Hydrodynamic bearing high speed motorized spindle and hydrodynamic bearing

Abstract

The application discloses a dynamic pressure bearing high-speed electric spindle and a dynamic pressure bearing. The dynamic pressure bearing high-speed electric spindle comprises a stator part, a rotor part and at least one dynamic pressure bearing. The rotor part is rotatably arranged in the stator part. The dynamic pressure bearing is arranged between the rotor part and the stator part and is connected to the rotor part. An air floating gap is arranged between the outer wall of the dynamic pressure bearing and the inner wall of the stator part. The dynamic pressure bearing is provided with a pressure increasing cavity, a pressure maintaining cavity, a gas guiding channel, a gas outlet hole, at least one first impeller and at least one second impeller. The first impeller is arranged on one side of the pressure increasing cavity. The second impeller is arranged on the other side of the pressure increasing cavity. The rotor part can be rotatably arranged in the stator part by the dynamic pressure bearing. There is no contact friction, so that the dynamic pressure bearing can be prevented from being damaged due to abrasion. The service life of the dynamic pressure bearing can be prolonged, and the failure rate of the electric spindle can be reduced.

Description

Technical Field

[0001] This invention relates to a high-speed electric spindle with a hydrodynamic bearing and the hydrodynamic bearing. Background Technology

[0002] Currently, electric spindles are a new technology that integrates the machine tool spindle and spindle motor, and are widely used in the field of CNC machine tools. The rotor component in an electric spindle needs to be rotated within the stator component via bearings. For example, Chinese patent CN210016369U discloses a bearing-cooled permanent magnet synchronous electric spindle, in which the rotor component is rotated within the stator component via bearings. However, in existing electric spindles, the bearing life is not long enough. Contact friction within the bearings during high-speed rotation leads to gradual wear and damage, resulting in frequent spindle failures due to bearing failure and a high failure rate. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to overcome the defects of the prior art and provide a high-speed electric spindle with a dynamic pressure bearing. It can make the rotor component air-float and rotate in the stator component through the dynamic pressure bearing, eliminating contact friction and thus avoiding wear and damage to the dynamic pressure bearing, extending the service life of the dynamic pressure bearing, and thus reducing the failure rate of the electric spindle.

[0004] To solve the above-mentioned technical problems, the technical solution of the present invention is: a high-speed electric spindle with a hydrodynamic bearing, comprising a stator assembly, a rotor assembly, and at least one hydrodynamic bearing; wherein,

[0005] The rotor component is rotatably disposed within the stator component;

[0006] The hydrodynamic bearing is disposed between the rotor component and the stator component and connected to the rotor component, and an air flotation gap is provided between the outer peripheral wall of the hydrodynamic bearing and the inner wall of the stator component;

[0007] The hydrodynamic bearing is provided with a pressure boosting chamber, a pressure holding chamber, an air guide channel, an air outlet, at least one first impeller and at least one second impeller;

[0008] The pressurization chamber is arranged around the rotor component;

[0009] The first impeller is located on one side of the pressurization chamber, and the second impeller is located on the other side of the pressurization chamber, so that when the rotor component rotates, it drives the dynamic pressure bearing to rotate, thereby causing the first impeller and the second impeller to rotate respectively to draw external air into the pressurization chamber;

[0010] The pressure-holding cavity is arranged around the outside of the pressure-boosting cavity and located inside the air flotation gap;

[0011] The air guide channel is arranged between the pressure boosting cavity and the pressure maintaining cavity and is used to connect the pressure boosting cavity and the pressure maintaining cavity so that the pressure air in the pressure boosting cavity flows into the pressure maintaining cavity;

[0012] The air outlet hole is arranged between the pressure maintaining cavity and the air floating gap and is used to connect the pressure maintaining cavity and the air floating gap so that the pressure air in the pressure maintaining cavity flows into the air floating gap to form an air film, and the dynamic pressure bearing is supported in the stator component by the air film.

[0013] Further, the first impeller is provided with at least two and is arranged in a stacked manner on one side of the pressure boosting cavity;

[0014] The second impeller is provided with at least two and is arranged in a stacked manner on the other side of the pressure boosting cavity.

[0015] Further, the first impeller is arranged in a circumferentially staggered and stacked manner, and the second impeller is arranged in a circumferentially staggered and stacked manner.

[0016] Further, the first impeller is provided with a first positioning hole, and the first positioning hole in the first impeller is aligned with the first positioning hole in the adjacent first impeller;

[0017] The second impeller is provided with a second positioning hole, and the second positioning hole in the second impeller is aligned with the second positioning hole in the adjacent second impeller.

