An electric spindle structure and an electric spindle

Abstract

The present invention discloses an electric spindle structure and an electric spindle, and relates to the technical field of electric spindles. The electric spindle structure includes a housing, a separation ring is arranged between the housing and the rotating shaft, and the inner cavity of the housing is divided into two relatively independent spaces, a first chamber and a second chamber, by the separation ring. Preload rings are arranged on the outer sides of the two bearings, and the preload rings are slidably sleeved between the housing and the rotating shaft, and the preload rings apply force to the bearings along the axial direction of the rotating shaft toward the direction close to the bearings; the inner wall of the stator is installed with several guide rings, and the guide rings are located in the gap and are provided with guide parts for changing the movement direction of the coolant near the end face of the rotor. The present invention adjusts the size of the bearing preload by controlling the amount of coolant entering, and realizes the dynamic adjustment of the rotating shaft speed and the bearing preload. At the same time, the flow direction of the coolant away from the boundary layer is changed by the guide ring, so as to break the boundary layer and replace the boundary layer fluid, thereby improving the heat exchange efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of electric spindles, and in particular to an electric spindle structure and an electric spindle. Background Art

[0002] The electric spindle is a high-precision mechanical device that integrates an electric motor and a spindle. It is widely used in CNC machine tools, machining centers, and automation equipment. The core components of the electric spindle include a rotor, a stator, a bearing, and a cooling system. When the electric spindle runs at high speed, a large amount of heat will be generated due to bearing friction, the rotor cutting the magnetic flux lines, and the thermal effect of the motor itself. If the temperature rise is not effectively controlled, this heat will cause the internal temperature of the electric spindle to rise, affecting the lubrication and life of the bearings, and even causing overheating and damage to the bearings. High temperature will also cause thermal expansion of the spindle components, change the geometry of the spindle, and thus affect the machining accuracy. In addition, by controlling the bearing preload, a larger preload can be provided at low speeds to ensure rigidity, while the preload can be reduced at high speeds to reduce friction and heat, extend the bearing life, and ensure machining accuracy.

[0003] For example, a Chinese patent with announcement number CN112658294B discloses an electric spindle structure and an electric spindle, in which the relationship between the rotational speed and the preload force is pre-stored in the control mechanism, and then the purpose of controlling the piezoelectric ceramic column by the rotational speed is achieved by matching the preload force with the length of the piezoelectric ceramic column, thereby achieving the optimal preload force of the rotating shaft under different rotational speeds and different processing parts in given actual production.

[0004] Although the above-mentioned prior art realizes adaptive control of bearing preload and spindle speed, there is still room for improvement in controlling the temperature rise of the spindle. If the high temperature inside the spindle is maintained for a long time, it will affect the collection of spindle-related parameters by the data acquisition mechanism and affect the accuracy of adaptive adjustment of the bearing preload. Based on this, the present invention proposes an electric spindle structure and an electric spindle. Summary of the invention

[0005] The object of the present invention is to provide an electric spindle structure and an electric spindle to solve the problems raised in the above background technology.

[0006] To achieve the above object, the technical solution adopted by the present invention is:

[0007] An electric spindle structure includes a housing, a rotating shaft and a bearing are arranged inside the housing, two bearings are arranged, the outer ring of the bearing is fixedly connected to the inner wall of the housing, the inner ring of the bearing is fixedly sleeved on the circumferential surface of the rotating shaft, the circumferential surface of the rotating shaft is also fixedly sleeved with a rotor, a stator adapted to the rotor is installed at a position corresponding to the rotor inside the housing, a gap is formed between the stator and the rotor, a separation ring is arranged between the housing and the rotating shaft, the separation ring is fixedly connected to the inner wall of the housing, the separation ring is movably sleeved on the circumferential surface of the rotating shaft, and the inner cavity of the housing is divided into a first chamber and a second chamber by the separation ring. For the independent space, the two bearings are both located in the first chamber, and pre-tightening rings are arranged on the outer sides of the two bearings. The pre-tightening rings are slidably sleeved between the shell and the rotating shaft, and the pre-tightening rings apply force to the bearings along the axial direction of the rotating shaft toward the direction close to the bearings; a plurality of guide rings are installed on the inner wall of the stator, and the guide rings are located in the gap and are provided with guide parts for changing the movement direction of the coolant close to the end face of the rotor; the rotation speed of the rotating shaft is detected by the collection component arranged inside the shell, and when the rotation speed of the rotating shaft increases, the force applied by the pre-tightening ring on the bearing is reduced, and at the same time, the guide ring is flipped toward the direction close to the rotor.

