Hydraulic-controlled mechanical feedback one-way diaphragm throttling high-rigidity static pressure spindle

Abstract

The present invention provides a hydraulically controlled, mechanically feedback-type, one-way, diaphragm-throttling, high-rigidity hydrostatic spindle, comprising a rotating spindle, a first cylinder body, and a second cylinder body. A shaft shoulder is formed in the middle portion of the rotating spindle. The first cylinder body and the second cylinder body are respectively mounted on the rotating spindle on either side of the shaft shoulder. Hydrostatic bearings for achieving hydrostatic support and sealing are respectively established between the first cylinder body and the rotating spindle and between the second cylinder body and the rotating spindle. One-way diaphragm-feedback throttles for providing hydrostatic oil to the hydrostatic bearings are also respectively fixed to the first cylinder body and the second cylinder body. Compared with the prior art, the present invention utilizes hydrostatic support technology to enable the rotating spindle to rotate without mechanical friction, and utilizes a diaphragm-feedback throttle to provide variable stiffness. As the load increases, the stiffness increases accordingly, further increasing the pressure difference in the hydrostatic oil chamber, balancing the load of the rotating spindle, restoring the rotating spindle to its original position, and improving the rotation accuracy of the hydrostatic spindle.

Description

Technical Field

[0001] The invention relates to the technical field of static pressure spindles, in particular to a hydraulically controlled mechanical feedback type one-way diaphragm throttling high-rigidity static pressure spindle. Background Art

[0002] High-speed, high-rigidity machine tool spindles are currently the main development direction of the machine tool industry. However, traditional machine tool spindles are limited by materials, design concepts and process processing, and can only use machine tool spindles mainly with ceramic bearings. Mechanical friction will occur between the machine tool spindle and the bearings. Due to the life and clearance of the bearings themselves, the speed and rotation accuracy of the machine tool spindle are limited, making it impossible for traditional machine tool spindles to achieve both high speed and high rigidity. Summary of the Invention

[0003] The purpose of the present invention is to provide a hydraulically controlled mechanical feedback type one-way diaphragm throttling high rigidity static pressure spindle to solve the problem that traditional machine tool spindles cannot achieve both high speed and high rigidity.

[0004] To achieve the above objectives, the present invention adopts the following specific technical solutions:

[0005] The hydraulically controlled mechanical feedback type one-way diaphragm throttling high-rigidity hydrostatic main shaft provided by the present invention includes: a rotating main shaft, a first cylinder body and a second cylinder body. A shaft shoulder is formed in the middle part of the rotating main shaft. The first cylinder body and the second cylinder body are respectively mounted on the rotating main shaft on both sides of the shaft shoulder. Hydrostatic bearings for realizing hydrostatic support sealing are respectively established between the first cylinder body and the rotating main shaft and between the second cylinder body and the rotating main shaft. One-way diaphragm feedback throttles for providing hydrostatic oil to the hydrostatic bearings are also fixed on the first cylinder body and the second cylinder body.

[0006] Preferably, the hydrostatic bearing includes a main shaft hydrostatic oil chamber and a shoulder hydrostatic oil chamber which are radially symmetrically distributed and opened on the first cylinder body and the second cylinder body. The main shaft hydrostatic oil chamber and the shoulder hydrostatic oil chamber are respectively filled with hydrostatic oil, so that a hydrostatic oil film is formed between the rotating main shaft and the first cylinder body and between the rotating main shaft and the second cylinder body.

[0007] Preferably, the spindle static pressure oil chamber is respectively opened on the spindle matching surface of the first cylinder body and the second cylinder body and the rotating spindle, and the shoulder static pressure oil chamber is respectively opened on the shoulder matching surface of the first cylinder body and the second cylinder body and the rotating spindle.

