CN212163047U - Main shaft and direct drive motor with same - Google Patents

Abstract

The utility model relates to a main shaft and have motor that directly drives of this main shaft, the main shaft includes: pivot, bearing subassembly and preceding gland. The bearing assembly is provided with an inner ring, a supporting body and an outer ring, the inner ring and the outer ring can rotate relatively, the bearing assembly is fixedly connected with one side of the rotating shaft through the inner ring, a hole is formed in the center of the front gland, the bearing assembly is arranged in the hole and fixedly connected with the front gland through the outer ring, and the central axes of the rotating shaft and the bearing assembly are overlapped. After the current gland is fixed in the hollow fixture, in the operation process, when the temperature of a part rises, the rotating shaft is perpendicular to the central axis direction of the rotating shaft, the central axis is used as the center, the change of the rotating shaft in any direction has isotropy, the direction of the rotating shaft which is far away from the fixed surface in the central axis direction changes, the connecting position of the front end surface of the rotating shaft and the inner ring of the bearing assembly is kept unchanged, the rotating shaft and the inner ring of the bearing assembly have high thermal stability, and when the spindle is applied to a direct drive motor, the direct drive motor has the same.

Description

Main shaft and direct drive motor with same

Technical Field

The utility model relates to the field of machinary, especially, relate to a main shaft and have motor that directly drives of this main shaft.

Background

With the improvement of the requirement of people on the machining precision of machine parts, a spindle of a machine tool must keep the stability of the position of an axis under the condition of long-time operation, but when the spindle of the machine tool operates, the temperature of the spindle and parts around the spindle rises under the influence of the rotation of a bearing and the heat generated by a direct drive motor, and the temperature rise of the parts can cause the position of the axis to change due to the physical effect of thermal expansion and cold contraction, so that the dimension of the machined parts generates errors. At present, three main schemes are provided for solving the problem, namely, a fan is arranged outside a main shaft, and forced heat dissipation is achieved through blowing. And secondly, a cooling water channel is arranged around the main shaft, and the heat of the main shaft is taken away through the flowing of liquid. Thirdly, thermal deformation compensation is carried out through system detection by a sensor. However, these methods can only partially reduce the influence of heat on the deformation of the spindle, and the position of the spindle axis is still changed after being heated, so that the problem cannot be completely solved.

SUMMERY OF THE UTILITY MODEL

In view of this, it is necessary to provide a spindle having high thermal stability and a direct drive motor having the same.

A spindle, comprising:

the rotating shaft main body is cylindrical;

the bearing assembly is sequentially provided with an inner ring, a support body and an outer ring from inside to outside, the inner ring and the outer ring can rotate relatively, and the bearing assembly is fixedly connected with one side of the rotating shaft through the inner ring;

the center of the front gland is provided with a through hole, the bearing assembly is arranged in the through hole, and the front gland is fixedly connected with the outer ring;

the central axes of the bearing assembly and the rotating shaft are coincident.

In one embodiment, the width of the inner ring in the direction parallel to the central axis of the bearing assembly is greater than that of the outer ring, an annular step is formed between the inner ring and the outer ring, an annular step is arranged on the side wall of the through hole, and the annular step is matched with the annular step and is fixedly connected with the front gland through a screw.

The inner ring of the bearing assembly of the spindle is fixedly connected with the rotating shaft. The bearing assembly outer ring is fixedly connected with the front gland, the front gland is fixedly connected with a hollow fixture through a connecting hole arranged at the edge, and the central axes of the rotating shaft and the bearing assembly are overlapped. At the moment, the bearing assembly inner ring and the rotating shaft form a first whole, and the first whole is in a suspended state and can rotate along with the bearing assembly inner ring. The bearing assembly outer ring, the front gland and the hollow fixture form a second whole, and the second whole keeps a static state along with the hollow fixture. When the temperature of the parts is increased due to the overlong operation time in the rotating process of the first whole, although the volume of each part is changed due to the physical effect of expansion with heat and contraction with cold, the volume change of each part in any direction on a plane perpendicular to the central axis of the rotating shaft is isotropic around the axis, and therefore the axis height of the rotating shaft is kept unchanged. Since the bearing assembly outer race is fixed to the second body, the dimension of the first body in the longitudinal direction can be changed only to the side away from the bearing assembly. Therefore, the connecting position of the front end faces of the rotating shaft and the bearing assembly inner ring can be kept unchanged, so that the bearing assembly inner ring has high thermal stability, and further, the error caused by the change of the spindle axis due to the temperature change of the spindle in the machining process of a workpiece is avoided.

A direct drive motor, comprising:

the rotating shaft main body is cylindrical;

the bearing assembly is sequentially provided with an inner ring, a support body and an outer ring from inside to outside, the inner ring and the outer ring can rotate relatively, and the bearing assembly is fixedly connected with one side of the rotating shaft through the inner ring;

the center of the front gland is provided with a through hole, the bearing assembly is arranged in the through hole, and the front gland is fixedly connected with the outer ring of the bearing assembly;

the central axes of the bearing assembly and the rotating shaft are coincident.

Further comprising:

the spindle sleeve is arranged in a hollow mode, the rotating shaft is arranged in the spindle sleeve, and the front gland is fixedly connected with the spindle sleeve;

the direct drive motor stator is fixedly arranged on the inner side of the spindle sleeve;

a direct drive motor rotor fixedly arranged outside the rotating shaft,

an air gap is reserved between the direct drive motor rotor and the direct drive motor stator;

the supporting blocks comprise a first supporting block and a second supporting block, the first supporting block is fixedly connected with one side of the spindle sleeve, and the second supporting block is fixedly connected with the other side of the spindle sleeve.

