Technical background
Present domestic horizontal Machining centers 110mm main shaft rated speed is generally 2500r/min, 130mm main shaft rated speed is generally 2000r/min, generally be provided in middle-size and small-size horizontal Machining centers, 160mm main shaft rated speed is generally 1500r/min, then is used for the large-size horizontal machining center.At home, middle-size and small-size horizontal Machining centers realizes that high-speed cutting has had the history in a lot of years, and large-scale big main shaft horizontal Machining centers realizes that high-speed cutting is still more rarely seen at home.Trace it to its cause main because to realize the major diameter main shaft rotate at a high speed just must capture that main shaft bearing is lubricated, axis system cools off, the bottleneck of all many-sides such as assembly technology of the processing and manufacturing of main shaft, the dynamic balancing of main shaft group, main shaft.At present domestic also not have this class main shaft diameter of manufacturer production be the above high rotating speed large-size horizontal machining center of 160mm, and the user can only be from external import, and price is very expensive.Therefore, it is extremely urgent for domestic lathe manufacturing enterprise to develop this type of large-size horizontal machining center high-speed main spindle system.
Oil-air lubrication is a kind of lubricating system that just grows up recent years.Briefly, the lubricant of independent feed and compressed air mixed and form the mixed stream of oil gas of turbulent shape after be fed to oil site again, this process is exactly an oil-air lubrication.In heterogeneous object or the system, respectively exist interfacial independent material to be referred to as phase.It is solid phase, liquid and gas that the common material of nature has three-phase.Oil gas is exactly a kind of two phase flow.Just formed two-phase oil gas mixed flow after monophasic fluid oil and monophasic fluid compressed air are mixed, oil and compressed air really do not merge in the two-phase oil gas mixed flow, but under compressed-air actuated mobilization, drive lubricating oil along inner-walls of duct constantly helical form flow and form one deck continuous oil film, the mode with meticulous continuous oil droplet is sprayed onto oil site at last.Oil-air lubrication is similar to fog lubrication, but is different from fog lubrication.The both is to be that power is transported to bearing with thin oil with compressed air, and different be that oil-air lubrication is not the oil bump mist, but utilize compressed air to flow oil is transported to bearing along pipeline, therefore no longer need condensing.
Summary of the invention
The purpose of this utility model is to provide a kind of oil-air lubrication device of big main shaft horizontal Machining centers, when thoroughly solving large-size horizontal machining center diameter and be the above main shaft of 160mm and rotating at a high speed, because the main shaft bearing specification becomes big bigger friction and the heating problem that produces.
The oil-air lubrication device of big main shaft horizontal Machining centers, to diameter is that high-speed main spindle more than the 160mm adopts oil-air lubrication, the oil gas generation part that comprises external source of the gas and fuel tank is characterized in that oil gas signal output in the part and the electric program of oil gas circulation Long-distance Control takes place is connected, disposes respectively in source of the gas pipeline and the fuel tank inductance spare and pressure valve, pump connection oil gas generation oil gas mixed allocation unit partly with the machining center control system by binding post; The main shaft upper forepart of work in-process heart equipment is coaxial successively to be provided with four fore bearings, two rear bearings are established at the rear portion, and in each bearing both sides and middle all coaxial arrangement forward and backward outer separator, forward and backward bearing holder (housing, cover) are arranged, the outer separator that is distributed in bearing osculum end is provided with four nozzles, and jet hole is facing to the oil site of bearing; Axially and the radially gas channel that communicates is arranged in the cylindrical wall of each bearing holder (housing, cover) and outer separator, and connect, form oil gas and enter main shaft to the oil gas circulating conveying channel of discharging main shaft with oil gas input, fuel tank loop in the oil gas mixed allocation unit.
Adopted the interior outer separator of large-size horizontal machining center high-speed spindle bearing of this novel oil-air lubrication device and the coefficient of friction between the ball can hang down to 0.001 even lower, the frictional resistance of this moment mainly is the low shearing resistance of mutual slippage between hydrodynamic lubrication film interior molecules.The oil gas transport portion can make oil gas generation part distribute oil gas and directly be delivered to the optimal site that main shaft bearing need lubricate in the main shaft group like clockwork in main shaft group inside among the design, avoid leaking midway, interruption and multichannel are mixed mutually and delivery site is inaccurate etc. that anomaly takes place, bearing is carried out trace, accurate quantification fuel feeding, and be equipped with compressed air and cool off, make the bearing heating amount few, heat up low, lubricated reliable, limit speed improves and increase the service life.In case it is unusual that this novel automatic control design can also guarantee that the lubricating system operation occurs, as: compressed-air actuated pressure is undesired, the fuel tank low oil level, and during situations such as filling pump operation irregularity, lathe can be implemented automatic stopping.The oil gas nozzle is the miniature nozzle opening of tilting, and the nozzle opening spray angle is 15 degree, has guaranteed that like this oil gas sprays to the main shaft bearing inner ring, moves to the outer ring under action of centrifugal force then, reaches best lubrication effect.
