Double-shaft synchronous spin-coating main shaft based on hydrostatic bearings

Abstract

The invention discloses a double-shaft synchronous spin-coating main shaft based on hydrostatic bearings, and belongs to the technical field of spin-coating. Comprising a belt pulley, a first spindle system, a cross joint coupler and a second spindle system. Rotation of a first spindle and a second spindle in the first spindle system and the second spindle system provides precise support through the synergistic effect of a hydrostatic bearing and a mechanical bearing. The double-shaft design shares the load, the radial load of the hydrostatic bearing is reduced, the stability of the double-shaft synchronous spin-coating main shaft is improved, and the precision and the coating quality in the spin-coating process are ensured. The hydrostatic bearing reduces friction force, reduces heat accumulation, and prolongs the service life of the double-shaft synchronous spin-coating main shaft and the bearings. The shock pad effectively reduces the influence of external vibration on the double-shaft synchronous spin-coating main shaft, ensures the coating uniformity and stability in the coating process, and improves the coating efficiency. The hydrostatic bearing and the mechanical bearing are used in a combined mode, higher load bearing capacity is provided, and it is ensured that the double-shaft synchronous spin-coating main shaft can stably operate under the high-load condition.

Description

Technical Field

[0001] The present invention belongs to the field of spin coating technology and is applicable to the fields of semiconductors, optoelectronics, optical films and functional coatings. It specifically proposes a dual-axis synchronous spin coating spindle based on hydrostatic bearings, aiming to improve the precision of the dual-axis synchronous spin coating spindle through the dual-axis design, improve coating efficiency, extend the service life of the dual-axis synchronous spin coating spindle, reduce vibration and ensure coating quality. Background Art

[0002] The spin coating process is a commonly used process in thin film coating technology and is widely used in the fields of semiconductors, optoelectronics, optical films, functional coatings, etc. The traditional spin coating spindle usually adopts a single-axis structure. Although it can meet certain precision requirements, it is prone to vibration, excessive temperature rise, unstable precision and other problems under high-speed rotation and high load conditions, and its service life is relatively short. Chinese patent CN104646248A discloses "A method and device for preparing thin film materials using spin coating". The inventor adopts a single-axis high-speed rotation. When the spindle rotates at high speed, the vibration is difficult to suppress. Long-term operation can easily cause spindle wear, affecting the coating quality and equipment life. Then, the dual-axis collaborative system based on hydrostatic bearings of the present invention reduces the vibration amplitude by dynamically balancing the pressure, while reducing friction loss and extending the service life of the spindle.

[0003] To meet the demands for higher precision and longer service life, improvements to spindle rigidity, lubrication systems, and bearing structure are being used to enhance rotational accuracy and stability. However, single-axis designs still struggle to fully address the challenges of high loads and high-speed rotation, limiting performance.

[0004] Therefore, how to design a spin coating spindle that can not only improve spin coating accuracy and reduce vibration, but also improve the stability and durability of the system has become a difficulty and challenge in current technology. Summary of the Invention

[0005] In order to solve the above-mentioned problems existing in the prior art, the present invention provides a dual-axis synchronous spin coating spindle based on hydrostatic bearings to solve the problems existing in the prior art such as unstable precision, excessive vibration, insufficient load-bearing capacity, etc., thereby improving the stability, precision and service life of the dual-axis synchronous spin coating spindle.

[0006] In order to achieve the above object, the technical solution of the present invention is as follows:

[0007] A dual-axis synchronous spin coating spindle based on a hydrostatic bearing includes a pulley 1, a first spindle system, a cross coupling 8, and a second spindle system; the first spindle system includes a cylindrical roller bearing 2, a first spindle 4, a deep groove ball bearing 5, and a first spindle bearing seat 6; the second spindle system includes a second spindle bearing seat 10, a second spindle bearing 11, and a second spindle 12;