[0008] Preferably, the one-way diaphragm feedback throttle includes a throttle housing, a throttle disc and an elastic diaphragm. A sink is formed on the top surface of the throttle disc, an oil groove is provided on the sink, an external oil inlet hole, a static oil chamber oil inlet hole and a slit throttling ring are respectively provided in the throttle disc, the elastic diaphragm is installed on the sink of the throttle disc and is installed on the throttle housing together with the throttle disc, the oil groove and the elastic diaphragm form a lower cavity of the elastic diaphragm, the throttle housing and the elastic diaphragm form an upper cavity of the elastic diaphragm, the upper cavity of the elastic diaphragm is connected with the external oil inlet hole, and the lower cavity of the elastic diaphragm is respectively connected with the static oil chamber oil inlet hole, the slit throttling ring, the main shaft static oil chamber and the shoulder static oil chamber.

[0009] Preferably, an oil inlet is provided on the first cylinder body, an oil drain port is provided on the second cylinder body, an oil inlet circuit and an oil drain circuit are provided in the first cylinder body and the second cylinder body respectively, the oil inlet is connected with the oil supply port of the one-way diaphragm feedback throttle, the oil outlet of the one-way diaphragm feedback throttle is connected with the main shaft static pressure oil chamber and the shoulder static pressure oil chamber respectively through the oil inlet circuit, and the main shaft static pressure oil chamber and the shoulder static pressure oil chamber are also connected with the oil drain port respectively through the oil drain circuit.

[0010] Preferably, a cooling water trough and a circulating water channel are respectively processed on the first cylinder body and the second cylinder body, a water trough sealing end cover is installed in the cooling water trough, a cooling water inlet is processed on the first cylinder body, and a cooling water return port is processed on the second cylinder body, and the cooling water inlet is connected to the cooling water return port through the circulating water channel.

[0011] Preferably, a sealing ring groove is processed on the cooling water trough, and a sealing ring is installed in the sealing ring groove to achieve sealing between the cooling water trough and the water trough sealing end cover.

[0012] Preferably, the rotating main shaft is a hollow structure.

[0013] Preferably, positioning stops are machined at both ends of the rotating spindle.

[0014] Compared with the existing machine tool spindles, the present invention adopts hydrostatic support technology to establish a hydrostatic bearing between the rotating spindle and the cylinder body, so that a hydrostatic oil film is formed between the rotating spindle and the cylinder body, ensuring that there is no mechanical friction between the rotating spindle and the cylinder body, and adopts a one-way diaphragm feedback throttle to provide hydrostatic oil to the hydrostatic chamber of the hydrostatic bearing. The one-way diaphragm feedback throttle is a variable liquid resistance throttle. The elastic diaphragm of the one-way diaphragm feedback throttle deforms as the load pressure increases, thereby changing the liquid resistance of the one-way diaphragm feedback throttle, improving the stiffness of the hydrostatic oil film, and keeping the eccentricity of the rotating spindle center unchanged, thereby obtaining higher rotation accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1This is a schematic diagram of the overall structure of a hydraulically controlled mechanical feedback type one-way diaphragm throttling high-rigidity static pressure spindle according to an embodiment of the present invention;

[0016] Figure 2 2. It is a schematic cross-sectional view of a hydraulically controlled mechanical feedback type one-way diaphragm throttling high-rigidity static pressure spindle according to an embodiment of the present invention;

[0017] Figure 3 Schematic diagram of the structure of a one-way membrane feedback throttle according to an embodiment of the present invention.

[0018] The accompanying drawings include: rotating spindle 1, first cylinder body 2, second cylinder body 3, one-way diaphragm feedback throttle 4, water tank sealing end cover 5, spindle static oil chamber 6, shoulder static oil chamber 7, oil inlet 8, oil drain port 9, sealing ring 10, throttle housing 11, throttling disc 12, elastic diaphragm 13, external oil inlet hole 14, static oil chamber oil inlet hole 15, slit throttle ring 16, elastic diaphragm lower chamber 17, elastic diaphragm upper chamber 18, O-ring 19. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and do not constitute a limitation of the present invention.

[0020] Figure 1 and Figure 2 The overall structure and cross-sectional structure of a hydraulically controlled mechanical feedback type one-way diaphragm throttling high-rigidity static pressure main shaft according to an embodiment of the present invention are respectively shown.

