Adjustable braking device and braking method for direct-drive rotating shaft

Abstract

The invention discloses an adjustable braking device of a direct-drive type rotating shaft. A hydraulic cylinder body is upwards and fixedly connected with a fixed part, and a limiting plate is fixedly mounted on the outer edge of the hydraulic cylinder body; a hydraulic cylinder assembly is arranged on the inner edge of the hydraulic cylinder body; a piston is sleeved between the hydraulic cylinder body and the hydraulic cylinder assembly, and a hydraulic cavity is formed by the lower end face of the piston and the combination part of the hydraulic cylinder assembly of the inner ring and the hydraulic cylinder body of the outer ring; a plurality of vertical through holes are formed in the hydraulic cylinder body below the piston along the circumference, a guide sleeve extends into each through hole, and each guide sleeve is sleeved with an adjusting pad and a disc spring; a brake pad is fixedly installed on the lower end face of the rotating shaft, and the brake pad and the hydraulic cylinder combination body form a rotating brake face downwards. The invention further discloses an adjustable braking method of the direct drive type rotating shaft. The invention belongs to the technical field of mechanical equipment, and solves the problems that in the prior art, the output force of an elastic assembly is difficult to adjust, and the whole braking device needs to be disassembled when individual elastic elements break down.

Description

Technical Field

[0001] The invention belongs to the technical field of mechanical equipment, and relates to an adjustable braking device for a direct drive rotary shaft. The invention also relates to an adjustable braking method for a direct drive rotary shaft. Background Art

[0002] In a machine tool system, a direct drive rotary shaft needs to simultaneously meet the requirements of precise positioning and rapid braking in case of sudden failures. The current hydraulic braking system adopts a passive logic of "braking under pressure and releasing the brake when losing pressure". If a sudden pressure loss fault such as a pipeline leak occurs during the machining process, the braking lock will be directly released, resulting in the out-of-control of the rotary shaft and triggering a tool collision accident. Existing technical solutions also have significant engineering problems: the debugging of the braking system needs to be carried out after the assembly of the shafting is completed, and the leakage of hydraulic medium may damage the core transmission components; during maintenance, the shafting structure needs to be disassembled extensively, which not only takes time and effort, but also easily affects the system accuracy due to repeated assembly. These design defects significantly increase the maintenance cost and the risk of equipment reliability.

[0003] For the existing ring-type rotary shaft braking device, the elastic components are limited by the limited mechanical space. To change the braking force, it is necessary to replace the quantity, specifications or even the combination form of the elastic components; in addition, as the vulnerable parts of the braking device, the working state of the elastic components (such as directly measuring the deformation amount of the elastic components and detecting the wear state of the elastic components) cannot be directly observed during inspection and maintenance. When a certain elastic element fails, all the elastic components must be removed for troubleshooting, which directly affects the work efficiency. Summary of the Invention

[0004] The purpose of the invention is to provide an adjustable braking device for a direct drive rotary shaft, which solves the problems that the output force of the elastic components in the existing braking device is difficult to adjust and the entire braking device needs to be disassembled when a certain elastic element fails.

[0005] Another purpose of the invention is to provide an adjustable braking method for a direct drive rotary shaft, which solves the problem that the entire braking device is prone to failure after the elastic components in the existing braking device are damaged.

[0006] The technical solution adopted by the invention is that the adjustable braking device for a direct drive rotary shaft includes a hydraulic cylinder body, the hydraulic cylinder body is fixedly connected to a stationary part upward, and a limiting plate is fixedly installed on the outer edge of the hydraulic cylinder body; a hydraulic cylinder assembly is arranged along the inner edge of the hydraulic cylinder body; A piston is sleeved between the hydraulic cylinder body and the hydraulic cylinder assembly, and a hydraulic cavity is jointly formed by the lower end surface of the piston and the joint part of the inner-ring hydraulic cylinder assembly and the outer-ring hydraulic cylinder body; a plurality of vertical through holes are arranged along the circumference in the hydraulic cylinder body below the piston, and a guide sleeve extends into each through hole, and each guide sleeve is sleeved with an adjusting pad and a disc spring; A brake pad is fixedly installed on the lower end face of the rotating shaft, and the brake pad forms a rotary braking surface downward with the hydraulic cylinder assembly.