[0008] The central outer periphery of the first main shaft 4 is fixed to the inner rings of the cylindrical roller bearing 2 and the deep groove ball bearing 5, respectively. The cylindrical roller bearing 2 is arranged at one end close to the pulley 1. The outer rings of the cylindrical roller bearing 2 and the deep groove ball bearing 5 are embedded and fixed in the inner cavity of the first main shaft bearing seat 6. The output end of the first main shaft 4 is connected to the input end of the second main shaft 12 via a cross coupling 8, so that the first main shaft 4 and the second main shaft 12 rotate synchronously. The input end of the first main shaft 4 is fixed to one end of the pulley 1 via a keyway, and the other end of the pulley 1 is connected to the drive system. The drive system and the belt transmit power to the first main shaft 4, ensuring the stable rotation of the first main shaft 4 and providing continuous driving force.

[0009] Furthermore, the first spindle system further includes a first spindle bearing sleeve 3, which is sleeved on the first spindle 4 near the pulley 1, axially positioning and supporting the cylindrical roller bearing 2, ensuring stable operation of the cylindrical roller bearing 2 and reducing wear;

[0010] Furthermore, the first spindle system further includes a first spindle end cover 7, which is used to seal one end of the first spindle system, thereby preventing external impurities from entering the first spindle system and ensuring the sealing of the first spindle system.

[0011] The first and second spindles serve as hydrostatic bearings and mechanical bearings, respectively. The combination of the hydrostatic bearings and mechanical bearings provides dual support, and the two work together to reduce friction while carrying a large load, further improving the stability and precision of the dual-axis synchronous spin coating spindles during the spin coating process. Specifically, the first spindle 4 is supported by cylindrical roller bearings 2 and deep groove ball bearings 5, which can ensure the uniformity of the coating process. The deep groove ball bearings 5 ​​are used to reduce friction during the rotation of the first spindle 4 and improve rotation precision. The cylindrical roller bearings 2 provide high load capacity and rigidity, ensuring that the dual-axis synchronous spin coating spindles do not deform under high-speed rotation and maintain stability. The first spindle bearing seat 6 provides support for the cylindrical roller bearings 2 and deep groove ball bearings 5. The cross-coupling 8 takes into account the high load-bearing capacity of the dual-axis synchronous spin coating spindles, ensuring a stable connection and synchronous rotation between the two spindles, eliminating errors caused by misalignment or vibration, and avoiding the impact of linkage instability on the rotation precision of the dual-axis synchronous spin coating spindles.

[0012] The inner ring of the second main shaft bearing 11 is sleeved and fixed on the outer periphery of the second main shaft 12 , and the outer ring is fixed to the inner cavity of the second main shaft bearing seat 10 .

[0013] Furthermore, the second spindle bearing lower end cover 9 is arranged at the lower end of the second spindle system, the second spindle bearing upper end cover 14 is arranged at the upper end of the second spindle system, and the second spindle sealing end cover 15 is arranged at the top of the entire dual-axis synchronous spin coating spindle.

[0014] The second spindle 12 bears the mechanical load of the first spindle 4 and provides stable rotational power through linkage with the first spindle 4. The second spindle 12 is mainly responsible for spin coating accuracy, and the first spindle 4 is mainly responsible for radial load. The second spindle bearing 11 provides support and bearing capacity for the second spindle 12 to ensure that the second spindle 12 can operate stably. The second spindle bearing seat 10 supports the second spindle bearing 11 to ensure the rigidity and stability of the second spindle 12 during rotation; the second spindle bearing lower end cover 9 is used to protect the lower end of the second spindle bearing 11 to ensure the stable operation of the second spindle bearing 11 and reduce wear; the second spindle bearing upper end cover 14 is used to protect the upper end of the second spindle bearing 11 to ensure the sealing and stability of the second spindle bearing 11; the second spindle sealing end cover 15 is used to seal the other end of the entire dual-axis synchronous spin coating spindle to prevent external impurities from entering the system and ensure the stability and long-term efficient operation of the dual-axis synchronous spin coating.