[0018] Further provided is a specific structure of the dynamic pressure bearing, which comprises a shell body; wherein,

[0019] The air floating gap is arranged between the outer peripheral wall of the shell body and the inner wall of the stator component;

[0020] The outer peripheral part of the first impeller is connected with the shell body, and the inner peripheral part of the first impeller is connected with the rotor component;

[0021] The outer peripheral part of the second impeller is connected with the shell body, and the inner peripheral part of the second impeller is connected with the rotor component;

[0022] The pressure boosting cavity is located between the shell body and the rotor component, and is also located between the first impeller and the second impeller;

[0023] The pressure maintaining cavity, the air guide channel and the air outlet hole are all arranged in the shell body.

[0024] Further provided is a specific structure of the shell body, which comprises an outer ring wall, a left cavity wall, a right cavity wall, a left inner ring wall and a right inner ring wall; wherein,

[0025] The air floating gap is arranged between the outer ring wall and the inner wall of the stator component;

[0026] The outer peripheral part of the left cavity wall and the outer peripheral part of the right cavity wall are connected to the outer ring wall;

[0027] The left inner ring wall is connected to the inner peripheral part of the left cavity wall, and the right inner ring wall is connected to the inner peripheral part of the right cavity wall;

[0028] The pressure maintaining cavity is arranged between the left cavity wall and the right cavity wall;

[0029] The air outlet hole is arranged in the outer ring wall and communicates with the pressure maintaining cavity;

[0030] The air guiding channel is arranged between the left inner ring wall and the right inner ring wall and communicates with the pressure maintaining cavity;

[0031] The pressure boosting cavity is located at the inner side of the left inner ring wall and the right inner ring wall;

[0032] The outer peripheral part of the first impeller and the outer peripheral part of the second impeller are connected to the outer ring wall, respectively.

[0033] Further, the stator component is provided with a first cavity corresponding to the dynamic pressure bearing and located at one side of the corresponding dynamic pressure bearing, and the first impeller is used to pump the air in the first cavity to the pressure boosting cavity when the first impeller rotates;

[0034] The stator component is provided with a second cavity corresponding to the dynamic pressure bearing and located at the other side of the corresponding dynamic pressure bearing, and the second impeller is used to pump the air in the second cavity to the pressure boosting cavity when the second impeller rotates.

[0035] Further, one end of the air floating gap communicates with the corresponding first cavity, and the other end of the air floating gap communicates with the corresponding second cavity.

[0036] Further, the first cavity communicates with the outside through at least one first through hole;

[0037] The second cavity communicates with the outside through at least one second through hole;

[0038] The first through hole and the second through hole are arranged in the stator component.

[0039] The application also provides a dynamic pressure bearing, which is a dynamic pressure bearing used in a high-speed electric spindle as described above.

[0040] With the above technical scheme, since the dynamic pressure bearing is connected to the rotor component, when the rotor component rotates at high speed, the dynamic pressure bearing rotates at high speed, and the first impeller and the second impeller in the dynamic pressure bearing also rotate at high speed. When the first impeller and the second impeller rotate, external air is simultaneously sucked from both sides to the plenum chamber. The air is continuously compressed in the plenum chamber, so that the air pressure in the plenum chamber is increased. Then, the high-pressure air in the plenum chamber flows into the pressure maintaining chamber through the gas guide channel, and then flows into the air-film gap through the air outlet hole to form an air film. The rotor component and the dynamic pressure bearing are supported in the stator component by the air film during high-speed rotation. There is no contact and friction between the dynamic pressure bearing and the stator component, so that the dynamic pressure bearing is not damaged due to wear, thereby prolonging the service life of the dynamic pressure bearing, avoiding the failure of the electric spindle due to the damage of the dynamic pressure bearing, and reducing the failure rate of the electric spindle.

[0041] The air film provides non-contact support to make the high-speed rotating rotor component and the dynamic pressure bearing float in the stator component. The dynamic pressure bearing does not contact and rub with the stator component during rotation, so it will not be worn and will not vibrate. The service life is longer, the high-speed performance is better, and the higher the speed of the rotor component, the more the rotor component tends to rotate around the central axis, and the more accurate the automatic centering is. Therefore, the overall performance of the dynamic pressure bearing high-speed electric spindle of the embodiment is obviously better than that of the conventional high-speed electric spindle.