[0007] Another technical solution adopted by the present invention is an adjustable braking method for a direct drive rotating shaft. Using the above-mentioned adjustable braking device for the direct drive rotating shaft, it is implemented according to the following steps: 1) When implementing braking, part or even all of the hydraulic medium in the hydraulic cavity is discharged from the liquid injection hole, the disc spring is freely released and deformed to press downward on the guide sleeve, the guide sleeve moves downward to pull the piston, and the piston presses downward so that the outer ring part of the brake pad contacts the upper surface of the hydraulic cylinder assembly, realizing the braking of the rotating shaft; 2) When releasing the braking, hydraulic medium is injected into the hydraulic cavity from the liquid injection hole, the piston moves upward to release the pressing on the brake pad, so that the outer ring part of the brake pad separates from the upper surface of the hydraulic cylinder assembly or reduces the pressing force under the action of its own elastic force, and the braking state of the rotating shaft is released or the braking force is reduced.

[0008] The beneficial effects of the present invention are as follows: Through the hydraulic braking release mechanism, the shafting braking state is automatically maintained during abnormal hydraulic pressure loss, effectively preventing the tool from colliding with the workpiece; the design of the structure greatly simplifies the debugging process of the braking unit, reduces the disassembly ratio of the overall structure of the shafting, and reduces the risk of loss of the secondary assembly accuracy of the shafting; the external disc spring structure can realize the adjustment of the braking force and the accurate judgment and maintenance of disc spring faults. Description of the Drawings

[0009] Figure 1 is a cross-sectional view of the internal structure of the modular braking device of the present invention; Figure 2 is Figure 1 the partial enlarged view at I in Figure 3 is an exploded view of the external structure of the braking device of the present invention; Figure 4 is a schematic cross-sectional view of the present invention device cut along the hydraulic conduit and the seal; Figure 5 is a schematic diagram of the installation position of the present invention device, the rotating shaft and the stationary part; Figure 6 is a schematic diagram of the placement state of the present invention device during installation and debugging; Figure 7 is a schematic diagram of the present invention device in the braking state; Figure 8 is a schematic diagram of the present invention device in the braking release state.

[0010] In the figure, 1. limit plate, 2. piston, 3. brake pad, 4. hydraulic cylinder assembly, 5. hydraulic cylinder body, 6. guide sleeve, 7. disc spring, 8. seal ring I, 9. retaining ring, 10. seal ring II, 11. hydraulic cavity, 12. seal ring III, 13. guide ring, 14. adjusting pad, 15. bolt, 16. seal ring IV, 17. vent hole, 18. liquid injection hole, 19. stationary part, 20. rotating shaft, 21. hydraulic conduit, 22. seal, 23. debugging tooling. Specific embodiments

[0011] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0012] Refer to Figure 1 、 Figure 2 、 Figure 3 The structure of the braking device of the present invention is as follows: It includes a hydraulic cylinder body 5 in the shape of a ring. The outer edge step of the hydraulic cylinder body 5 is fixedly connected upward to a stationary part 19 (i.e., the fixed part of the rotating shaft system). The upper end surface of the outer edge of the hydraulic cylinder body 5 is also fixedly installed with a limit plate 1, which together serves as a fixed base. On the inner edge step surface of the hydraulic cylinder body 5, there is a hydraulic cylinder assembly 4. The hydraulic cylinder assembly 4 and the hydraulic cylinder body 5 are assembled through clearance fit, and their relative positions are fixed after assembly. A circular piston 2 is sleeved between the hydraulic cylinder body 5 and the hydraulic cylinder assembly 4. The upper part of the piston 2 is set as a stepped ring (the actual shape is a stepped ring, Figure 1 The cross-sectional shape in is similar to a tongue-shaped convex ring shape for pressing the brake pad 3 downward). The lower end surface of the piston 2 and the joint parts of the inner-ring hydraulic cylinder assembly 4 and the outer-ring hydraulic cylinder body 5 together form a closed hydraulic cavity 11. In the hydraulic cylinder body 5 below the piston 2, a plurality of vertical through holes are arranged along the circumference. Each through hole extends into a guide sleeve 6, and all the guide sleeves 6 are slidably sleeved in the through holes of the hydraulic cylinder body 5. The piston 2 surrounds the lower end of the rotary shaft 20. A brake pad 3 is fixedly installed on the lower end surface of the rotary shaft 20. The brake pad 3 is a rotating body, that is, the inner annular part of the brake pad 3 is fixedly connected to the rotary shaft 20, and the outer annular part of the brake pad 3 is located below the piston 2. When the brake pad 3 contacts the hydraulic cylinder assembly 4 downward, a rotary brake surface can be formed. The up and down movement of the piston 2 can loosen or press down the brake pad 3, so that the outer ring part of the brake pad 3 moves up and down synchronously, so that the brake pad 3 can be loosened or pressed against the hydraulic cylinder assembly 4, and cooperate to achieve the release of the brake state or the brake state.

