CN115194498B - Electric spindle - Google Patents
Electric spindle Download PDFInfo
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- CN115194498B CN115194498B CN202210985610.6A CN202210985610A CN115194498B CN 115194498 B CN115194498 B CN 115194498B CN 202210985610 A CN202210985610 A CN 202210985610A CN 115194498 B CN115194498 B CN 115194498B
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- 230000002093 peripheral effect Effects 0.000 claims abstract description 12
- 210000004907 gland Anatomy 0.000 claims description 33
- 238000000034 method Methods 0.000 claims description 9
- 230000000903 blocking effect Effects 0.000 claims description 6
- 230000005540 biological transmission Effects 0.000 description 7
- 230000009467 reduction Effects 0.000 description 7
- 238000010438 heat treatment Methods 0.000 description 6
- 238000009434 installation Methods 0.000 description 6
- 238000005520 cutting process Methods 0.000 description 5
- 238000003754 machining Methods 0.000 description 5
- 230000008569 process Effects 0.000 description 3
- 230000008859 change Effects 0.000 description 2
- 238000001816 cooling Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000006073 displacement reaction Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000005484 gravity Effects 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 238000007789 sealing Methods 0.000 description 2
- 230000002159 abnormal effect Effects 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 230000000087 stabilizing effect Effects 0.000 description 1
Classifications
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23Q—DETAILS, COMPONENTS, OR ACCESSORIES FOR MACHINE TOOLS, e.g. ARRANGEMENTS FOR COPYING OR CONTROLLING; MACHINE TOOLS IN GENERAL CHARACTERISED BY THE CONSTRUCTION OF PARTICULAR DETAILS OR COMPONENTS; COMBINATIONS OR ASSOCIATIONS OF METAL-WORKING MACHINES, NOT DIRECTED TO A PARTICULAR RESULT
- B23Q1/00—Members which are comprised in the general build-up of a form of machine, particularly relatively large fixed members
- B23Q1/70—Stationary or movable members for carrying working-spindles for attachment of tools or work
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
- Y02P70/10—Greenhouse gas [GHG] capture, material saving, heat recovery or other energy efficient measures, e.g. motor control, characterised by manufacturing processes, e.g. for rolling metal or metal working
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- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Support Of The Bearing (AREA)
Abstract
The application relates to an electric spindle, which relates to the technical field of machine tools, and comprises a shell and a spindle which is rotatably inserted in the shell, wherein a stator is fixedly arranged in the shell, and a rotor corresponding to the stator is fixedly arranged on the peripheral surface of the spindle; the two ends of the shell are respectively and fixedly provided with a front bearing chamber and a rear bearing chamber; a first front bearing group sleeved at the front end of the mandrel is arranged in the front bearing chamber, and a rear bearing group sleeved at the rear end of the mandrel is arranged in the rear bearing chamber; the front bearing chamber is also internally provided with a second front bearing group which is sleeved on the mandrel and is positioned between the first front bearing group and the rear bearing group; a front elastic pre-tightening structure is arranged between the second front bearing group and the front bearing chamber; a rear elastic pre-tightening structure is arranged between the rear bearing group and the rear bearing chamber. The application improves the service life, precision and rigidity of the electric spindle.
Description
Technical Field
The application relates to the technical field of machine tools, in particular to an electric spindle capable of being applied to a numerical control machine tool.
Background
The motorized spindle is a driving piece integrating a rotary spindle and a driving motor and is often applied to the field of numerical control machine tools. The main shaft motor in the numerical control machine tool and the main shaft of the machine tool are combined into a whole, so that the main shaft component of the machine tool is relatively independent from the transmission system and the whole structure of the machine tool, and can be made into a main shaft unit commonly called an electric main shaft (ElectricSpindle, motorSpindle). The electric spindle is used as a main functional component of the numerical control machine tool, is a key component for realizing high speed, high precision, high efficiency and high reliability of the numerical control machine tool, and the performance of the electric spindle directly determines the quality of the numerical control machine tool.
The motor rotor in the electric spindle is integrated with the spindle (core shaft) by a press fit method, and the spindle is supported by front and rear bearings. The motor stator is arranged in the shell through the cooling sleeve, the speed change of the main shaft is controlled by the main shaft driving module, the temperature rise in the main shaft unit is limited by the cooling device, the rear end of the main shaft is also provided with a speed measuring and angle measuring displacement sensor, and the inner taper hole and the end face of the front end of the main shaft are used for installing a cutter. Because the electric spindle integrates the motor into the spindle unit, and the rotating speed is very high, a large amount of heat can be generated during operation, so that the temperature rise of the electric spindle is caused, the thermal state characteristic and the dynamic characteristic of the electric spindle are deteriorated, and the normal operation of the electric spindle is affected. Therefore, measures must be taken to control the temperature of the motorized spindle so that it is constant within a certain value.