[0042] The air pressure in the plenum chamber increases with the increase of the speed of the rotor component. The higher the speed of the rotor component, the greater the air pressure in the plenum chamber, and the higher the support stiffness of the air film formed in the air-film gap. Therefore, stable support can be provided during high-speed rotation, and the stability and reliability at high speed are improved.

[0043] The pressure maintaining chamber can be used to maintain the high-pressure gas from the plenum chamber for a certain period of time. The flow rate of the gas in the pressure maintaining chamber from the air outlet hole to the air-film gap is very small, so the air pressure in the pressure maintaining chamber can be maintained for a long time, so that the high-pressure gas in the plenum chamber has enough time to supplement the pressure maintaining chamber. The pressure fluctuation in the pressure maintaining chamber is small, a stable air film can be formed in the air-film gap, and the stability of the air-film is improved. In addition, since the flow rate in the air-film gap is very small, the exhaust sound cannot be heard.

[0044] The first impeller and the second impeller rotate at high speed to suck and compress air into the plenum chamber, and then form high-pressure air in the plenum chamber. No additional high-pressure gas source is needed, the structure is very simple, the cost is low, and the cost can be saved.

[0045] The air on both sides is simultaneously pumped into the plenum chamber through the first impeller and the second impeller, so that the corresponding speed can be improved; and the small air passage ratio is adopted in the dynamic pressure bearing to enhance the air floating pressure and improve the support stiffness. BRIEF DESCRIPTION OF DRAWINGS

[0046] Figure 1 is a sectional view of a dynamic pressure bearing high-speed motorized spindle of the present application;

[0047] Figure 2 is an enlarged view of A of Figure 1

[0048] Figure 3 is a partial structural schematic view of a dynamic pressure bearing high-speed motorized spindle of the present application;

[0049] Figure 4 is a structural schematic view of a dynamic pressure bearing high-speed motorized spindle of the present application;

[0050] Figure 5 is a sectional view of a dynamic pressure bearing of the present application;

[0051] Figure 6 is an assembly explosion view of a dynamic pressure bearing of the present application;

[0052] Figure 7 is a structural schematic view of a dynamic pressure bearing of the present application;

[0053] Figure 8 is a structural schematic view of a first impeller and a second impeller of the present application. DETAILED DESCRIPTION

[0054] In order to make the content of the present application more easily and clearly understood, the present application will be further described in detail below according to specific embodiments and in conjunction with the accompanying drawings.

[0055] Example One

[0056] As shown in Figures 1-8 , a dynamic pressure bearing high-speed motorized spindle comprises a stator component 1, a rotor component 2 and at least one dynamic pressure bearing 3; wherein,

[0057] The rotor component 2 is rotationally arranged in the stator component 1;

[0058] The dynamic pressure bearing 3 is arranged between the rotor component 2 and the stator component 1 and connected to the rotor component 2, and an air floating gap 4 is arranged between the outer peripheral wall of the dynamic pressure bearing 3 and the inner wall of the stator component 1;

[0059] The dynamic pressure bearing 3 is provided with a plenum chamber 5, a pressure maintaining chamber 6, a gas guiding passage 7, a gas outlet hole 8, at least one first impeller 9 and at least one second impeller 10; ​

[0060] The plenum chamber 5 is arranged around the rotor component 2;

[0061] The first impeller 9 is arranged on one side of the plenum chamber 5, and the second impeller 10 is arranged on the other side of the plenum chamber 5, so that when the rotor component 2 rotates, the dynamic pressure bearing 3 is driven to rotate, and then the first impeller 9 and the second impeller 10 are driven to rotate to pump external air into the plenum chamber 5;

[0062] The pressure maintaining chamber 6 is arranged outside the plenum chamber 5 and inside the air floating gap 4;

[0063] The air guide channel 7 is arranged between the plenum chamber 5 and the pressure maintaining chamber 6 and is used to connect the plenum chamber 5 and the pressure maintaining chamber 6, so that the pressure air in the plenum chamber 5 flows into the pressure maintaining chamber 6;

