CN100513836C

CN100513836C - Bidirectional-equilibration push type mechanical sealing device

Info

Publication number: CN100513836C
Application number: CNB2006101341333A
Authority: CN
Inventors: 纪德宏; 马宇
Original assignee: Dandong Kelong Group Co Ltd
Current assignee: Dandong Colossus Group Co Ltd; Dandong Kelong Group Co Ltd
Priority date: 2006-10-31
Filing date: 2006-10-31
Publication date: 2009-07-15
Anticipated expiration: 2026-10-31
Also published as: CN101131209A

Abstract

The bidirectional balance pushing mechanical sealing device includes one pair of dynamic ring and static ring, one spring as elastic element to make the dynamic ring or the static ring serve as compensation ring for close contacting while rotation fitting, and one auxiliary sliding sealing ring set between the compensation ring and other connect piece. The mechanical sealing device is not affected by the pressure state, and has high sealing performance.

Description

Bidirectional-equilibration push type mechanical sealing device

Technical field

What the present invention relates to is shaft sealer, particularly mechanical seal device.

Background technique

Mechanical seal device is by at least one pair of rotating ring and stationary ring perpendicular to axis, and rotating ring or stationary ring act as compensated loop under axial elasticity compensating element (spring) effect makes dynamic and static ring keep the formation that is rotatably assorted of sliding of fitting, prevent the device that working fluid leaks along running shaft, rotating ring is connected with axle or axle sleeve, stationary ring is connected with end cap or stationary seat, rotates by rotating ring and stationary ring abrasive end face slide relative and finishes the rotation axis seal effect.

Push type mechanical sealing device is can slide vertically to be installed in Seal Design form between compensated loop and axle sleeve or the end cover with the auxiliary seal of eliminating wearing and tearing and eccentric influence, promptly compensated loop and and its link between be provided with the design form of slippage auxiliary seal ring.The most common slippage auxiliary seal ring is a round section joint ring.

The balance coefficient B of mechanical seal device (also claiming equilibrium ratio) has reflected the influence degree of pressure medium to the mechanical seal device seal face.The construction size of mechanical seal device member and position concern, determine and influence the balance coefficient B of mechanical seal device.

B_{o} = \frac{S_{p}}{S_{b}} = \frac{\frac{π}{4} (D_{2}^{2} - D_{O}^{2})}{\frac{π}{4} (D_{2}^{2} - D_{1}^{2})} = \frac{(D_{2}^{2} - D_{O}^{2})}{(D_{2}^{2} - D_{1}^{2})}

..................①

B_{i} = \frac{S_{p}}{S_{b}} = \frac{\frac{π}{4} (D_{i}^{2} - D_{1}^{2})}{\frac{π}{4} (D_{2}^{2} - D_{1}^{2})} = \frac{(D_{i}^{2} - D_{1}^{2})}{(D_{2}^{2} - D_{1}^{2})}

..................②；

B---balance coefficient;

S _p---the useful area of sealing-fluid pressure effect;

S _b---the seal face area;

B _oThe balance coefficient of external diameter high pressure sealing;

B _i---the balance coefficient of internal diameter high pressure sealing;

D _o---the balance diameter of external diameter high pressure sealing, i.e. slippage seal groove internal diameter on the compensated loop;

D _i---the balance diameter of internal diameter high pressure sealing, i.e. slippage seal groove external diameter on the compensated loop;

D ₂---the seal face external diameter;

D ₁---the seal face internal diameter;

B---seal face radius width, b=(D ₂-D ₁)/2 ... 3.;

d _w---the radius width of slippage seal groove, d _w=(D _i-D _o)/2 ... 4.;

D---sealing specification, the i.e. diameter of axle;

D---slippage O-ring seals line footpath, d _w=(0.85～0.92) d ... 5.;

Mechanical seal device is under high-pressure situations, and the unreasonable of balance coefficient design will cause friction sealed end face generation heat rising under the effect of pressure, causes seal failure.