Currently, in the high-precision machining fields of numerical control machine tools, intelligent machining centers and the like, in order to meet the working condition requirements of high speed and high precision, angular contact ball bearings are generally selected as bearings matched with an electric spindle, and in order to improve the rigidity and the rotation precision of the electric spindle, vibration and abnormal sounds of the spindle are restrained, and the bearings are generally pre-tightened and then used. The traditional bearing pre-tightening mode mainly comprises positioning pre-tightening and elastic pre-tightening; the elastic pre-tightening is a method for applying pre-tightening force to the bearing by using elastic elements such as a belleville spring, a spiral spring and the like; positioning pre-tightening refers to a pre-tightening method in which the axial relative position of the combined bearing is not changed in the use process.
When the traditional elastic pre-tightening mode is adopted, the pre-tightening force required by the front end bearing group and the rear end bearing group, the gravity of the shafting and other factors are comprehensively considered because the elastic force potential of the obtained rear end bearing group is required to be much larger than the pre-tightening force required by the rear bearing group bearing per se when the elastic elements such as the disc springs, the spiral springs and the like are used for pre-tightening; for a machine tool with an electric spindle transversely arranged, the front end of the electric spindle is used for installing a machining tool to carry out machining operation, larger acting force is needed to bear in the working process, correspondingly, a bearing with a larger model is needed to be selected for the front end bearing group, and the pretightening force needed by the bearing with the larger model is larger; in contrast, for the rear end bearing group, a bearing with a smaller model is generally selected, and the corresponding required pretightening force is smaller. However, when the pretightening force is applied, the mutual connection structure of the motorized spindle and the front and rear bearing sets determines that the forces acting on the front and rear bearing sets are equal, which leads to that the force acting on the rear bearing set is actually larger than the pretightening force required by the motorized spindle; for the machine tool with the vertical electric spindle, factors such as shafting gravity and the like are considered on the basis, and finally the force acting on the rear end bearing set is larger than the pretightening force required by the machine tool, and the pretightening force which is too large can cause the temperature rise of the rear bearing set to be too high in the high-speed running process of the electric spindle, so that the heating is too large, the precision and the service life are influenced, and the machining precision of the whole machine tool is further influenced.
For traditional location pretension mode, when shafting part generates heat and makes length dimension change, the pretightning force also can become big, leads to the temperature of bearing to rise too high, and life-span reduces, and electric main shaft vibration increases, and the precision reduces.
Disclosure of Invention
The application provides an electric spindle which is used for solving the problems of service life and precision reduction of the electric spindle caused by overhigh temperature rise due to overlarge pretightening force of a bearing group after the traditional bearing pretightening method is used for the electric spindle.
The application provides an electric spindle which adopts the following technical scheme:
an electric spindle comprises a shell and a spindle which is rotatably inserted in the shell, wherein a stator is fixedly arranged in the shell, and a rotor corresponding to the stator is fixedly arranged on the outer peripheral surface of the spindle;
a front bearing chamber and a rear bearing chamber are respectively and fixedly arranged at two ends of the shell; the front bearing chamber is internally provided with a first front bearing group sleeved at the front end of the mandrel, and the rear bearing chamber is internally provided with a rear bearing group sleeved at the rear end of the mandrel;
the front bearing chamber is also internally provided with a second front bearing group which is sleeved on the mandrel and is positioned between the first front bearing group and the rear bearing group;
a front elastic pre-tightening structure is arranged between the second front bearing group and the front bearing chamber; and a rear elastic pre-tightening structure is arranged between the rear bearing group and the rear bearing chamber.
In the prior art, only the first front bearing group and the rear bearing group in the application are generally provided, the second front bearing group and the corresponding assembly structure are not provided, the second front bearing group is added in the application, the elastic pre-tightening structures are respectively arranged at the positions of the second front bearing group and the rear bearing group, and the front elastic pre-tightening structure and the rear elastic pre-tightening structure are respectively formed, so that a double elastic pre-tightening structure is formed, which is equivalent to that the pre-tightening force originally applied to the rear bearing group is shared by the second front bearing group and the rear bearing group, and the force applied to each bearing group is correspondingly reduced. By adopting the technical scheme, the double-elasticity pre-tightening structure is arranged, so that the problems of service life and precision reduction of the electric spindle caused by too high temperature rise due to too large pre-tightening force of the bearing group after the electric spindle is arranged in the traditional bearing pre-tightening mode are solved; meanwhile, the problems that the length of the traditional positioning pre-tightening mode lower shafting part is increased due to heating, the pre-tightening force is increased, the temperature rise of the bearing is too high, the service life is shortened and the like, and the electric spindle vibration, the precision reduction and the like caused by the conventional positioning pre-tightening mode lower shafting part are solved.