In one embodiment, the spindle sleeve is provided with a positioning step, one end of the direct-drive motor stator is fixed to the positioning step, the other end of the direct-drive motor stator is fixedly connected with the front gland, the rotating shaft is provided with the positioning step, one end of the direct-drive motor rotor is fixedly arranged on the positioning step, and the other end of the direct-drive motor rotor is fixed to the rotating shaft through a nut.

In one embodiment, the bearing assembly further comprises a rotating shaft member, wherein the rotating shaft member is arranged on one side, away from the rotating shaft, of the bearing assembly and is fixedly connected with the bearing assembly through the inner ring.

In one embodiment, a gap is formed between the rotating shaft member and the front gland, and compressed air is introduced into the gap.

In one embodiment, the support block is integrally formed with the spindle sleeve.

In one embodiment, a first connecting block and a second connecting block are arranged outside the spindle sleeve, a central connecting line of the first connecting block and the second connecting block is perpendicular to and coplanar with a central axis of the spindle sleeve, the plane is a horizontal plane, the supporting block is provided with a first supporting block and a second supporting block, the first connecting block is fixedly connected with the first supporting block, and the second connecting block is fixedly connected with the second supporting block.

In one embodiment, the first connecting block and the second connecting block are integrally formed with the spindle sleeve.

In one embodiment, the supporting blocks are provided with grooves, the first supporting block and the second supporting block are respectively arranged on two sides of the groove, the width of the groove is larger than the diameter of the spindle sleeve, and the distance from the central axis of the first connecting block to the bottom of the groove is larger than the radius of the spindle sleeve.

According to the direct drive motor with the spindle, the inner ring of the bearing assembly is fixedly connected with the rotating shaft, and the rotor of the direct drive motor is fixedly connected with the rotating shaft. The bearing assembly outer ring is fixedly connected with the front gland, the front gland is fixedly connected with the hollow spindle sleeve through a connecting hole formed in the edge, the direct-drive motor stator is fixedly arranged on the inner side of the spindle sleeve, and the central axes of the rotating shaft and the bearing assembly are overlapped. At the moment, the bearing assembly inner ring, the rotating shaft and the direct drive motor rotor form a first whole body, and the first whole body can rotate along with the main shaft assembly inner ring. The bearing assembly outer ring, the front gland, the hollow spindle sleeve and the direct drive motor stator form a second whole, and the second whole keeps a static state along with the hollow spindle sleeve. When the first integral direct-drive motor rotor is connected with direct current, a coil in the direct-drive motor rotor is driven by Lorentz force to start rotating. When the temperature of the parts of the direct drive motor is increased due to overlong operation time, although the volume of each part is changed due to the physical effect of expansion with heat and contraction with cold, the volume change of each part in any direction on a plane perpendicular to the central axis of the rotating shaft is isotropic with the axis as the center, and therefore, the height of the axis of the rotating shaft is kept unchanged. Since the bearing assembly outer race is fixed to the second body, the dimension of the first body in the longitudinal direction can be changed only to the side away from the bearing assembly. Therefore, the connecting position of the front end faces of the rotating shaft and the bearing assembly inner ring can be kept unchanged, so that the bearing assembly inner ring has high thermal stability, and further, the error caused by the change of the spindle axis due to the temperature change of the spindle in the machining process of a workpiece is avoided.

Drawings

FIG. 1 is a schematic structural diagram of a spindle according to an embodiment;

FIG. 2 is a schematic longitudinal sectional view of a direct drive motor with the spindle according to an embodiment;

FIG. 3 is a schematic longitudinal sectional view of a direct drive motor with the spindle according to another embodiment;

FIG. 4 is a schematic cross-sectional view of the direct drive motor with the spindle shown in FIG. 3;

FIG. 5 is a schematic cross-sectional view of a direct drive motor having the spindle according to another embodiment;

FIG. 6 is a schematic cross-sectional view of a direct drive motor having the spindle according to another embodiment;

FIG. 7 is a schematic cross-sectional view of a direct drive motor having the spindle according to another embodiment;

fig. 8 is a schematic transverse sectional structure view of a direct drive motor with the spindle according to another embodiment.

Detailed Description

In order to make the above objects, features and advantages of the present invention more comprehensible, embodiments of the present invention are described in detail below with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein, as those skilled in the art will be able to make similar modifications without departing from the spirit and scope of the present invention.

It will be understood that when an element is referred to as being "secured to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" or "in communication with" another element, it can be directly connected to the other element or intervening elements may also be present. The terms "upper", "lower", "vertical", "horizontal", "left", "right" and the like as used herein are for illustrative purposes only and do not denote a unique embodiment.

Referring to fig. 1, a spindle 100 according to an embodiment includes a bearing assembly 12, a rotating shaft 15, and a front gland 13.

The bearing assembly 12 is sequentially provided with an inner ring 12-1, a support body 12-3 and an outer ring 12-2 from inside to outside, the support body 12-3 is arranged between the inner ring 12-1 and the outer ring 12-2, so that the inner ring 12-1 and the outer ring 12-2 are in a relatively independent state and can rotate relatively, the bearing assembly inner ring 12-1 is fixedly connected with the rotating shaft 15, the central lines of the rotating shaft 15 and the bearing assembly 12 are superposed, and the bearing assembly inner ring 12-1 and the rotating shaft 15 form a first whole. The bearing assembly outer ring 12-2 is fixedly connected with the front gland 13, the front gland 13 is fixedly connected with a hollow fixture, and the bearing assembly outer ring 12-2, the front gland 13 and the hollow fixture form a second whole. The first integral can rotate along with the inner ring 12-1, and the second integral is fixed by a fixed object and keeps a static state.

Specifically, the support body 12-3 may be any one of a rolling body, a fluid, or a grease, and the bearing assembly 12 may be any one of a rolling bearing, a sliding bearing, and a hydrostatic bearing.

Further, the width of the bearing assembly inner ring 12-1 in a direction parallel to the central axis of the bearing assembly 12 is larger than the width of the bearing assembly outer ring 12-2, and an annular step is formed between the inner ring 12-1 and the outer ring 12-2.