[0021] like Figure 1 and Figure 2 As shown, the hydraulically controlled mechanical feedback type one-way diaphragm throttling high-rigidity hydrostatic spindle provided by an embodiment of the present invention comprises: a rotating spindle 1, a first cylinder body 2, a second cylinder body 3, a one-way diaphragm feedback throttle 4, and a water tank sealing end cover 5; wherein, a shaft shoulder is formed in the middle portion of the rotating spindle 1, and the first cylinder body 2 and the second cylinder body 3 are respectively mounted on the rotating spindle 1 on both sides of the shaft shoulder. Hydrostatic bearings for achieving hydrostatic support sealing are respectively established between the first cylinder body 2 and the rotating spindle 1 and between the second cylinder body 3 and the rotating spindle 1. The one-way diaphragm feedback throttle 4 is fixed to the first cylinder body 2 and the second cylinder body 3 to provide hydrostatic oil for the hydrostatic bearings. Seal grooves are respectively provided on the first cylinder body 2 and the second cylinder body 3, and an O-ring 19 is used to seal the oil between the first cylinder body 2 and the second cylinder body 3.

[0022] The high-rigidity liquid hydrostatic spindle of the present invention utilizes liquid hydrostatic support technology to establish hydrostatic bearings between the rotating spindle 1 and the first cylinder body 2, and between the rotating spindle 1 and the second cylinder body 3, forming a hydrostatic oil film. This ensures that there is no mechanical friction between the rotating spindle 1 and the first cylinder body 2, and between the rotating spindle 1 and the second cylinder body 3, thereby achieving high rotation speed and long life for the rotating spindle 1. A one-way diaphragm feedback throttle 4 is used to provide hydrostatic support for the oil chamber of the hydrostatic bearing, and the oil film stiffness of the hydrostatic bearing is increased by one-way diaphragm feedback throttling. Under a specific oil pressure, as the lateral load on the rotating spindle 1 increases, the fluid resistance of the one-way diaphragm feedback throttle 4 decreases accordingly, further increasing the balancing load of the oil chamber pressure and returning the rotating spindle 1 to its original position. This improves the oil film stiffness of the rotating spindle 1 and maintains the eccentricity of the center of the rotating spindle 1, thereby achieving higher rotational accuracy.

[0023] Since a hydrostatic bearing is used as the rotation guide and seal of the rotating spindle 1, increasing the load does not affect the rotation speed of the rotating spindle 1 within the allowable range of its oil film stiffness. The friction torque on the rotating spindle 1 depends closely on the viscosity of the oil.

[0024] The rotating spindle 1 adopts a hollow structure, and positioning stops are processed at its front and rear ends respectively, which reduces the moving mass while ensuring strength. The outer surface of the rotating spindle 1 adopts a thermal spraying process and is polished, which has the advantages of high processing precision and long service life.

[0025] At least four radially symmetrically distributed spindle static oil chambers 6 are provided on the spindle mating surface between the first cylinder block 2 and the rotating spindle 1. Each spindle static oil chamber 6 is filled with static oil to form a static oil film between the first cylinder block 2 and the rotating spindle 1, thereby establishing a static bearing along the axial direction of the rotating spindle 1.

[0026] At least two radially symmetrically distributed shoulder static oil chambers 7 are provided on the shoulder mating surface between the first cylinder block 2 and the rotating main shaft 1. Each shoulder static oil chamber 7 is filled with static oil to form a static oil film between the first cylinder block 2 and the shoulder, thereby establishing a hydrostatic bearing along the radial direction of the rotating main shaft 1.

[0027] An oil inlet 8 is provided on the outside of the first cylinder body 2, and an oil inlet circuit and an oil drain circuit are provided on the inside of the first cylinder body 2. The oil inlet 8 is connected to the oil supply port of the one-way diaphragm feedback throttle 4 fixed on the first cylinder body 2, and the oil outlet of the one-way diaphragm feedback throttle 4 is connected to the main shaft static pressure oil chamber 6 and the shoulder static pressure oil chamber 7 of the first cylinder body 2 through the oil inlet circuit. The oil drain circuit in the first cylinder body 2 is also connected to the main shaft static pressure oil chamber 6 and the shoulder static pressure oil chamber 7 of the first cylinder body 2.