According to the application, through the arrangement structure of the front, middle and rear three groups of bearings, the overall rigidity of the electric spindle can be improved, and the second front bearing group can properly share the cutting force and the like which are completely born by the first front bearing group during processing, so that the overall rigidity of a product is improved.
Optionally, the front bearing chamber is annular, an annular boss is arranged on the inner wall of the front bearing chamber, and the annular boss divides the interior of the front bearing chamber into a first bearing cavity for mounting the first front bearing group and a second bearing cavity for mounting the second front bearing group; a front bearing gland is fixedly arranged at one end of the front bearing chamber, which is close to the stator; and a front end cover is fixedly arranged at the other end of the front bearing chamber.
Through adopting above-mentioned technical scheme, first preceding bearing group and the interval setting of second preceding bearing group in preceding bearing room, the second preceding bearing group has shared the partial cutting force that first preceding bearing group bore, is convenient for the dispersion of force. Through setting up front end housing and preceding bearing gland, can carry out the axial spacing to first preceding bearing group and the preceding bearing group of second, the installation and the axial fixity of bearing group before first preceding bearing group and the second of being convenient for are used for sealing preceding bearing room simultaneously, prevent that the foreign matter from getting into preceding bearing room and damaging the bearing.
Optionally, the first front bearing group comprises at least two angular contact ball bearings arranged side by side in a first bearing cavity; and outer rings of two angular contact ball bearings at two outermost sides in the first front bearing group are respectively abutted against the annular boss and the front end cover.
By adopting the technical scheme, the plurality of angular contact ball bearings play a role in stabilizing and supporting, and during installation, the plurality of angular contact ball bearings are sequentially sleeved on the mandrel, the innermost angular contact ball bearing is abutted against the side surface of the annular boss in the front bearing chamber, and after the last angular contact ball bearing is sleeved, the front end cover is fixedly installed on the end surface of the front bearing chamber through the screw, so that the front bearing chamber is sealed, and the first front bearing group is axially limited; the distance between the front end cover and the annular boss is equal to the sum of the widths of the plurality of installed angular contact ball bearings. The first front bearing set in the application is preferably two angular contact ball bearings arranged side by side.
Optionally, the front elastic pre-tightening structure comprises a sliding seat and a first elastic piece, the sliding seat is sleeved on the second front bearing group, the outer peripheral surface of the sliding seat is in clearance fit with the cavity wall of the second bearing cavity, and two ends of the first elastic piece respectively act on the end surface of the sliding seat and the annular boss; an annular blocking edge is arranged on the inner wall of one end, facing the annular boss, of the sliding seat, and the other end of the sliding seat is abutted against the front bearing pressure cover;
the second front bearing group comprises at least two angular contact ball bearings which are arranged in the second bearing cavity side by side; and outer rings of two angular contact ball bearings at two outermost sides in the second front bearing group are respectively abutted against the annular blocking edge and the front bearing gland.
Through adopting above-mentioned technical scheme, preceding bearing room, sliding seat, first elastic component, preceding bearing gland constitution preceding elasticity pretension structure, the sliding seat can be in the second bearing intracavity axial displacement of preceding bearing room, provides the pretightning force to second preceding bearing group and whole dabber through the elastic force of first elastic component.
Optionally, a blind hole is formed in the sliding seat towards one end of the annular boss, the first elastic piece is a coil spring, one end of the first elastic piece is embedded in the blind hole, and the other end of the first elastic piece abuts against the annular boss.
Through adopting above-mentioned technical scheme, coil spring part inlays and establishes in the blind hole of sliding seat, is convenient for install like this, also is difficult to drop to can be stable and reliable provide pretightning force, in addition, coil spring low in manufacturing cost uses reliable and stable.
Optionally, the outer peripheral surface of the front bearing chamber is provided with an annular abutting boss, the inner wall of the casing close to the end part is provided with an annular abutting boss, one end of the casing is sleeved at one end of the front bearing chamber, the end face of the casing abuts against the abutting boss, and the end face of the front bearing chamber abuts against the abutting boss.
The front bearing chamber is fixedly connected with the end part of the shell through the bolts, namely a plurality of bolts are distributed along the circumferential direction by the abutting boss, and can be screwed on the end surface of the shell.
Optionally, the rear bearing chamber is annular, a first annular abutting flange is arranged on the peripheral surface of the rear bearing chamber, the end part of the casing is sleeved at one end of the rear bearing chamber, and the end face of the casing abuts against the first abutting flange;
an annular second abutting flange is arranged on the inner wall of one end of the rear bearing chamber, which faces the stator; the other end of the rear bearing chamber is provided with a rear bearing gland; the rear bearing set and the rear elastic pre-tightening structure are both arranged between the second abutting flange and the rear bearing gland.