The rotating shaft 15 is cylindrical in appearance, one end face of the rotating shaft 15 is fixedly connected with the inner ring 12-1, and the central axis of the rotating shaft 15 coincides with that of the bearing assembly 12. The bearing assembly inner race 12-1 forms a first integral body with the shaft 15, which is free to rotate with the bearing assembly inner race 12-1.

In the embodiment, the bearing assembly inner ring 12-1 is fixedly connected with the rotating shaft 15 through screws,

the center of the front gland 13 is provided with a round hole, the edge of the front gland 13 is provided with a connecting hole 13-1, the bearing assembly 12 is arranged in the round hole and is fixedly connected with the front gland 13 through the outer ring 12-2, the front gland 13 is fixedly connected with a hollow fixture through the connecting hole 13-1, so that the outer ring 12-2 of the bearing assembly, the front gland 13 and the hollow fixture form a second whole, and the second whole keeps a static state along with the hollow fixture.

Specifically, the bearing assembly outer ring 12-2 is screwed to the front gland 13.

In this embodiment, the front gland 13 is provided with an annular step therein which is matched with the annular step between the inner ring 12-1 and the outer ring 12-2 of the bearing assembly, so that the positioning connection can be easily achieved.

The main shaft and the bearing assembly inner ring 12-1 are fixedly connected with the rotating shaft 15. The bearing assembly outer ring 12-2 is fixedly connected with the front gland 13, the front gland 13 is fixedly connected with a hollow fixture through a connecting hole 13-1 arranged on the edge, and the central axes of the rotating shaft 15 and the bearing assembly 12 are overlapped. At this time, the bearing assembly inner ring 12-1 and the rotating shaft 15 form a first whole body, and the first whole body is in a suspended state and can rotate along with the bearing assembly inner ring 12-1. The bearing assembly outer ring 12-2, the front gland 13 and the hollow stationary object form a second whole which is kept in a stationary state with the hollow stationary object. When the temperature of the parts is increased due to the long operation time in the rotation process of the first body, although the volume of each part is changed due to the physical effect of expansion with heat and contraction with cold, the volume change of each part in any direction on the plane perpendicular to the central axis of the rotating shaft 15 is isotropic with the axis as the center, so the axis height of the rotating shaft 15 is kept unchanged. Since the bearing assembly outer ring 12-2 is fixed to the second body, the dimension of the first body in the longitudinal direction can be changed only to the side away from the bearing assembly 12. Therefore, the connection position of the front end face of the rotating shaft 15 and the bearing assembly inner ring 12-1 can be kept unchanged, so that the bearing assembly inner ring has high thermal stability, and further, the error caused by the change of the spindle axis due to the temperature change of the spindle in the machining process of a workpiece is avoided.

Referring to fig. 2, an embodiment of a direct drive motor 200 having the spindle includes a bearing assembly 12, a rotating shaft 15, a direct drive motor rotor 14-2, a front gland 13, a spindle sleeve 16, and a direct drive motor stator 14-1.

The bearing assembly 12 is sequentially provided with an inner ring 12-1, a support body 12-3 and an outer ring 12-2 from inside to outside, the inner ring 2-1 and the outer ring 12-2 can rotate relatively, the bearing assembly inner ring 12-1 is fixedly connected with a rotating shaft 15, the central lines of the rotating shaft 15 and the bearing assembly 12 are superposed, the rotating shaft 15 is provided with a direct-drive motor rotor 14-2, and the bearing assembly inner ring 12-1, the rotating shaft 15 and the direct-drive motor rotor 14-2 form a first whole. The bearing assembly outer ring 12-2 is fixedly connected with the front gland 13, the front gland 13 is fixedly connected with the hollow spindle sleeve 16, the direct drive motor stator 14-1 is fixedly arranged in the spindle sleeve 16, and an air gap is reserved between the direct drive motor stator 14-1 and the direct drive motor rotor 14-2. The bearing assembly outer ring 12-2, the front gland 13, the hollow spindle sleeve 16 and the direct drive motor stator 14-1 form a second whole. The first unit is free to rotate with the inner ring 12-1 and the second unit is held stationary by the spindle sleeve 16.

Specifically, the bearing assembly 12 may be any one of a rolling bearing, a sliding bearing, and a hydrostatic bearing.

Further, the width of the bearing assembly inner ring 12-1 in a direction parallel to the central axis of the bearing assembly 12 is larger than the width of the outer ring 12-2, and an annular step is formed between the inner ring 12-1 and the outer ring 12-2.

Furthermore, the outer ring 12-2 is arranged in the center, and an annular step is formed between the inner ring 12-1 and the outer ring 12-2 in bilateral symmetry.

In this embodiment, the bearing assembly inner ring 12-1 is provided with a plurality of coupling holes through which it is fixedly coupled to the rotating shaft 15.

The main body of the rotating shaft 15 is cylindrical in appearance, one end face of the rotating shaft 15 is fixedly connected with the inner ring 12-1, a direct drive motor rotor 14-2 is fixedly arranged on the rotating shaft 15, and the center line of the rotating shaft 15 is overlapped with the center line of the bearing assembly 12. The bearing assembly inner ring 12-1, the rotating shaft 15 and the direct drive motor rotor 14-2 form a first whole body which can freely rotate along with the bearing assembly inner ring 12-1. The shaft 15 is disposed in the spindle sleeve 16. An air gap is reserved between the direct drive motor rotor 14-2 and the direct drive motor stator 14-1.

Specifically, a circular base is arranged at one end of the rotating shaft 15 close to the bearing assembly 12, the diameter of the base is larger than that of the main body of the rotating shaft 15, and the base of the rotating shaft 15 is fixedly connected with the bearing assembly inner ring 12-1.