Because all can produce a large amount of heats between the friction sealed end face of mechanical seal device.Along with the increase of balance coefficient, fluid-encapsulated pressure can more act on the seal face of seal closure, thereby causes the increase of seal friction power and friction horsepower.Thereby the coking of auxiliary seal O type circle will occur and lose sealing and cause leaking if the heat that friction horsepower produces is excessive, temperature rise is too fast; The rapid seal face that causes that expands of seal face also can occur bursts, falls quarrel, collapses pernicious faults such as limit even fracture.

Therefore the too high physics and chemistry state that can influence conveyance fluid of some occasion temperature also will control the transmission of heat of conveyance fluid in addition, runs well to keep sealing.

Because the control of the temperature of sealing plays important effect to the successful running of sealing, and balance coefficient directly affects the frictional heating power of sealing, thus, balance coefficient directly affects the performance of sealing.

Balance coefficient has determined pressure medium to act on the size of closing force between seal face.When pressure medium is low, be enough to the shutoff medium in order to guarantee the seal face closing force, make pressure medium more be used for the seal face closure by improving the sealing and balancing coefficient; And when pressure medium was higher, the then artificial balance coefficient that reduces sealing was eliminated the seal face closing force that excessive medium effect produces.The traditional mechanical Seal Design during greater than 1.2MPa, adopts the balanced seal of balance coefficient＜1 at pressure.General balance coefficient value has significant practical applications between 0.6～0.9.

Traditional mechanical seal theory thinks that mechanical seal can only be worked under predetermined pressure state.That is, when pressure during greater than 1.2MPa, under the external diameter high pressure conditions (that is, when the cylindrical side pressure of mechanical seal end surface is higher than the endoporus side pressure), design B _o＜1 sealing; Under the internal diameter high pressure conditions (that is, when the endoporus side pressure of mechanical seal end surface is higher than the cylindrical side pressure), design B _i＜1 sealing.B _o＜1 be sealed under the internal diameter high pressure conditions its B _iThere is not the effective method adjustment; Same B _i＜1 be sealed under the external diameter high pressure conditions its B _oThere is not effective method control yet.That is to say, no matter sealing is in the external diameter high pressure conditions still is the internal diameter high pressure conditions, sealing is in the past all carried out the design of unidirectional balance coefficient according to predetermined pressure bearing direction, promptly in design process only by formula 1. or formula come 2. to determine that the relevant size configurations of seal arrangement neutral equilibrium coefficient concerns.She Ji mechanical seal device is only worked under predetermined pressure bearing direction state and is possessed rational balance coefficient like this, and next out of hand when the pressure bearing direction changes, and causes mechanical seal device to damage.

The working pressure direction transformation that can meet accident in the reality, She Ji balance coefficient is no longer valid in advance, thereby causes seal failure.For example: the flow process pressure medium is 2.5MPa in the Seal cage, and insulating liquid pressure is that 3.0MPa is supplied with by the oil outer station.Because oily station failure pressure disappears, for script proper functioning (B under the internal diameter high pressure conditions _i＜1) sealing is in external diameter high pressure (the flow process pressure medium 2.5MPa in the Seal cage, B suddenly _oOut of control) state work down, will cause mechanical seal device to damage.

There are abnormal conditions such as pump depletion or the forfeiture of seal isolation hydraulic coupling again really in reality, makes the pressure direction conversion, therefore makes mechanical seal device cause damage, and the flow process dielectric leakage causes disasters such as environmental pollution, fire, poisoning.

In addition, same pump tends to select for use different seal form owing to carry medium of different nature.In other words, with a kind of pump according to the often not only high pressure sealing of needs external diameter but also the high pressure sealing of needs internal diameter of use condition.Unidirectional balancing machine seal arrangement will satisfy the user demand of pump under different situations, will develop 2 kinds of products of external diameter high pressure sealing and internal diameter high pressure sealing simultaneously.So just increase the kind and the complexity of product, caused manufacture cost to rise.