The rear bearing chamber is fixedly connected with the other end part of the shell through the bolts, namely a plurality of bolts are circumferentially distributed on the first abutting flange and can be screwed on the end face of the shell, through the adoption of the technical scheme, the axial installation position of the rear bearing chamber and the shell can be rapidly positioned, so that the assembly and the fixation of the rear bearing chamber and the shell are facilitated, and the axial positions of the rear bearing chamber and the shell are stable and reliable through the axial limiting of the rear bearing chamber and the shell.
Optionally, the rear elastic pre-tightening structure comprises a bushing and a second elastic piece, the bushing is sleeved on the rear bearing group, the rear bearing gland is fixedly connected with the bushing, and a roller sleeve is sleeved outside the bushing; one end of the bushing is propped against the rear bearing gland; both ends of the second elastic member act on the second abutment flange and the other end of the bushing, respectively.
Through adopting above-mentioned technical scheme, back bearing room, bush, roller, second elastic component constitute back elasticity pretension structure, and back elasticity pretension structure cooperatees with preceding elasticity pretension structure, and the combined action is through two sets of elasticity pretension structures around, and the application pretension on the electric main shaft axle system jointly has improved life-span and the reliability of each group bearing under the circumstances that satisfies the required pretightning force of each bearing. According to the application, the roller sleeve is sleeved on the bushing, and is positioned between the rear bearing chamber and the bushing, and the bushing can axially slide in the rear bearing chamber through the roller sleeve, so that the effects of high precision, high load, wear resistance and low noise during axial movement of the bushing are realized.
Optionally, a mounting hole is formed in one end, facing the second abutting flange, of the bushing, the second elastic piece is a coil spring, one end of the second elastic piece is embedded in the mounting hole, and the other end of the second elastic piece abuts against the second abutting flange.
Through adopting above-mentioned technical scheme, coil spring part inlays and establishes in the mounting hole of bush, is convenient for install like this, also be difficult to drop to can be stable and reliable provide pretightning force, in addition, coil spring low in manufacturing cost uses reliable and stable.
Optionally, an inner wall of an end of the bushing, facing the second abutting flange, is provided with an annular baffle, and the rear bearing group comprises at least two angular contact ball bearings arranged side by side; and outer rings of two angular contact ball bearings at two outermost sides in the rear bearing group are respectively abutted against the baffle table and the rear bearing gland.
Through adopting above-mentioned technical scheme, back bearing gland passes through screw connection with the bush, and back bearing group is located the bush, and back bearing room passes through screw fixation on the casing. The elasticity of the second elastic piece directly acts on the rear bearing group through the bushing, which is equivalent to the force transmission of only one intermediate piece, so that the excessive intermediate piece transmission forceful loss or transmission error in the prior art is avoided. Meanwhile, the bush is matched with the roller sleeve and can axially slide in the rear bearing chamber, and when the length dimension of the shafting part is changed due to heating, the bush, the rear bearing group and the rear bearing gland move integrally relative to the rear bearing chamber to the rear end.
In summary, the motorized spindle of the present application has at least one of the following advantages:
1. according to the application, the front bearing chamber, the sliding seat, the first elastic piece and the front bearing gland form a front elastic pre-tightening structure, the rear bearing chamber, the bushing, the roller sleeve and the second elastic piece form a rear elastic pre-tightening structure, the rear elastic pre-tightening structure is matched with the front elastic pre-tightening structure to jointly act, and the front elastic pre-tightening structure and the rear elastic pre-tightening structure jointly apply pre-tightening to the electric spindle shaft system, so that the service life and reliability of each group of bearings are improved under the condition of meeting the pre-tightening force required by each bearing.
2. According to the application, through the arrangement structure of the front, middle and rear three groups of bearings, the overall rigidity of the electric spindle can be improved, and the second front bearing group can properly share the cutting force and the like which are completely born by the first front bearing group during processing, so that the overall rigidity of a product is improved.
3. The application can solve the problems of the prior positioning pre-tightening mode that the length size is increased due to the heating of the lower shafting part, the pre-tightening force is increased, the temperature rise of the bearing is too high, the service life is reduced and the like, and the problems of vibration, precision reduction and the like of the electric spindle caused by the combination of the problems.
4. The double-elasticity pre-tightening structure is adopted in the application, so that the problems of service life and precision reduction of the electric spindle caused by too high temperature rise due to too high pre-tightening force of the rear bearing set in the traditional pre-tightening method can be solved.
Drawings
Fig. 1 is a schematic perspective view of an electric spindle according to the present application.
Fig. 2 is a schematic perspective view of an electric spindle according to the present application.
Fig. 3 is a schematic cross-sectional view of the motorized spindle of the present application.
Fig. 4 is a partially enlarged structural schematic diagram at a in fig. 3.
Fig. 5 is a partially enlarged structural schematic diagram at B in fig. 3.
