CN101345450A - Electric principal shaft with annular permanent magnet vibration damping system - Google Patents

Abstract

The invention relates to a motorized spindle with an annular permanent magnet damping system comprising a shaft, a motor rotor fixed with the shaft into a whole, a casing, a motor stator fixed with the casing into a whole, a front end cover and a back bearing seat respectively fixedly connected with the front end and back end of the casing, a back end cover fixedly connected with the back end of the back bearing seat, a bearing and an internal and external space ring respectively arranged on the front end cover and the back bearing seat as well as the bearing. The annular permanent magnet damping system is formed by a group concentric permanent magnet rings on the front and back end of the built-in motor. The motorized spindle of the invention has advantages of little vibration, low noise, high rotation accuracy and long service life of the bearing.

Description

The electric main shaft that has annular permanent magnet vibration damping system

Technical field

The present invention relates to the electric main shaft in a kind of electromechanical engineering field, particularly a kind of electric main shaft that has the annular permanent magnet vibration insulating system.

Background information

The electricity main shaft is to adopt dress in the spindle motor, and the motor stator that will have coolant jacket is assemblied in the housing of main axle unit the functional part that the rotating parts of rotor and main shaft is made of one.The rotating accuracy of present electric main shaft rotating shaft mainly guarantees by design, processing and assembling process.Although the rotating shaft of electric main shaft part had been done accurate dynamic balancing before installing, but still there is a certain amount of mass eccentricity inevitably, add the radially effect of external applied load in the practical work process, rotor-support-foundation system very easily produces bigger radial vibration when high speed, at present, the electric main shaft of overwhelming majority inside does not almost take effective measures the vibration that suppresses and reduce rotating shaft, has a strong impact on the precision of electric main shaft and the raising of rotating speed, greatly reduces the useful life of electric mainshaft bearing yet.

Thereby need develop a kind of novel high-speed electric main shaft, make it can increase the rigidity and the damping of rotor-support-foundation system at work, running accuracy, suppress in good time and reduce the radial vibration of rotor-support-foundation system, improve the comprehensive technical performance of electric main shaft, satisfy the high-precision function of electric main shaft, and the useful life of improving electric main shaft.

Summary of the invention

To the objective of the invention is the limitation that lacks vibration insulating system in the present various electric main shaft in order overcoming, a kind of electric main shaft that has annular permanent magnet vibration damping system to be provided, reduce rotating shaft vibration, improve the rotating accuracy of rotating shaft.

For achieving the above object, the present invention adopts following technical scheme:

A kind ofly will have the high-speed electric main shaft that annular permanent magnet is loaded on electric main shaft inside, comprise rotating shaft, with rotating shaft fixedly all-in-one-piece rotor, housing, fixedly connected with housing the motor stator that is integral, the front end housing of fixedlying connected with the housing front and back end respectively and rear bearing block, the rear end cap of fixedlying connected with the rear bearing block rear end, be installed in front end housing and rear bearing block, interior bearing and internal space ring and external space ring respectively.It is characterized in that the front and back end at built-in motor, each installs one group of concentric permanent-magnetic clamp looping permanent magnet vibration insulating system.

The structure of above-mentioned annular permanent magnet vibration insulating system is: the inboard that at the two ends of roller is bearing is fixed an annular permanent magnet respectively, on the front end housing of correspondence and rear bearing block an annular permanent magnet is set respectively also.The pole orientation of inside and outside two annular permanent magnets of every group is all along electric main shaft axial direction, and the pole orientation of inner and outer rings is identical, like this, understand the repulsion that produces radial direction between every group of inner and outer rings, the size of radial clearance is inversely proportional between the size of repulsion and the inside and outside magnet ring.Therefore, when rotor makes gap between inside and outside magnet ring change in that vibration radially takes place, can make the radial load between inside and outside magnet ring produce energy imbalance: the big position of the radial clearance radially repulsion of magnetic becomes big, and the little position of radial clearance radially the repulsion of magnetic diminish, the existing additional magnetic force that rotor is replied to the center plays inhibitory action to the radially amplitude of rotor-support-foundation system.Simultaneously,, the radially damping of rotor-support-foundation system is increased, produce damping effect by magneticaction, and, in order to increase effectiveness in vibration suppression, adopt two groups of permanent magnet concentric ring structures separated by a distance.

Design feature of the present invention is: consider electric main shaft in the radial direction vibration effect gyration precision in rotation process, two interior toroidal magnets are separately fixed at the two ends of rotating shaft, two outer ring magnets be fixed on corresponding front end housing of interior ring and rear bearing block on.To except that rotor vertically and 4 degrees of freedom around axial motion play the effect of further constraint, suppress and reduce electric main shaft in the radial direction vibration, can improve the rotating accuracy of electric main shaft.

The present invention has following substantive distinguishing features and technological progress compared with prior art:

(1) utilizes the magnetic force and the damping advantage of permanent magnet, two groups of concentric permanent-magnetic clamps have been formed the vibration insulating system of electric main shaft;

(2) realized the integrated of electric main shaft and vibration insulating system, vibration insulating system has played electric spindle rotor system in radial direction

The vibration function that suppresses and reduce;

(3) electric spindle vibration is little, noise is low, rotating accuracy is high, the bearing long service life.

Description of drawings

Fig. 1 is the structural representation of one embodiment of the invention.