[0064] The air outlet hole 8 is arranged between the pressure maintaining chamber 6 and the air floating gap 4 and is used to connect the pressure maintaining chamber 6 and the air floating gap 4, so that the pressure air in the pressure maintaining chamber 6 flows into the air floating gap 4 to form an air film, and then the dynamic pressure bearing 3 is supported in the stator component 1 by the air film. Specifically, since the dynamic pressure bearing 3 is connected to the rotor component 2, when the rotor component 2 rotates at high speed, the dynamic pressure bearing 3 is driven to rotate at high speed, and then the first impeller 9 and the second impeller 10 in the dynamic pressure bearing 3 also rotate at high speed. The first impeller 9 and the second impeller 10 simultaneously pump external air from both sides into the plenum chamber 5. After the air is continuously compressed in the plenum chamber 5, the air pressure in the plenum chamber 5 increases, and then the high-pressure air in the plenum chamber 5 flows from the air guide channel 7 into the pressure maintaining chamber 6, and then flows from the air outlet hole 8 into the air floating gap 4 to form an air film. The rotor component 2 and the dynamic pressure bearing 3 are supported in the stator component 1 by the air film during high-speed rotation. There is no contact and friction between the dynamic pressure bearing 3 and the stator component 1, so the dynamic pressure bearing 3 is not damaged by wear and tear, the service life of the dynamic pressure bearing 3 is prolonged, the electric spindle is not damaged due to the damage of the dynamic pressure bearing 3, and the failure rate of the electric spindle is reduced.

[0065] Specifically, the air film provides non-contact support to make the high-speed rotating rotor component 2 and the dynamic pressure bearing 3 air-float in the stator component 1. The dynamic pressure bearing 3 does not contact and rub with the stator component 1 during rotation, so it will not be worn and will not vibrate, has a longer service life, better high-speed performance, and the higher the speed of the rotor component 2, the more the rotor component 2 tends to rotate around the center axis, and the more accurate the automatic centering is, and then the overall performance of the dynamic pressure bearing high-speed electric spindle of the present application is significantly better than that of conventional high-speed electric spindles.

[0066] Specifically, the air pressure in the plenum chamber 5 increases with the increase of the rotating speed of the rotor component 2, the higher the rotating speed of the rotor component 2, the greater the air pressure in the plenum chamber 5, and the higher the support stiffness of the gas film formed in the gas-floating gap 4, thus providing stable support at high speed and improving the stability and reliability at high speed.

[0067] Specifically, the pressure maintaining chamber 6 can be used to maintain the high-pressure gas from the plenum chamber 5 for a certain period of time, the flow rate of the gas in the pressure maintaining chamber 6 discharged from the gas outlet 8 into the gas-floating gap 4 is very small, thus the air pressure in the pressure maintaining chamber 6 can be maintained for a long enough time to allow the high-pressure gas in the plenum chamber 5 to be replenished into the pressure maintaining chamber 6, the pressure fluctuation in the pressure maintaining chamber 6 is small, a stable gas film can be formed in the gas-floating gap 4, and thus the stability of the gas-floating can be improved; and since the flow rate in the gas-floating gap 4 is very small, the exhaust sound can not be heard.

[0068] Specifically, the high-speed rotation of the first impeller 9 and the second impeller 10 can pump and compress air into the plenum chamber 5 to form high-pressure air in the plenum chamber 5, without the need for additional access to a high-pressure gas source, thus the structure is very simple and the cost is low, and the cost can be saved.

[0069] Specifically, the simultaneous pumping of air on both sides into the plenum chamber 5 by the first impeller 9 and the second impeller 10 can also improve the corresponding speed; the small air passage ratio is adopted in the dynamic pressure bearing 3 to enhance the gas-floating pressure and thus improve the support stiffness; the rotation directions of the first impeller 9 and the second impeller 10 are opposite.

[0070] As shown in Figure 1 , 2 , 3, 5, 6, 8, the first impeller 9 is provided with at least two and is stacked on one side of the plenum chamber 5, and the second impeller 10 is provided with at least two and is stacked on the other side of the plenum chamber 5; specifically, the first impeller 9 and the second impeller 10 are respectively stacked with more than two to increase the air pressure in the plenum chamber 5, thus improving the support stiffness of the gas film and avoiding vibration of the rotor component 2 during rotation. Specifically, the more the number of layers of the first impeller 9 and the second impeller 10 is stacked, the higher the air pressure in the plenum chamber 5 is, if the design rotating speed of the rotor component 2 is 18000 rpm, the first impeller 9 and the second impeller 10 need to be stacked by 2 layers respectively, and if the design rotating speed of the rotor component 2 is 24000 rpm, the first impeller 9 and the second impeller 10 need to be stacked by 3 layers respectively. In this embodiment, the first impeller 9 and the second impeller 10 are respectively stacked by 3 layers.