[0008] Preferably, a separator ring is provided between the shell and the rotating shaft, the separator ring is fixedly connected to the inner wall of the shell, the separator ring is movably sleeved on the circumferential surface of the rotating shaft, and the inner cavity of the shell is divided into two relatively independent spaces, a first chamber and a second chamber, by the separator ring, the two bearings are both located in the first chamber, and the stator and the rotor are both located in the second chamber; the first chamber is connected to and installed with a first liquid inlet pipe and a first liquid outlet pipe, and the connecting position of the first liquid inlet pipe and the first chamber is set between the two pre-tightening rings, the second chamber is connected to and installed with a second liquid inlet pipe and a second liquid outlet pipe, the first liquid inlet pipe and the second liquid inlet pipe are connected to the liquid inlet main pipe through a three-way pipe, the other end of the liquid inlet main pipe is connected to the output end of the cooling liquid supply device, and the other ends of the first liquid outlet pipe and the second liquid outlet pipe are both connected to the input end of the cooling liquid supply device to form two cold cycles.

[0009] Preferably, an electric control valve is provided on the liquid inlet main pipe, and the electric control valve is electrically connected to the collection component. When the collection component detects that the rotation speed of the shaft increases, the opening of the electric control valve increases.

[0010] Preferably, the guide ring has a cavity structure, and several guide rings are not only connected to each other but also to the second chamber. An expansion part is provided on the side of the guide ring away from the guide part, and the expansion coefficient of the expansion part is greater than the expansion coefficient of the remaining part of the guide ring.

[0011] Preferably, a spring is provided on a side of the preload ring away from the bearing, and a force is applied to the preload ring through the spring to cause the preload ring to move toward the bearing.

[0012] Preferably, the cross-section of the guide portion is an outwardly concave arc-shaped structure, and after the guide ring is flipped toward the direction close to the rotor, the movement direction of the guided coolant in the axial direction of the shaft is opposite to the movement direction of the coolant in the boundary layer.

[0013] Preferably, the separating ring is in the form of a pump body structure, and a liquid inlet is installed on the end face of the separating ring close to the pre-tightening ring, the liquid inlet is sleeved on the rotating shaft, the circumferential surface of the separating ring is provided with a liquid outlet communicating with the second chamber, the inner cavity of the separating ring is provided with an impeller, and the impeller is fixedly sleeved on the circumferential surface of the rotating shaft.

[0014] Preferably, the two preload rings perform synchronous relative motion.

[0015] Preferably, the liquid outlet is connected to one end of the gap, and the liquid outlet is arranged at an angle.

[0016] An electric spindle comprises the above-mentioned electric spindle structure.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] (1) The present invention divides the inner cavity of the shell into two relatively opposite spaces, a first chamber and a second chamber, by arranging a separation ring. A portion of the coolant flows through the first chamber to cool the bearing, and the other portion of the coolant flows into the second chamber to cool the rotor and the stator, thereby avoiding mutual interference caused by the asynchronous heat exchange efficiency of the two heat sources, reducing the cooling path length of a single heat source, and improving the cooling efficiency.

[0019] (2) The present invention provides a spring to apply a force to the preload ring in a direction close to the bearing, thereby increasing the preload force of the bearing when the spindle is at low speed to ensure stiffness. When the rotor speed increases, the force applied to the preload ring in a direction away from the bearing is gradually increased by increasing the amount of coolant entering, thereby reducing bearing friction and heat generation, extending the bearing life and ensuring processing accuracy, realizing dynamic adjustment of the bearing preload force, and improving the optimal comprehensive performance of the spindle.