In this embodiment, the base of the rotating shaft 15 is provided with a plurality of connecting holes corresponding to the bearing assembly inner ring 12-1, and the two are connected by the connecting holes through screws.

The direct-drive motor rotor 14-2 is internally provided with a direct-drive rotor winding which is fixed on the rotating shaft 15, and after the direct-drive rotor winding is connected with direct current, the conducting wire can generate torque in the magnetic field of the direct-drive motor stator 14-1 through the action of Lorentz force, so that the rotating shaft 15 is driven to rotate.

Specifically, a positioning step is arranged on the spindle sleeve 16, one end of the direct drive motor rotor 14-2 is fixedly arranged in the positioning step, and the other end is fixedly connected through a nut 17.

Further, the nut 17 is a precision nut.

The center of the front gland 13 is provided with a round hole, the edge of the front gland 13 is provided with a connecting hole 13-1, the bearing assembly 12 is arranged in the round hole and is fixedly connected with the front gland 13 through an outer ring 12-2, the front gland 13 is fixedly connected with a hollow fixture through the connecting hole 13-1, and the direct-drive motor stator 14-1 is fixedly arranged at the inner side of the spindle sleeve 16, so that the bearing assembly outer ring 12-2, the front gland 13, the direct-drive motor stator 14-1 and the hollow spindle sleeve 16 form a second whole body which keeps a static state along with the spindle sleeve 16.

Specifically, an annular step is arranged in the front gland 13, the annular step is matched with the annular step of the bearing assembly 12 in shape, a connecting hole corresponding to the bearing assembly outer ring 12-2 is formed in the annular step of the front gland 13, and a screw is arranged in the connecting hole to enable the front gland and the bearing assembly outer ring to be fixedly connected. The front gland 13 is in screw connection with the main shaft sleeve 16 through a connecting hole 13-1.

The main shaft sleeve 16 is arranged in a hollow mode and is arranged on the outer side of the rotating shaft 15, the opening of the main shaft sleeve is fixedly connected with the front gland 13, the bearing assembly outer ring 12-2 is fixedly connected with the front gland 13, the bearing assembly inner ring 12-1 is fixedly connected with the rotating shaft 15, and the direct-drive motor stator 14-1 is fixedly arranged on the inner side of the main shaft sleeve 16. And the center lines of the spindle sleeve 16, the rotating shaft 15 and the bearing assembly 12 are coincident.

In this embodiment, the spindle sleeve 16 has a circular transverse cross-section.

The direct drive motor stator 14-1 is used for generating a magnetic field and providing conditions for generating torque for the energized direct drive motor rotor 14-2, and the optional direct drive motor stator 14-1 comprises a permanent magnet or an electromagnet. An air gap is reserved between the direct drive motor stator 14-1 and the direct drive motor rotor 14-2.

Specifically, a positioning step is arranged on the spindle sleeve 16, one end of the direct drive motor stator 14-1 is fixed on the positioning step, and the other end is clamped and fixed through the front gland 13.

In some embodiments, a rotating shaft member 11 is further provided, and referring to fig. 3, the rotating shaft member 11 is disposed on a side of the bearing assembly 12 away from the rotating shaft 15, and is fixedly connected to the inner ring 12-1 of the bearing assembly 12 for protecting the bearing assembly 12.

Specifically, the rotating shaft member 11 is provided with a connecting hole corresponding to the bearing assembly inner ring 12-1 and the base of the rotating shaft 15, and a screw is arranged in the connecting hole to fix the three into a whole. A gap is formed between the front gland 13 and the rotating shaft piece 11, and friction force between the front gland and the rotating shaft piece is avoided through isolation.

Further, compressed air is provided in the gap between the front gland 13 and the rotating shaft member 11, so that a positive pressure greater than the ambient atmospheric pressure is generated between the bearing assembly outer ring 12-2 and the inner side of the rotating shaft member 11, and an air flow from the inside to the outside is generated in the gap, thereby preventing impurities such as dust in the environment from entering the bearing assembly 11 and maintaining the inside of the bearing assembly 11 in a clean state.

In some embodiments, a connecting block is further provided, referring to fig. 4, a first connecting block 19 and a second connecting block 20 are provided outside the spindle sleeve 16, the first connecting block 19 and the second connecting block 20 are respectively provided at two sides of the spindle sleeve 16, and a central connection line of the first connecting block 19 and the second connecting block 20 is perpendicular to and coplanar with a central axis of the spindle sleeve 16, and a plane where the central connection line is located is a horizontal plane.

Specifically, one end of the first connecting block 19 is fixedly connected to the spindle sleeve 16, the other end is fixedly connected to the first supporting block 21-1 of the supporting block 21, one end of the second connecting block 20 is fixedly connected to the spindle sleeve 16, and the other end is fixedly connected to the second supporting block 21-2 of the supporting block 21.

Referring to fig. 5 and 7, in some embodiments of the connection hole structure, the first connection block 19 and the second connection block 20 are integrally formed with the spindle sleeve 16.

The supporting block 21 is used for supporting the spindle sleeve 16 to enable the main body of the spindle sleeve 16 to be in a suspended state, the supporting block 21 comprises a first supporting block 21-1 and a second supporting block 21-2, the first supporting block 21-1 is fixedly connected with the first connecting block 19, and the second supporting block 21-2 is fixedly connected with the second connecting block 20.

Specifically, the supporting block 21 is selected from any one of invar steel or granite material.

In some embodiments of the supporting block structure, referring to fig. 5, the supporting block 21 is provided with a groove, the width of the groove is greater than the diameter of the spindle sleeve 16 and smaller than the distance between the center points of the first connecting block 19 and the second connecting block 20, the distance from the central axis of the first connecting block 19 and the second connecting block 20 to the bottom of the groove is greater than the radius of the spindle sleeve 16, and the first supporting block 21-1 and the second supporting block 21-2 are respectively disposed at two sides of the groove.

