CN2176856Y

CN2176856Y - High-precision dynamical-statical pressure oil film bearing numerically controlled machine tool

Info

Publication number: CN2176856Y
Application number: CN 93242039
Authority: CN
Inventors: 张锡圣
Original assignee: Individual
Current assignee: Individual
Priority date: 1993-10-18
Filing date: 1993-10-18
Publication date: 1994-09-14
Anticipated expiration: 2003-10-18

Abstract

The utility model discloses a high precision simple numerically controlled machine tool retrofitted with the dynamical-statical pressure oil film technique. A dynamic-static pressure oil film bearing on a bed head adopts a new slot restrictor; four shallow cavities are arranged on the inner surface of the dynamic-static pressure oil film bearing; both ends of the cavities are provided with steps to form the staged dynamical pressure effect and combined with axial static pressure thrust oil films; the comprehensive rigidity is favorable, the running accuracy is high, and the surface smoothness is improved; the oil films are supported on a lead screw, and pressure oil passes through the slot restrictor, an oil supply hole and enter the shallow cavities on both sides of a thread to cause the lead screw to be suspended in the nut; the friction power consumption is decreased, the vibration is lightened, the feeding accuracy is improved, and the cost is low; The utility model improves the production rate and the qualified rate of finished products, solves the key problem of the precision of a numerically controlled machine tool and is suitable to be popularized and used in each factory.

Description

High-precision dynamical-statical pressure oil film bearing numerically controlled machine tool

The utility model relates to a kind of dynamic and static pressure oil film technology and is retrofitted on the existing simple cnc lathe, improving its machining accuracy, and becomes the high accuracy simple cnc lathe.

Existing simple cnc lathe can be divided into two classes on structure: a class is that main shaft supports with rolling bearing, comes speed change with the multi-stage gear transmission, and slide carriage drags with the sliding nut leading screw, and its shortcoming is that the main shaft resistance to shock is poor, running accuracy is low.The gear graduation noise is big, efficient is low, and the lead screw friction power loss is big, precision is low.Another kind of is that main shaft supports with rolling bearing, with controllable silicon direct current or frequency-changing AC infinitely variable speeds, slide carriage drags with ball-screw nut, its main shaft shortcoming is identical with the former, power little (because it is permanent moment of torsion speed governing) when infinite variable speed shortcoming is low speed, the shortcoming of ball-screw is the cost height, and resistance to shock and precision are all relatively poor.

The purpose of this utility model is to avoid above-mentioned weak point of the prior art and a kind of high accuracy dynamic and static pressure oil film supporting simple cnc lathe is provided, the rolling bearing that replaces spindle of numerical control lathe with hybrid hydrodynamic oil film journal bearing, its centering property is good, replaces slip or ball-screw nut to improve the lathe precision with novel dynamic and static pressure feed screw nut simultaneously.

Hybrid hydrodynamic oil film journal bearing on the head of a bed, adopt novel groove flow controller, gash depth is 0.07～0.12 millimeter, flow controller is difficult for stopping up, 4 shallow chambeies on bearing inner surface, form the static pressure oil film of 4 symmetries, respectively there is the step of a symmetry at two ends, therefore no matter just main shaft, counter-rotating can form " staged dynamic pressure effect " equally in shallow chamber, improve the dynamic stiffness of oil film greatly, will be radially dynamic and hydrostatic bearing and axial static pressure thrust bearing the two join together, the radial and axial integral stiffness of oil film all is greatly improved, the two drainback passage flows into fuel tank and becomes zero-pressure, thus oil return do not disturb mutually, simple in structure.

