A high-precision liquid static pressure electric spindle

Abstract

The present invention discloses a high-precision liquid hydrostatic electric spindle, comprising a spindle housing, a rotating spindle and two sleeves arranged in the spindle housing, the two sleeves are sleeved on the rotating spindle, multiple oil chambers are processed on the inner hole walls of the two sleeves, and multiple oil channels are processed in the two sleeves, one end of the oil channel is connected with any oil chamber, and the other end of the oil channel passes through the outer ring wall of the sleeve, a high-pressure oil inlet hole is arranged on one side of the spindle housing, and an oil outlet hole is arranged on the other side, one end of each oil channel away from the oil chamber is connected with the high-pressure oil inlet hole, and a plunger-type feedback throttle is arranged in each oil channel. The present invention adopts liquid as the suspension support medium of the rotating spindle, and then configures the plunger-type feedback throttle in the corresponding oil channel, and the plunger-type feedback throttle can make the corresponding sleeve form a high-strength and high-rigidity support for the spindle, thereby ensuring the high rotation accuracy of the rotating spindle.

Description

Technical Field

[0001] The invention relates to the technical field of precision and ultra-precision machining, and in particular to a high-precision liquid static pressure electric spindle. Background Art

[0002] At present, most of the electric spindles used in CNC lathes and CNC machining centers use ball and roller bearings, which belong to the mechanical bearing hard contact support structure. The electric spindles using such mechanical bearings are very complex inside, and the precision requirements of each component are very high and the assembly is difficult. The machining accuracy of such mechanical bearing electric spindles will be affected by the rotation accuracy of its bearings, and because of the use of ball and roller bearings, the bearings themselves will have a certain amount of wear, and the high rotation accuracy of the bearings cannot be guaranteed for a long time. Summary of the invention

[0003] The object of the present invention is to provide a high-precision liquid hydrostatic electric spindle, which uses liquid as the suspension support medium of the rotating spindle, and then configures a plunger-type feedback throttle in the corresponding oil channel. The plunger-type feedback throttle can enable the corresponding shaft sleeve to form a high-strength and high-rigidity support for the spindle, thereby ensuring the high rotation accuracy of the rotating spindle.

[0004] An embodiment of the present invention is implemented as follows: a high-precision liquid static pressure electric spindle comprises a spindle housing and a rotating spindle, a first sleeve and a second sleeve arranged in the spindle housing, the first sleeve and the second sleeve are both sleeved on the rotating spindle, a motor rotor and a motor stator are sleeved on the rotating spindle in sequence from the inside to the outside, the motor rotor and the motor stator are located between the first sleeve and the second sleeve, a plurality of first oil chambers are machined on the inner hole wall of the first sleeve, the plurality of first oil chambers are arranged circumferentially along the central axis of the first sleeve, a plurality of first oil channels are machined in the first sleeve, one end of the first oil channel is connected to any first oil chamber, and the other end of the first oil channel passes through the outer wall of the first sleeve. annular wall, a plurality of second oil chambers are machined on the inner hole wall of the second sleeve, the plurality of second oil chambers are arranged circumferentially along the central axis of the second sleeve, a plurality of second oil channels are machined in the second sleeve, one end of the second oil channel is connected with any second oil chamber, the other end of the second oil channel passes through the outer annular wall of the second sleeve, a high-pressure oil inlet hole connected with its inner chamber is arranged on one side of the spindle housing, an oil outlet hole connected with its inner chamber is arranged on the other side of the spindle housing, one end of each first oil channel away from the first oil chamber is connected with the high-pressure oil inlet hole, one end of each second oil channel away from the second oil chamber is connected with the high-pressure oil inlet hole, and a plunger-type feedback throttle is arranged in each first oil channel and each second oil channel.

[0005] Furthermore, the outer annular walls of the first sleeve and the second sleeve are matched with the inner hole wall of the spindle housing, a cooling sleeve is provided on the motor stator, a spiral groove is processed on the outer annular wall of the cooling copper sleeve, and the two ends of the spiral groove respectively penetrate the two side end faces of the cooling copper sleeve, the high-pressure oil inlet hole of the spindle housing is connected with the spiral groove of the cooling copper sleeve, and a cooling oil storage cavity is formed between the two ends of the cooling copper sleeve and the end faces of the first sleeve and the second sleeve.

[0006] Furthermore, an even number of first oil channels are processed in the first sleeve, and every two first oil channels form a group. The two first oil channels in each group are symmetrically distributed about the central axis of the first sleeve. An even number of second oil channels are processed in the second sleeve, and every two second oil channels form a group. The two second oil channels in each group are symmetrically distributed about the central axis of the second sleeve.

[0007] Further, the plunger-type feedback throttle comprises a working body and a comparison body, both of which have an inner cavity. The inner cavity of the working body passes through one side of the working body, and the inner cavity of the comparison body passes through one side of the comparison body. The side of the working body penetrated by its inner cavity is sealed and connected with the side of the comparison body penetrated by its inner cavity. The inner cavity of the working body comprises a first liquid inlet channel, a working cavity and a first liquid outlet channel. One end of the first liquid inlet channel passes through one side of the working body and is connected to the corresponding oil channel, the other end of the first liquid inlet channel is connected to the working cavity, one end of the first liquid outlet channel passes through one side of the working body and is connected to the corresponding oil channel, and the other end of the first liquid outlet channel is connected to the working cavity. The inner cavity of the comparison body comprises a second liquid inlet channel and a comparison cavity. One end of the second liquid inlet channel is connected to the first liquid inlet channel, and the other end of the second liquid inlet channel is connected to the comparison cavity. The working cavity and the comparison cavity are connected to each other, and a feedback adjustment cavity is formed between the working cavity and the comparison cavity, and an adjustment plunger is movably arranged in the feedback adjustment cavity.