Fig. 2 is Fig. 1 example shaft vibration insulating system schematic diagram.

Embodiment

A preferred embodiment of the present invention is: referring to Fig. 1, the electric main shaft that has the annular permanent magnet vibration insulating system, comprise rotating shaft 1, with the fixing all-in-one-piece rotor 11 of rotating shaft 1, housing 9, fixedly connected the motor stator 10 that is integral with housing 9, the front end housing 3 and the rear bearing block 18 of fixedlying connected respectively with housing 9 front and back ends, the rear end cap 20 of fixedlying connected with rear bearing block 18 rear ends, be installed in the bearing 4 in front end housing 3 and the rear bearing block 18 respectively, 6,15,17 and internal space ring and external space ring 5,16, in the front and back end of built-in motor, each installs one group of concentric permanent-magnetic clamp looping permanent magnet vibration insulating system.The structure of above-mentioned annular permanent magnet vibration insulating system is: internal magnetic ring 7 is installed in the rotating shaft in front end housing 31, outer magnetic ring 8 is installed on front end housing 3, internal magnetic ring 13 is installed in the rotating shaft 1 in rear bearing block 18, outer magnetic ring 14 is installed on rear end cap 18, constitute two groups of concentric annular permanent magnet rings, electric main shaft has been played corresponding inhibition and reduced effect in the radial vibration of rotation process rotor system.

The structure of permanent magnet vibration damping system as shown in Figure 2, the mutual alignment of the annular permanent magnet of two axial magnetizeds is that internal magnetic ring 7 and outer magnetic ring 8 are one group, internal magnetic ring 13 and outer magnetic ring 14 are one group, interior outer magnetic ring combination results is repulsive force radially, size is relevant with permanent magnet magnetization intensity and size, can use radial stiffiness k _rExpression, its formula is:

$K_r=-\frac{M^{2}L}{4\mathrm{\&pi;}{\mathrm{\&mu;}}_0}\ln \frac{e^2{(2l+e)}^2{[{(l+e)}^2+h^2]}^2}{{(l+e)}^4({\mathrm{<figure-callout\; id="2"\; label="e"\; filenames="A20081003773200061.png"\; state="\{\{state\}\}">e</figure-callout>}}^2+h^2)[{(2l+e)}^2+h^2]}$

In the formula: M-permanent magnet magnetization intensity (Wb/m ²);

The average perimeter of air gap (m) between the L-bearing;

The axial height of h-bearing (m);

The radial thickness of l-bearing (m);

The monolateral radial air gap of e-(m);

μ ₀-permeability of vacuum.

Position dimension according to annular permanent magnet among Fig. 2 can be obtained radial stiffiness K _rIf electric main shaft produces relative displacement at the central axis of rotation process shaft, the position distance that radial clearance is big is e ₁The little position of radial clearance distance is, then relative displacement S=e ₁-e ₂, also be the relative displacement of the central axis generation of two permanent-magnetic clamps, can obtain the radially magnetic restoring force F=K that two permanent-magnetic clamps are produced thus _rS.To stop the rotating shaft skew in case rotating shaft off-center axis, the answer magnetic force that annular permanent magnet produces increase, along with rotor is got back to central axis, radial magnetic force reaches balance, reaches effectiveness in vibration suppression.

Claims (3)

1, a kind of electric main shaft that has the annular permanent magnet vibration insulating system, comprise rotating shaft (1), with the fixing all-in-one-piece rotor (11) of rotating shaft (1), housing (9), fixedly connected the motor stator (10) that is integral with housing (9), the front end housing (3) and the rear bearing block (18) of fixedlying connected respectively with housing (9) front and back end, the rear end cap (20) of fixedlying connected with rear bearing block (18) rear end, be installed in the bearing (4 in front end housing (3) and the rear bearing block (18) respectively, 6,15,17) and internal space ring and external space ring (5,16), it is characterized in that the front and back end at built-in motor, each installs one group of concentric permanent-magnetic clamp looping permanent magnet vibration insulating system.

2, the electric main shaft that has the annular permanent magnet vibration insulating system according to claim 1, the structure that it is characterized in that described annular permanent magnet vibration insulating system is: the rotating shaft (1) in front end housing (3) is gone up internal magnetic ring (7) is installed, go up installation outer magnetic ring (8) at front end housing (3), rotating shaft (1) in rear bearing block (18) is gone up internal magnetic ring (13) is installed, go up installation outer magnetic ring (14) at rear end cap (18), constitute two groups of concentric annular permanent magnet rings, electric main shaft has been played corresponding inhibition and reduced effect in the radial vibration of rotation process rotor system.

3, the electric main shaft that has the annular permanent magnet vibration insulating system according to claim 2, it is characterized in that the central axis of two groups of concentric annular permanent magnet rings and the dead in line of electric main shaft, the vibration of electricity main shaft rotating shaft (1) is the skew of internal magnetic ring (7) axis and outer magnetic ring (8) axis and the skew of internal magnetic ring (13) and outer magnetic ring (14) axis, thereby between permanent-magnetic clamp (7) and (8), (13) produce and between (14) make rotating shaft reply among heart repulsion and radially damping, make electric spindle axis line and two groups of permanent-magnetic clamp deads in line, reach and reduce rotor-support-foundation system radially amplitude and effectiveness in vibration suppression.

Images