[0013] A set of seal ring 8 and retaining ring 9 are provided on the contact surface between the inner circumference of the piston 2 and the hydraulic cylinder assembly 4 to achieve sealing; another set of seal ring 8 and retaining ring 9 are provided on the contact surface between the outer circumference of the piston 2 and the hydraulic cylinder body 5 to achieve sealing; a seal ring four 16 is provided on the joint surface between the lower surface of the hydraulic cylinder assembly 4 and the hydraulic cylinder body 5 to achieve the sealing of the joint surface between the two; a seal ring two 10 is installed on the joint surface between the top surface of the guide sleeve 6 and the piston 2 to achieve the integral movement of the two and the sealing of the internal bolt holes (bolts 15 are installed); a seal ring three 12 and a guide ring 13 are installed between the outer circumference of the guide sleeve 6 and the hydraulic cylinder body 5 to achieve the sealing and guiding during the up and down movement of the guide sleeve 6. In short, through the combined action of the seal ring 8, the seal ring two 10, and the seal ring three 12, the sealing performance of the hydraulic chamber 11 can be ensured.

[0014] Refer to Figure 7 and Figure 8 As shown in and, the limiting plate 1 is L-shaped, the notch of the limiting plate 1 faces the piston 2, and there is a gap in the vertical direction with the step surface on the upper part of the piston 2. When the pressure in the hydraulic chamber 11 is too high or the disc spring 7 is damaged, the piston 2 will have a tendency to rush upward. Since the limiting plate 1 is fixed to the stationary part 19 through the hydraulic cylinder body 5, it can prevent the piston 2 from continuing to move upward, thus avoiding the occurrence of the following faults: the seal ring 8 fails due to excessive rising height, resulting in leakage of hydraulic medium; abnormal collision occurs between the piston 2 and the rotary shaft 20 and the parts on the shaft, damaging the rotary shaft and the parts on the shaft.

[0015] The guide ring 13 is made of polytetrafluoroethylene material, which can withstand a certain radial force, maintain a small gap between the guide sleeve 6 and the hydraulic cylinder body 5, and avoid direct friction between the outer surface of the guide sleeve 6 and the inner wall of the through hole of the hydraulic cylinder body 5, so as to avoid abnormal phenomena such as the piston 2 creeping during movement and abnormal braking force.

[0016] The adjusting pad 14 and the disc spring 7 can both be replaced with different specifications of accessories according to different needs.

[0017] Refer to Figure 4 and Figure 5, a vent hole 17 and a liquid injection hole 18 are provided at the bottom of the hydraulic cylinder body 5. The hydraulic chamber 11 is externally connected to the machine tool liquid injection mechanism through the liquid injection hole 18 and the hydraulic conduit 21; they are the inlets and outlets for the hydraulic medium in the hydraulic chamber 11. A seal 22 is usually provided on the vent hole 17 (equivalent to a seal plug at the outlet end). Only when initially filling the hydraulic chamber 11 completely with the hydraulic medium and when it is necessary to completely empty the hydraulic medium in the hydraulic chamber 11, the seal 22 will be removed. At this time, the vent hole 17 is connected to the atmosphere to balance the pressure in the hydraulic chamber 11.