In some embodiments of the support block configuration referring to fig. 6, the first support block 21-1 and the second support block 21-2 are integrally formed with the spindle sleeve 16.

Referring to fig. 7, in some embodiments of the supporting block structure, the first supporting block 21-1 and the second supporting block 21-2 are independently arranged, the cross sections of the first supporting block 21-1 and the second supporting block 21-2 are L-shaped, and the bottoms of the first supporting block 21-1 and the second supporting block 21-2 are fixedly connected with the bearing surface through screws.

Referring to fig. 8, in some embodiments of the supporting block structure, the first supporting block 21-1 and the second supporting block 21-2 are independently provided, and have a wedge-shaped section.

In the direct drive motor with the spindle, the bearing assembly inner ring 12-1 is fixedly connected with the rotating shaft 15, and the direct drive motor rotor 14-2 is fixedly connected with the rotating shaft 15. The bearing assembly outer ring 12-2 is fixedly connected with the front gland 13, the front gland 13 is fixedly connected with the hollow spindle sleeve 16 through a connecting hole 13-1 arranged at the edge, and the direct drive motor stator 14-1 is fixedly arranged at the inner side of the spindle sleeve 16. The central axes of the shaft 15, the bearing assembly 12 and the spindle sleeve 16 coincide. At this time, the bearing assembly inner ring 12-1, the rotating shaft 15 and the direct drive motor rotor 14-2 form a first whole body, and the first whole body can rotate along with the bearing assembly inner ring 12-1. The bearing assembly outer ring 12-2, the front gland 13, the spindle sleeve 16 and the direct drive motor stator 14-1 form a second whole, and the second whole keeps a static state along with the spindle sleeve 16. When the first integral direct drive motor rotor 14-2 is energized with direct current, the winding coils in the direct drive motor rotor 14-2 generate torque in the stator magnetic field due to lorentz force, thereby starting to rotate. When the temperature of the parts of the direct drive motor is increased due to the overlong operation time, although the volume of each part is changed due to the physical effect of expansion with heat and contraction with cold, the volume change of each part in any direction on a plane perpendicular to the central axis of the rotating shaft 15 is isotropic with the axis as the center, and therefore, the height of the axis of the rotating shaft 15 is kept unchanged. Since the bearing unit outer ring 12-2 is fixed to the second unit, the dimension of the first unit in the longitudinal direction can be changed only to the side away from the bearing unit 12. Therefore, the connection position of the front end face of the rotating shaft 15 and the bearing assembly inner ring 12-1 can be kept unchanged, so that the bearing assembly inner ring has high thermal stability, and further, the error caused by the change of the spindle axis due to the temperature change of the spindle in the machining process of a workpiece is avoided.

The following are specific examples

Example 1

Fig. 1 is a schematic structural view of the spindle 100 of the present embodiment. The main shaft 100 includes a bearing assembly 12, a rotation shaft 15, and a front gland 13. The bearing assembly 12 is sequentially provided with an inner ring 12-1, a support body 12-3 and an outer ring 12-2 from inside to outside, the inner ring 12-1 and the outer ring 12-2 can rotate relatively, the width of the inner ring 12-1 in the direction parallel to the central axis of the bearing assembly 12 is larger than that of the outer ring 12-2, and an annular step is formed between the inner ring 12-1 and the outer ring 12-2. The main body of the rotating shaft 15 is cylindrical, one end surface of the main body is fixedly connected with the bearing assembly inner ring 12-1 through a screw, and the central axis of the bearing assembly 12 is overlapped with that of the rotating shaft 15. The center of the front gland 13 is provided with a circular hole with an annular step that matches the annular step of the bearing assembly 12. The bearing assembly outer ring 12-2 is fixedly connected with the front gland 13 through screws.

The spindle, the bearing assembly inner ring 12-1 and the rotating shaft 15 form a first whole, and the first whole is in a suspended state and can rotate along with the bearing assembly inner ring 12-1. When the front gland 13 is fixedly connected with the hollow fixture through the connecting hole 13-1 at the edge, the bearing assembly outer ring 12-2, the front gland 13 and the hollow fixture form a second whole body, and the second whole body is kept in a static state along with the hollow fixture. When the temperature of the parts is increased due to the long operation time in the rotation process of the first body, although the volume of each part is changed due to the physical effect of expansion with heat and contraction with cold, the volume change of each part in any direction on the plane perpendicular to the central axis of the rotating shaft 15 is isotropic with the axis as the center, so the axis height of the rotating shaft 15 is kept unchanged. Since the bearing assembly outer ring 12-2 is fixed to the second body, the dimension of the first body in the longitudinal direction can be changed only to the side away from the bearing assembly 12. Therefore, the connection position of the front end face of the rotating shaft 15 and the bearing assembly inner ring 12-1 can be kept unchanged, so that the bearing assembly inner ring has high thermal stability, and further, the error caused by the change of the spindle axis due to the temperature change of the spindle in the machining process of a workpiece is avoided.

A schematic structural diagram of the direct drive motor 200 with the spindle of the present embodiment can be seen in fig. 2, which includes the spindle 100, a spindle sleeve 16, a direct drive motor stator 14-1, and a direct drive motor rotor 14-2. The opening end of the main shaft sleeve 16 is connected with the front gland 13 through a screw, a permanent magnet is arranged in the direct drive motor stator 14-1 and is fixedly arranged on the inner side of the main shaft sleeve 16, one end of the permanent magnet is fixed on the positioning step of the main shaft sleeve 16, and the other end of the permanent magnet is fixed through the front gland. A winding coil is arranged in the direct drive motor rotor 14-2, one end of the winding coil is fixed on a positioning step of the rotating shaft 15, the other end of the winding coil is fixed on the rotating shaft 15 through a precision nut 17, and an air gap is reserved between the direct drive motor stator 14-1 and the direct drive motor rotor 14-2.