[0071] AsFigure 3 、 5 , as shown in 8, the first impeller 9 is arranged in a circumferential staggered manner, and the second impeller 10 is arranged in a circumferential staggered manner.

[0072] As shown in Figure 2 、 6 , 7, 8, the first impeller 9 is provided with a first positioning hole 11, and the first positioning hole 11 in the first impeller 9 is aligned with the first positioning hole 11 in the adjacent first impeller 9, thereby ensuring that the adjacent first impeller 9 is arranged in a circumferential staggered manner.

[0073] The second impeller 10 is provided with a second positioning hole 12, and the second positioning hole 12 in the second impeller 10 is aligned with the second positioning hole 12 in the adjacent second impeller 10, thereby ensuring that the adjacent second impeller 10 is arranged in a circumferential staggered manner.

[0074] As shown in Figure 1 、 2 , 3, 5, the dynamic pressure bearing 3 can include a shell body 13; wherein,

[0075] The gas floating gap 4 is arranged between the outer peripheral wall of the shell body 13 and the inner wall of the stator component 1;

[0076] The outer peripheral part of the first impeller 9 is connected with the shell body 13, and the inner peripheral part of the first impeller 9 is connected with the rotor component 2;

[0077] The outer peripheral part of the second impeller 10 is connected with the shell body 13, and the inner peripheral part of the second impeller 10 is connected with the rotor component 2;

[0078] The pressurizing cavity 5 is located between the shell body 13 and the rotor component 2, and the pressurizing cavity 5 is also located between the first impeller 9 and the second impeller 10;

[0079] The pressure maintaining cavity 6, the gas guiding channel 7 and the gas outlet hole 8 are all arranged in the shell body 13. Specifically, the rotor component 2 drives the first impeller 9 and the second impeller 10 to rotate, and the first impeller 9 and the second impeller 10 in turn drive the shell body 13 to rotate, thereby making the entire dynamic pressure bearing 3 rotate with the rotor component 2. The gas floating gap 4 is arranged between the shell body 13 and the stator component 1, which can make the shell body 13 float and support in the stator component 1, and also can avoid the stator component 1 and the shell body 13 from being worn.

[0080] Further specifically, the shell body 13 floating in the stator component 1 can make the entire dynamic pressure bearing 3 and the rotor component 2 all float and rotate in the stator component 1.

[0081] like Figure 1 , 2 As shown in Figures 3 and 5, the outer shell body 13 includes, for example but not limited to, the following structure: an outer ring wall 14, a left cavity wall 15, a right cavity wall 16, a left inner ring wall 17, and a right inner ring wall 18; wherein,

[0082] The air flotation gap 4 is located between the outer ring wall 14 and the inner wall of the stator component 1;

[0083] The outer periphery of the left cavity wall 15 and the outer periphery of the right cavity wall 16 are both connected to the outer ring wall 14;

[0084] The left inner ring wall 17 is connected to the inner circumference of the left cavity wall 15, and the right inner ring wall 18 is connected to the inner circumference of the right cavity wall 16.

[0085] The pressure-holding cavity 6 is located between the left cavity wall 15 and the right cavity wall 16;

[0086] The air outlet 8 is located in the outer ring wall 14 and communicates with the pressure holding cavity 6;

[0087] The air guide channel 7 is located between the left inner ring wall 17 and the right inner ring wall 18 and communicates with the pressure holding chamber 6;

[0088] The pressurization chamber 5 is located inside the left inner ring wall 17 and the right inner ring wall 18;

[0089] The outer periphery of the first impeller 9 and the outer periphery of the second impeller 10 are respectively connected to the outer ring wall 14; in this embodiment, the outer ring wall 14, the left cavity wall 15, the right cavity wall 16, the left inner ring wall 17, the right inner ring wall 18, the pressure holding cavity 6 and the air guiding channel 7 are all annular structures, and the air outlet 8 is provided in multiple ways and is evenly distributed in the outer ring wall 14 along the circumference.

[0090] like Figures 1-3 As shown, the stator component 1 is provided with a first chamber 19 corresponding to the dynamic pressure bearing 3 and located on one side of the corresponding dynamic pressure bearing 3. When the first impeller 9 rotates, it is used to pump the air in the first chamber 19 to the pressurization chamber 5.

[0091] The stator component 1 is provided with a second chamber 20 corresponding to the dynamic pressure bearing 3 and located on the other side of the corresponding dynamic pressure bearing 3. When the second impeller 10 rotates, it is used to draw the air in the second chamber 20 to the pressurization chamber 5. In this embodiment, the first chamber 19 and the second chamber 20 correspond one-to-one with the dynamic pressure bearing 3.

