CN1021891C - Grinding method for mechnical seal ring - Google Patents

Abstract

The present invention relates to a grinding method for a mechanical seal ring with high speed, high efficiency and high precision, which belongs to a precision machining method. The grinding method can finely grind and polish an annular plane of hard alloy or engineering ceram at high speed. The grinding method reaches the purposes of high efficiency and low cost. The grinding method also ensures the machining precision of planeness and surface roughness simultaneously and is suitable for machining seal rings of hard materials in dynamic seal rubbing pairs such as various pumps, etc.

Description

Grinding method for mechnical seal ring

The invention belongs to mechanical precision machining method, be applicable to the grinding step of the mechanical seal ring that difficult-to-machine materials such as carbide alloy are made, processed position is a planar annular, relates to equipment and grinding tool simultaneously.

Existing processing method is like this, as U.S. EG﹠amp; G SEALOL company grinder (Lapping Machine) product description is introduced, referring to Fig. 1, a whole set of operation relates to three same grinders, carry out rough lapping, half smooth grinding and smooth grinding respectively, abrasive material is respectively with the diadust glycerol adding of three kinds of granularities and modulates the abrasive pastes that form, be coated on the cast iron mill (1), be thrown out of in order to prevent abrasive pastes, mill (1) is taked the low speed rotation mode.At first the several sealed ring is placed on the mill (1) during grinding, with lasso (2) it is divided into two groups, lasso (2) bottom has several identical slits of spacing, passes through in order to abrasive pastes, adds one again and heavily cut or polish jade with an emery wheel (3) on every group of sealing ring.After grinding a few hours, sealing ring taken off carry out strictness cleaning, in case the coarseness diadust is brought to next process and produces cut.And then carry out half smooth grinding and smooth grinding with sampling technology, and mill (1) needs finishing regularly, and this mill (1) is very heavy, also needs during finishing alternately to grind with the mill of three same sizes, till satisfying the precision needs.In the prior art, also have a kind of Ginding process that is used for optical element processing, see the nineteen eighty-three China national invention award project " the compensation processing method of non-swing of annular diamond abrasive tool " of awarding a prize, numbering 83-12-091.This method generally is used for processing optical glass, and this method is mainly used a kind of high-speed grinder, sees Fig. 2, and working position is a plane.Used is a kind of grinding tool that is stained with diamond disk on the cast aluminium dish, thinly is distributed in cast aluminium dish periphery in abrasive disc is close outward, forms to have the annular of certain width, sees Fig. 3.Add man-hour, grinding tool is following, and workpiece is last, and grinding tool rotates at a high speed, the passive rotation of workpiece, and equipment is pneumatic to be stressed on the workpiece, and cooling fluid circulates automatically.First method comprises three process, mill (1) rotating speed has only 30-50 rev/min, grind required time and reach a few hours, all needing manually with gasoline workpiece to be carried out strictness after the per pass operation cleans, make a large amount of abrasive pastes reactive power consumptions simultaneously, when grinding, also unavoidably throw away some abrasive pastes, operating personnel also need move the heavily stone roller (3) of 10 kilogram weights, also need move the cast iron mill (1) of 500 millimeters of diameters during the finishing grinding tool, three process takies three equipment, and abrasive material is the different diadust of granularity only, and whole process lacks theoretical direction and accurate mill method for trimming, processing capacity is less, has only the 0.005-0.010 millimeter altogether.So this method efficient is low, cost is high, labour intensity is big, take fixed assets and the place is many, machining accuracy is low and unstable, grinding tool needs finishing regularly, to workpiece accuracy requirement height before processing.And second method can only be used for the continuous level of processing optical part, and correct grinding just, can not polish.

For can efficient, low-cost, low labour intensity, high accuracy, need not repair grinding tool, lowly take, to the low planar annular that requires the mechanical seal ring of difficult Material Processing such as ground processing rigid alloy of workpiece before processing, promptly adopt first kind of workpiece of the prior art of second kind of prior art processing, and making it to reach the nanoscale surface roughness, we have invented a kind of mechanical seal ring Ginding process.