[0008] Furthermore, the working body and the comparison body are both cylinders, the working body has a protrusion processed on one end face, the comparison body has a groove matched with the protrusion processed on one end face, the protrusion of the working body and the groove of the comparison body are sealed and plugged into each other and cooperate with each other, the working body has a trough cavity processed on the end face away from the protrusion, and one end of the first liquid outlet channel is connected to the trough cavity; the working body has a plurality of diversion holes connected to the working cavity processed on the end face away from the protrusion, and each diversion hole is connected to the trough cavity at one end away from the working cavity.

[0009] Further, the first liquid inlet channel includes a first inlet channel, a first branch channel and a first inlet channel, one end of the first inlet channel penetrates a side wall of a working body and is connected to the corresponding oil channel, the other end of the first inlet channel is connected to the first inlet channel, one end of the first inlet channel away from the first inlet channel is connected to the working chamber, one end of the first branch channel is connected to the first inlet channel, the other end of the first branch channel penetrates a side end surface of the working body close to the comparison body, the second liquid inlet channel includes a second inlet channel and a second inlet channel, one end of the second inlet channel penetrates a side end surface of the comparison body close to the working body, and one end of the second inlet channel penetrating the comparison body is connected to and communicated with one end of the first branch channel penetrating the working body, the other end of the second inlet channel is connected to the second inlet channel, and one end of the second inlet channel away from the second inlet channel is connected to the comparison chamber.

[0010] Furthermore, the first inlet channel is arranged along the axial direction of the working body, the second inlet channel is arranged along the axial direction of the comparison body, the feedback adjustment chamber is a columnar cavity, the first inlet channel, the second inlet channel and the feedback adjustment chamber are coaxially distributed, the adjustment plunger matches the shape of the feedback adjustment chamber, and the axis of the adjustment plunger coincides with or is parallel to the axis of the feedback adjustment chamber.

[0011] Furthermore, the distance between one side end face of the regulating plunger and the end face of the feedback regulating chamber close to each other is 0.1-0.4 mm, and the distance between the side ring wall of the regulating plunger and the side ring wall of the feedback regulating chamber is 0.001-0.005 mm.

[0012] Furthermore, the working chamber and the comparison chamber are both two-stage stepped cylindrical chambers, the expanded section of the working chamber is connected to the first inlet channel, the expanded section of the comparison chamber is connected to the second inlet channel, the reduced section of the working chamber is connected to and connected to the reduced section of the comparison chamber, and the side ring wall of the regulating plunger is 0.001 to 0.005 mm away from the reduced section of the working chamber and the reduced section of the comparison chamber.

[0013] Furthermore, an annular groove is processed on the side wall of the working body, the axis of the annular groove coincides with the axis of the working body, the end of the first inlet channel away from the first inlet channel is connected to the annular groove, and the end of the second inlet channel away from the second inlet channel is connected to the annular groove.

[0014] The beneficial effects of the embodiments of the present invention are:

[0015] The hydrostatic electric spindle provided in an embodiment of the present invention is achieved by filling liquid (hydraulic oil) into the spindle housing, and the liquid then enters the supporting sleeve and performs "oil floating support" on both ends of the rotating spindle. At the same time, a plunger-type feedback throttle is arranged in the oil channel of the supporting sleeve. The plunger-type feedback throttle has the advantages of spontaneity and active compensation, and can throttle and control the liquid, so that the corresponding sleeve forms a high-strength and high-rigidity support for the rotating spindle, ultimately ensuring the high rotation accuracy of the rotating spindle. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0017] Figure 1 A schematic cross-sectional view of a hydrostatic electric spindle provided in an embodiment of the present invention;

[0018] Figure 2 A cross-sectional schematic diagram of a plunger-type feedback throttle provided in an embodiment of the present invention;

[0019] Figure 3 A schematic diagram of the internal structure of a plunger-type feedback throttle provided in an embodiment of the present invention.

[0020] Icons: 1- plunger feedback throttle; 2- spindle housing; 3- rotating spindle; 4- motor rotor; 5- motor stator; 6- cooling sleeve; 7- first sleeve; 8- second sleeve; 9- high-pressure oil inlet hole; 10- oil outlet hole; 11- oil channel hole; 12- first oil channel; 13- first oil chamber; 14- second oil channel; 15- second oil chamber; 101- working body; 102- comparison body; 103- first liquid inlet Flow channel; 104-working chamber; 105-first liquid outlet flow channel; 106-protrusion; 107-sinking chamber; 108-diverter hole; 109-second liquid inlet flow channel; 110-comparison chamber; 111-adjusting plunger; 112-expanding groove; 113-annular groove; 1031-first inlet flow channel; 1032-first inlet flow channel; 1033-first diverter flow channel; 1091-second inlet flow channel; 1092-second inlet flow channel. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, 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 part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0022] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0024] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, or the positions or positional relationships in which the product of the invention is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0025] In addition, the terms "parallel", "vertical", etc. do not mean that the components must be absolutely parallel or vertical, but can be slightly tilted. For example, "parallel" only means that its direction is more parallel than "vertical", and does not mean that the structure must be completely parallel, but can be slightly tilted.