[0018] Referring to Figure 7 and Figure 8 , the brake pad 3 is a rotating body. The inner ring of the brake pad 3 is fixed to the lower end face of the rotary shaft 20, and the inner ring of the brake pad 3 is located between the piston 2 and the hydraulic cylinder assembly 4. If the hydraulic medium is injected into the hydraulic chamber 11, the piston 2 moves upward to release the brake pad 3, and the brake pad 3 will be separated from the hydraulic cylinder assembly 4, which is the released brake state; if the medium in the hydraulic chamber 11 suddenly disappears (equivalent to being discharged), the piston 2 moves downward to press the brake pad 3, and the brake pad 3 will be in close contact with the hydraulic cylinder assembly 4, which is the braking state.

[0019] The braking principle of the device of the present invention is: 1) Referring to Figure 6 , in the installation and debugging process of the device of the present invention, first, the hydraulic cylinder body 5 in the assembled device of the present invention is pre-assembled with the debugging tooling 23 (equivalent to a bracket for supporting the device of the present invention). The hydraulic cylinder body 5 is sleeved and supported on the debugging tooling 23. After checking that the debugging braking function is normal and there is no overall leakage, the brake pad 3 is fixedly installed on the lower end face of the rotary shaft 20, and the limit plate 1 is reliably connected to the fixed part 19 as a whole through the hydraulic cylinder body 5. By configuring the adjustment pads 14 with the same thickness, each set of disc springs 7 obtains the same pre-compression amount. After tightening the bolts 15, the disc springs 7 push the guide sleeve 6 downward to drive the piston 2 and the brake pad 3. The brake pad 3 squeezes the upper surface of the hydraulic cylinder assembly 4 downward to form close contact, generating a preset pressing force, and the installation is completed. In the initial installed state, the braking device is in the braking state (that is, the rotary shaft 20 and the fixed part 19 cannot rotate freely relative to each other).

[0020] 2) By configuring the adjustment pads 14 with the same thickness, each set of disc springs 7 obtains the same pre-compression amount. After tightening the bolts 15, the disc springs 7 push the guide sleeve 6 downward to drive the piston 2 and the brake pad 3. The brake pad 3 squeezes the upper surface of the hydraulic cylinder assembly 4 downward to form close contact, generating a preset pressing force. According to needs, by changing the thickness of the adjustment pad 14, the pre-compression amount of the disc spring 7 changes, and the preset pressing force between the brake pad 3 and the hydraulic cylinder assembly 4 changes, so that the device of the present invention can generate different braking forces without changing the number, specification, and combination form of the disc springs 7.

[0021] 3) During use, when it is found that a certain disc spring 7 fails (such as fracture, severe wear, etc.) and causes the device of the present invention to be unable to brake normally, remove the seal 22 on the vent hole 17, evacuate the hydraulic medium in the hydraulic chamber 11, all the disc springs 7 are in a free-extended state, unscrew the bolt 15 corresponding to the failed disc spring 7, remove the guide sleeve 6, replace the failed disc spring 7, reinstall the disc spring 7, the adjusting pad 14 and the guide sleeve 6; then, after completely filling the hydraulic chamber 11 with the hydraulic medium, install the seal 22 on the vent hole 17 (that is, install the seal 22 after evacuating the air in the hydraulic chamber 11 to ensure that there is no more air in the hydraulic chamber 11), after debugging that the braking function is normal and there is no overall leakage, it can be used normally.

[0022] The braking method of the present invention is implemented according to the following steps: 1) When implementing braking, refer to Figure 7 , discharge part or all of the hydraulic medium in the hydraulic chamber 11 through the liquid injection hole 18, reduce the pressure in the hydraulic chamber 11, the disc spring 7 freely releases and deforms and stretches downward to press against the guide sleeve 6, so that the guide sleeve 6 moves downward to pull the piston 2, and the piston 2 presses downward to make the brake pad 3 closely contact the upper surface of the hydraulic cylinder assembly 4, thereby realizing the braking of the rotating shaft 20.