In the direct drive motor with the spindle, the bearing assembly inner ring 12-1, the rotating shaft 15 and the direct drive motor rotor 14-2 form a first whole, and the central axes of the bearing assembly 12 and the rotating shaft 15 are overlapped. The first body is rotatable with the bearing assembly inner race 12-1. The bearing assembly outer ring 12-2, the front gland 13, the spindle sleeve 16 and the direct drive motor stator 14-1 form a second whole, and the second whole is kept in a static state along with the hollow spindle sleeve 16. When the winding coil of the direct drive motor rotor 14-2 is switched on with direct current, the winding coil in the direct drive motor rotor 14-2 generates torque under the action of lorentz force, so that the direct drive motor rotor starts to rotate. When the temperature of the parts of the direct drive motor is increased due to the overlong operation time, although the volume of each part is changed due to the physical effect of expansion with heat and contraction with cold, the volume change of each part in any direction on a plane perpendicular to the central axis of the rotating shaft 15 is isotropic with the axis as the center, and therefore, the height of the axis of the rotating shaft 15 is kept unchanged. Since the bearing unit outer ring 12-2 is fixed to the second unit, the dimension of the first unit in the longitudinal direction can be changed only to the side away from the bearing unit 12. Therefore, the connection position of the front end face of the rotating shaft 15 and the bearing assembly inner ring 12-1 can be kept unchanged, so that the bearing assembly inner ring has high thermal stability, and further, the error caused by the change of the spindle axis due to the temperature change of the spindle in the machining process of a workpiece is avoided.

Example 2

The spindle of this embodiment is the same as embodiment 1.

A schematic structural diagram of a direct drive motor 300 with the spindle of this embodiment can be seen in fig. 3, and the direct drive motor is similar to the direct drive motor in embodiment 1, except that a rotating shaft member 11 is further provided.

In the direct drive motor with the spindle, the rotating shaft part 11, the bearing assembly inner ring 12-1, the rotating shaft 15 and the direct drive motor rotor 14-2 form a first whole body, and the first whole body can rotate along with the bearing assembly inner ring 12-1. The bearing assembly outer ring 12-2, the front gland 13, the hollow spindle sleeve 16 and the direct drive motor stator 14-1 form a second whole, and the second whole keeps a static state along with the spindle sleeve 16. When the direct-drive motor rotor 14-2 is switched on with direct current, the winding coil in the direct-drive motor rotor 14-2 is acted by the lorentz force to generate torque, so that the direct-drive motor rotor starts to rotate. When the direct drive motor is operated for a long time to cause the temperature of parts to rise, although the volume of each part is changed due to the physical effect of expansion with heat and contraction with cold, the volume change of any direction on a plane perpendicular to the central axis of the rotating shaft 15 has isotropy, so the axial center height of the rotating shaft 15 is kept unchanged. Since the bearing unit outer ring 12-2 is fixed to the second unit, the dimension of the first unit in the longitudinal direction can be changed only to the side away from the bearing unit 12. Therefore, the connection position of the front end face of the rotating shaft 15 and the bearing assembly inner ring 12-1 can be kept unchanged, so that the bearing assembly inner ring has high thermal stability, and further, the error caused by the change of the spindle axis due to the temperature change of the spindle in the machining process of a workpiece is avoided.

Example 3

The spindle of this embodiment is the same as embodiment 1.

A schematic structural diagram of a direct drive motor 400 having the spindle of this embodiment can be seen from fig. 4, and the direct drive motor is similar to the direct drive motor of embodiment 1, except that a first connecting block 19, a second connecting block 20 and a supporting block 21 are further provided. The first connecting block 19 and the second connecting block 20 are respectively arranged on two sides of the spindle sleeve 16, and a central connecting line of the first connecting block 19 and the second connecting block 20 is perpendicular to and coplanar with a central axis of the spindle sleeve 16, and the plane where the central connecting line is located is a horizontal plane. The supporting block 21 is provided with a groove, the width of the groove is larger than the diameter of the spindle sleeve 16, and the distance from the central line connecting line of the first connecting block 19 and the second connecting block 20 to the bottom of the groove is larger than the radius of the spindle sleeve 16. One end of the first connecting block 19 is fixedly connected with the spindle sleeve, the other end is connected with the first supporting block 21-1, one end of the second connecting block 20 is fixedly connected with the spindle sleeve, and the other end is connected with the second supporting block 21-2.

In the direct drive motor with the spindle, the rotating shaft part 11, the bearing assembly inner ring 12-1, the rotating shaft 15 and the direct drive motor rotor 14-2 form a first whole body, and the first whole body can rotate along with the bearing assembly inner ring 12-1. The bearing assembly outer ring 12-2, the front gland 13, the hollow spindle sleeve 16 and the direct drive motor stator 14-1 form a second whole, and the second whole keeps a static state along with the spindle sleeve 16. When the direct-drive motor rotor 14-2 is switched on with direct current, the winding coil in the direct-drive motor rotor 14-2 is acted by the lorentz force to generate torque, so that the direct-drive motor rotor starts to rotate. When the direct drive motor is operated for a long time to cause the temperature of parts to rise, although the volume of each part is changed due to the physical effect of expansion with heat and contraction with cold, the volume change of any direction on a plane perpendicular to the central axis of the rotating shaft 15 has isotropy, so the axial center height of the rotating shaft 15 is kept unchanged. Since the bearing unit outer ring 12-2 is fixed to the second unit, the dimension of the first unit in the longitudinal direction can be changed only to the side away from the bearing unit 12. Therefore, the connection position of the front end face of the rotating shaft 15 and the bearing assembly inner ring 12-1 can be kept unchanged, so that the bearing assembly inner ring has high thermal stability, and further, the error caused by the change of the spindle axis due to the temperature change of the spindle in the machining process of a workpiece is avoided.