[0020] (3) After the shaft speed increases, the guide ring is driven to gradually move toward the rotor by increasing the amount of coolant entering, and the coolant outside the original boundary layer is guided to move toward the boundary layer. This can disturb and destroy the original boundary layer, allowing the fluid in the boundary layer to be quickly renewed, significantly improving the thermal conduction and convection heat transfer performance of the boundary layer.

[0021] (4) The present invention designs the separation ring as a pump body structure, and uses the rotating shaft to drive the impeller to form a negative pressure at the liquid inlet, thereby forming a suction force on the preload ring, thereby offsetting part of the thrust of the spring on the preload ring, thereby realizing automatic adjustment of the bearing preload force.

[0022] (5) The present invention drives the two preload rings to move relative to each other by setting a relative motion mechanism, so that the two preload rings move synchronously, thereby achieving synchronous adjustment of the preload forces of the two bearings and improving the adjustment accuracy of the bearing preload forces.

[0023] (6) The present invention designs the position and inclination angle of the liquid outlet so that the coolant near the gap port area forms turbulence, thereby improving the mixing effect of the coolant and enhancing convective heat transfer. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0025] Figure 1 It is a cross-sectional view of the entire electric spindle structure proposed in the first embodiment of the present invention;

[0026] Figure 2 Schematic diagram of the structure of the first chamber and the second chamber in the first embodiment of the present invention;

[0027] Figure 3 This is a schematic diagram of the structure of the pre-tightening ring in the first embodiment of the present invention;

[0028] Figure 4 The structure of the guide ring in the first embodiment of the present invention is shown in FIG. Figure 1 ;

[0029] Figure 5 The structure of the guide ring in the first embodiment of the present invention is shown in FIG. Figure 2 ;

[0030] Figure 6 for Figure 4 Schematic diagram of the enlarged structure of the A area in the middle;

[0031] Figure 7 for Figure 5 Schematic diagram of the enlarged structure of the middle B area;

[0032] Figure 8 Schematic diagram of the structure of the initial state and the expanded state of the guide ring in the first embodiment of the present invention, wherein E is a diagram of the initial state of the pre-tightening ring, and F is a diagram of the expanded state of the pre-tightening ring;

[0033] Fig. 9 It is a cross-sectional view of the entire electric spindle structure proposed in the second embodiment of the present invention;

[0034] Fig.10 It is a partial cross-sectional view of the entire electric spindle structure proposed in the second embodiment of the present invention;

[0035] Fig.11It is a schematic diagram of the structure of the separation ring in the second embodiment of the present invention;

[0036] Fig.12 This is a schematic diagram of the assembly structure of the preload ring in the second embodiment of the present invention;

[0037] Fig.13 for Figure 1 Schematic diagram of the enlarged structure of the middle C region;

[0038] Fig.14 for Fig. 9 Schematic diagram of the enlarged structure of the D area in the middle.

[0039] In the figure: 1. shell; 2. separator ring; 21. liquid inlet; 22. liquid outlet; 23. impeller; 3. rotating shaft; 4. first chamber; 41. intermediate separator ring; 42. piezoelectric ceramic column; 5. second chamber; 6. stator; 61. guide ring; 611. guide part; 612. expansion part; 613. opening; 62. connecting channel; 63. reserved chamber; 7. rotor; 8. bearing; 9. preload ring; 91. limit groove; 92. spring; 93. rack; 94. gear; 95. guide rib; 10. first liquid inlet pipe; 11. second liquid inlet pipe; 12. liquid inlet main pipe; 13. electric control valve; 14. first liquid outlet pipe; 15. second liquid outlet pipe; 16. gap; 17. collection component. DETAILED DESCRIPTION

[0040] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. The components of the embodiments of the present invention generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents the selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present invention.