[0026] The terms "roughly" and "basically" are intended to explain that the relevant content does not require absolute accuracy, but can have certain deviations. For example, "roughly equal to" does not only mean absolute equality. Since it is difficult to achieve absolute "equality" in actual production and operation, there are generally certain deviations. Therefore, in addition to absolute equality, "roughly equal to" also includes the above-mentioned situation with certain deviations. Taking this as an example, in other cases, unless otherwise specified, the terms "roughly" and "basically" have similar meanings to the above.

[0027] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" 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 direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0028] Example

[0029] Please refer to Figure 1 to Figure 3The present embodiment provides a high-precision liquid static pressure electric spindle, including a spindle housing 2, a rotating spindle 3, a first sleeve 7 and a second sleeve 8 arranged in the spindle housing 2, wherein the first sleeve 7 and the second sleeve 8 are both sleeved on the rotating spindle 3. Preferably, the first sleeve 7 and the second sleeve 8 are respectively located near the two ends of the rotating spindle 3, and can support the positions near the two ends of the rotating spindle 3 to obtain higher stability. The rotating spindle 3 is sleeved with a motor rotor 4 and a motor stator 5 in sequence from the inside to the outside, and the motor rotor 4 and the motor stator 5 are located between the first sleeve 7 and the second sleeve 8, so as to form a structural condition for driving the middle part of the rotating spindle 3 to rotate. In the present embodiment, four first oil chambers 13 are machined on the inner hole wall of the first sleeve 7, and the four first oil chambers 13 are evenly arranged along the circumferential direction of the central axis of the first sleeve 7, and an oil drain groove is arranged between adjacent first oil chambers 13, and the liquid (hydraulic oil) in the first oil chamber 13 can be discharged into the inner cavity space in the middle part of the spindle housing 2 through the communication effect of the oil drain groove. Similarly, four second oil chambers 15 are machined on the inner hole wall of the second sleeve 8, and the four second oil chambers 15 are arranged circumferentially along the central axis of the second sleeve 8, and an oil drain groove is provided between adjacent first oil chambers 13, and the liquid (hydraulic oil) in the first oil chamber 13 can be discharged into the inner cavity space in the middle of the spindle housing 2 through the communication function of the oil drain groove. A high-pressure oil inlet hole 9 communicating with the inner cavity of the spindle housing 2 is provided on one side of the spindle housing 2, and an oil outlet hole 10 communicating with the inner cavity of the spindle housing 2 is provided on the other side of the spindle housing 2. The positions of the high-pressure oil inlet hole 9 and the oil outlet hole 10 are relatively arranged so that the high-pressure oil can fill the entire spindle housing 2 to form a complete oil circuit recovery channel (its sealing consideration is not the invention point of this application, so it will not be repeated).

[0030] A plurality of first oil passages 12 are machined in the first sleeve 7, and one end of the first oil passage 12 is connected to any first oil chamber 13, which means that one end of each first oil passage 12 can be connected to any first oil chamber 13, so as to ensure that the proximal end of the rotating spindle 3 is supported by oil floating through the first oil chamber 13. The other end of the first oil passage 12 passes through the outer ring wall of the first sleeve 7, and is connected to the high-pressure oil inlet hole 9 through the oil passage hole 11 machined in the spindle housing 2, so that the liquid entering the high-pressure oil inlet hole 9 enters each first oil passage 12 through the oil passage hole 11, so that the proximal end of the rotating spindle 3 can be supported by oil floating. Similarly, a plurality of second oil passages 14 are machined in the second sleeve 8, one end of the second oil passage 14 is connected to any second oil chamber 15, and the other end of the second oil passage 14 passes through the outer ring wall of the second sleeve 8, and is connected to the high-pressure oil inlet hole 9 through the oil passage hole 11 machined in the spindle housing 2. The oil passage hole 11 here and the above-mentioned oil passage hole 11 can be located in the same working horizontal plane, or in different working horizontal planes, and can be designed and machined according to the requirements for convenient machining of the entire spindle housing 2. In order to make the liquid in the first oil chamber 13 and the second oil chamber 15 have a better throttling control effect when the rotating spindle 3 is oil-floating supported, so as to make the rotating spindle 3 obtain sufficient support stiffness and high-precision rotation performance, a plunger-type feedback throttle 1 is provided in each first oil passage 12 and each second oil passage 14, and the plunger-type feedback throttle 1 is fixedly assembled in the corresponding oil passage, and the corresponding oil passage refers to the first oil passage 12 or the second oil passage 14 corresponding to the installation position, and the corresponding oil passages are referred to as the same in the following. In this embodiment, the plunger-type feedback throttle 1 has the advantages of spontaneity and active compensation, and can throttle and control the liquid, so that the corresponding first sleeve 7 or second sleeve 8 forms a high-strength and high-rigidity support for the rotating spindle 3, ultimately ensuring the high rotation accuracy of the rotating spindle 3.

