CN1055989C - Uniformly compressed shaft seal assembly - Google Patents

Abstract

A shaft seal assembly for a slurry pump comprising a body (3) having a through bore (4) for receiving a rotatable shaft (50), a packing receiving area in the through bore (4), a packing comprising at least two packing rings (8), and a packing sleeve (25) surrounding the packing rings (8) arranged such that axial compression of the packing sleeve (25) can be at least partially converted into radial compression of the packing rings (8).

Description

The gland seal assembly of even compression

The present invention relates to the black box of pump, have more this locality but not only relate to the black box of centrifugal mud pump.

For many years, on Centrifugal water pump and slurry pump, use gland seal assembly always.Typical plain shaft sealing assembly such as Fig. 1 are shown in 2 and 3.Fig. 1,2 and 3 is partial sections of plain shaft sealing assembly.This assembly generally comprises a housing 2, is commonly referred to Stuffing box, has 4, rotating axles 50 of a circular hole and passes circular hole 4.For example, axle 50 can be the axle of pump.One end wall 35 is arranged on an end in hole.Can be provided with on the axle 50, also can not establish protection sleeve.Annular space 7 between hole 4 and axle 50 generally is filled with filler 5, and filler 5 can be some packing rings 8.Filler can change according to use occasion, but generally is that fiber is made into, and has square or the rectangular cross-section, can be cut into annular.Filler can be selected according to requirement of strength, and can add other oiling agent (as teflon) to reduce friction.

It is in the Stuffing box that filler 5 generally is placed on housing, is subjected to the compression of follower 9 from the outside.Because the compressibility of filler 5, the annular space 7 that makes follower 9 move into and shift out the formation filling space can be regulated the gap between filler 5 and axle (or its sleeve) 50.Generally carry out this adjusting by outer bolt (not drawing).The leakage from assembly can be controlled in gap 7 between the axle 50 of regulating static filler 5 and rotating.In some application, this leakage is for the suitable cooling that guarantees filler and axle and to take away fricative heat may be vital.

When being used for water pump, this black box can utilize the liquid that is pumped that leaks from black box when work to help cooling package.The assembly of sufficient lubrication is necessary for the permanent life-span.

Because slurry pump is used for pumping and contains the mud of particle, this can bring other problem.These particles can cause the additional friction of filler and axle sleeve and wearing and tearing.For slurry pump, generally be from external water source minimizing the problems referred to above with clean sealing water fill assembly, guarantee the permanent life-span.Water passes through transfer passage 14 fill assemblies until a collar (Lantern ring) assembly 10.The cover ring member can comprise a collar 10 and a throttling element 12.In Fig. 1, throttling element 12 is made of metal, and in Fig. 2, it is a non-metal part.In Fig. 3, a collar 11 is spaced apart by filler 8D and a neck ring (neck ring) 17.The collar and throttling element will be by the threaded shaft of water introducing of passage 14 introducings or the gaps of axle sleeve.This makes water can enter filler and the exigent gap of axle between 50, so that suit and effective lubricating.But the collar and throttling element assembly make in some sealing water inflow pumps.Particle is washed away from black box, thereby reduce the danger that mud is stained gland seal assembly inside.

Above-mentioned common gland seal assembly has intrinsic structure problem, also can cause the work of mud and the problem in the maintaining.For example, the general compression inequality on each packing ring of said structure.High pressure can aggravate this problem.General one, two packing ring will be subjected to the bigger extruding of follower than other packing ring, make sealing and wear and tear inhomogeneous.In addition, depend on operator's adjusting, used filling kind and other variable factor, the use condition of water is also differed widely.Some manufacturing process depends on the solid drying that makes pumping in the mud by removing moisture.Therefore, use other water can make the subsequent treatment stage increase expense.The cause of another problem is because the operator can not always guarantee to carry out suitable adjusting.The water source may change, even causes the wear-out failure of filler and axle sleeve.Water also may leak around the filler radial outside rather than around its radially inner side.

The objective of the invention is to overcome above-mentioned one or more problems of conventional seals assembly.

Comprise a main body according to the gland seal assembly of slurry pump that is applicable to provided by the invention with the through hole that holds rotating axle, filler in described through hole holds the district, the filler that comprises at least two packing rings, and the filler cover that centers on packing ring, its layout makes the axial compression of filler cover can change into the radial compression to packing ring at least in part.