The static pressure nut leading screw is the oil film supporting second throttle structure based on static pressure, replaces the non-yielding prop of original sliding nut leading screw, alleviates vibration, reduces friction, eliminates the gap, improves precision, cost is low; Install easy one-level three retaining mechanical reduction gears behind this external AC frequency conversion speed regulator additional, make lathe power when low speed rotation is worked reduce few, the shortcoming of " permanent moment of torsion speed governing " when improving low speed, above-mentioned aggregate measures, can make existing simple cnc lathe under the condition that does not increase cost, repack " high accuracy dynamic and static pressure oil film supporting simple cnc lathe " into; Headstock and feed screw nut place at simple cnc lathe, reequip with high accuracy dynamic and static pressure oil film supporting, to replace the headstock bearing and the feed screw nut of former lathe, studding with the outer sleeve hybrid hydrodynamic oil film journal bearing in the front-end bearing pedestal of former spindle stock packs in it, the thrust shaft shoulder respectively is equipped with at two ends, the filmatic bearing left and right sides, there is sealing ring on the right of filmatic bearing, is contained in the cover annular distance to seal; The headstock hybrid hydrodynamic oil film journal bearing adopts the new construction of horizontal oblate groove flow controller and shallow chamber second throttle, the fuel feeding cannelure of filmatic bearing and oblate groove flow controller, radially totally 4 in oil supplying hole, eccentric circular arc static pressure oil groove, its central angle is 60 °～65 ° and 4 rectangular shallow chambeies, oil circuit is interconnected, and the latter is slightly more shallow than arc static pressure oil groove; The annular thrust oil groove on filmatic bearing two sides is connected with two groove flow controllers on the bearing top circle face by oil supplying hole.Dynamic and static pressure nut on the lathe leading screw is contained in the outer sleeve, it matches with the endoporus of former lathe nut support seat, outer sleeve has warp-wise oilhole totally 4 oblate groove flow controllers with the sleeve periphery, the annular oil supply tank is connected, 4 grooves such as prolate shape such as branch such as grade are arranged on the nut cylindrical, radially the nearly internal thread tooth of oil supplying hole place is a pore, corresponding at circumference 4 equally divided positions with prolate shape groove position, and divide the every row of 4 rows to have 5-7 holes to be respectively in the both sides of internal thread facing, nut is discerptible two semicircular bodies, lock with two locating cones and to close the location, be inserted in the outer sleeve hole fastening again with countersunk bolt, the ridge both sides respectively have 4 shallow chambeies to be shaped with etch weekly, and it is to corrode shallow chamber for the ease of pad pasting to be shaped that nut is done discerptible into two.Respectively there are two shallow chambeies another kind of ridge two sides, and shallow chamber increases arc length, and is simple in structure.

Advantageous effect and purposes:

1, the rolling bearing that replaces spindle of numerical control lathe with novel hybrid hydrodynamic oil film journal bearing not only reduces vibration, reduces noise and frictional dissipation, prolong bearing life, and the raising running accuracy, make machining accuracy and surface smoothness improve the 2-3 level, surface smoothness can be increased to

9～

10, out-of-roundness reaches 3 μ, can realize that the cylindrical finish turning replaces grinding.

2, replace former lathe lead screw nut or ball-screw nut (former leading screw nut friction power loss is big, ball-screw nut valency height) with novel dynamic and static pressure feed screw nut, the latter reduces cost relatively, and improves precision, increases the service life, and resistance to shock is good.

3, behind the variable-frequency governor of AC speed regulating, installed easy one-level third gear deceleration device additional, it is few that lathe power when low speed rotation is worked is reduced, the shortcoming of " permanent moment of torsion speed governing " when improving low speed.

4, the simple cnc lathe advantage of dynamic and static pressure oil film repacking is many, again because its cost is not high, and programming and easy and simple to handle, its productivity ratio and product qualified rate are all much higher than general numerically controlled lathe of the same type.The energy extensive use also has the value of promoting the use of in the factory of rural area in general middle-size and small-size factory.

The drawing explanation of accompanying drawing:

Fig. 1 is a repacking hybrid hydrodynamic oil film journal bearing generalized section on the spindle of numerical control lathe

Fig. 2 is headstock hybrid hydrodynamic oil film journal bearing profile (Fig. 3 B-B section)

Fig. 3 is Fig. 2 A-A generalized section

Fig. 4 is Fig. 2 side view

Fig. 5 is a repacking dynamic and static pressure nut generalized section (Fig. 6 D-D section) on the numerically controlled lathe lead screw

Fig. 6 is Fig. 5 C-C generalized section

Embodiment of the present utility model is further described in conjunction with the accompanying drawings;

See Fig. 1, on lathe spindle, reequip profile with hybrid hydrodynamic oil film journal bearing, use former lathe spindle (8) that the bearing of former spindle stock is removed, in front-end bearing pedestal (12), load onto hybrid hydrodynamic oil film journal bearing (11) and outer sleeve (10) thereof, brearing bore cooperates with collar bush, end is equipped with the thrust shaft shoulder (9), (13) about bearing, leaning against on the end face is contained on the main shaft jointly, left end is fastening with double nut, rotate with main shaft, the sealing ring of filmatic bearing is contained in the collar (14) hole and seals; N represents oil-feed place, and all the other piece numbers see that Fig. 2 illustrates.