Summary of the invention

The purpose of this invention is to provide a kind of bidirectional-equilibration push type mechanical sealing device, overcome the shortcoming deficiency of unidirectional balancing machine seal arrangement structure, improve adaptive capacity and the simplification mechanical seal device kind of sealing fortuitous event.

The present invention includes a pair of rotating ring and stationary ring perpendicular to axis, and rotating ring or stationary ring act as compensated loop under the spring action of axial elasticity compensating element makes dynamic and static ring keep the applying slip to be rotatably assorted, compensated loop and and its link between be provided with the slippage auxiliary seal ring, particularly O-ring seals constitutes, and it is characterized in that the construction size of member and pass, position are:

B_{o} = \frac{(D_{2}^{2} - D_{O}^{2})}{(D_{2}^{2} - D_{1}^{2})} = B_{i} = \frac{(D_{i}^{2} - D_{1}^{2})}{(D_{2}^{2} - D_{1}^{2})} < 1

Construction size parameter and the position relation of the present invention by determining the mechanical seal device member makes B _o=B _iThereby realized be not stressed direction situation influence of mechanical seal device, and simplification mechanical seal device kind, improved the adaptive capacity that mechanical seal device changes pressure direction, the actual working pressure direction meets accident when changing, She Ji balance coefficient will can not change in advance, thereby guarantee the sealing stable operation.

For example: the flow process pressure medium is 2.5MPa in the Seal cage, and insulating liquid pressure is that 3.0MPa is supplied with by the oil outer station.Because oily station failure pressure disappears, for script proper functioning (B under the internal diameter high pressure conditions _i＜1) sealing is in work under the external diameter high pressure conditions suddenly, the flow process pressure medium 2.5MPa in the Seal cage, B _o=B _i＜1 can guarantee to seal proper functioning.

As a same reason, on-the-spot exist such as: find time, during abnormal conditions such as seal isolation hydraulic coupling forfeiture, because the balance coefficient of mechanical seal is two-way all is reasonable balance, so all can not cause damage to mechanical seal, and the assurance sealing effect, fundamentally stopped disasters such as the environmental pollution that the flow process dielectric leakage causes, fire, poisoning.

The present invention has simplified the kind of mechanical seal device simultaneously, and a kind of structure just can satisfy the equipment of not only needs external diameter high pressure sealing but also the high pressure sealing of needs internal diameter.That is, a kind of specification structure series just can satisfy the demand of pump under different situations, has reduced by 50% product category.Both reduce the complexity that designs, caused manufacture cost to descend.

Description of drawings

Fig. 1,2,3, the 4th, embodiment of the invention structural representation, wherein:

Shown in Fig. 1 embodiment, rotating ring 1 is a compensated loop, and slippage auxiliary seal ring 5 is located between rotating ring 1 interior circle and the axle 7;

Shown in Fig. 2 embodiment, stationary ring 2 is a compensated loop, and slippage auxiliary seal ring 5 is located between stationary ring 2 interior circles and the stationary seat 21;

Shown in Fig. 3 embodiment, rotating ring 1 is a compensated loop, and slippage auxiliary seal ring 5 is located between rotating ring 1 cylindrical and the rotating seat 11;

Shown in Fig. 4 embodiment, stationary ring 2 is a compensated loop, and slippage auxiliary seal ring 5 is located between stationary ring 2 cylindricals and the stationary seat 21.

Embodiment

The present invention includes a pair of rotating ring 1 and stationary ring 2 perpendicular to axis, and rotating ring 1 or stationary ring 2 act as compensated loop under 3 effects of axial elasticity compensating element spring makes dynamic and static ring keep the applying slip to be rotatably assorted, compensated loop and and its link between be provided with the auxiliary O-ring seals 5 of slippage, by suitably reducing the groove width d of slippage auxiliary seal groove 41 _wSize makes its width b less than seal face 6; And the relative position relation by suitable adjustment slippage auxiliary seal groove 41 and seal face 6 forms construction size and position relation:

B_{o} = \frac{(D_{2}^{2} - D_{O}^{2})}{(D_{2}^{2} - D_{1}^{2})} = B_{i} = \frac{(D_{i}^{2} - D_{1}^{2})}{(D_{2}^{2} - D_{1}^{2})} < 1

B particularly _o=B _i∈ [0.6,0.9]

Instantiation is as follows:

According to the line footpath d={1.8 of slippage O-ring seals in the standards such as GB3452.1, JB/T7757.2,2.65,3.1,3.55,4.1,4.5,4.7,5.3,5.7,6.4,7}.