In the figure, 1, a shell; 1a, a stator; 1b, an abutment projection; 2. a mandrel; 2a, a rotor; 3. a front bearing chamber; 31. an annular boss; 32. a first bearing cavity; 33. a second bearing cavity; 34. abutting against the boss; 4. a rear bearing chamber; 41. a first abutment flange; 42. a second abutment flange; 5. a first front bearing set; 6. a rear bearing set; 7. a second front bearing set; 8. a front elastic pre-tightening structure; 81. a sliding seat; 81a, annular flanges; 81b, blind holes; 82. a first elastic member; 9. a rear elastic pre-tightening structure; 91. a bushing; 91a, mounting holes; 91b, a baffle; 92. a second elastic member; 93. a roller sleeve; 10. a front bearing gland; 11. a front end cover; 12. a rear bearing gland; 13. and a rear end cover.
Detailed Description
The present application will be described in further detail with reference to fig. 1 to 5.
Referring to fig. 1 and 2, the electric spindle includes a housing 1 and a spindle 2 rotatably inserted in the housing 1.
Referring to fig. 3, a stator 1a is fixed in a casing 1, and a rotor 2a corresponding to the stator 1a is fixed on the outer circumferential surface of a spindle 2; the front bearing chamber 3 and the rear bearing chamber 4 are respectively fixed at two ends of the casing 1.
Referring to fig. 4 and 5, a first front bearing set 5 sleeved at the front end of the mandrel 2 is arranged in the front bearing chamber 3, and a rear bearing set 6 sleeved at the rear end of the mandrel 2 is arranged in the rear bearing chamber 4; the front bearing chamber 3 is also internally provided with a second front bearing group 7 which is sleeved on the mandrel 2 and is positioned between the first front bearing group 5 and the rear bearing group 6; a front elastic pre-tightening structure 8 is arranged between the second front bearing group 7 and the front bearing chamber 3; a rear elastic pre-tightening structure 9 is arranged between the rear bearing group 6 and the rear bearing chamber 4.
In the present application, the front bearing chamber 3 is annular, referring to fig. 4, the inner wall of the front bearing chamber 3 has an annular boss 31, and the annular boss 31 divides the interior of the front bearing chamber 3 into a first bearing chamber 32 for mounting the first front bearing group 5 and a second bearing chamber 33 for mounting the second front bearing group 7; a front bearing gland 10 is fixedly arranged at one end of the front bearing chamber 3, which is close to the stator 1 a; the other end of the front bearing chamber 3 is fixedly provided with a front end cover 11; the first front bearing group 5 and the second front bearing group 7 are arranged at intervals in the front bearing chamber 3, and the second front bearing group 7 shares part of the cutting force borne by the first front bearing group 5, so that the force can be dispersed conveniently. Through setting up front end housing 11 and preceding bearing gland 10, can carry out the axial spacing to first preceding bearing group 5 and the preceding bearing group 7 of second, the installation and the axial fixity of bearing group 7 before first preceding bearing group 5 and the second of being convenient for are used for sealing preceding bearing room 3 simultaneously, prevent that the foreign matter from getting into preceding bearing room 3 and damaging the bearing. The first front bearing group 5 comprises at least two angular contact ball bearings arranged side by side in the first bearing cavity 32; the outer rings of the two angular contact ball bearings at the two outermost sides in the first front bearing group 5 are respectively abutted against the annular boss 31 and the front end cover 11. The plurality of angular contact ball bearings play a role in stable support, and are sequentially sleeved on the mandrel 2 when being installed, the innermost angular contact ball bearing is abutted against the side surface of the annular boss 31 in the front bearing chamber 3, and after the last angular contact ball bearing is sleeved, the front end cover 11 is fixedly installed on the end surface of the front bearing chamber 3 through screws, so that the front bearing chamber 3 is sealed, and the first front bearing group 5 is axially limited; the distance between the front end cover 11 and the annular boss 31 is equal to the sum of the widths of the plurality of angular contact ball bearings mounted. The first front bearing set 5 in the present application is preferably two angular contact ball bearings arranged side by side.
Referring to fig. 4, the front elastic pre-tightening structure 8 includes a sliding seat 81 and a first elastic member 82, the sliding seat 81 is sleeved on the second front bearing set 7, the outer peripheral surface of the sliding seat 81 is in clearance fit with the cavity wall of the second bearing cavity 33, and two ends of the first elastic member 82 act on the end surface of the sliding seat 81 and the annular boss 31 respectively; the inner wall of one end of the sliding seat 81 facing the annular boss 31 is provided with an annular blocking edge 81a, and the other end of the sliding seat 81 is abutted against the front bearing gland 10; the second front bearing set 7 comprises at least two angular contact ball bearings arranged side by side in a second bearing cavity 33; the outer rings of the two angular contact ball bearings at the two outermost sides in the second front bearing group 7 are respectively abutted against the annular blocking edge 81a and the front bearing gland 10. Further, a blind hole 81b is formed in one end of the sliding seat 81 facing the annular boss 31, the first elastic member 82 is a coil spring, one end of the first elastic member 82 is embedded in the blind hole 81b, and the other end abuts against the annular boss 31. In the application, the front bearing chamber 3, the sliding seat 81, the first elastic piece 82 and the front bearing gland 10 form a front elastic pre-tightening structure 8, the sliding seat 81 can axially move in the second bearing cavity 33 of the front bearing chamber 3, and the pre-tightening force is provided for the second front bearing group 7 and the whole mandrel 2 through the elastic force of the first elastic piece 82.