A high speed polisher lapper is adopted in being achieved in that of the inventive method, sees Fig. 2, and two kinds of cast aluminium square position grinding tools are seen Fig. 3, a kind of correct grinding that is used for, and a kind of being used for polishes.The used abrasive disc of processing optical part is basic identical in diamond disk on the microabrasive tools (5) and the prior art, and the diadust granularity is 40 millimeters.Abrasive disc (5) arrangement mode is generally in outer the dredging close, forms an annular, external diameter R ₂Be generally the 60-100 millimeter, can process the sealing ring that mean radius is the 15-50 millimeter (6).Diamond disk on the polishing abrasive tool (5) is special for the present invention, its bond is formed (percentage by weight), copper powder 68%, silica flour 22%, phenolic aldehyde 6%, talcum powder 4%, is granularity the amount adding of the diadust of 5-7 micron with the 11-12% of bond weight, and add 2% phenolic curing agent hexamethylenetetramine of gross weight, mixing sieves, and compression moulding is put into baking oven and be incubated 0.5 hour under 150-160 ℃ temperature, promptly made diamond set polished section (5), its arrangement mode on cast aluminium square position (4) is identical with microabrasive tools.Because no matter be correct grinding or polishing, abrasive material all is to exist with the set state, so can process at a high speed, general grinding tool rotating speed is between 460-850 rev/min, because this at a high speed, adds high pressure, make that process is to carry out in the plastic zone of fragile material, processing capacity is bigger.The mechanical seal ring that difficult-to-machine material such as carbide alloy, engineering ceramics is manufactured (6) is put on diamond disk (5) endless belt at grinding tool, see Fig. 2 and Fig. 4, make its location by locating rack (7) and head (8), eccentric throw between sealing ring (6) center and the grinding tool center is a key parameter, this eccentric throw should make sealing ring (6) consistent with contact pressure distribution between the grinding tool, and high-speed grinder is by adding air cylinder (10) and the pneumatic pressurization 15-50 of head (8) kgf on sealing ring (6).Cooling fluid cycles through machined surface automatically by spray orifice (11), and milling time is controlled automatically, and correct grinding is generally 30-40 second/part.Two operations of fine-grinding and polishing are carried out on same lathe.Sealing ring behind the correct grinding (6) does not need any cleaning, can directly enter polishing process, and polishing time is generally 10-30 second/part.

Adopt the inventive method processing equipment sealing ring (6), only worthwhile from milling time, the existing sealing ring processing method of efficient has improved 20.6-36.0 doubly, and average every the three process of existing method needs 24 minutes altogether, and every two procedures of the present invention takes time only 40-70 second altogether.It is worthwhile to consume from abrasive material, and the expense of the inventive method only accounts for 21.7% of existing method, and average every of the present invention needs abrasive material cost 0.22-0.28 unit, and existing method is at least 1.0-1.3 unit/part.Flatness and two the key technical indexes of surface roughness from sealing ring (6), precision is higher than existing method, flatness peak-to-valley value of the present invention is the 0.07-0.11 micron, existing method≤0.9 micron, surface roughness of the present invention is the 0.005-0.007 micron, existing method is the 0.015-0.030 micron, from the grinding tool finishing cycle, the mill (1) of existing method (first kind) needs finishing (being generally month) regularly, and grinding tool of the present invention just no longer needs finishing after finishing.From processing capacity,, be the 1.0-1.2 micron so only require the surface roughness of the preceding sealing ring of processing because processing capacity of the present invention reaches the 0.01-0.10 millimeter.And existing method processing capacity has only the 0.005-0.010 millimeter, then requires the preceding sealing ring surface roughness of processing to be lower than 0.8 micron.The present invention only needs an equipment, and workpiece need not clean, and does not have heavily stone roller (3), and grinding tool is light and handy, has reduced equipment place occupancy, has alleviated labour intensity, has improved environment.Owing to adopted annular diamond abrasive tool, then can from theory is calculated, obtain rational eccentric throw, thereby improve machining accuracy and precision stability; The grinding tool even wear then need not repaired.The annular diamond abrasive tool can carry out optics according to the eccentric throw that provides and dynamically repairs during beginning, and is accurately convenient.