[0028] The positions of the main shaft static pressure oil chamber and the shaft shoulder static pressure oil chamber opened on the second cylinder body 3 are the same as those of the main shaft static pressure oil chamber and the shaft shoulder static pressure oil chamber on the first cylinder body 2, so they are not repeated here.

[0029] An oil drain port 9 is provided on the outside of the second cylinder body 3, and an oil inlet circuit and an oil drain circuit are respectively provided inside the second cylinder body 3. The oil supply port of the one-way diaphragm feedback throttle 4 fixed on the second cylinder body 3 is connected with the oil inlet 8 of the first cylinder body 2, and the oil outlet port of the one-way diaphragm feedback throttle 4 is respectively connected with the main shaft static pressure oil chamber 6 and the shoulder static pressure oil chamber 7 of the second cylinder body 3 through the oil inlet circuit in the second cylinder body 3. The oil drain port 9 in the second cylinder body 3 is also connected with the main shaft static pressure oil chamber 6 and the shoulder static pressure oil chamber 7 of the second cylinder body 3.

[0030] High-pressure oil flows in from the oil inlet 8 and enters the one-way diaphragm feedback throttles 4 fixed to the first cylinder body 2 and the second cylinder body 3, respectively. After being reduced in pressure by the two one-way diaphragm feedback throttles 4, it becomes hydrostatic oil. It flows through the oil inlet circuit in the first cylinder body 2 into each spindle hydrostatic oil chamber 6 and shoulder hydrostatic oil chamber 7 of the first cylinder body 2, and through the oil inlet circuit in the second cylinder body 32 into each spindle hydrostatic oil chamber and shoulder hydrostatic oil chamber of the second cylinder body 3, respectively, providing hydrostatic support force and forming a hydrostatic oil film. The hydrostatic oil in the spindle hydrostatic oil chamber 6 and shoulder hydrostatic oil chamber 7 of the first cylinder body 2 reaches the drain port 9 through the drain circuit in the first cylinder body 2 and is discharged through the drain port 9. The hydrostatic oil in the spindle hydrostatic oil chamber and shoulder hydrostatic oil chamber of the second cylinder body 3 reaches the drain port 9 through the drain circuit in the second cylinder body 3 and is discharged through the drain port 9.

[0031] Since the increase in oil temperature affects the viscosity of the hydraulic oil and thus the fluid resistance of the one-way diaphragm feedback throttle 4, a cooling water inlet and a cooling water tank are machined on the first cylinder body 2, and a cooling water return port and a cooling water tank are machined on the second cylinder body 3. Circulating water paths are also machined inside the first cylinder body 2 and the second cylinder body 3, respectively. The circulating water paths are connected to the cooling water inlet and the cooling water return port, respectively. The water tank sealing end cover 5 is installed on the cooling water tank to achieve sealing of the cooling water tank. A sealing ring groove is machined on the cooling water tank, and a sealing ring 10 is installed in the sealing ring groove to achieve sealing between the cooling water tank and the water tank sealing end cover 5.

[0032] Cooling water enters the first cylinder 2 from the water inlet, flows through the circulating water path between the first cylinder 2 and the second cylinder 3, and then flows out from the cooling water return port. The cooling water circulates throughout the entire hydrostatic spindle, maintaining the oil temperature at a constant level and ensuring that the hydrostatic spindle's rotational accuracy is not affected by changes in oil temperature.

[0033] Figure 3 The structure of a one-way film feedback throttle according to an embodiment of the present invention is shown.