[0041] Embodiment 1

[0042] See also Figure 1-Figure 8 and Fig.13The present embodiment proposes an electric spindle structure, including a housing 1, wherein a rotating shaft 3 and a bearing 8 are arranged inside the housing 1, wherein two bearings 8 are arranged, wherein the outer ring of the bearing 8 is fixedly connected to the inner wall of the housing 1, and the inner ring of the bearing 8 is fixedly sleeved on the circumferential surface of the rotating shaft 3, and the bearing 8 serves as a rotating support component for the rotating shaft 3 to rotate freely inside the housing 1, and a rotor 7 is also fixedly sleeved on the circumferential surface of the rotating shaft 3, and a stator 6 adapted to the rotor 7 is installed at a position corresponding to the rotor 7 inside the housing 1, and a gap 16 is formed between the stator 6 and the rotor 7, and a rotating magnetic field is generated by the current of the stator 6, thereby driving the rotor 7 to rotate, and since the rotor 7 is fixedly sleeved on the rotating shaft 3, the rotating shaft 3 also rotates accordingly; the temperature rise of the main shaft It comes from two aspects: the heat generated by bearing friction and the heat generated by the rotor cutting the magnetic field. First, as the core of the rotating support component of the shaft 3, the preload force of the shaft 3 has an important influence on the stiffness and temperature rise of the main shaft. For example, at low speed, the heat generated by the bearing 8 is small and the internal clearance is large. In order to improve the stiffness of the main shaft, the preload force needs to be increased; at high speed, the heat generated by the bearing 8 increases significantly, and the internal clearance will decrease due to thermal expansion, so the preload force should be appropriately reduced; second, when the rotor 7 rotates at high speed, due to the viscosity of the fluid, this means that there is a viscous force between the fluid molecules and between the fluid and the solid surface. The layer of fluid close to the solid surface is called the boundary layer. In the high-speed rotating rotor 7, The fluid molecules on the surface of the rotor 7 will be dragged by the movement of its surface. This viscous drag force will produce an "adsorption" effect between the fluid and the surface of the rotor 7, so that the fluid molecules are tightly attached to the surface of the rotor 7, forming a laminar boundary layer with smooth flow. The gap 16 between the stator 6 and the rotor 7 is relatively small, resulting in a small volume of fluid that can flow per unit time. Affected by the boundary layer, the fluid renewal speed in the boundary layer is slowed down, further reducing the heat exchange efficiency between the fluid and the rotor 7. Therefore, preload rings 9 are provided on the outer sides of the two bearings 8. The preload rings 9 are slidably sleeved between the housing 1 and the shaft 3. The preload rings 9 apply a force to the bearing 8 along the axial direction of the shaft 3 toward the direction close to the bearing 8. Increase the preload force of the bearing 8; a plurality of guide rings 61 are installed on the inner wall of the stator 6, and the guide ring 61 is located in the gap 16 and is provided with a guide portion 611 for changing the movement direction of the coolant near the end face of the rotor 7; the rotation speed of the shaft 3 is detected by the collecting component 17 arranged inside the housing 1, and when the rotation speed of the shaft 3 increases, the force applied by the preload ring 9 to the bearing 8 is reduced, so as to achieve the purpose of reducing the preload force of the bearing 8, and at the same time, the guide ring 61 is flipped toward the direction close to the rotor 7, and the coolant away from the boundary layer is guided to move in the direction close to the boundary layer, disturbing and destroying the original boundary layer, so that the fluid in the boundary layer is quickly renewed, and the overheating and heat accumulation problems near the surface of the rotor 7 are effectively reduced.