Fig. 1 is the equipment schematic perspective view of processing equipment sealing ring in first kind of prior art.Fig. 2 is the high-speed grinder schematic side view that second kind of prior art and the present invention adopt.Fig. 3 is the present invention's a grinding tool vertical view.Fig. 4 is an operating mode schematic perspective view of the present invention.In above-mentioned accompanying drawing, (1) is mill, and (2) are lassos, (3) be heavily to cut or polish jade with an emery wheel, (4) are the cast aluminium square positions, and (5) are abrasive discs, (6) be mechanical seal ring, (7) be locating rack, (8) are heads, and (9) are main shafts, (10) be to add air cylinder, (11) be spray orifice, R1 is annular internal diameter, and R2 is annular external diameter.

Now giving an actual example further specifies the present invention's method, and high speed polisher lapper main shaft (9) is rotated counterclockwise, 560 rev/mins of rotating speeds, and head (8) pressure is 30 kgfs.The workpiece mean radius is 25 millimeters, is manufactured by the tungsten-cobalt hard alloy material.The width of planar annular is 7 millimeters, and processing front surface roughness is 0.8 micron.Correct grinding diamond disk diadust granularity is 40 little material, polishing diamond abrasive disc diadust granularity is 7 microns, make the correct grinding diamond disk by prior art, make the polishing diamond abrasive disc by the present invention, two kinds of abrasive disc diameters are 8 millimeters, it is on 140 millimeters the cast aluminium square position that two kinds of several abrasive discs that make are bonded at two diameters respectively, it is close in outer the dredging that density roughly becomes, form an annular, annular internal diameter R1 is 30 millimeters, external diameter R2 is 67.5 millimeters, press the dynamic grinding tool method for trimming of optics with after the two grinding tools finishings, microabrasive tools is contained in main shaft (9) goes up (polishing abrasive tool is contained on another main shaft), workpiece is put in the grinding tool left side, adjust locating rack (7), making eccentric throw is 45.9 millimeters, put down head (8), start grinder, process about 30-40 second, can finish grind one, on second of same lathe, polish, process 10-30 second for every, can process the flatness peak-to-valley value and reach the 0.07-0.10 micron, surface roughness reaches the mechanical seal ring of 0.005-0.007 micron.It is 15-45 millimeter mechanical seal ring that above-mentioned specification two grinding tools can be used to process mean radius, and actual a large amount of mechanical seal ring mean radius of using are generally 20,25 and 30 millimeters, all in this scope, see table with the corresponding eccentric throw of this scope

Unit: millimeter

Sealing ring mean radius 15 20 25 30 35 40 45

Eccentric throw 50.0 48.2 45.9 42.8 38.8 33.6 26.5

Claims (3)

1, a kind of rotary grinding method, grinding tool are shape metal square positions, garden, at a high speed rotation, abrasive material is a diadust, and exist to make the set form that abrasive disc (5) is bonded on the grinding tool, workpiece is put in the above, passive rotating, and it is under pressure, it is characterized in that, the mechanical seal ring (6) of workpiece for making by difficult-to-machine material, processed position is a planar annular, operation comprises correct grinding and polishing, adopts special abrasive disc (5) in the polishing process.

2, Ginding process according to claim 1 is characterized in that, alleged difficult-to-machine material comprises carbide alloy and engineering ceramics.

3, processing method according to claim 1 is characterized in that, is used for the abrasive disc (5) of polishing process, and its bond consists of (percentage by weight), copper powder 68%, silica flour 22%.Phenolic aldehyde 6%, talcum powder 4%, the diadust granularity is the 5-7 micron, addition accounts for the 11-12% of bond gross weight.

Images