[0031] In this embodiment, since the motor rotor 4 and the motor stator 5 will generate a lot of heat when working, the hydraulic oil has an oil cooling effect. Most of the current electric spindles adopt the outer shell oil cooling method. Although it can have a good cooling effect on the outer shell, it has little cooling effect on the motor rotor 4 and the motor stator 5 therein. A cooling sleeve 6 is added here, which not only has a better cooling effect on the spindle housing 2, but also has a good cooling effect on the motor rotor 4 and the motor stator 5. In addition, it can guide the hydraulic oil to make it more evenly distributed in the inner cavity of the spindle housing 2, so as to achieve a uniform cooling effect while also achieving a uniform oil floating support effect. Specifically, the outer annular walls of the first sleeve 7 and the second sleeve 8 are matched with the inner hole wall of the spindle housing 2, and the match here refers to one of clearance fit, transition fit or interference fit. A cooling sleeve 6 is sleeved on the motor stator 5, and the outer annular wall of the cooling sleeve 6 is matched with the inner hole wall of the spindle housing 2, and a spiral groove is processed on the outer annular wall of the cooling copper sleeve 6. The spiral groove is preferably one, and the two end ports of the spiral groove respectively penetrate the two side end faces of the cooling copper sleeve 6. The high-pressure oil inlet hole 9 of the spindle housing 2 is connected with the spiral groove of the cooling copper sleeve 6, and the liquid enters the spiral groove through the high-pressure oil inlet hole 9, and enters the middle inner cavity of the spindle housing 2 from both sides of the spiral groove. A cooling oil storage cavity is formed between the two ends of the cooling copper sleeve 6 and the end faces of the first sleeve 7 and the second sleeve 8. The liquid entering the spindle housing 2 is mainly distributed to the cooling oil storage cavities on both sides, and the motor rotor 4, the motor stator 5 and the interior of the entire spindle housing 2 can be oil-cooled. In addition, the longitudinal cross-section of the cooling oil storage cavity is annular. After the liquid fills the spindle housing 2, it can flow back to the hydraulic station from the oil outlet 10, thereby forming a complete oil channel circulation and making the liquid in the spindle housing 2 form a dynamic balance.

[0032] When one side of the rotating spindle 3 is loaded, the equilibrium state of the liquid in the spindle housing 2 will be broken. In order to increase the stability of this equilibrium state, in this embodiment, an even number of first oil passages 12 are processed in the first sleeve 7, and every two first oil passages 12 form a group. The two first oil passages 12 in each group are symmetrically distributed about the central axis of the first sleeve 7. Similarly, an even number of second oil passages 14 are processed in the second sleeve 8, and every two second oil passages 14 form a group. The two second oil passages 14 in each group are symmetrically distributed about the central axis of the second sleeve 8. This distribution form of the oil passages can better play the throttling control function of the plunger-type feedback throttle 1 in the corresponding oil passages. When one side of the rotating spindle 3 is loaded, the plunger-type feedback throttles 1 in the corresponding two oil passages in a group complement each other, which can form a relatively sufficient pulling effect on the rotating spindle, so that the force and offset generated by the rotating spindle 3 when loaded are instantly restored, thereby ensuring a good rigidity of the rotating spindle 3.

[0033] The plunger-type feedback throttle 1 in one group of oil passages and the inner thereof is used for explanation. The plunger-type feedback throttle 1 includes a working body 101 and a comparative body 102, both of which have inner cavities. The shapes of the working body 101 and the comparative body 102 can be regular cuboids, regular polygonal prisms, cones, cylinders, or a combination of the two, or irregular stepped cylinders or other shapes. In this embodiment, in order to adapt to the shape of the corresponding oil passage (the first oil passage 12 or the second oil passage 14), the working body 101 and the comparative body 102 are roughly cylindrical, and the outer wall of the cylinder cooperates with the inner wall of the corresponding oil passage to ensure a better sealing barrier effect. The working body 101 and the comparative body 102 are preferably coaxially distributed, and the two can be welded, screwed, integrally fused or spliced, and only need to ensure good connection performance and sealing performance. A sealed splicing is adopted here. Specifically, a cylindrical protrusion 106 is processed on one end face of the working body 101, and a groove matching the protrusion 106 is processed on one end face of the comparison body 102. The protrusion 106 of the working body 101 and the groove of the comparison body 102 are sealedly plugged and matched with each other. The sealed plug-in and matching can be sealed by a metal sealing ring after a transition or clearance fit between the two. An interference fit between the groove and the protrusion 106 is adopted here to achieve the purpose of stable connection and sealed connection. The interference fit method adopts the method of high-temperature expansion of the groove and then stable plugging with the protrusion 106 (clearance or transition fit), and the groove directly reaches the form of interference fit with the protrusion 106 after cooling.