And press d _w=(0.85～0.92) d determines d _w

The mechanical seal that connects size by ISO3069, DIN24960, GB6556, ASME B73.1 standard is example.

Diameter of axle D is below 120mm, and design is between 3～6mm usually for the width b of seal face 6, and it can keep lower seal friction heat when keeping desirable face pressure.That is b ∈ [3,6].

Shown in accompanying

drawing

1,2, i.e. slippage O-ring seals embedding structure

In this structure Design, the ISO3069 standard has determined that diameter of axle D and slippage diameter are the balance diameter D of external diameter high pressure sealing _o

D＝{10，14，16，18，20，22，24，25，28，30，32，33，35，38，40，43，45，48，50，53，55，58，60，63，65，70，75，80，85，90，95，100，110，120}

D _o＝{14，18，20，22，24，26，28，30，36，38，40，43，50，53，55，58，60，65，68，70，75，80，85，90，95，100，115，125}。

B_{o} = \frac{S_{p}}{S_{b}} = \frac{\frac{π}{4} (D_{2}^{2} - D_{O}^{2})}{\frac{π}{4} (D_{2}^{2} - D_{1}^{2})} = \frac{(D_{2}^{2} - D_{O}^{2})}{(D_{2}^{2} - D_{1}^{2})}

……………………①

B_{i} = \frac{S_{p}}{S_{b}} = \frac{\frac{π}{4} (D_{i}^{2} - D_{1}^{2})}{\frac{π}{4} (D_{2}^{2} - D_{1}^{2})} = \frac{(D_{i}^{2} - D_{1}^{2})}{(D_{2}^{2} - D_{1}^{2})}

……………………②

d _w＝(D _i-D _o)/2 ……………………………④

d _w=f (D) and D ∈ 10,14 ..., 120}, d _w∈ [1,4] ... 7.

B _o＝B _i ……………………………………………⑩

The above-mentioned formula of simultaneous, separate 3 yuan of 2 equation of n th order n group, can draw construction size, the parameter of push-press type seal arrangement, be listed as follows:

Specification (mm)	D	B _o＝B _i	d _w	b	D _o	D ₁	D ₂	D ₁
Specification (mm)	D	B _o＝B _i	d _w	b	D _o	D ₁	D ₂	D ₁	10	10	0.76	1.55	3	14	17.1	18.3	12.3
12	12	0.77	1.55	3	16	19.1	20.4	14.4	10	10	0.76	1.55	3	14	17.1	18.3	12.3
12	12	0.77	1.55	3	16	19.1	20.4	14.4	14	14	0.76	1.55	3	18	21.1	22.4	16.4
16	16	0.76	1.55	3	20	23.1	24.4	18.4	14	14	0.76	1.55	3	18	21.1	22.4	16.4
16	16	0.76	1.55	3	20	23.1	24.4	18.4	18	18	0.76	1.55	3	22	25.1	26.4	20.4
20	20	0.76	1.55	3	24	27.1	28.4	22.4	18	18	0.76	1.55	3	22	25.1	26.4	20.4
20	20	0.76	1.55	3	24	27.1	28.4	22.4	22	22	0.75	1.55	3	26	29.1	30.4	24.4

B as seen from the above table _o=B _i, so this device is a bidirectional-equilibration push type mechanical sealing device.