[0092] like Figures 1-3As shown, one end of the air flotation gap 4 is connected to the corresponding first chamber 19, and the other end of the air flotation gap 4 is connected to the corresponding second chamber 20, so that the air in the air flotation gap 4 flows into the first chamber 19 and the second chamber 20.

[0093] like Figures 1-3 As shown, the first chamber 19 is connected to the outside through at least one first through hole 21;

[0094] The second chamber 20 is connected to the outside through at least one second through hole 22;

[0095] Both the first through hole 21 and the second through hole 22 are provided in the stator component 1; in this embodiment, the first chamber 19 is connected to the outside through a plurality of first through holes 21 evenly distributed along the circumference, and the second chamber 20 is connected to the outside through a plurality of second through holes 22 evenly distributed along the circumference.

[0096] In this embodiment, two of each of the dynamic pressure bearing 3, the first chamber 19, and the second chamber 20 are provided, one in front of the other. The front dynamic pressure bearing 3 is located between the front first chamber 19 and the front second chamber 20, and the rear dynamic pressure bearing 3 is located between the rear first chamber 19 and the rear second chamber 20.

[0097] A front protective bearing 23 and a rear protective bearing 24 are provided between the stator component 1 and the rotor component 2. A front nut 25 and a rear nut 26 are connected to the rotor component 2. The front nut 25 is used to abut against the front protective bearing 23 and thus fix the front protective bearing 23. The rear nut 26 is used to abut against the rear protective bearing 24 and thus fix the rear protective bearing 24.

[0098] The stator component 1 includes a stator housing 27, a front end cover 28 connected to the front end of the stator housing 27, and a rear end cover 29 connected to the rear end of the stator housing 27.

[0099] The first chamber 19 at the front is located in the front end cover 28, the second chamber 20 at the front is located between the stator housing 27 and the front nut 25, the first chamber 19 at the rear is located between the stator housing 27 and the rear nut 26, and the second chamber 20 at the rear is located in the rear end cover 29.

[0100] Specifically, the rotor component 2 is rotationally arranged in the stator housing 27, the front end of the rotor component 2 passes through the front end cover 28, the rear end of the rotor component 2 passes through the rear end cover 29, the dynamic pressure bearing 3 is arranged between the stator housing 27 and the rotor component 2, the gas floating gap 4 is arranged between the outer ring wall 14 and the stator housing 27, and the front protection bearing 23 and the rear protection bearing 24 are both arranged between the rotor component 2 and the stator housing 27.

[0101] Further specifically, the first impeller 9 includes a first wheel ring part 30 and a plurality of first blade parts 31 arranged in sequence in the circumferential direction, the first wheel ring part 30 is connected to the rotor component 2, one end of the first blade part 31 is connected to the first wheel ring part 30, the other end of the first blade part 31 is connected to the outer ring wall 14 in the housing body 13, and the first positioning hole 11 is arranged on the first wheel ring part 30.

[0102] Further specifically, the second impeller 10 includes a second wheel ring part 32 and a plurality of second blade parts 33 arranged in sequence in the circumferential direction, the second wheel ring part 32 is connected to the rotor component 2, one end of the second blade part 33 is connected to the second wheel ring part 32, the other end of the second blade part 33 is connected to the outer ring wall 14 in the housing body 13, and the second positioning hole 12 is arranged on the second wheel ring part 32.

[0103] In the embodiment, the rotation directions of the first blade part 31 and the second blade part 33 are opposite, and the rotor component 2 can include a rotor shaft.

[0104] In summary, since the dynamic pressure bearing 3 is connected to the rotor component 2, when the rotor component 2 rotates at high speed, the dynamic pressure bearing 3 will also rotate at high speed, and the first impeller 9 and the second impeller 10 in the dynamic pressure bearing 3 will also rotate at high speed. When the first impeller 9 and the second impeller 10 rotate, they will simultaneously pump external air into the plenum chamber 5 from both sides. After the air is continuously compressed into the plenum chamber 5, the air pressure in the plenum chamber 5 increases, and then the high-pressure air in the plenum chamber 5 flows into the pressure maintaining chamber 6 from the gas guide channel 7, and then flows into the gas floating gap 4 from the air outlet hole 8 to form an air film. During high-speed rotation of the rotor component 2 and the dynamic pressure bearing 3, the rotor component 2 and the dynamic pressure bearing 3 are supported in the stator component 1 by the air film. There is no contact friction between the dynamic pressure bearing 3 and the stator component 1, so the dynamic pressure bearing 3 can be prevented from being damaged due to wear, thereby prolonging the service life of the dynamic pressure bearing 3, avoiding failure of the motorized spindle due to damage of the dynamic pressure bearing 3, and reducing the failure rate of the motorized spindle.