The filler cover preferably includes an elastic ring that is arranged between packing ring and the through-hole inner surface.In a kind of form of the present invention, the filler cover can have a ringwise substantially perimeter wall.In another form, the filler cover can wrap a perimeter wall, has a sidewall that extends radially inwardly at an end of described perimeter wall, and on rigging position, above-mentioned sidewall can extend under a side direction of filler.

In a kind of form of recommendation, be provided with two groups of packing rings, every group with one of above-mentioned filler cover cooperating.Two groups of packing rings can be come by a cover ring member or similar member space.In a kind of layout of recommendation, the above-mentioned collar comprises the second portion that is assemblied in two groups of first portions between the packing ring and its shape compressible filler cover on the mounting point.O shape ring or similar device also can be set to form sealing between the collar and shell.

Shell can have any suitable structure.For example, shell can comprise a main body, and this main body has a through hole that is used to hold a rotating axle.Main body can comprise first and second parts, and the filler that every part has in through hole holds the district.In first portion and the second portion each comprises that constitutes an end wall and the contacting wall that above-mentioned filler holds the district.Also be provided with controlling device can be used to cause between the contacting wall through hole axially on relative movement.

Filler holds the district can be included in the annular space between the outer surface of through-hole inner surface and rotating axle on the rigging position.

Each contacting wall can comprise the flange that extends radially inwardly substantially with respect to through-hole inner surface.The flange of contacting wall is preferably on first and second parts of shell and forms.When being in rigging position, above-mentioned contacting wall is far apart mutually and is come.Hole in each part of shell can relatively be opened wide, and can be spaced apart slightly mutually so that place the cover ring member betwixt.

The flange of each contacting wall has a free inner edge, this free inner edge surperficial adjacent with axle when rigging position, and itself and/or match with neck ring and can bring into play the effect of restrictor.A plurality of packing rings preferably are set in each housing parts.

The part that the part of shell preferably has work to be connected with another and pump case is fixed on the pump case, because the work of controlling device, it can do axial motion with respect to the part of at first mentioning.

The form of controlling device can be the bolt that a plurality of first and second parts that make housing are connected, and the rotation of these bolts can cause two-part axial motion.In addition, at least one in two-part of shell has two sections that are connected by bolt, and its layout makes two-part to separate so that the approaching and dismounting of housing.

Contrast the following drawings is described preferred embodiment of the present invention now:

Fig. 4 is the partial side view according to gland seal assembly of the present invention;

Fig. 5 is the front elevation of gland seal assembly shown in Figure 4;

Fig. 6 is the view similar to Fig. 4, and expression is according to a kind of modification of assembly of the present invention;

Fig. 7-the 9th can constitute the side view of the modified model collar of the part of gland seal assembly of the present invention.

Consult Figure 4 and 5 now, assembly of the present invention comprises some feature similar to the conventional seals assembly, and identical feature is used identical label.The purpose of the black box of pump fundamentally all is in order to hold the pumping liquid of pressurization.The decay of the sealed assembly of pressure, making pressure is atmospheric pressure outside the sealing.

Seal casinghousing is that Stuffing box 2 has one and is parallel to the hole 4 of rotating axle 50 and forms an annular space 7.Stuffing box 2 comprises a main body 3, and main body 3 comprises 3A of first portion and second portion 3B.The form of contacting wall is flange 14 and 15, and each flange has inner edge 16 and 17.The internal diameter of Stuffing box approaches the diameter of axle.Inner edge 16 and 17 itself and/or with neck ring as current limiting gaps, wash away mud to assist water.Contacting wall 14 and 15 also constitutes the shoulder of a supporting filler 5.Stuffing box generally is a metal, but also can use other suitable material, can make with low lost material such as high ferrochrome (High ChromeIron), because it can bear the wearing and tearing of mud.

Axle 50 is generally protected to reduce wearing and tearing by hard metal sleeve or plating cover.

Two-part 3A of main body 3 and the layout of 3B, make the controlling device of bolt 21 forms that the position of these two parts is axially relatively being adjusted, thereby change compression, the gap between control filler and sleeve or the axle, thereby the leakage of control black box to filler 5.Bolt 21 is carried on the flange 32 of part 3B.

Different with common unit is, contacting wall does not enter in the hole of Stuffing box, and they constitute the annular sealed chamber on internal diameter.As shown in the figure, housing parts 3B is tightened together by fixing bolt 23 in two, and part 3A also can similarly separate.When maintenance, housing parts can separate, unload from axle 50, thereby can be easily near frame.