Shown in accompanying drawing 3,4, i.e. slippage O-ring seals external structure

According to ASME B73.1 standard, determine D=24,25,1 ", 28,1.125 ", 30,1.25 " and, 32; 33,1.375 ", 35,38,1.5 " and, 40,1.625 ", 43,1.75 "; 45,1.875 ", 48,50,2 ", 53,2.125 " and, 55,2.25 "; 58,60,2.375 ", 63,2.5 ", 65,2.625 " and, 2.75 ", 70; 2.875 " and, 75,3 ", 80,3.25 " and, 85,3.375 ", 3.5 " and, 90,3.625 ", 95,3.75 ", 3.875 ", 100,4 " and, 110,120.

In this structure Design, owing to consider the restriction in Seal cage space, the outer diameter D of at first given seal face ₂, deduct corresponding radial clearance by ASME B73.1 standard seal chamber size and draw D ₂

B_{o} = \frac{S_{p}}{S_{b}} = \frac{\frac{π}{4} (D_{2}^{2} - D_{O}^{2})}{\frac{π}{4} (D_{2}^{2} - D_{1}^{2})} = \frac{(D_{2}^{2} - D_{O}^{2})}{(D_{2}^{2} - D_{1}^{2})}

……………………①

B_{i} = \frac{S_{p}}{S_{b}} = \frac{\frac{π}{4} (D_{i}^{2} - D_{1}^{2})}{\frac{π}{4} (D_{2}^{2} - D_{1}^{2})} = \frac{(D_{i}^{2} - D_{1}^{2})}{(D_{2}^{2} - D_{1}^{2})}

……………………②

d _w＝(D _i-D _o)/2 ……………………………④

d _w=g (D) and D ∈ 24,25 ..., 120}, d _w∈ [1,4] ... 6.

B _o＝B _i ……………………………………………⑩

Specification (mm)	D ₂	d	d _w	B _o＝B _i	D ₁	D _o	D _i
Specification (mm)	D ₂	d	d _w	B _o＝B _i	D ₁	D _o	D _i	24	38	1.8	1.5	0.75	31.98	33.59	36.59
25	39.5	1.8	1.5	0.75	33.48	35.09	38.09	24	38	1.8	1.5	0.75	31.98	33.59	36.59
25	39.5	1.8	1.5	0.75	33.48	35.09	38.09	28	42	1.8	1.5	0.75	35.99	37.58	40.58
30	44.5	2.65	2.3	0.75	35.25	37.78	42.38	28	42	1.8	1.5	0.75	35.99	37.58	40.58
30	44.5	2.65	2.3	0.75	35.25	37.78	42.38	32	47	2.65	2.3	0.75	37.76	40.27	44.87

Claims

1, bidirectional-equilibration push type mechanical sealing device, include a pair of rotating ring and stationary ring perpendicular to axis, and rotating ring or stationary ring act as compensated loop under the spring action of axial elasticity compensating element makes rotating ring, stationary ring keep the applying slip to be rotatably assorted, compensated loop and and its link between be provided with the slippage auxiliary seal ring, it is characterized in that the construction size of compensated loop and position are closed and be:

B_{o} = \frac{(D_{2}^{2} - D_{O}^{2})}{(D_{2}^{2} - D_{1}^{2})} = B_{i} = \frac{(D_{i}^{2} - D_{1}^{2})}{(D_{2}^{2} - D_{1}^{2})} < 1

D _o---the balance diameter of external diameter high pressure sealing, i.e. slippage auxiliary seal ring recess internal diameter on the compensated loop;

D _i---the balance diameter of internal diameter high pressure sealing, i.e. slippage auxiliary seal ring recess external diameter on the compensated loop;

D ₂---compensated loop seal face external diameter;

D ₁---compensated loop seal face internal diameter;

B _o---the balance coefficient of external diameter high pressure sealing;

B _i---the balance coefficient of internal diameter high pressure sealing.

2, bidirectional-equilibration push type mechanical sealing device according to claim 1 is characterized in that B _o=B _i∈ [0.6,0.9]; The slippage auxiliary seal ring is an O-ring seals.