Example 4

The spindle of this embodiment is the same as embodiment 1.

A schematic structural diagram of a direct drive motor 500 having the spindle of this embodiment can be seen from fig. 5, and the direct drive motor is similar to the direct drive motor of embodiment 3, except that the first connecting block 19 and the second connecting block 20 are integrally formed with the spindle sleeve 16.

In the direct drive motor with the spindle, the rotating shaft part 11, the bearing assembly inner ring 12-1, the rotating shaft 15 and the direct drive motor rotor 14-2 form a first whole body, and the first whole body can rotate along with the bearing assembly inner ring 12-1. The bearing assembly outer ring 12-2, the front gland 13, the hollow spindle sleeve 16 and the direct drive motor stator 14-1 form a second whole, and the second whole keeps a static state along with the spindle sleeve 16. When the direct-drive motor rotor 14-2 is switched on with direct current, the winding coil in the direct-drive motor rotor 14-2 is acted by the lorentz force to generate torque, so that the direct-drive motor rotor starts to rotate. When the direct drive motor is operated for a long time to cause the temperature of parts to rise, although the volume of each part is changed due to the physical effect of expansion with heat and contraction with cold, the volume change of any direction on a plane perpendicular to the central axis of the rotating shaft 15 has isotropy, so the axial center height of the rotating shaft 15 is kept unchanged. Since the bearing unit outer ring 12-2 is fixed to the second unit, the dimension of the first unit in the longitudinal direction can be changed only to the side away from the bearing unit 12. Therefore, the connection position of the front end face of the rotating shaft 15 and the bearing assembly inner ring 12-1 can be kept unchanged, so that the bearing assembly inner ring has high thermal stability, and further, the error caused by the change of the spindle axis due to the temperature change of the spindle in the machining process of a workpiece is avoided.

Example 5

The spindle of this embodiment is the same as embodiment 1.

Referring to fig. 6, a schematic structural diagram of a direct drive motor 600 having the spindle of this embodiment is similar to the direct drive motor in embodiment 1, except that the spindle sleeve 16 is integrally formed with the first support block 21-1 and the second support block 21-2, and the first support block 21-1 and the second support block 21-2 are L-shaped, and end portions thereof are provided with connection holes capable of being fixedly connected with a bearing surface.

In the direct drive motor with the spindle, the rotating shaft part 11, the bearing assembly inner ring 12-1, the rotating shaft 15 and the direct drive motor rotor 14-2 form a first whole body, and the first whole body can rotate along with the bearing assembly inner ring 12-1. The bearing assembly outer ring 12-2, the front gland 13, the hollow spindle sleeve 16 and the direct drive motor stator 14-1 form a second whole, and the second whole keeps a static state along with the spindle sleeve 16. When the direct-drive motor rotor 14-2 is switched on with direct current, the winding coil in the direct-drive motor rotor 14-2 is acted by the lorentz force to generate torque, so that the direct-drive motor rotor starts to rotate. When the direct drive motor is operated for a long time to cause the temperature of parts to rise, although the volume of each part is changed due to the physical effect of expansion with heat and contraction with cold, the volume change of any direction on a plane perpendicular to the central axis of the rotating shaft 15 has isotropy, so the axial center height of the rotating shaft 15 is kept unchanged. Since the bearing unit outer ring 12-2 is fixed to the second unit, the dimension of the first unit in the longitudinal direction can be changed only to the side away from the bearing unit 12. Therefore, the connection position of the front end face of the rotating shaft 15 and the bearing assembly inner ring 12-1 can be kept unchanged, so that the bearing assembly inner ring has high thermal stability, and further, the error caused by the change of the spindle axis due to the temperature change of the spindle in the machining process of a workpiece is avoided.

Example 6

The spindle of this embodiment is the same as embodiment 1.

Referring to fig. 7, a schematic structural diagram of a direct drive motor 700 with the spindle of this embodiment is similar to that of embodiment 5, except that the first support block 21-1 and the second support block 21-2 are separately designed and fixedly connected to the spindle sleeve 16 by screws.

In the direct drive motor with the spindle, the rotating shaft part 11, the bearing assembly inner ring 12-1, the rotating shaft 15 and the direct drive motor rotor 14-2 form a first whole body, and the first whole body can rotate along with the bearing assembly inner ring 12-1. The bearing assembly outer ring 12-2, the front gland 13, the hollow spindle sleeve 16 and the direct drive motor stator 14-1 form a second whole, and the second whole keeps a static state along with the spindle sleeve 16. When the direct-drive motor rotor 14-2 is switched on with direct current, the winding coil in the direct-drive motor rotor 14-2 is acted by the lorentz force to generate torque, so that the direct-drive motor rotor starts to rotate. When the direct drive motor is operated for a long time to cause the temperature of parts to rise, although the volume of each part is changed due to the physical effect of expansion with heat and contraction with cold, the volume change of any direction on a plane perpendicular to the central axis of the rotating shaft 15 has isotropy, so the axial center height of the rotating shaft 15 is kept unchanged. Since the bearing unit outer ring 12-2 is fixed to the second unit, the dimension of the first unit in the longitudinal direction can be changed only to the side away from the bearing unit 12. Therefore, the connection position of the front end face of the rotating shaft 15 and the bearing assembly inner ring 12-1 can be kept unchanged, so that the bearing assembly inner ring has high thermal stability, and further, the error caused by the change of the spindle axis due to the temperature change of the spindle in the machining process of a workpiece is avoided.

Example 7

The spindle of this embodiment is the same as embodiment 1.

A schematic structural diagram of a direct drive motor 800 with the spindle of this embodiment can be seen in fig. 8, and the direct drive motor is similar to the direct drive motor of embodiment 4, except that the first supporting block 21-1 and the second supporting block 21-2 are designed separately.