Referring to fig. 4, the outer peripheral surface of the front bearing chamber 3 has an annular abutment boss 34, the inner wall of the casing 1 near the end has an annular abutment boss 1b, one end of the casing 1 is sleeved at one end of the front bearing chamber 3 and the end surface of the casing 1 abuts against the abutment boss 34, and the end surface of the front bearing chamber 3 abuts against the abutment boss 1 b. The front bearing chamber 3 is fixedly connected with the end part of the casing 1 through screws, namely a plurality of screws are circumferentially distributed on the abutting boss 34, and can be screwed on the end surface of the casing 1, so that the axial installation positions of the front bearing chamber 3 and the casing 1 can be rapidly positioned, the assembly and the fixation of the front bearing chamber 3 and the casing 1 are facilitated, and the axial positions of the front bearing chamber 3 and the casing 1 are ensured to be stable and reliable through the axial limiting of the front bearing chamber 3 and the casing 1.
Referring to fig. 5, the rear bearing chamber 4 is annular, the outer peripheral surface of the rear bearing chamber 4 has an annular first abutment flange 41, the end of the casing 1 is sleeved at one end of the rear bearing chamber 4, and the end surface of the casing 1 abuts against the first abutment flange 41; the rear bearing chamber 4 has an annular second abutment flange 42 on the inner wall of the end facing the stator 1 a; the other end of the rear bearing chamber 4 is respectively provided with a rear bearing gland 12 and a rear end cover 13, the rear bearing gland 12 and the rear end cover 13 are circular plate pieces, and the outer diameter of the rear bearing gland 12 is smaller than the inner diameter of the rear end cover 13; the rear bearing set 6 and the rear resilient pretensioning structure 9 are both arranged between the second abutment flange 42 and the rear bearing gland 12. The rear bearing chamber 4 and the rear end cover 13 are fixedly connected with the other end of the casing 1 through screws, namely a plurality of first through holes are circumferentially distributed on the first abutting flange 41, second through holes corresponding to the first through holes one by one are also formed in the rear end cover 13, the screws sequentially penetrate through the first through holes and the second through holes and then are connected to the end face of the casing 1 in a screwed mode, and therefore the axial installation positions of the rear bearing chamber 4 and the casing 1 can be rapidly located, assembly and fixation of the rear bearing chamber 4 and the casing 1 are facilitated, and stable and reliable axial positions of the rear bearing chamber 4 and the casing 1 are guaranteed through axial limiting of the rear bearing chamber 4 and the casing 1.
Referring to fig. 5, the rear elastic pre-tightening structure 9 includes a bushing 91 and a second elastic member 92, the bushing 91 is sleeved on the rear bearing group 6, the rear bearing gland 12 is fixedly connected with the bushing 91, and a roller 93 is sleeved outside the bushing 91; one end of the bushing 91 abuts against the rear bearing cover 12; the second elastic member 92 has both ends acting on the second abutment flange 42 and the other end of the bushing 91, respectively. The rear bearing chamber 4, the bushing 91, the roller sleeve 93 and the second elastic piece 92 form a rear elastic pre-tightening structure 9, the rear elastic pre-tightening structure 9 is matched with the front elastic pre-tightening structure 8 to jointly act, pre-tightening is jointly applied to the electric spindle shaft system through the front elastic pre-tightening structure and the rear elastic pre-tightening structure, and service life and reliability of each group of bearings are improved under the condition that the pre-tightening force required by each bearing is met. In the application, the roller rollers 93 are sleeved on the bushing 91, the roller rollers 93 are positioned between the rear bearing chamber 4 and the bushing 91, and the bushing 91 can axially slide in the rear bearing chamber 4 through the roller rollers 93, so that the effects of high precision, high load, wear resistance and low noise during the axial movement of the bushing 91 are realized.
Further, a mounting hole 91a is formed in one end of the bushing 91 facing the second abutment flange 42, the second elastic member 92 is a coil spring, one end of the second elastic member 92 is embedded in the mounting hole 91a, and the other end abuts against the second abutment flange 42. The coil spring is partially embedded in the mounting hole 91a of the bushing 91, thus facilitating the mounting and not easily falling off, thereby stably and reliably providing the pretightening force.