The specific embodiment
The oil-air lubrication device of big main shaft horizontal Machining centers, carry two parts to form by oil gas generation and oil gas, it is characterized in that: part takes place oil gas external source of the gas and fuel tank, see Fig. 2, source of the gas is through the two-bit triplet magnetic valve, air pressure regulator, water filter, pressure switch is switched to oil gas mixed allocation unit, configuration high pressure oiling pump in the fuel tank, liquid level relay, electric control unit, the two-bit triplet magnetic valve, pressure switch, overflow valve, Pressure gauge is to oil gas mixed allocation unit, it is characterized in that the binding post of electric control unit by 14 pins that oil gas takes place in the part is connected with the machining center control system, the feedback of status signal and carry out the operation control instruction of this machining center in the realization external device.The operation of lubricated circulation of electric control unit programme-control and control filling pump.Electrical control program lubricants capacity on demand and suitable cycle are handled the mixing valve of the stackable combination in the oil gas mixed allocation unit, the lubricating oil compartment of terrain is expelled to the cooling blast of compression (in the constant compression force about 0.3 ~ 0.4MPa), the compressed gas that flows is blown out oil droplet to oil, attached to forming oil film on the tube wall, the thickness of oil lamella attenuate gradually in flow process, do not condense, oil film is along with the direction of gas continues to flow without interruption along tube wall, and is assigned to six output pipe R1-R6 by the oil circuit distributing valve in the oil gas mixed allocation unit of oil gas transport portion.The oil pump intermittent time can be adjusted between 0-20 minute.
The oil gas transport portion is seen Fig. 1, it is characterized in that the gas channel structure: with main shaft is coaxial four fore bearings 1 are set successively in the main shaft front portion, and at five preceding outer separators 17 of each equal coaxial arrangement in fore bearing 1 both sides, at two rear bearings 2 of main shaft rear portion coaxial arrangement, and after three of each equal coaxial arrangement in rear bearing 2 both sides outer separator 18.The outer separator that is located at the little oral-lateral of bearing all has four micro nozzles 5 or back outer separator to have two nozzles 6 and the inner opposite tilt of the radial hole of oil-feed to join, and the nozzle opening spray angle is 15 degree, and jet hole is facing to the oil site of bearing.Main spindle front bearing cover 3 is wrapped in preceding outer separator 17 and main spindle front bearing 1 wherein on periphery, see Fig. 3: the axially and radially gas channel that communicates is arranged in the cylindrical wall of main spindle front bearing cover 3: external diameter orifice ring flute profile oil gas passing away 7 on axial passage and the preceding outer separator 17 and the radial passage of leading to nozzle 5 intersect, also with front axle bearing sleeve 3 outer rings on radially slotted eye oil gas passing away 13, radially annular groove oil gas admission passage 12 intersects, radially annular groove oil gas admission passage 12 and with oil gas mixed allocation unit in oil-air lubrication inlet R1-R4, the connection of fuel tank loop; Oil-air lubrication inlet R5-R6 is communicated with the corresponding interface of the rear axle bearing sleeve 4 that is positioned at the machine spindle rear portion respectively, also have in the barrel communicate axially and the radial passage, respectively with outer separator 18 on oil gas admission passage 14, oil gas passing away 8 and connect with the oil gas passing away 15 of fuel tank circuit communication; Be distributed with sealing ring 10 between the gas channel 12, be provided with sealing ring 9 at place, outer separator 17 outer rings.
As shown in Figure 1, mainshaft rear bearing overlaps the identical of 4 structures and front axle bearing sleeve 3, too and will back outer separator 18 and mainshaft rear bearing 2 be wrapped in wherein.Mainshaft rear bearing overlap be provided with too on 4 outer rings also have in annular groove oil gas admission passage 14, oil gas passing away 15 sealing rings 11, the barrel communicate axially and the radial passage, respectively with outer separator 18 on oil gas admission passage 14, oil gas passing away 8 and connect with the oil gas passing away 15 of fuel tank circuit communication.The place establishes sealing ring 16 in outer separator 18 outer rings, back, leaks midway or mixes mutually with the oil gas of outlet with the oil gas that prevents to enter each main shaft bearing.
Five kinds of outer separator structures are arranged in the oil gas transport portion: detailed structure see Fig. 4 a b c, Fig. 5 a b; Forward and backward outer separator 17,18 is and the isometrical ring bodies of the forward and backward bearing of main shaft, the cylindrical side has radially annular groove in its wall, be respectively oil drain out that communicates with oil gas passing away 13,15 or the oil-in that communicates with oil gas admission passage 12,14, radially have ring to lack embedded seal ring 9 between the annular groove; Oil gas passing away 7,8 the inners have axial annular groove to communicate with bearing 1,2, and outer separator and bearing holder (housing, cover) cylindrical side have many sealing rings 10,11,16.