In the direct drive motor with the spindle, the rotating shaft part 11, the bearing assembly inner ring 12-1, the rotating shaft 15 and the direct drive motor rotor 14-2 form a first whole body, and the first whole body can rotate along with the bearing assembly inner ring 12-1. The bearing assembly outer ring 12-2, the front gland 13, the hollow spindle sleeve 16 and the direct drive motor stator 14-1 form a second whole, and the second whole keeps a static state along with the spindle sleeve 16. When the direct-drive motor rotor 14-2 is switched on with direct current, the winding coil in the direct-drive motor rotor 14-2 is acted by the lorentz force to generate torque, so that the direct-drive motor rotor starts to rotate. When the direct drive motor is operated for a long time to cause the temperature of parts to rise, although the volume of each part is changed due to the physical effect of expansion with heat and contraction with cold, the volume change of any direction on a plane perpendicular to the central axis of the rotating shaft 15 has isotropy, so the axial center height of the rotating shaft 15 is kept unchanged. Since the bearing unit outer ring 12-2 is fixed to the second unit, the dimension of the first unit in the longitudinal direction can be changed only to the side away from the bearing unit 12. Therefore, the connection position of the front end face of the rotating shaft 15 and the bearing assembly inner ring 12-1 can be kept unchanged, so that the bearing assembly inner ring has high thermal stability, and further, the error caused by the change of the spindle axis due to the temperature change of the spindle in the machining process of a workpiece is avoided.

The above-mentioned embodiments only represent some embodiments of the present invention, and the description thereof is specific and detailed, but not to be construed as limiting the scope of the present invention. It should be noted that, for those skilled in the art, without departing from the spirit of the present invention, several variations and modifications can be made, which are within the scope of the present invention. Therefore, the protection scope of the present invention should be subject to the appended claims.

Claims (10)

1. A spindle, comprising:

the rotating shaft (15), the main body of the rotating shaft (15) is cylindrical;

the bearing assembly (12) is sequentially provided with an inner ring (12-1), a support body (12-3) and an outer ring (12-2) from inside to outside, the inner ring (12-1) and the outer ring (12-2) can rotate relatively, and the bearing assembly (12) is fixedly connected with one side of the rotating shaft (15) through the inner ring (12-1);

the center of the front gland (13) is provided with a through hole, the bearing assembly (12) is arranged in the through hole, and the front gland (13) is fixedly connected with the outer ring (12-2);

the central axes of the bearing assembly (12) and the rotating shaft (15) are coincident.

2. The main shaft according to claim 1, characterized in that the width of the inner ring (12-1) in a direction parallel to the central axis of the bearing assembly (12) is greater than the width of the outer ring (12-2), an annular step is formed between the inner ring (12-1) and the outer ring (12-2), and the side wall of the through hole is provided with an annular step which is matched with the annular step and fixedly connected with the front gland (13) through screws.

3. A direct drive motor comprising the spindle of any one of claims 1 to 2, further comprising:

the main shaft sleeve (16) is arranged in a hollow mode, the rotating shaft (15) is arranged in the main shaft sleeve (16), and the front gland (13) is fixedly connected with the main shaft sleeve (16);

the direct drive motor stator (14-1) is fixedly arranged on the inner side of the main shaft sleeve (16);

the direct-drive motor rotor (14-2) is fixedly arranged on the outer side of the rotating shaft (15), and an air gap is reserved between the direct-drive motor rotor (14-2) and the direct-drive motor stator (14-1);

the supporting block (21) comprises a first supporting block (21-1) and a second supporting block (21-2), the first supporting block (21-1) is fixedly connected with one side of the spindle sleeve (16), and the second supporting block (21-2) is fixedly connected with the other side of the spindle sleeve (16).

4. The direct-drive motor according to claim 3, wherein a positioning step is arranged on the spindle sleeve (16), one end of the direct-drive motor stator (14-1) is fixed on the positioning step, the other end of the direct-drive motor stator is fixedly connected with the front gland (13), a positioning step is arranged on the rotating shaft (15), one end of the direct-drive motor rotor (14-2) is fixedly arranged on the positioning step, and the other end of the direct-drive motor rotor is fixed on the rotating shaft (15) through a nut (17).

5. A direct drive motor according to claim 4, further comprising a rotating shaft member (11), wherein the rotating shaft member (11) is arranged on one side of the bearing assembly (12) far away from the rotating shaft (15) and is fixedly connected with the bearing assembly (12) through the inner ring (12-1).

6. The direct drive motor according to claim 5, wherein a gap is arranged between the rotating shaft member (11) and the front gland (13), and compressed air is introduced into the gap.

7. A direct drive motor according to claim 3, characterized in that the support block (21) is integrally formed with the spindle sleeve (16).

8. The direct drive motor according to claim 3, wherein a first connecting block (19) and a second connecting block (20) are arranged outside the spindle sleeve (16), a central connecting line of the first connecting block (19) and the second connecting block (20) is perpendicular to and coplanar with a central axis of the spindle sleeve (16), the plane is a horizontal plane, the supporting block (21) is provided with a first supporting block (21-1) and a second supporting block (21-2), the first connecting block (19) is fixedly connected with the first supporting block (21-1), and the second connecting block (20) is fixedly connected with the second supporting block (21-2).

9. Direct drive motor according to claim 8, characterized in that the first and second connecting blocks (19, 20) are integrally formed with the spindle sleeve (16).

10. The direct drive motor according to claim 8, wherein the supporting block (21) is provided with a groove, the first supporting block (21-1) and the second supporting block (21-2) are respectively arranged at two sides of the groove, the width of the groove is larger than the diameter of the spindle sleeve (16), and the distance from the central axis of the first connecting block (19) and the central axis of the second connecting block (20) to the bottom of the groove is larger than the radius of the spindle sleeve (16).

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