[0043] On the basis of the above scheme, the present invention utilizes the method of increasing the amount of coolant entering to achieve the reduction of the bearing preload and the action of the guide ring 61. Specifically, a separation ring 2 is arranged between the shell 1 and the rotating shaft 3. The separation ring 2 is fixedly connected to the inner wall of the shell 1. The separation ring 2 is movably sleeved on the circumferential surface of the rotating shaft 3. The inner cavity of the shell 1 is divided into two relatively independent spaces, a first chamber 4 and a second chamber 5, by the separation ring 2. The two bearings 8 are both located in the first chamber 4, and the stator 6 and the rotor 7 are both located in the second chamber 5. Through this design, the two heat sources are first separated for separate cooling, thereby reducing the heat generated by asynchronous heat exchange. interference, and secondly, effectively reducing the cooling path length of a single heat source and improving the cooling efficiency; the first chamber 4 is connected to a first liquid inlet pipe 10 and a first liquid outlet pipe 14, and the communication position of the first liquid inlet pipe 10 and the first chamber 4 is set between the two pre-tightening rings 9, and the second chamber 5 is connected to a second liquid inlet pipe 11 and a second liquid outlet pipe 15. The first liquid inlet pipe 10 and the second liquid inlet pipe 11 are connected to the liquid inlet main pipe 12 through a three-way pipe, and the other end of the liquid inlet main pipe 12 is connected to the output end of the coolant supply device. The liquid inlet main pipe 12 is provided with an electric control valve 13, which is electrically connected to the collection component 17. The first outlet The other ends of the liquid pipe 14 and the second liquid outlet pipe 15 are connected to the input end of the coolant supply device and form two cold cycles. When the collection component 17 detects that the speed of the shaft 3 increases, the opening of the electric control valve 13 increases, increasing the amount of coolant entering. A part of the coolant enters the first chamber 4 through the first liquid inlet pipe 10. This part of the coolant exerts a force on the two preload rings 9 in a direction away from the bearing 8, forcing the preload ring 9 to exert a force on the bearing 8 to reduce, thereby achieving the purpose of reducing the preload force of the bearing 8. At the same time, the method of increasing the coolant also improves the heat exchange efficiency of the bearing 8; the guide ring 61 is a cavity structure, and several guide rings 6 1 are not only interconnected, but also connected to the second chamber 5. The side of the guide ring 61 away from the guide portion 611 is provided with an expansion portion 612 with a larger expansion coefficient, and the remaining portion has a smaller expansion coefficient. When another part of the coolant enters the second chamber 5 through the second liquid inlet pipe 11, as the volume of the coolant flowing into the inner cavity of the guide ring 61 increases, the expansion portion 612 expands, causing the guide ring 61 to move toward the direction close to the rotor 7, changing the original flow direction of the coolant away from the boundary layer to move toward the direction close to the boundary layer, so as to break the boundary layer and replace the fluid in the boundary layer, thereby significantly improving the heat conduction and convection heat transfer performance of the boundary layer.

[0044] In this embodiment, a spring 92 is provided on the side of the preload ring 9 away from the bearing 8, and a force is applied to the preload ring 9 toward the bearing 8 through the spring 92. Preferably, the spring 92 is a conical disc spring. In order to limit the movement stroke of the preload ring 9, a limiting groove 91 is provided inside the housing 1 corresponding to the position of the preload ring 9, and the maximum movement stroke of the preload ring 9 is limited by the limiting groove 91 to avoid excessive extrusion of the preload ring 9 on the bearing 8.

[0045] In order to further improve the ability to accurately control the bearing preload, in this embodiment, an intermediate ring 41 is arranged between the two bearings 8, the circumferential surface of the intermediate ring 41 is fixedly connected to the inner wall of the shell 1, and the intermediate ring 41 is movably sleeved on the circumferential surface of the rotating shaft 3. A plurality of piezoelectric ceramic columns 42 are embedded in the end surface of the intermediate ring 41 close to the bearing 8. By adjusting the length of the piezoelectric ceramic columns 42, the preload of the bearing 8 can be further adjusted, thereby increasing the adjustment range of the bearing preload.

[0046] In this embodiment, the cross-section of the guide portion 611 is an outwardly concave arc-shaped structure, and the coolant away from the boundary layer is guided by the guide portion 611 to move toward the boundary layer, and the movement direction of the guided coolant in the axial direction of the shaft 3 is opposite to the movement direction of the coolant in the boundary layer. This design can frequently update the boundary layer fluid, reduce the temperature and velocity gradients, and form turbulence in the boundary layer, thereby improving the heat transfer efficiency.

[0047] In addition, in order to ensure that the expansion part 612 can fully expand, a reserved chamber 63 matching the expansion part 612 is opened inside the stator 6 in this embodiment, and sufficient space is reserved for the expansion of the expansion part 612 through the reserved chamber 63; an opening 613 is opened on the surface of the guide ring 61, and the opening 613 is connected to a connecting channel 62 opened on the stator 6, and the connecting channel 62 is connected to the second chamber 5. The other end of the connecting channel 62 is arranged near the connection position between the second liquid inlet pipe 11 and the shell 1, which is conducive to the coolant entering the inner cavity of the guide ring 61.