[0034] The inner cavity of the working body 101 passes through one end face of the working body 101 close to the comparison body 102, and the inner cavity of the comparison body 102 passes through one end face of the comparison body 102 close to the working body 101. The inner cavities of the two are connected to each other. Since the protrusion 106 and the groove are sealed and plugged in, a good connection and sealing performance between the inner cavities of the two can be guaranteed. The inner cavity of the working body 101 includes a first liquid inlet channel 103, a working cavity 104 and a first liquid outlet channel 105. One end of the first liquid inlet channel 103 passes through one side of the working body 101 and is connected to the inner cavity of the corresponding oil channel. The other end of the first liquid inlet channel 103 is connected to the working cavity 104. One end of the first liquid outlet channel 105 passes through one side of the working body 101 and is connected to the inner cavity of the corresponding oil channel. The other end of the first liquid outlet channel 105 is connected to the working cavity 104. The inner cavity of the comparison body 102 includes a second inlet channel 103, a working cavity 104 and a first liquid outlet channel 105. The second liquid inlet channel 109 and the comparison chamber 110, one end of the second liquid inlet channel 109 is connected to the first liquid inlet channel 103, and the other end of the second liquid inlet channel 109 is connected to the comparison chamber 110, and the working chamber 104 and the comparison chamber 110 are connected to each other, which means that the working body 101 is sealed and connected with the comparison chamber 110 of the comparison body 102 through its working chamber 104, and the working chamber 104 and the comparison chamber 110 are combined to form a feedback regulating chamber, and an adjusting plunger 111 is movably provided in the feedback regulating chamber. When liquid enters from the first liquid inlet channel 103 through the corresponding oil channel, a part of the liquid enters the working chamber 104 through the first liquid inlet channel 103 and then flows out through the first liquid outlet channel 105, and the other part of the liquid enters the comparison chamber 110 through the second liquid inlet channel 109, and then converges into the working chamber 104 and flows out through the first liquid outlet channel 105, so that the liquid fills the entire feedback adjustment chamber and forms a static pressure balance state of the liquid.

[0035] The first liquid outlet channel 105 is communicated with the oil channel on the corresponding sleeve. When the rotating main shaft 3 is subjected to load on one side, it will cause the rotating main shaft 3 to squeeze the supporting oil film at the first oil chamber 13 or the second oil chamber 15. The oil film at the place with higher pressure will flow back to the first liquid outlet channel 105 through the corresponding oil channel, so that the side of the regulating plunger 111 close to the first liquid outlet channel 105 is instantly squeezed, causing the regulating plunger 111 to move toward the side away from the first liquid outlet channel 105. The displacement distance is very short, generally not exceeding 0.5mm, and the time required for the displacement process is also very short, thereby instantly breaking the balanced state of the oil pressure in the entire feedback regulating chamber, especially at both ends of the regulating plunger 111, where the oil pressure imbalance is most serious. An instantaneous negative pressure is formed on the side of the regulating plunger 111 close to the first liquid outlet channel 105, and the side of the regulating plunger 111 away from the first liquid outlet channel 105 An instantaneous high pressure is formed on the side, and the pressure difference on both sides causes the regulating plunger 111 to shift to the equilibrium position again. This process takes a very short time, so that the oil pressure in the entire feedback regulating chamber reaches a balanced state again. In addition, due to the instantaneous negative pressure formed on the side of the regulating plunger 111 close to the first liquid outlet channel 105, the liquid in the first liquid inlet channel 103 will press the liquid into the space between the side of the regulating plunger 111 close to the first liquid outlet channel 105 and the working chamber 104 during this instantaneous process. When the feedback regulating chamber recovers from an imbalance to a balanced state, the pressed oil is replenished from the first liquid outlet channel 105 to the oil channel of the corresponding shaft sleeve, thereby providing a restoring support force for the rotating spindle 3, so that the rotating spindle 3 returns to a balanced state (a state close to the axis) again, so that the rotating spindle 3 can obtain higher rotation accuracy and support stiffness between dynamic and static changes.

[0036] On the contrary, the two plunger-type feedback throttles 1 in a group of corresponding oil passages have opposite forces. Taking the other plunger-type feedback throttle 1 on the corresponding side as an example, the side of the rotating main shaft 3 away from the extrusion support oil film will form a pulling force on the oil film, which will accelerate the liquid in the first outlet flow channel 105 to be discharged into the corresponding oil passage, so that the oil pressure on the side of the regulating plunger 111 close to the first outlet flow channel 105 suddenly decreases, while the liquid on the other side of the regulating plunger 111 is at a relatively high pressure. Under the action of the pressure difference, the regulating plunger 111 moves toward The first liquid outlet channel 105 moves to one side, and the moving distance is also very short, generally not exceeding 0.5 mm, so that the liquid cannot be quickly and in large quantities replenished from the first liquid inlet channel 103 through the working chamber 104 to the first liquid outlet channel 105. Due to the action of the plunger-type feedback throttle 1 used in conjunction with it on the opposite side, the rotating spindle 3 returns to a balanced state again, and part of the liquid flows back to the first liquid outlet channel 105 of the plunger-type feedback throttle 1 on this side, and the pressure is restored to balance, so that the regulating plunger 111 returns to a balanced state again. Therefore, a group of inner plunger-type feedback throttles 1 can be used in conjunction to obtain a very large supporting stiffness of the rotating spindle 3, thereby ensuring a very high rotation accuracy of the rotating spindle 3. Compared with other throttles, this plunger-type feedback throttle 1 has the advantages of spontaneous and active compensation, and has high feedback sensitivity and extremely short action time. It is very suitable for the application of hydrostatic support structures in precision and ultra-precision spindle rotation technology, and plays a role in supporting and ensuring rotation accuracy.