Referring to fig. 5, the bushing 91 has an annular stop 91b on the inner wall of one end facing the second abutment flange 42, the rear bearing set 6 comprising at least two angular contact ball bearings arranged side by side; the outer rings of the two angular contact ball bearings on the two outermost sides in the rear bearing group 6 are abutted against the stopper 91b and the rear bearing cover 12, respectively. The rear bearing cover 12 is connected with the bushing 91 through screws, the rear bearing group 6 is positioned in the bushing 91, and the rear bearing chamber 4 is fixed on the casing 1 through screws. The elastic force of the second elastic member 92 directly acts on the rear bearing set 6 through the bushing 91, which is equivalent to force transmission by only one intermediate member, so that excessive intermediate member transmission forceful loss or transmission error in the prior art is avoided. At the same time, the bushing 91 is also matched with the roller rollers 93 to axially slide in the rear bearing chamber 4, and when the length dimension changes due to the heating of the shafting part, the bushing 91 together with the rear bearing group 6 and the rear bearing gland 12 moves the whole body to the rear end relative to the rear bearing chamber 4.
The implementation principle is as follows: in the prior art, only the first front bearing set 5 and the rear bearing set 6 in the application are usually provided, the second front bearing set 7 and the corresponding assembly structure are not provided, the assembly structure only comprises a group of pre-tightening structures, namely a rear elastic pre-tightening structure 9, the second front bearing set 7 is added, elastic pre-tightening structures are respectively arranged at the positions of the second front bearing set 7 and the rear bearing set 6, namely a front elastic pre-tightening structure 8 and a rear elastic pre-tightening structure 9, so that a double elastic pre-tightening structure is formed, the pre-tightening force applied to the rear bearing set 6 is shared by the existing second front bearing set 7 and rear bearing set 6, and the corresponding force applied to each bearing set is reduced. The double-elasticity pre-tightening structure is arranged, so that the problems of service life and precision reduction of the motorized spindle caused by overhigh temperature rise due to overlarge pre-tightening force of the bearing group 6 after the motorized spindle is arranged in the traditional bearing pre-tightening mode are solved; meanwhile, the problems that the length of the traditional positioning pre-tightening mode lower shafting part is increased due to heating, the pre-tightening force is increased, the temperature rise of the bearing is too high, the service life is shortened and the like, and the electric spindle vibration, the precision reduction and the like caused by the conventional positioning pre-tightening mode lower shafting part are solved.
According to the application, through the arrangement structure of the front, middle and rear three groups of bearings, the overall rigidity of the electric spindle can be improved, and the second front bearing group 7 can properly share the cutting force and the like which are completely born by the first front bearing group 5 during processing, so that the overall rigidity of a product is improved.
The embodiments of the present application are all preferred embodiments of the present application, and are not intended to limit the scope of the present application, wherein like reference numerals are used to refer to like elements throughout. Therefore: all equivalent changes in structure, shape and principle of the application should be covered in the scope of protection of the application.
Claims (7)
1. An electric spindle comprises a machine shell (1) and a spindle (2) rotatably inserted in the machine shell (1), wherein a stator (1 a) is fixedly arranged in the machine shell (1), and a rotor (2 a) corresponding to the stator (1 a) is fixedly arranged on the outer peripheral surface of the spindle (2); it is characterized in that the method comprises the steps of,
a front bearing chamber (3) and a rear bearing chamber (4) are respectively and fixedly arranged at two ends of the shell (1); a first front bearing group (5) sleeved at the front end of the mandrel (2) is arranged in the front bearing chamber (3), and a rear bearing group (6) sleeved at the rear end of the mandrel (2) is arranged in the rear bearing chamber (4);
a second front bearing group (7) sleeved on the mandrel (2) and positioned between the first front bearing group (5) and the rear bearing group (6) is also arranged in the front bearing chamber (3);
a front elastic pre-tightening structure (8) is arranged between the second front bearing group (7) and the front bearing chamber (3); a rear elastic pre-tightening structure (9) is arranged between the rear bearing group (6) and the rear bearing chamber (4);
the front bearing chamber (3) is annular, an annular boss (31) is arranged on the inner wall of the front bearing chamber (3), and the annular boss (31) divides the interior of the front bearing chamber (3) into a first bearing cavity (32) for mounting the first front bearing group (5) and a second bearing cavity (33) for mounting the second front bearing group (7); a front bearing gland (10) is fixedly arranged at one end of the front bearing chamber (3) close to the stator (1 a); a front end cover (11) is fixedly arranged at the other end of the front bearing chamber (3);
the first front bearing group (5) comprises at least two angular contact ball bearings which are arranged side by side in a first bearing cavity (32); the outer rings of the two angular contact ball bearings at the two outermost sides in the first front bearing group (5) are respectively abutted against the annular boss (31) and the front end cover (11);
the front elastic pre-tightening structure (8) comprises a sliding seat (81) and a first elastic piece (82), the sliding seat (81) is sleeved on the second front bearing group (7), the outer peripheral surface of the sliding seat (81) is in clearance fit with the cavity wall of the second bearing cavity (33), and two ends of the first elastic piece (82) respectively act on the end surface of the sliding seat (81) and the annular boss (31); an annular blocking edge (81 a) is arranged on the inner wall of one end, facing the annular boss (31), of the sliding seat (81), and the other end of the sliding seat (81) is abutted against the front bearing gland (10);
the second front bearing group (7) comprises at least two angular contact ball bearings arranged side by side in the second bearing cavity (33); the outer rings of the two angular contact ball bearings at the two outermost sides in the second front bearing group (7) are respectively abutted against the annular blocking edge (81 a) and the front bearing gland (10).