[0048] Embodiment 2

[0049] See also Figure 9-12 and Fig.14This embodiment and the first embodiment adopt the same inventive concept, and the difference between this embodiment and the first embodiment is that: the separation ring 2 is designed to be a pump body structure, and a liquid inlet 21 is installed on the end face of the separation ring 2 close to the preload ring 9, and the liquid inlet 21 is sleeved on the rotating shaft 3. The circumferential surface of the separation ring 2 is provided with a liquid outlet 22 communicated with the second chamber 5, and the inner cavity of the separation ring 2 is provided with an impeller 23, and the impeller 23 is fixedly sleeved on the circumferential surface of the rotating shaft 3. When the impeller 23 rotates at a high speed, a negative pressure is formed, and a suction force is formed at the opening of the liquid inlet 21. The suction force forms a pulling force on the preload ring 9 close to the side of the separation ring 2, and the pulling force offsets part of the thrust of the spring 92 on the preload ring 9, thereby achieving the purpose of automatically reducing the preload force of the bearing 8 at high speed, and realizing the adaptive adjustment of the bearing preload force.

[0050] In order to achieve synchronous adjustment of the preload force of the two bearings, a relative motion mechanism is provided between the two preload rings 9 in this embodiment. When the preload ring 9 on the side close to the separation ring 2 is subjected to suction and moves in a direction away from the bearing 8, the other preload ring 9 moves in a direction away from the bearing 8 simultaneously. Specifically, the relative motion mechanism adopts a gear rack structure, that is, the two preload rings 9 are both equipped with a set of centrally symmetrically arranged racks 93, and a gear 94 is meshed and connected between the two racks 93 located on the same horizontal plane, and the gear 94 is installed inside the housing 1 through a short shaft rotation; in order to ensure that the preload ring 9 cannot produce self-rotation during movement, a guide rib 95 arranged parallel to the axial direction of the rotating shaft 3 is installed on the circumferential surface of the preload ring 9, and a slide groove adapted to the guide rib 95 is opened inside the housing 1, and the guide rib 95 is slidably assembled in the slide groove. It should be noted that after the rack 93 is installed, the entire preload ring 9 is still slidably assembled between the housing 1 and the rotating shaft 3, and there is no gap between the three, which meets the condition of pushing the preload ring 9 to move in a direction away from the bearing 8 by adding coolant.

[0051] In this embodiment, the liquid outlet 22 is connected to one end of the gap 16, and the liquid outlet 22 is inclined. The high-speed rotating impeller 23 pumps the sucked coolant out through the liquid outlet 22. The coolant is ejected at a certain angle through the liquid outlet 22, so that the coolant near the port area of ​​the gap 16 forms turbulence, thereby improving the mixing effect of the coolant and enhancing the convective heat transfer.

[0052] The cooling liquid supply device, the piezoelectric ceramic column 42, and the collection component 17 use currently known equipment. Since they are not the focus of the technical solution to be protected by this application, they will not be described in detail.