[0023] 2) When releasing the brake, refer to Figure 8 , inject hydraulic medium with a certain pressure into the hydraulic chamber 11 through the liquid injection hole 18, overcome the spring force of the disc spring 7, the piston 2 moves upward to release the pressing on the brake pad 3, so that the brake pad 3 separates from the upper surface of the hydraulic cylinder assembly 4 or reduces the pressing force under its own elastic force, and at this time the braking state of the rotating shaft 20 is released or the braking force is reduced.

[0024] Embodiment 1 The structure of this Embodiment 1 is that a total of 8 hydraulic chambers 11 are provided, including a hydraulic cylinder body 5 in the shape of an annular body. The outer edge step of the hydraulic cylinder body 5 is fixedly connected upward to the stationary part 19 (i.e., the fixed part of the rotating shaft system). The upper end surface of the outer edge of the hydraulic cylinder body 5 is also fixedly installed with a limit plate 1, which together serves as a fixed base; on the inner edge step surface of the hydraulic cylinder body 5, a hydraulic cylinder assembly 4 is arranged. The hydraulic cylinder assembly 4 and the hydraulic cylinder body 5 are assembled through clearance fit, and their relative positions are fixed after being assembled; A circular piston 2 is sleeved between the hydraulic cylinder body 5 and the hydraulic cylinder assembly 4. The upper part of the piston 2 is set in the shape of a tongue-shaped convex ring (so as to press the brake pad 3 downward). The lower end surface of the piston 2 and the joint parts of the inner-ring hydraulic cylinder assembly 4 and the outer-ring hydraulic cylinder body 5 together form a closed hydraulic chamber 11; in the hydraulic cylinder body 5 below the piston 2, a plurality of vertical through holes are arranged along the circumference, and a guide sleeve 6 extends into each through hole, and all the guide sleeves 6 are slidably sleeved in the through holes of the hydraulic cylinder body 5; Each guide sleeve 6 is fixedly connected to the piston 2 upward through respective bolts 15. The lower end of each guide sleeve 6 is in the shape of a flange. An adjusting pad 14 and a disc spring 7 are sleeved on the outer circumference of each guide sleeve 6 outside the through hole of the hydraulic cylinder body 5. The adjusting pad 14 is located between the lower surface of the hydraulic cylinder body 5 and the disc spring 7, and the lower end surface of the disc spring 7 abuts against the upper surface of the flange of the guide sleeve 6. The piston 2 surrounds the lower end of the rotary shaft 20. A brake pad 3 is fixedly installed on the lower end surface of the rotary shaft 20. The brake pad 3 is a rotating body. When the brake pad 3 contacts the hydraulic cylinder assembly 4 downward, a rotary braking surface can be formed. The up and down movement of the piston 2 can drive the rotary shaft 20 and the brake pad 3 to move up and down synchronously. The cooperation between the brake pad 3 and the hydraulic cylinder assembly 4 realizes the braking state and the release of the braking state.

[0025] The single-piece specification of the disc spring 7 in this Embodiment 1 is: outer diameter 50 mm, thickness 3 mm, free height 1.1 mm, and the combination form of the disc spring 7 is two stacks and two pairs; the thickness of the adjusting pad 14 is 5 mm, and the total compression amount of the disc spring 7 is 0.2 mm; at this time, the pressing force that can be generated by the present invention is 25400 N.

[0026] Embodiment 2 The structure of this Embodiment 2 is the same as that of Embodiment 1. The difference is that the relevant components are matched according to the following specifications: The single-piece specification of the disc spring 7 is: outer diameter 50 mm, thickness 3 mm, free height 1.1 mm, and the combination form of the disc spring 7 is two pairs; the thickness of the adjusting pad 14 is 11 mm, and the total compression amount of the disc spring 7 is 0.6 mm; at this time, the pressing force that can be generated by the present invention is 37008 N.

[0027] Embodiment 3 The structure of this Embodiment 3 is basically the same as that of Embodiment 1. The difference is that a total of 6 hydraulic chambers 11 are provided, and the relevant components are matched according to the following specifications: The single-piece specification of the disc spring 7 is: outer diameter 45 mm, thickness 2.5 mm, free height 0.95 mm, and the combination form of the disc spring 7 is two stacks and two pairs; the thickness of the adjusting pad 14 is 7.2 mm, and the total compression amount of the disc spring 7 is 0.2 mm; at this time, the pressing force that can be generated by the present invention is 17040 N.