2. Motorized spindle according to claim 1, characterized in that the sliding seat (81) has a blind hole (81 b) open towards one end of the annular boss (31), the first elastic element (82) is a coil spring, one end of the first elastic element (82) is embedded in the blind hole (81 b), and the other end abuts against the annular boss (31).
3. Motorized spindle according to claim 1 or 2, characterized in that the front bearing chamber (3) has an annular abutment boss (34) on its outer peripheral surface, the inner wall of the housing (1) near the end has an annular abutment projection (1 b), one end of the housing (1) is sleeved at one end of the front bearing chamber (3) and the end face of the housing (1) abuts against the abutment boss (34), and the end face of the front bearing chamber (3) abuts against the abutment projection (1 b).
4. Motorized spindle according to claim 1 or 2, characterized in that the rear bearing chamber (4) is annular, the outer peripheral surface of the rear bearing chamber (4) being provided with a first abutment flange (41) of annular shape, the end of the casing (1) being sleeved on one end of the rear bearing chamber (4) and the end face of the casing (1) being abutted against the first abutment flange (41);
an annular second abutment flange (42) is provided on the inner wall of the end of the rear bearing chamber (4) facing the stator (1 a); the other end of the rear bearing chamber (4) is provided with a rear bearing gland (12); the rear bearing set (6) and the rear elastic pretensioning structure (9) are both arranged between the second abutment flange (42) and the rear bearing gland (12).
5. The motorized spindle as defined in claim 4, wherein the rear elastic pre-tightening structure (9) comprises a bushing (91) and a second elastic member (92), the bushing (91) is sleeved on the rear bearing group (6), the rear bearing gland (12) is fixedly connected with the bushing (91), and a roller sleeve (93) is sleeved outside the bushing (91); one end of the bushing (91) is abutted against the rear bearing gland (12); both ends of the second elastic member (92) act on the other ends of the second abutment flange (42) and the bushing (91), respectively.
6. The motorized spindle according to claim 5, characterized in that the bushing (91) has a mounting hole (91 a) formed at an end facing the second abutment flange (42), the second elastic member (92) is a coil spring, and one end of the second elastic member (92) is embedded in the mounting hole (91 a), and the other end abuts against the second abutment flange (42).
7. Motorized spindle according to claim 5, characterised in that the bushing (91) has an annular abutment (91 b) on the inner wall of the end facing the second abutment flange (42), the rear bearing set (6) comprising at least two angular contact ball bearings arranged side by side; the outer rings of the two angular contact ball bearings at the two outermost sides of the rear bearing group (6) are respectively abutted against the baffle table (91 b) and the rear bearing gland (12).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210985610.6A CN115194498B (en) | 2022-08-17 | 2022-08-17 | Electric spindle |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210985610.6A CN115194498B (en) | 2022-08-17 | 2022-08-17 | Electric spindle |
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| CN115194498A CN115194498A (en) | 2022-10-18 |
| CN115194498B true CN115194498B (en) | 2023-08-11 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN202210985610.6A Active CN115194498B (en) | 2022-08-17 | 2022-08-17 | Electric spindle |
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| WO2022083575A1 (en) * | 2020-10-22 | 2022-04-28 | 北京工业大学 | Withdrawable electric spindle for friction stir welding |
| CN114453602A (en) * | 2022-02-12 | 2022-05-10 | 深圳市爱贝科精密工业股份有限公司 | Main shaft of horizontal milling machine |
| CN216881747U (en) * | 2022-06-06 | 2022-07-05 | 泉州鲤城区铭宏机械有限公司 | High-rigidity lathe spindle |
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|---|---|---|---|---|
| CN104174879A (en) * | 2014-08-08 | 2014-12-03 | 无锡机床股份有限公司 | High-power high-rigidity electric spindle |
| CN105458306A (en) * | 2015-12-31 | 2016-04-06 | 西安交通大学 | High-speed electric main shaft device where ultra-precise angular contact ball and cylindrical roller bearings are used |
| CN208908395U (en) * | 2018-10-26 | 2019-05-28 | 中山大洋电机股份有限公司 | A kind of external rotor electric machine |
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|---|---|
| CN115194498A (en) | 2022-10-18 |
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