[0053] In the description of the present invention, the terms "first", "second", "another", and "yet another" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, the features defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of the embodiments of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0054] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. In addition, in the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0055] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. An electric spindle structure, comprising a housing (1), wherein a rotating shaft (3) and a bearing (8) are arranged inside the housing (1), wherein two bearings (8) are arranged, wherein an outer ring of the bearing (8) is fixedly connected to an inner wall of the housing (1), wherein an inner ring of the bearing (8) is fixedly sleeved on a circumferential surface of the rotating shaft (3), wherein a rotor (7) is also fixedly sleeved on the circumferential surface of the rotating shaft (3), wherein a stator (6) adapted to the rotor (7) is installed at a position corresponding to the rotor (7) inside the housing (1), wherein a gap (16) is formed between the stator (6) and the rotor (7), wherein the structure is characterized in that: A separation ring (2) is provided between the housing (1) and the rotating shaft (3). The separation ring (2) is fixedly connected to the inner wall of the housing (1). The separation ring (2) is movably sleeved on the circumferential surface of the rotating shaft (3). The inner cavity of the housing (1) is divided into two relatively independent spaces, a first cavity (4) and a second cavity (5), by the separation ring (2). Both bearings (8) are located in the first cavity (4). Both bearings (8) are provided with preload rings (9) on the outer sides. The preload rings (9) are slidably sleeved between the housing (1) and the rotating shaft (3). The preload rings (9) are slidably sleeved along the circumference of the rotating shaft (3). A force is applied to the bearing (8) axially in a direction close to the bearing (8); a plurality of guide rings (61) are installed on the inner wall of the stator (6); the guide ring (61) is located in the gap (16) and is provided with a guide portion (611) for changing the movement direction of the coolant on the end surface close to the rotor (7); the rotation speed of the rotating shaft (3) is detected by a collecting component (17) arranged inside the housing (1); when the rotation speed of the rotating shaft (3) increases, the force applied by the preload ring (9) to the bearing (8) is reduced, and at the same time, the guide ring (61) is turned in a direction close to the rotor (7); The first chamber (4) is connected to a first liquid inlet pipe (10) and a first liquid outlet pipe (14), and the connection position between the first liquid inlet pipe (10) and the first chamber (4) is arranged between the two pre-tightening rings (9). The second chamber (5) is connected to a second liquid inlet pipe (11) and a second liquid outlet pipe (15). The first liquid inlet pipe (10) and the second liquid inlet pipe (11) are connected to a liquid inlet main pipe (12) via a three-way pipe. The other end of the liquid inlet main pipe (12) is connected to the output end of a cooling liquid supply device. The other ends of the first liquid outlet pipe (14) and the second liquid outlet pipe (15) are connected to the input end of the cooling liquid supply device to form two cooling cycles. An electric control valve (13) is provided on the liquid inlet main pipe (12), and the electric control valve (13) is electrically connected to the collection component (17). When the collection component (17) detects that the rotation speed of the rotating shaft (3) increases, the opening of the electric control valve (13) increases; The guide ring (61) is in a cavity structure, and the plurality of guide rings (61) are not only connected to each other but also connected to the second chamber (5). An expansion portion (612) is provided on a side of the guide ring (61) away from the guide portion (611), and the expansion coefficient of the expansion portion (612) is greater than the expansion coefficient of the remaining portion of the guide ring (61); The coolant enters the second chamber (5) through the second liquid inlet pipe (11). As the volume of the coolant flowing into the inner cavity of the guide ring (61) increases, the expansion portion (612) expands, causing the guide ring (61) to move in a direction close to the rotor (7), thereby changing the flow direction of the coolant that was originally away from the boundary layer.

2. The electric spindle structure according to claim 1, characterized in that: A spring (92) is provided on a side of the preload ring (9) away from the bearing (8), and a force is applied to the preload ring (9) through the spring (92) to move the preload ring (9) in a direction close to the bearing (8).

3. The electric spindle structure according to claim 1, characterized in that: The cross section of the guide portion (611) is an outwardly concave arc-shaped structure, and after the guide ring (61) is turned in a direction close to the rotor (7), the movement direction of the guided coolant in the axial direction of the rotating shaft (3) is opposite to the movement direction of the coolant in the boundary layer.

4. The electric spindle structure according to claim 1, characterized in that: The separation ring (2) is in the form of a pump body structure. The end surface of the separation ring (2) close to the preload ring (9) is provided with a liquid inlet (21), which is sleeved on the rotating shaft (3). The circumferential surface of the separation ring (2) is provided with a liquid outlet (22) which is in communication with the second chamber (5). The inner cavity of the separation ring (2) is provided with an impeller (23), which is fixedly sleeved on the circumferential surface of the rotating shaft (3).

5. The electric spindle structure according to claim 4, characterized in that: The two preload rings (9) perform synchronous relative motion.

6. The electric spindle structure according to claim 4, characterized in that: The liquid outlet (22) is connected to one end of the gap (16), and the liquid outlet (22) is arranged in an inclined manner.

7. An electric spindle, characterized in that: The electric spindle structure comprises the electric spindle structure as claimed in any one of claims 1 to 6.

Images