[0015] Furthermore, the dual-axis synchronous spin coating spindle also includes a shock-absorbing pad 13, which is embedded in the bottom groove of the second spindle bearing seat 10 to absorb external vibrations, reduce the impact of vibration on the dual-axis synchronous spin coating spindle, and ensure the stable operation of the dual-axis synchronous spin coating spindle; the shock-absorbing pad 13 is made of highly elastic and high-temperature resistant materials, which can effectively absorb external vibrations and ensure that the accuracy is not disturbed during the rotation process, and is particularly suitable for the field of high-precision micromachining.

[0016] Furthermore, a stepped hole is provided in the inner cavity of the first spindle bearing seat 6 for fixing with the outer rings of the cylindrical roller bearing 2 and the deep groove ball bearing 5; the first spindle bearing seat 6 is fixed on the base, and an oil filling hole is provided on the top.

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

[0018] 1. The dual-axis design shares the load, reduces the radial load of the hydrostatic bearing, improves the stability of the dual-axis synchronous spin coating spindle, and ensures the accuracy and coating quality during the spin coating process.

[0019] 2. The hydrostatic bearing reduces friction, reduces heat accumulation, and extends the service life of the dual-axis synchronous spin coating spindle and bearings.

[0020] 3. The design of the shock-absorbing pad effectively reduces the impact of external vibration on the dual-axis synchronous spin coating spindle, ensuring the coating uniformity and stability during the coating process and improving the coating efficiency.

[0021] 4. By combining the use of hydrostatic bearings and mechanical bearings, the present invention provides a higher load-bearing capacity, ensuring that the dual-axis synchronous spin coating spindle can operate stably under high load conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1A schematic cross-sectional view of a high-precision dual-axis spin coating spindle;

[0023] Figure 2 Schematic diagram of the first main shaft structure;

[0024] Figure 3 Schematic diagram of the second main shaft structure;

[0025] Figure 4 Schematic diagram of the coupling structure.

[0026] In the figure: 1-pulley; 2-cylindrical roller bearing; 3-first spindle bearing sleeve; 4-first spindle; 5-deep groove ball bearing; 6-first spindle bearing seat; 7-first spindle end cover; 8-cross coupling; 9-second spindle bearing lower end cover; 10-second spindle bearing seat; 11-second spindle bearing; 12-second spindle; 13-shock absorber pad; 14-second spindle bearing upper end cover; 15-second spindle sealing end cover. DETAILED DESCRIPTION

[0027] The present invention will be further described below in conjunction with the accompanying drawings. Figure 1 As shown, a high-precision dual-axis spin coating spindle with improved accuracy, stability and load-bearing capacity is composed of a pulley 1, a cylindrical roller bearing 2, a first spindle bearing sleeve 3, a first spindle 4, a deep groove ball bearing 5, a first spindle bearing seat 6, a first spindle end cover 7, a cross-head coupling 8, a second spindle bearing lower end cover 9, a second spindle bearing seat 10, a second spindle bearing 11, a second spindle 12, a shock-absorbing pad 13, a second spindle bearing upper end cover 14 and a second spindle sealing end cover 15.

[0028] The pulley 1 is fixed to the input end of the first main shaft 4 through a keyway and is used to transmit external power. Figure 1 As shown;

[0029] The inner ring of the cylindrical roller bearing 2 and the outer cylindrical surface of the middle part of the first main shaft 4 are fixed in the circumferential direction by interference fit, and the axial positioning is completed by the shaft shoulder and the locking nut; the outer ring is embedded in the inner cavity of the first main shaft bearing seat 6, and the outer cylindrical surface of the outer ring is interference fit with the inner cavity wall of the first main shaft bearing seat 6, as shown in FIG. Figure 1 As shown;

[0030] The first spindle bearing sleeve 3 is sleeved on the first spindle 4 near the pulley 1 to axially position the cylindrical roller bearing 2. Figure 1 As shown;

[0031] The surface of the first main shaft 4 is subjected to high frequency quenching treatment, and the uppermost end of the first main shaft 4 is provided with a coupling connection flange. Figure 1 、 Figure 2 As shown;

[0032] The deep groove ball bearing 5 is installed near the output end of the first main shaft 4, adjacent to the cross coupling 8. Figure 1 As shown;