[0034] like Figure 3 As shown, the one-way film feedback throttle includes a throttle housing 11, a throttle disc 12 and an elastic diaphragm 13. A sink is formed on the top surface of the throttle disc 12, an oil groove is opened on the sink, and an external oil inlet hole 14, a static oil chamber oil inlet hole 15 and a slit throttle ring 16 are opened in the throttle disc 13. The elastic diaphragm 13 is a one-way film that can only deform in one direction. The elastic diaphragm 13 is installed on the sink of the throttle disc 12 and is connected to the throttle disc 12. The throttle disc 12 is installed together on the throttle housing 11, the oil groove and the elastic diaphragm 13 form an elastic diaphragm lower chamber 17, the throttle housing 11 and the elastic diaphragm 13 form an elastic diaphragm upper chamber 18, the elastic diaphragm upper chamber 18 is connected to the external oil inlet hole 14, the elastic diaphragm lower chamber 17 is connected to the static oil chamber oil inlet hole 15, and the static oil chamber oil inlet hole 15 is also respectively connected to the slit throttle ring 16, the main shaft static oil chamber 6, and the shoulder static oil chamber 7.

[0035] The working process of the present invention is as follows:

[0036] High-pressure oil at a constant pressure is fed into the oil inlet 8. The high-pressure oil enters the one-way diaphragm feedback restrictors 4 fixed to the first and second cylinder bodies 2 and 3, respectively. Through each one-way diaphragm feedback restrictor 4, the hydrostatic oil is delivered to each spindle hydrostatic oil chamber 6 and each shoulder hydrostatic oil chamber 7, thereby establishing a hydrostatic bearing and providing hydrostatic support force. This hydrostatic support force allows the rotating spindle 1 to be suspended above the hydrostatic oil film. Excess oil in the spindle hydrostatic oil chamber 6 and shoulder hydrostatic oil chamber 7 flows through the drain circuits of the first and second cylinder bodies 2 and 3 to the drain port 9, where it is discharged.

[0037] When the rotating spindle 1 is subjected to external load in the radial or axial direction, the one-way film feedback throttle 4 plays a role in regulating the stiffness of the oil film. The high-pressure oil with constant pressure enters the upper cavity 18 of the elastic diaphragm through the external oil inlet hole 14 of the one-way film feedback throttle 4. The high-pressure oil in the upper cavity 18 of the elastic diaphragm squeezes the elastic diaphragm 13, causing the elastic diaphragm 13 to deform. At this time, there is a certain gap h0 between the elastic diaphragm 13 and the sinking platform of the throttle disk 12, forming a certain liquid resistance. After the high-pressure oil is reduced in pressure, it enters the lower cavity 17 of the elastic diaphragm, flows through the slit throttle ring 16 and the static oil cavity oil inlet hole 15, enters the main shaft static oil cavity 6 and the shoulder static oil cavity 7, forms a static pressure support force, and establishes a certain oil film stiffness.

[0038] When the external load of the rotating spindle 1 increases, as the oil pressure in the static oil chamber of the load increases, the lower chamber 17 of the elastic diaphragm is squeezed by the oil pressure, causing the deformation of the elastic diaphragm 13 to decrease and the gap h0 to increase, resulting in a decrease in the fluid resistance of the high-pressure oil flowing through the gap h0, increasing the flow rate, and increasing the pressure in the oil inlet hole 15 of the static oil chamber, thereby increasing the pressure in the static oil chamber and increasing the stiffness of the oil film, thereby balancing the external load, restoring the rotating spindle 1 to its original position, and keeping the radial or axial displacement of the rotating spindle 1 unchanged, thereby improving the rotation accuracy of the static spindle, that is, while achieving high-speed rotation of the rotating spindle 1, the static spindle can obtain higher rotation accuracy.

[0039] In the description of this specification, the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0040] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention.

[0041] The above specific embodiments of the present invention do not constitute a limitation on the scope of protection of the present invention. Any other corresponding changes and modifications made based on the technical concept of the present invention should be included in the scope of protection of the claims of the present invention.