[0105] The air film provides non-contact support for the high-speed rotating rotor part 2 and the dynamic pressure bearing 3 to float in the stator part 1, and the dynamic pressure bearing 3 does not contact the stator part 1 during rotation, without friction, so it will not be worn and will not vibrate, has a longer service life, better high-speed performance, and the higher the speed of the rotor part 2, the more the rotor part 2 tends to rotate around the center axis, and the more accurate the automatic centering, thereby making the overall performance of the dynamic pressure bearing high-speed electric spindle of the embodiment significantly better than that of conventional high-speed electric spindles.

[0106] The air pressure in the plenum chamber 5 increases with the increase of the rotating speed of the rotor part 2, the higher the rotating speed of the rotor part 2, the greater the air pressure in the plenum chamber 5, and the higher the support stiffness of the air film formed in the air-float gap 4, so that stable support can be provided during high-speed rotation, improving the stability and reliability at high speed.

[0107] The pressure maintaining chamber 6 can be used to maintain the high-pressure gas from the plenum chamber 5 for a certain period of time, the flow rate of the gas in the pressure maintaining chamber 6 from the air outlet hole 8 into the air-float gap 4 is very small, so the air pressure in the pressure maintaining chamber 6 can be maintained for a long enough time to allow the high-pressure gas in the plenum chamber 5 to have enough time to supplement into the pressure maintaining chamber 6, the pressure fluctuation in the pressure maintaining chamber 6 is small, a stable air film can be formed in the air-float gap 4, thereby improving the stability of the air-float; and since the flow rate in the air-float gap 4 is very small, the exhaust sound cannot be heard.

[0108] The high-speed rotation of the first impeller 9 and the second impeller 10 pumps and compresses air into the plenum chamber 5, thereby forming high-pressure air in the plenum chamber 5, without the need for additional high-pressure gas sources, the structure is very simple, the cost is lower, and the cost can be saved.

[0109] Pumping air from both sides into the plenum chamber 5 by the first impeller 9 and the second impeller 10 can also improve the corresponding speed; the dynamic pressure bearing 3 adopts a small air passage ratio to enhance the air-float pressure and thereby improve the support stiffness.

[0110] Embodiment two

[0111] As shown in Figures 6-8 A dynamic pressure bearing, which is the dynamic pressure bearing 3 used in the dynamic pressure bearing high-speed electric spindle as described in embodiment one.

[0112] The above-described specific embodiments further illustrate the technical problems solved by the present application, technical solutions and beneficial effects, and it should be understood that the above-described specific embodiments are only specific embodiments of the present application and are not intended to limit the present application, and any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A high-speed electric spindle with a hydrodynamic bearing, characterized in that, It includes a stator assembly (1), a rotor assembly (2), and at least one hydrodynamic bearing (3); wherein, The rotor component (2) is rotatably disposed in the stator component (1); The dynamic pressure bearing (3) is disposed between the rotor component (2) and the stator component (1) and connected to the rotor component (2). An air flotation gap (4) is provided between the outer peripheral wall of the dynamic pressure bearing (3) and the inner wall of the stator component (1). The dynamic pressure bearing (3) is provided with a pressure boosting chamber (5), a pressure holding chamber (6), an air guide channel (7), an air outlet (8), at least one first impeller (9) and at least one second impeller (10). The pressurization chamber (5) is arranged around the rotor component (2); The first impeller (9) is located on one side of the pressurization chamber (5), and the second impeller (10) is located on the other side of the pressurization chamber (5) so that when the rotor component (2) rotates, it drives the dynamic pressure bearing (3) to rotate, thereby causing the first impeller (9) and the second impeller (10) to rotate respectively to draw external air into the pressurization chamber (5); The pressure-holding chamber (6) is arranged around the outside of the pressure-boosting chamber (5) and located inside the air flotation gap (4); The air guide channel (7) is located between the pressurization chamber (5) and the pressure holding chamber (6) and is used to connect the pressurization chamber (5) and the pressure holding chamber (6) so that the pressurized air in the pressurization chamber (5) flows into the pressure holding chamber (6); The air outlet (8) is located between the pressure holding chamber (6) and the air float gap (4) and is used to connect the pressure holding chamber (6) and the air float gap (4) so ​​that the pressurized air in the pressure holding chamber (6) flows into the air float gap (4) to form an air film, thereby allowing the dynamic pressure bearing (3) to float and be supported in the stator component (1) by the air film.