[0037] In order to further adapt to the shape of the oil channel in the corresponding sleeve and enable the plunger-type feedback throttle 1 to achieve a uniform and balanced oil supply state with the corresponding oil channel, a cylindrical groove cavity 107 is processed on the end face of the working body 101 away from the protrusion 106. The diameter of the groove cavity 107 is smaller than the diameter of the corresponding oil channel, so that all liquids can be discharged into the corresponding oil channel through the groove cavity 107. One end of the first liquid outlet channel 105 is connected to the sink cavity 107. A plurality of diverter holes 108 connected to the working cavity 104 are processed on the end surface of the working body 101 away from the protrusion 106. The end of each diverter hole 108 away from the working cavity 104 is connected to the sink cavity 107. In this way, the liquid in the working cavity 104 can flow into the oil channel of the corresponding shaft sleeve through the first liquid outlet channel 105 and each diverter hole 108, thereby increasing the uniformity and stability of the oil supply between the working body 101 and the oil channel. In addition, by adding the sink cavity 107, The first liquid outlet channel 105 and each diversion hole 108 can converge in the trough chamber 107 to form a converging effect, so as not to disperse and turbulent the liquid flow, thereby affecting the stability of liquid reflux or outflow; in order to increase the smoothness and uniformity of the liquid flow in the working chamber 104 and the trough chamber 107, each diversion hole 108 has the same aperture and length as the first liquid outlet channel 105, and each diversion hole 108 is parallel to the first liquid outlet channel 105. The first liquid outlet channel 105 and all the diversion holes 108 can be arranged circumferentially around the axis of the trough chamber 107.

[0038] In order to facilitate the processing of the first liquid inlet channel 103 and the second liquid inlet channel 109 and to provide a certain bending, deflection or blocking effect on the liquid, the first liquid inlet channel 103 includes a first inlet channel 1031, a first branch channel 1033 and a first inlet channel 1032. The first inlet channel 1031 is arranged radially along the working body 101. One end of the first inlet channel 1031 passes through a side wall of the working body 101 and is connected to the corresponding oil channel. The other end of the first inlet channel 1031 is connected to the first inlet channel 1032. The end of the first inlet channel 1032 away from the first inlet channel 1031 is connected to the working chamber 104. One end of the flow channel 1033 is connected to the first flow inlet channel 1031, and the other end of the first branch flow channel 1033 passes through one end surface of the working body 101 close to the comparison body 102. The second liquid inlet flow channel 109 includes a second flow inlet channel 1091 and a second flow inlet channel 1092. The second flow inlet channel 1091 is roughly L-shaped. One end of the second flow inlet channel 1091 passes through one end surface of the comparison body 102 close to the working body 101, and one end of the second flow inlet channel 1091 passing through the comparison body 102 is connected and communicated with one end of the first branch flow channel 1033 passing through the working body 101. The connection and communication are carried out in a seamless or micro-seam connection manner. The other end of the second inlet channel 1091 is connected to the second inlet channel 1092, and the end of the second inlet channel 1092 away from the second inlet channel 1091 is connected to the comparison chamber 110, and one of the middle turning points of the second inlet channel 1091 adopts a through hole, which means that one of the long end or the short end of the second inlet channel 1091 is in the form of a through hole, so as to facilitate processing to form an L-shaped turning point, and the end of the through hole that is connected to the corresponding oil channel is a sealed end, which can be sealed with a sealing plug or a fixed plug. The first liquid inlet channel 103 and the second liquid inlet channel 109 are connected in sections to increase the degree of bending of the two. After multiple bends, a certain deflection or blocking effect can be formed on the fluid, which reduces the smoothness of the fluid flow relative to the flow of the straight channel, thereby further increasing the throttling effect and function, and making the equilibrium state formed in the entire feedback regulation chamber more stable.

[0039] In order to allow the liquid to evenly enter the first inlet channel 1031 and the second inlet channel 1091, an annular groove 113 is processed on the side wall of the working body 101, and the annular groove 113 is connected to the corresponding oil channel hole 11, and the axis of the annular groove 113 coincides with the axis of the working body 101. The end of the first inlet channel 1031 away from the first inlet channel 1032 is connected to the annular groove 113, and the end of the second inlet channel 1091 away from the second inlet channel 1092 is connected to the annular groove 113, and the part of the first inlet channel 1031 connected to the annular groove 113 and the part of the second inlet channel 1091 connected to the annular groove 113 are located at the same position of the annular groove 113 and meet each other. By adding the annular groove 113, the liquid can be filled with the annular groove 113 through the oil channel hole 11 and can be simultaneously or synchronously poured into the first inlet channel 1031 and the second inlet channel 1091 from the meeting point, so that the entire feedback regulation chamber forms a balanced state more quickly.

[0040] In order to make the regulating plunger 111 move smoothly in the feedback regulating chamber and have the conditions for rapid feedback regulation, the first inlet channel 1032 is arranged along the axial direction of the working body 101, and the second inlet channel 1092 is arranged along the axial direction of the comparison body 102. The feedback regulating chamber is a roughly cylindrical chamber. The first inlet channel 1032, the second inlet channel 1092 and the feedback regulating chamber are coaxially distributed. The regulating plunger 111 matches the shape of the feedback regulating chamber, and the axis of the regulating plunger 111 coincides with or is parallel to the axis of the feedback regulating chamber. This ensures that the regulating plunger 111 and the feedback regulating chamber are highly matched or highly similar, thereby ensuring smooth and quick movement. Secondly, the axes of the first inlet channel 1032, the second inlet channel 1092, the feedback regulating chamber and the regulating plunger 111 are at least parallel or even coincide with each other, so that the action direction of the liquid can be fully or completely directed to the end face of the regulating plunger 111. Not only will there be no load offset or incomplete action, but there will also be no load non-concentration, making the movement of the regulating plunger 111 more stable and quick.

