more and more a little less than.Balance disc can automatically reach the effect of complete equilibrium axial force, and is not easy wear damage, but its leakage loss is maximum.Three kinds of traditional methods all have very big leakage loss, thereby make pump efficiency reduce more than 2%-8%.

No. 87100241 national inventing patents " balance unit for pump axial force " that Jiangsu Polytechnical College closes the invention in 8 or seven years such as all three people such as grade of waking up have proposed to separate the high low pressure zone with the method for mechanical seal.This leakage loss than conventional method reduces greatly, thereby has improved pump efficiency.But the mechanical seal in this patent adopts conventional method to manufacture and design, and under the bigger and rotating ratio condition with higher, general material all is easy to wear and tear when the water pump size.If adopt precious materials, make manufacture cost very high again

The utility model has increased by one group of slide thrust bearing that fuses with mechanical seal on the basis of No. 87100241 patent of invention, make the mechanical seal of this device also be not easy wearing and tearing with very cheap material, thereby both solved the leakage loss problem in the conventional method, solved the high problem of manufacture cost of No. 87100241 patent of invention existence again.

The utility model is to adopt following method to realize:

As shown in Figure 1, impeller 1 in the dress in the final stage pump housing 8, the slide thrust bearing of one group of mechanical seal of being made up of rotating ring 2, stationary ring 5, spring 10 and O RunddichtringO 11 being installed on back shroud of impeller top and being made up of

bearing

3,4,6,7 etc. (can 3,6 or 4,7) has also been beaten a relief hole 9 in the pump housing 8, (this is a kind of radial passage, also can make axial passage and lead to pump housing outside with pump shaft) makes the part on back shroud of impeller top communicate with pump housing low pressure area outward.

Before implementing the utility model, back shroud of impeller top is the zone of high pressure, fluid pressure acts on and produces a very big downward axial force on the impeller, implements to have reduced axial force greatly thereby the part on back shroud of impeller top has become low pressure area after the utility model.We can control the size of axial force by the size of control mechanical seal.It is too fast that the slide thrust bearing of being made up of bearing 3,4,6,7 etc. is used for protecting mechanical seal end surface not wear and tear.After some wearing and tearing of seal face, because the supporting of thrust-bearing, seal clearance will keep certain size, and the rate of wear is slowed down, and leakage loss remains on the smallest number.

When the pressure of pump is very high, can also make two seals or three seals to the seal face of mechanical seal, leak to reduce.

The design of thrust-bearing can also according to the structure needs with the friction arrangement of thrust-bearing with the arbitrary plane of sealing surface in.

1 introduce the embodiment of the utility model in deep well submerged pump in detail in conjunction with the accompanying drawings more below.

Accompanying drawing 1 is the balance unit for pump axial force schematic representation in the deep well submerged pump.

On impeller 1, process or installed a sealing rotating ring 2 and bearing 3 and 4 (perhaps as long as 3 and 4 one), on stationary seal ring 5, process or installed bearing 6 and 7 (perhaps as long as 6 and 7 one), on the final stage pump housing 8, beaten a relief hole 9, make the cavity at final stage pump housing middle part identical, between the stationary ring 5 and the pump housing 8, adorned a spring 10 and an O RunddichtringO 11 with pump housing low pressure area outward.Rotating ring 4, stationary ring 5, spring 10 and seal ring 11 are formed a cover mechanical seal, the middle part of the final stage pump housing, highly pressurised liquid in the cavity on back shroud of impeller top and the pump housing separates, and communicates with low pressure area by relief hole, makes the part on back shroud of impeller top be in low pressure area.

Before implementing this model utility, the back shroud top of impeller 1 is among the highly pressurised liquid of the final stage pump housing 8 fully, the suffered pressure in back shroud of impeller top is greater than the pressure of impeller inlet, pressure difference superposition on all impellers of this pressure difference and impeller bottom gets up, formed downward axial force very big on the pump shaft, and be delivered on the thrust-bearing that is installed in submersible motor inside always by axle.If the thrust-bearing in the motor can't stand that so big axial force just is easy to damage motor.

After implementing this model utility, the part on the back shroud top of impeller 1 is in the low pressure area, this a part of pressure is well below the pressure of this impeller inlet, pressure difference between them has formed a responsive to axial force that makes progress on pump shaft, this has just cancelled each other with the downward axial force of all impeller action on pump shaft of impeller bottom, thereby has guaranteed that the thrust-bearing in the motor is not damaged.

Bearing 3 and 6,4 and 7 has been formed a secondary slide thrust bearing separately, and before implementing this model utility, the seal face of being made up of rotating ring 4 and stationary ring 5 is big owing to size, rotating speed is high, so be easy to damage, perhaps adopts very expensive material to make.After implementing this model utility, the wearing and tearing of seal face are subjected to the restriction of slide thrust bearing, as long as slide thrust bearing does not does not wear and tear, seal face does not just have more wearing and tearing yet.Because slide thrust bearing has extraordinary lubricating condition, and the thrust that is subjected to is very little, therefore there is very long working life.

Before implementing this model utility, pump shaft is in the working condition of vertical rod pressurized under the effect of axial force, be easy to bending, thereby the wearing and tearing of pump shaft and impeller port ring are very fast.After implementing this model utility, the pressure that pump shaft is subjected to reduces greatly, and the pump shaft major part is subjected to is pulling force, and this just makes pump shaft be not easy bending, thereby has improved the working life of pump.

Claims

1, a kind of pump that is used for, balance unit for pump axial force especially for the sectional type multistage pump, it is characterized in that: one group of mechanical seal is housed on the impeller back shroud of pump, highly pressurised liquid in the part of this back shroud of impeller and the final stage pump chamber is separated, and communicate by the external low pressure area of the axial passage that separates with the zone of high pressure or radial passage and final pumps.

2, balance unit for pump axial force according to claim 1, it is characterized in that also being equipped with one group of slide thrust bearing and fuse with mechanical seal on the impeller back shroud, the rubbing surface of thrust-bearing and the rubbing surface of mechanical seal are at grade or on plane parallel to each other.