Fig. 2 is the filmatic bearing profile, Fig. 3 is its A-A profile, Fig. 4 is its side view, pressure oil flows into fuel feeding cannelure (1) by the N place among Fig. 2, through oblate groove flow controller (2), (its bc width is 3～5 millimeters, gash depth hc=0.07～0.12 millimeter), flow into oilhole (3) to eccentric circular arc static pressure oil groove (4), oil is to the intermediate flow in the shallow chamber of rectangle cambered surface (5) then.Its degree of depth of oil groove (4) is 1.2～1.5 millimeters, the degree of depth α in shallow chamber=0.015～0.03 millimeter; Pressure oil to flow controller (7), is seen Fig. 4 by two oilholes simultaneously, flows in the annular oil groove (6), makes the both ends of the surface of bearing form static pressure thrust oil pocket to bear the axial load of bearing.

The dynamic and static pressure nut profile of Fig. 5 for reequiping on the lathe leading screw.Fig. 6 is its C-C profile, pressure oil is through the annular oil groove (19) of overcoat (16) cylindrical, flow into oblate groove flow controller (18), its gash depth hc=0.07～0.12 millimeter, its width bc=3～5 millimeters, it generally is 4-8, flow into radial direction oil hole (17) after the step-down, and then inflow oil supplying hole (20), 5-7 of oilhole one row, its nearly facing end is a pore, flows into weekly 4 shallow chambeies (22) of ridge side at last, see Fig. 6, the degree of depth in shallow chamber, ridge side is 0.06～0.12 millimeter.The static pressure oil film of ridge dual-side makes leading screw be suspended in the center of nut, after leading screw begins rotation, also produces certain dynamic pressure on the surface in shallow chamber, plays the booster action of suspension and thrust; Therefore nut and leading screw facing are separated by oil film, do not produce frictional force, and the nut (15) that is separated two halves is contained in the outer sleeve hole also fastening with countersunk bolt with taper pin (21) location.

Claims

1, high accuracy dynamic and static pressure oil film supporting simple cnc lathe is equipped with filmatic bearing on headstock and leading screw, it is characterized in that:

Hybrid hydrodynamic oil film journal bearing (11) and outer sleeve (10) thereof are housed in the front-end bearing pedestal of a, spindle stock (12), the filmatic bearing left end is equipped with the thrust shaft shoulder (9), and its right-hand member is equipped with the preceding thrust shaft shoulder (13), the right of filmatic bearing, there is sealing ring to be contained in the collar (14) hole, seals; The headstock hybrid hydrodynamic oil film journal bearing adopts the new construction of horizontal oblate groove flow controller and shallow chamber second throttle, the fuel feeding cannelure (1) of filmatic bearing and oblate groove flow controller (2), radially totally 4 in oil supplying hole (3), off-centre operation arc static pressure oil groove (4), its central angle is 60 °～65 °, and 4 shallow chambeies of rectangle cambered surface (5) oil circuit is interconnected, and the latter is slightly more shallow than arc static pressure oil groove (4); The annular thrust oil groove (6) on filmatic bearing two sides is connected with two groove flow controllers (7) on the bearing top circle face by oil supplying hole;

B, dynamic and static pressure nut (15) on the lathe leading screw is contained in the outer sleeve (16), outer sleeve has radial direction oil hole (17) totally 4 oblate groove flow controllers (18) with the sleeve periphery, annular oil supply tank (19) is connected, 4 grooves such as prolate shape such as branch such as grade are arranged on the nut cylindrical, radially the nearly internal thread tooth place of oil supplying hole (20) is a pore, corresponding at circumference 4 equally divided positions with prolate shape groove position, and divide 4 to arrange, every row has 5-7 holes to be respectively in the both sides of internal thread facing, nut is discerptible two semicircular bodies, fit the location with two location taper pins (21), be inserted in again in the outer sleeve hole, fastening with countersunk bolt, the ridge two sides respectively have 4 shallow chambeies to be shaped with etch weekly.

2, high accuracy dynamic and static pressure oil film supporting simple cnc lathe according to claim 1, it is characterized in that: the filmatic bearing of spindle stock, its oblate groove flow controller (2), gash depth hc=0.07～0.12 millimeter, width bc=3～5 millimeter, eccentric circular arc static pressure oil groove (4) in the filmatic bearing, its degree of depth is 1.2～1.5 millimeters, the shallow chamber of rectangle cambered surface (5) degree of depth σ=0.015～0.03 millimeter.

3, high accuracy dynamic and static pressure oil film supporting simple cnc lathe according to claim 1, it is characterized in that: the dynamic and static pressure nut on the lathe leading screw, its oblate groove flow controller (18), the degree of depth hc=0.07 of groove～0.12 millimeter, width bc=3～5 millimeter, its degree of depth of shallow chamber (22) of ridge side is 0.06～0.12 millimeter.