[0033] The first spindle bearing seat 6 has a stepped hole in the inner cavity and is fixed to the base by bolts. An oil filling hole is provided on the top. Figure 1 As shown;

[0034] The first spindle end cover 7 is pressed against the end face of the deep groove ball bearing 5 by screws to seal the area between the first spindle 4 and the first spindle bearing seat 6, and the first spindle end cover 7 has a built-in skeleton oil seal to prevent grease leakage. Figure 1 As shown;

[0035] The cross coupling 8 connects the first main shaft 4 and the second main shaft 12, and the flange surface is locked with a hinged hole bolt. Figure 1 、 Figure 4 As shown;

[0036] The second spindle bearing lower end cover 9 is fixed to the bottom of the second spindle bearing seat 10 by countersunk screws, sealing the lower end of the area between the second spindle 12 and the second spindle bearing seat 10, and an oil return groove is provided on the inner side of the second spindle bearing lower end cover 9, such as Figure 1 As shown;

[0037] The bottom of the second spindle bearing bush seat 10 is provided with a mounting groove for a shock-absorbing pad 13. Cooling water channels are provided on both sides of the second spindle bearing bush seat 10. The shock-absorbing pad 13 reduces the impact of vibration on the second spindle 12. Figure 1 As shown;

[0038] The second spindle bearing 11 is a split Babbitt alloy lining structure, and an oil storage groove is provided on the inner surface to provide continuous lubrication through the oil groove. Figure 1 As shown;

[0039] The output end of the second spindle 12 is processed with an external thread for installing the second spindle sealing end cover 15. Figure 1 、 Figure 3 As shown;

[0040] The shock-absorbing pad 13 is embedded in the bottom groove of the second main shaft bearing seat 10 and is tightened by the pre-tightening bolts. Figure 1 As shown;

[0041] The second spindle bearing upper end cover 14 seals the upper end of the area between the second spindle 12 and the second spindle bearing seat 10, and cooperates with the second spindle bearing lower end cover 9 to press the second spindle bearing 11. A temperature sensor interface is provided on the top of the second spindle bearing upper end cover 14. Figure 1 As shown;

[0042] The second spindle sealing end cover 15 has a built-in double-lip sealing ring and is screwed to the end of the second spindle 12. Figure 1 shown.

[0043] Furthermore, an adjustment shim is installed between the first spindle bearing seat 6 and the base to calibrate the horizontality of the dual-axis synchronous spin coating spindle;

[0044] Furthermore, the cross shaft of the cross coupling 8 is surface nitrided, and the pin hole is embedded with a self-lubricating copper sleeve;

[0045] Furthermore, the thickness of the babbitt alloy layer of the second spindle bearing 11 is 2-3 mm, and the oil storage grooves are staggered at 45°;

[0046] Furthermore, the combination of the hydrostatic bearing and the mechanical bearing provides dual support, which reduces friction while carrying a large load, further improving the stability and precision of the dual-axis synchronous spin coating spindle during the spin coating process;

[0047] Furthermore, the shock-absorbing pad 13 is made of a highly elastic and high-temperature resistant material, which can effectively absorb external vibrations and ensure that the precision is not disturbed during the rotation process, and is particularly suitable for the field of high-precision micromachining;

[0048] First, the hydrostatic bearing significantly reduces the contact friction issues found in traditional mechanical bearings by providing a stable oil film support. During operation, hydraulic oil is injected into a precise oil channel system via a high-pressure oil pump, forming a uniform oil film between the bearing and the two spindles, ensuring that the dual-axis synchronous spin coating spindles can rotate stably without physical contact. This design not only significantly reduces friction but also effectively suppresses temperature rise and wear through the lubrication and cooling properties of the oil film, thereby extending the service life of the dual-axis synchronous spin coating spindles while improving rotational accuracy and load-bearing capacity.

[0049] In terms of load-bearing capacity, the present invention utilizes a combination of deep groove ball bearings 5 ​​and cylindrical roller bearings 2. The deep groove ball bearings 5 ​​primarily provide low-friction, high-precision support, ensuring spindle stability during rotation. The cylindrical roller bearings 2 carry the larger radial loads, providing strong support rigidity. This dual bearing configuration enables the first spindle 4 to withstand high loads without compromising rotational precision and stability.