One collar 55 separates two ends of housing parts 3A and 3B.Its external diameter is to guarantee and to keep concentricity at housing within the aperture of Stuffing box.The collar generally can be a metal, but also can be at coating on the internal diameter or mold insert to reduce the wearing and tearing on axle or axle sleeve.Make water can inject gap between filler and axle or the axle sleeve at the radial hole on the internal diameter or circular groove in the both sides of the collar.Therefore, water can inflow pump in, also can flow to the external world.

Above-mentioned new structure can utilize any common filling kind.The braided ring that these fillers are normally cut on a position is so that be sleeved on the axle sleeve.The number of packing ring 8 can change at two ends.Every end has two packing rings among the figure.

Shown in Fig. 4 and 6, the filler that all is provided with around filler at the black box two ends overlaps 25.As shown in the figure, two fillers cover 25 respectively has a packing ring group 8A and a 8B.Above-mentioned filler cover 25 has elasticity, and therefore, the axial pressure that the relative movement between housing two-part causes is these filler covers of axial compression at first.Filler cover 25 shown in Figure 4 is the annular ring with perimeter wall substantially.The sidewall that filler cover shown in Figure 6 has perimeter wall and extends radially inwardly from perimeter wall one end.On rigging position, the sidewall of filler cover is clipped between the contacting wall and packing ring of shell.In the another kind that does not draw was arranged, the sidewall of filler cover was adjacent to the setting of cover ring member.Because the filler cover is in fact between shell 3 and the filler 5, thereby axial compression will be converted into the radial compression to filler.Therefore, filler will be subjected to axially and compression radially, will be more even from ring to the compression of ring.More uniform compression will provide much better control to black box and operation and leakage on each packing ring.The filler cover will help around the sealing of packing ring outside and stop uncontrolled leakage.

Fig. 7 to 9 expression is specially adapted to the various forms of collars of gland seal assembly of the present invention.In every kind of situation, the collar 55 comprises and is assemblied in the 55A of first portion between 5 groups of the fillers and acts on the filler cover 25 so that the enlarged portion 55B of part compressible filler cover 25.

In Fig. 8 and 9 illustrated embodiments, O shape ring 40 is assemblied between the collar 55 and the housing 3A/3B, so that form additional seal.

According to the above-mentioned layout of preferred embodiment, better sealing water management is provided, reduced water consumption, improved the life-span, reduced the intrusion of mud, and made wearing and tearing more even.The wearing and tearing of axle sleeve are distributed on all packing rings, rather than concentrate at one end resembling in the common Stuffing box structure, and this proof filler is subjected to uniform compression.The axle water shutoff of injecting the measurement of axle envelope can reduce than common shaft seal structure, and does not influence work.This structure is also controlled the axle water shutoff amount of the injection axle envelope of inflow and efflux pump.In addition, this layout makes that packing ring is easier to be got at, and the length of fixing annular sealed chamber is reduced, thereby is more convenient for maintenance.

Obviously can do various modifications to said structure and layout, change and replenish and do not exceed scope of the present invention.

Claims (8)

1. A shaft seal assembly for a mud pump comprising a body having a through hole for receiving a rotatable shaft, a packing receiving area in the through hole, packing comprising at least two packing rings surrounding said packing The packing sleeve of the ring is arranged such that the axial compression of the packing sleeve can be at least partially translated into a radial compression of said packing ring. 2. The shaft seal assembly according to claim 1, wherein the packing sleeve comprises an elastic ring disposed between the packing ring and the inner surface of the through hole. 3. A shaft seal assembly according to claim 1 or 2, characterized in that the packing sleeve comprises a substantially annular outer peripheral wall. 4. The shaft seal assembly according to claim 1 or 2, wherein the packing sleeve comprises an outer wall, and one end of the outer wall has a side wall extending radially inward. 5. A shaft seal assembly according to any one of the preceding claims, wherein two sets of packing rings are provided, each set cooperating with one of the packing sleeves. 6. A shaft seal assembly as claimed in claim 5, wherein said packing groups are spaced apart from each other by a collar. 7. The shaft seal assembly of claim 6 wherein said collar includes a first portion fitted between said packing set and a second portion shaped to compress said packing in the installed position set. 8. A shaft seal assembly as claimed in claim 7, further comprising an O-ring or the like forming a seal between said collar and housing.

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