[0041] In order to make the balanced state of the regulating plunger 111 in the feedback regulating chamber more stable and recover more quickly after imbalance, the distance between the end face of one side of the regulating plunger 111 and the end face close to each other in the feedback regulating chamber is 0.1-0.4mm, preferably 0.245mm, so that the regulating plunger 111 can be displaced in a very small gap after imbalance, and a relatively obvious pressure difference can be formed, so that the pressure difference on both sides of the regulating plunger 111 will not change much or be insignificant due to the large distance; the side ring wall of the regulating plunger 111 and the side ring wall of the feedback regulating chamber are 0.001-0.005mm, preferably 0.002mm, which can ensure that the liquids on both sides of the regulating plunger 111 will flow into each other, resulting in a relatively obvious "oil flow" phenomenon. In order to enable the liquid (hydraulic oil) in the feedback regulating chamber to form an "oil floating support" between the regulating plunger 111, so that the regulating plunger 111 moves more stably and smoothly, the working chamber 104 and the comparison chamber 110 are both two-stage step-type cylindrical cavities, the expanded diameter section of the working chamber 104 is connected to the first inlet channel 1032, and the diameter of the expanded diameter section of the working chamber 104 is 2 to 3 times the diameter of the first inlet channel 1032, the expanded diameter section of the comparison chamber 110 is connected to the second inlet channel 1092, and the diameter of the expanded diameter section of the comparison chamber 110 is 2 to 3 times the diameter of the second inlet channel 1092, and the reduced diameter section of the working chamber 104 is connected and connected to the reduced diameter section of the comparison chamber 110 , and the reduced diameter section of the working chamber 104 has the same diameter as the reduced diameter section of the comparison chamber 110, and the interface has a smooth transition, wherein the side ring wall of the regulating plunger 111 is spaced from the reduced diameter section of the working chamber 104 and the reduced diameter section of the comparison chamber 110 by the above-mentioned gap, and the gap range is 0.001-0.004mm, preferably 0.002mm. When the liquid passes through this gap, it can form an oil film support with a larger film pressure on the side ring wall of the regulating plunger 111, so that the regulating plunger 111 is more stable when moving, and the expanded diameter section of the working chamber 104 and the expanded diameter section of the comparison chamber 110 can store more liquid, which can be supplemented when necessary or the rate of liquid inflow or outflow can be increased. In addition, an expansion groove 112 is processed on the reduced diameter section of the working chamber 104 or the reduced diameter section of the comparison chamber 110. Here, it is preferred to set the expansion groove 112 at the junction of the reduced diameter section of the comparison chamber 110 and the groove. The expansion groove 112 can increase the rate of liquid flowing in or out of the middle part of the regulating plunger 111.

[0042] To sum up, the electric spindle provided by the embodiment of the utility model is provided with a plunger-type feedback throttle 1 in the corresponding sleeve. The distribution form of the throttle and the adjustment plunger 111 are provided in a channel of a specific shape in the throttle. The adjustment plunger 111 has a shape and a load-bearing surface that are highly symmetrical, can quickly return to a balanced state after an unbalanced state, and can spontaneously and actively adjust the oil pressure. Through the corresponding oil channel connection, the rotating spindle 3 will not easily be in a long-term offset state after being pressurized, so that the rotating spindle 3 has a very large support stiffness, so as to facilitate the high precision and reliability of subsequent processing.

[0043] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection scope of the present invention. It should be noted that the structures or components illustrated in the accompanying drawings are not necessarily drawn to scale, and the present invention omits the description of known components and processing technologies and processes to avoid unnecessary limitations on the present invention.