[0050] In this design, a cross coupling 8 connects the first and second spindles 4 and 12. This coupling ensures synchronous rotation of the two spindles during operation, preventing errors or vibrations caused by misalignment or torque imbalance. The coupling utilizes a high-precision flange connection to ensure smooth operation without relative displacement between the two spindles. Bolts are also used for centering and locking, enhancing the stability of the connection.

[0051] Furthermore, the design of the shock-absorbing pad 13 effectively reduces external vibration interference with the spindle system. Installed at the bottom of the second spindle bearing housing 10, the shock-absorbing pad 13 is secured in place by pre-tightening bolts. Its primary function is to absorb external vibration during the rotation of the dual-axis synchronous spin coating spindle, preventing vibration from affecting the spindle's precision and ensuring excellent stability during long-term operation.

Claims

1. A dual-axis synchronous spin-coating spindle based on a hydrostatic bearing, characterized in that: The invention comprises a pulley (1), a first spindle system, a cross coupling (8) and a second spindle system; the first spindle system comprises a cylindrical roller bearing (2), a first spindle (4), a deep groove ball bearing (5) and a first spindle bearing seat (6); the second spindle system comprises a second spindle bearing seat (10), a second spindle bearing (11) and a second spindle (12); The middle outer periphery of the first main shaft (4) is fixed to the inner rings of the cylindrical roller bearing (2) and the deep groove ball bearing (5), respectively, and the cylindrical roller bearing (2) is arranged at one end close to the pulley (1); the outer rings of the cylindrical roller bearing (2) and the deep groove ball bearing (5) are embedded and fixed in the inner cavity of the first main shaft bearing seat (6), and the output end of the first main shaft (4) is connected to the input end of the second main shaft (12) through a cross coupling (8), so that the first main shaft (4) and the second main shaft (12) rotate synchronously; the input end of the first main shaft (4) is fixed to one end of the pulley (1) through a keyway, and the other end of the pulley (1) is connected to the drive system, and the power is transmitted to the first main shaft (4) through the drive system and the belt, ensuring that the first main shaft (4) rotates stably and provides continuous driving force; The inner ring of the second main shaft bearing (11) is sleeved and fixed on the outer periphery of the second main shaft (12), and the outer ring is fixed to the inner cavity of the second main shaft bearing seat (10).

2. The dual-axis synchronous spin coating spindle based on hydrostatic bearing according to claim 1, characterized in that: The first spindle system further comprises a first spindle bearing stopper sleeve (3), which is sleeved on the first spindle (4) near the pulley (1) to axially position and support the cylindrical roller bearing (2), thereby ensuring stable operation of the cylindrical roller bearing (2) and reducing wear.

3. The dual-axis synchronous spin coating spindle based on hydrostatic bearing according to claim 1, characterized in that: The first spindle system further comprises a first spindle end cover (7), which is used to close one end of the first spindle system.

4. The dual-axis synchronous spin coating spindle based on hydrostatic bearing according to claim 1, characterized in that: The second spindle bearing lower end cover (9) is arranged at the lower end of the second spindle system, the second spindle bearing upper end cover (14) is arranged at the upper end of the second spindle system, and the second spindle sealing end cover (15) is arranged at the top end of the entire dual-axis synchronous spin coating spindle.

5. The dual-axis synchronous spin coating spindle based on hydrostatic bearing according to claim 1, characterized in that: The dual-axis synchronous spin coating spindle further comprises a shock-absorbing pad (13), which is embedded in the bottom groove of the second spindle bearing seat (10).

6. The dual-axis synchronous spin coating spindle based on hydrostatic bearing according to claim 1, characterized in that: The inner cavity of the first main shaft bearing seat (6) is provided with a stepped hole for fixing with the outer rings of the cylindrical roller bearing (2) and the deep groove ball bearing (5); the first main shaft bearing seat (6) is fixed on the base and has an oil injection hole on the top.

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