In five outer separators 17, be positioned at the preceding outer separator 17a shown in employing Fig. 4 a at fore bearing 1 two ends, have only unidirectional oil gas passing away 7 to communicate in this structure with oil outlet right angle radially, have two, the shape size is all identical, but the direction of placing is relative, is positioned at the first, the 4th fore bearing 1 two ends; Be positioned at the preceding outer separator 17b structure shown in employing Fig. 4 b of 1 of two pairs of fore bearing, nozzle 5 wherein is with radially oil outlet and bearing wall are the angle incision, formation is 15 degree to the spray angle of main shaft bearing inner ring, oil gas passing away 7 among the same 17b communicates with oil outlet right angle radially, two outer separator 17b and a preceding outer separator 17c are clipped in the middle secondary series, the 3rd row main spindle front bearing 1: two outer separator 17b are positioned at secondary series, the 3rd row main spindle front bearing 1 outside, and a preceding outer separator 17c is between secondary series, the 3rd row main spindle front bearing 1.Before the shape of outer separator 17c see Fig. 4 c, four nozzles 5 tangent with oil outlet angle radially are positioned at the structure two ends, incline direction is opposite, but the function of five preceding outer separators 17 is identical generally.
Structure back outer separator 18b identical, that be provided with is in opposite directions established in two rear bearing 2 front and back ends, establishes back outer separator 18a between two bearings.Two nozzle 6 structures among the back outer separator 18a are to be opposite tilt with same radially fuel feed hole, angle 15 degree.The shape of back outer separator 18b is that the three-way pipe structure that communicates with annular groove type oil gas passing away 8 is arranged in the ring wall.
The structure of main spindle front bearing 1, rear bearing 2: main shaft bearing is an angular contact ball bearing, bearing by bearing enclose and between support, ball formed, bearing divides the front and the back side, the gap of bearing back side bearing enclose is little, the gap of bearing front bearing enclose is big, because oil gas enters the lubricated good cooling results of bearing to bearing by little position, gap, so the bearing back side is relative with the oil gas nozzle, bearing is positive to join with the oil gas passing away.
Job state: the oil gas that part produces takes place in oil gas, four oil-air lubrications inlet R1-R4 in main spindle box below and radially annular groove gas channel 12, oil-air lubrication inlet R5-R6 and the gas channel 14 that is positioned at the mainshaft rear bearing below enter outer separator 18 behind on five preceding outer separators 17 of main spindle front bearing cover 3 and the rear axle bearing sleeve 4 three in Fig. 1.The oil gas of outer separator 17 is discharged by the big oral-lateral of bearing after the nozzle 5 on the main shaft bearing 1 osculum side outer separator is injected bearing before being transported to, be located at main spindle front bearing and overlap annular groove type oil gas passing away 13 on 3 outer rings by final arrival of the ring groove shape oil gas passing away on the preceding outer separator 17 7, the oil gas that lubricated behind the main spindle front bearing is discharged outside the main spindle box.The oil gas that is transported to back outer separator 18 is by establishing the oil gas nozzle 6 that thereon annular groove type gas channel arrives osculum one side be located at mainshaft rear bearing 2, and oil gas sprays to mainshaft rear bearing 2 by oil gas nozzle 6.Oil gas is discharged by the big oral-lateral of bearing after the little oral-lateral of mainshaft rear bearing is injected bearing, be located at mainshaft rear bearing and overlap oil gas passing away 15 on 4 outer rings by final arrival of the annular groove type oil gas passing away 8 of back on the outer separator 18, the oil gas that lubricated behind the mainshaft rear bearing is discharged outside the main spindle box.
Oil gas mixed allocation unit can separation of air and two kinds of different compositions of oil, size repairing one by one according to the oil and gas leakage amount, make each main shaft bearing oil site can both receive needed oil mass, the lubricated and cooling of main shaft bearing that the large-size horizontal machining center is rotated is at a high speed realized on automatic control ground.What it is to be noted in addition that oil gas enters that this section pipeline before the main shaft bearing oil site uses by output pipe R1-R6 is transparent PA pipe, and the supply situation in the oil pipe can be estimated easily.Tubing length is chosen between the 1-12 rice, and with the several circles of oil pipe dish, its axis is a horizontal direction, is used for storing when system shutdown a part of lubricating oil.Do not use transition joint in the pipeline, avoided the variation of oil pipe caliber like this, can not produce the successional phenomenon of destroying oil film because of the caliber variation.
The main spindle front bearing of big main shaft horizontal Machining centers selects for use the accurate angular contact ball bearing of internal diameter 220mm, mainshaft rear bearing to select the accurate angular contact ball bearing of internal diameter 200mm for use; Forward and backward bearing all adopts the oil-air lubrication mode that bearing is lubricated, guarantee that each main shaft bearing all disposes one group of independence oil-air lubrication loop, see Fig. 3, enter the mouth R1-R6 by behind arbitrary bearing annular chamber at oil gas mixture through oil-air lubrication, discharge main spindle box by oil gas vent, native system is totally 6 groups of oil-air lubrication loops.Adopted system of the present invention,, provide two groups of cooling circuits, significantly improved efficient because spacer and the design of overcoat cooling structure are arranged.Internal diameter can only reach 2000 rev/mins when being the general grease lubrication of the main spindle front bearing of 220mm, design and develop oil-air lubrication and spacer overcoat cooling system after, actual speed can reach 3600 rev/mins.