Claims

1. A high-precision liquid static pressure electric spindle, characterized in that: The invention comprises a spindle housing, a rotating spindle, a first sleeve and a second sleeve arranged in the spindle housing, the first sleeve and the second sleeve are both sleeved on the rotating spindle, a motor rotor and a motor stator are sleeved on the rotating spindle in sequence from the inside to the outside, the motor rotor and the motor stator are located between the first sleeve and the second sleeve, a plurality of first oil chambers are machined on the inner hole wall of the first sleeve, the plurality of first oil chambers are arranged circumferentially along the central axis of the first sleeve, a plurality of first oil channels are machined in the first sleeve, one end of the first oil channel is connected to any first oil chamber, the other end of the first oil channel passes through the outer ring wall of the first sleeve, the inner hole wall of the second sleeve is provided with a plurality of first oil chambers, and the inner hole wall of the second sleeve is provided with a plurality of first oil chambers. A plurality of second oil chambers are machined on the hole wall, and the plurality of second oil chambers are arranged circumferentially along the central axis of the second sleeve. A plurality of second oil passages are machined in the second sleeve, and one end of the second oil passage is connected to any second oil chamber, and the other end of the second oil passage passes through the outer annular wall of the second sleeve. A high-pressure oil inlet hole connected to the inner cavity of the spindle housing is provided on one side of the spindle housing, and an oil outlet hole connected to the inner cavity of the spindle housing is provided on the other side of the spindle housing. One end of each first oil passage away from the first oil chamber is connected to the high-pressure oil inlet hole, and one end of each second oil passage away from the second oil chamber is connected to the high-pressure oil inlet hole. A plunger-type feedback throttle is provided in each first oil passage and each second oil passage. The outer ring walls of the first sleeve and the second sleeve are matched with the inner hole wall of the main shaft housing, the motor stator is sleeved with a cooling sleeve, the outer ring wall of the cooling copper sleeve is processed with a spiral groove, the two ends of the spiral groove respectively penetrate the two side end faces of the cooling copper sleeve, the high-pressure oil inlet hole of the main shaft housing is connected with the spiral groove of the cooling copper sleeve, and the two ends of the cooling copper sleeve form a cooling oil storage cavity with the end faces of the first sleeve and the second sleeve; An even number of first oil passages are machined in the first sleeve, and every two first oil passages form a group, and the two first oil passages in each group are symmetrically distributed about the central axis of the first sleeve; an even number of second oil passages are machined in the second sleeve, and every two second oil passages form a group, and the two second oil passages in each group are symmetrically distributed about the central axis of the second sleeve; The plunger-type feedback throttle comprises a working body and a comparison body, both of which have inner cavities, the inner cavity of the working body passes through one side of the working body, the inner cavity of the comparison body passes through one side of the comparison body, the side of the working body penetrated by its inner cavity is sealed and connected with the side of the comparison body penetrated by its inner cavity, the inner cavity of the working body comprises a first liquid inlet flow channel, a working cavity and a first liquid outlet flow channel, one end of the first liquid inlet flow channel passes through one side of the working body and is connected to the corresponding oil channel, the other end of the first liquid inlet flow channel is connected to the working cavity, one end of the first liquid outlet flow channel passes through one side of the working body and is connected to the corresponding oil channel, the other end of the first liquid outlet flow channel is connected to the working cavity, the inner cavity of the comparison body comprises a second liquid inlet flow channel and a comparison cavity, one end of the second liquid inlet flow channel is connected to the first liquid inlet flow channel, the other end of the second liquid inlet flow channel is connected to the comparison cavity, the working cavity and the comparison cavity are connected to each other, and a feedback regulating cavity is formed between the working cavity and the comparison cavity, and an regulating plunger is movably arranged in the feedback regulating cavity.

2. The high-precision liquid static pressure electric spindle according to claim 1, characterized in that: The working body and the comparison body are both cylinders, the working body has a protrusion processed on one end face, the comparison body has a groove matched with the protrusion processed on one end face, the protrusion of the working body and the groove of the comparison body are sealed and plugged into and matched with each other, the working body has a trough cavity processed on the end face away from the protrusion, and one end of the first liquid outlet channel is connected to the trough cavity; the working body has a plurality of diversion holes connected to the working cavity processed on the end face away from the protrusion, and each diversion hole is connected to the trough cavity at one end away from the working cavity.

3. The high-precision liquid static pressure electric spindle according to claim 1, characterized in that: The first liquid inlet flow channel includes a first inlet flow channel, a first branch flow channel and a first inlet flow channel, one end of the first inlet flow channel passes through a side wall of the working body and is connected to the corresponding oil channel, the other end of the first inlet flow channel is connected to the first inlet flow channel, and the end of the first inlet flow channel away from the first inlet flow channel is connected to the working chamber, one end of the first branch flow channel is connected to the first inlet flow channel, and the other end of the first branch flow channel passes through an end surface of the working body close to the comparison body, the second liquid inlet flow channel includes a second inlet flow channel and a second inlet flow channel, one end of the second inlet flow channel passes through an end surface of the comparison body close to the working body, and one end of the second inlet flow channel passing through the comparison body is connected to and communicated with one end of the first branch flow channel passing through the working body, the other end of the second inlet flow channel is connected to the second inlet flow channel, and one end of the second inlet flow channel away from the second inlet flow channel is connected to the comparison chamber.

4. The high-precision liquid static pressure electric spindle according to claim 3, characterized in that: The first flow inlet channel is arranged along the axial direction of the working body, the second flow inlet channel is arranged along the axial direction of the comparison body, the feedback adjustment chamber is a columnar cavity, the first flow inlet channel, the second flow inlet channel and the feedback adjustment chamber are coaxially distributed, the adjustment plunger matches the shape of the feedback adjustment chamber, and the axis of the adjustment plunger coincides with or is parallel to the axis of the feedback adjustment chamber.

5. The high-precision liquid static pressure electric spindle according to claim 4, characterized in that: The distance between one side end surface of the regulating plunger and the end surface of the feedback regulating chamber that is close to each other is 0.1-0.4 mm, and the distance between the side ring wall of the regulating plunger and the side ring wall of the feedback regulating chamber is 0.001-0.005 mm.

6. The high-precision liquid static pressure electric spindle according to claim 4, characterized in that: The working chamber and the comparison chamber are both two-stage stepped cylindrical chambers. The expanded section of the working chamber is connected to the first inlet channel, the expanded section of the comparison chamber is connected to the second inlet channel, the reduced section of the working chamber is connected to and connected to the reduced section of the comparison chamber, and the side ring wall of the regulating plunger is 0.001 to 0.005 mm away from the reduced section of the working chamber and the reduced section of the comparison chamber.

7. The high-precision liquid static pressure electric spindle according to claim 3, characterized in that: An annular groove is processed on the side wall of the working body, the axis of the annular groove coincides with the axis of the working body, the end of the first inlet channel away from the first inlet channel is connected to the annular groove, and the end of the second inlet channel away from the second inlet channel is connected to the annular groove.

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