2. The high-speed electric spindle with hydrodynamic bearing according to claim 1, characterized in that, The first impeller (9) is provided in at least two and stacked on one side of the pressurization chamber (5); The second impeller (10) is provided in at least two and stacked on the other side of the pressurization chamber (5).

3. The high-speed electric spindle with hydrodynamic bearing according to claim 2, characterized in that, The first impeller (9) is stacked in a staggered manner along the circumference, and the second impeller (10) is stacked in a staggered manner along the circumference.

4. The high-speed electric spindle with hydrodynamic bearing according to claim 3, characterized in that, The first impeller (9) is provided with a first positioning hole (11), and the first positioning hole (11) in the first impeller (9) is aligned with the first positioning hole (11) in the adjacent first impeller (9); The second impeller (10) is provided with a second positioning hole (12), and the second positioning hole (12) in the second impeller (10) is aligned with the second positioning hole (12) in the adjacent second impeller (10).

5. The high-speed electric spindle with hydrodynamic bearing according to claim 1, characterized in that, The hydrodynamic bearing (3) includes a housing body (13); wherein, The air flotation gap (4) is located between the outer peripheral wall of the outer shell body (13) and the inner wall of the stator component (1); The outer periphery of the first impeller (9) is connected to the outer casing body (13), and the inner periphery of the first impeller (9) is connected to the rotor component (2); The outer periphery of the second impeller (10) is connected to the outer casing body (13), and the inner periphery of the second impeller (10) is connected to the rotor component (2); The pressurization chamber (5) is located between the outer casing (13) and the rotor component (2), and the pressurization chamber (5) is also located between the first impeller (9) and the second impeller (10); The pressure-holding cavity (6), the air guide channel (7), and the air outlet (8) are all located in the outer shell body (13).

6. The high-speed electric spindle with hydrodynamic bearing according to claim 5, characterized in that, The outer shell body (13) includes an outer ring wall (14), a left cavity wall (15), a right cavity wall (16), a left inner ring wall (17), and a right inner ring wall (18); wherein, The air flotation gap (4) is located between the outer ring wall (14) and the inner wall of the stator component (1); The outer periphery of the left cavity wall (15) and the outer periphery of the right cavity wall (16) are both connected to the outer ring wall (14); The left inner ring wall (17) is connected to the inner circumference of the left cavity wall (15), and the right inner ring wall (18) is connected to the inner circumference of the right cavity wall (16). The pressure-holding cavity (6) is located between the left cavity wall (15) and the right cavity wall (16); The air outlet (8) is located in the outer ring wall (14) and communicates with the pressure holding cavity (6); The air guide channel (7) is located between the left inner ring wall (17) and the right inner ring wall (18) and communicates with the pressure holding chamber (6); The pressurization chamber (5) is located inside the left inner ring wall (17) and the right inner ring wall (18); The outer periphery of the first impeller (9) and the outer periphery of the second impeller (10) are respectively connected to the outer ring wall (14).

7. The high-speed electric spindle with hydrodynamic bearing according to claim 1, characterized in that, The stator component (1) is provided with a first chamber (19) corresponding to the dynamic pressure bearing (3) and located on one side of the corresponding dynamic pressure bearing (3). When the first impeller (9) rotates, it is used to pump the air in the first chamber (19) to the pressurization chamber (5). The stator component (1) is provided with a second chamber (20) corresponding to the dynamic pressure bearing (3) and located on the other side of the corresponding dynamic pressure bearing (3). When the second impeller (10) rotates, it is used to pump the air in the second chamber (20) to the pressurization chamber (5).

8. The high-speed electric spindle with hydrodynamic bearing according to claim 7, characterized in that, One end of the air flotation gap (4) is connected to the corresponding first chamber (19), and the other end of the air flotation gap (4) is connected to the corresponding second chamber (20).

9. The high-speed electric spindle with hydrodynamic bearing according to claim 7, characterized in that, The first chamber (19) is connected to the outside through at least one first through hole (21); The second chamber (20) is connected to the outside through at least one second through hole (22); The first through hole (21) and the second through hole (22) are both provided in the stator component (1).

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