Claims

1. A hydraulically controlled mechanical feedback type one-way diaphragm throttling high rigidity static pressure spindle, characterized in that: include: A rotating main shaft, a first cylinder body and a second cylinder body, a shaft shoulder is formed in the middle part of the rotating main shaft, the first cylinder body and the second cylinder body are respectively mounted on the rotating main shaft and located on both sides of the shaft shoulder, a hydrostatic bearing for realizing hydrostatic support sealing is respectively established between the first cylinder body and the rotating main shaft and between the second cylinder body and the rotating main shaft, and a one-way film feedback throttle for providing hydrostatic oil to the hydrostatic bearing is also fixed on the first cylinder body and the second cylinder body respectively; the hydrostatic bearing includes a hole provided in the first cylinder body The main shaft static pressure oil chamber and the shoulder static pressure oil chamber are radially symmetrically distributed on the upper and second cylinder bodies, and the main shaft static pressure oil chamber and the shoulder static pressure oil chamber are respectively filled with static pressure oil, so that a static pressure oil film is formed between the rotating main shaft and the first cylinder body, and between the rotating main shaft and the second cylinder body; the main shaft static pressure oil chamber is respectively opened on the main shaft matching surface of the first cylinder body, the second cylinder body and the rotating main shaft, and the shoulder static pressure oil chamber is respectively opened on the shoulder matching surface of the first cylinder body, the second cylinder body and the rotating main shaft.

2. The hydraulically controlled mechanical feedback type one-way diaphragm throttling high rigidity static pressure spindle according to claim 1 is characterized in that: The one-way film feedback throttle includes a throttle housing, a throttle disc and an elastic diaphragm. A sink is formed on the top surface of the throttle disc, an oil groove is provided on the sink, an external oil inlet hole, a static oil chamber oil inlet hole and a slit throttling ring are respectively provided in the throttle disc. The elastic diaphragm is installed on the sink of the throttle disc and is installed on the throttle housing together with the throttle disc. The oil groove and the elastic diaphragm form an elastic diaphragm lower cavity, the throttle housing and the elastic diaphragm form an elastic diaphragm upper cavity, the elastic diaphragm upper cavity is connected with the external oil inlet hole, and the elastic diaphragm lower cavity is respectively connected with the static oil chamber oil inlet hole, the slit throttling ring, the main shaft static oil cavity and the shoulder static oil cavity.

3. The hydraulically controlled mechanical feedback type one-way diaphragm throttling high rigidity static pressure spindle according to claim 2 is characterized in that: An oil inlet is provided on the first cylinder body, an oil drain port is provided on the second cylinder body, an oil inlet circuit and an oil drain circuit are provided in the first cylinder body and the second cylinder body respectively, the oil inlet is connected with the oil supply port of the one-way diaphragm feedback throttle, the oil outlet of the one-way diaphragm feedback throttle is connected with the main shaft static pressure oil chamber and the shoulder static pressure oil chamber respectively through the oil inlet circuit, and the main shaft static pressure oil chamber and the shoulder static pressure oil chamber are also connected with the oil drain port respectively through the oil drain circuit.

4. The hydraulically controlled mechanical feedback type one-way diaphragm throttling high rigidity static pressure spindle according to claim 3 is characterized in that: A cooling water trough and a circulating water channel are respectively processed on the first cylinder body and the second cylinder body. A water trough sealing end cover is installed in the cooling water trough. A cooling water inlet is processed on the first cylinder body, and a cooling water return port is processed on the second cylinder body. The cooling water inlet is connected to the cooling water return port through the circulating water channel.

5. The hydraulically controlled mechanical feedback type one-way diaphragm throttling high rigidity static pressure spindle according to claim 4 is characterized in that: A sealing ring groove is processed on the cooling water trough, and a sealing ring is installed in the sealing ring groove to achieve sealing between the cooling water trough and the water trough sealing end cover.

6. The hydraulically controlled mechanical feedback type one-way diaphragm throttling high rigidity static pressure spindle according to claim 1 is characterized in that: The rotating main shaft is a hollow structure.

7. The hydraulically controlled mechanical feedback type one-way diaphragm throttling high rigidity static pressure spindle according to claim 6 is characterized in that: Positioning stops are machined on both ends of the rotating spindle.

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