[0028] Embodiment 4 The structure of this Embodiment 4 is basically the same as that of Embodiment 1. The difference is that a total of 6 hydraulic chambers 11 are provided, and the relevant components are matched according to the following specifications: The single-piece specification of the disc spring 7 is: outer diameter 45 mm, thickness 2.5 mm, free height 0.95 mm, and the combination form of the disc spring 7 is two stacks; the thickness of the adjusting pad 14 is 13.1 mm, and the total compression amount of the disc spring 7 is 0.1 mm; at this time, the pressing force that can be generated by the present invention is 8676 N.

[0029] Example 5 The structure of this Example 5 is basically the same as that of Example 1, except that a total of 10 hydraulic chambers 11 are provided, and the relevant components are matched according to the following specifications: The single-piece specifications of the disc spring 7 are: outer diameter 56 mm, thickness 1.5 mm, free height 1.95 mm, and the combination form of the disc spring 7 is two stacks and two pairs; the thickness of the adjusting pad 14 is 10 mm, and the total compression of the disc spring 7 is 0.9 mm; at this time, the pressing force that the present invention can generate is 27450 N.

[0030] Example 6 The structure of this Example 6 is basically the same as that of Example 1, except that a total of 10 hydraulic chambers 11 are provided, and the relevant components are matched according to the following specifications: The single-piece specifications of the disc spring 7 are: outer diameter 60 mm, thickness 3.5 mm, free height 1.5 mm, and the combination form of the disc spring 7 is two stacks and two pairs; the thickness of the adjusting pad 14 is 2.5 mm, and the total compression of the disc spring 7 is 0.5 mm; at this time, the pressing force that the present invention can generate is 89430 N.

Claims

1. Adjustable braking device for a direct drive rotary shaft, characterized in that: It includes a hydraulic cylinder body (5), the hydraulic cylinder body (5) is fixedly connected upward to a stationary part (19), and a limit plate (1) is fixedly installed on the outer edge of the hydraulic cylinder body (5); a hydraulic cylinder assembly (4) is arranged along the inner edge of the hydraulic cylinder body (5); A piston (2) is sleeved between the hydraulic cylinder body (5) and the hydraulic cylinder assembly (4), and a hydraulic cavity (11) is jointly formed at the joint of the lower end face of the piston (2) and the inner-ring hydraulic cylinder assembly (4) and the outer-ring hydraulic cylinder body (5); a plurality of vertical through holes are arranged along the circumference in the hydraulic cylinder body (5) below the piston (2), a guide sleeve (6) extends into each through hole, and each guide sleeve (6) is sleeved with an adjusting pad (14) and a disc spring (7); A brake pad (3) is fixedly installed on the lower end face of the rotary shaft (20), and the brake pad (3) forms a rotary braking surface downward with the hydraulic cylinder assembly (4).

2. The adjustable braking device of the direct drive rotary shaft according to claim 1, characterized in that The hydraulic cylinder assembly (4) and the hydraulic cylinder body (5) are in clearance fit with each other.

3. The adjustable braking device for a direct drive rotary shaft according to claim 1, characterized in that, The guide sleeve (6) is slidably sleeved in the through hole of the hydraulic cylinder body (5): each guide sleeve (6) is fixedly connected upward to the piston (2) through its respective bolt (15), the lower end head of each guide sleeve (6) is set in the shape of a flange, and an adjusting pad (14) and a set of disc springs (7) are sleeved on the outer circumference of each guide sleeve (6) exposed outside the through hole of the hydraulic cylinder body (5), the adjusting pad (14) is located between the lower surface of the hydraulic cylinder body (5) and the disc spring (7), and the lower end face of the disc spring (7) abuts against the upper surface of the flange of the guide sleeve (6).

4. The adjustable braking device for a direct drive rotary shaft according to claim 1, wherein, A set of seal ring I (8) and a retaining ring (9) are arranged on the contact surface between the inner circumference of the piston (2) and the hydraulic cylinder assembly (4); another set of seal ring I (8) and a retaining ring (9) are arranged on the contact surface between the outer circumference of the piston (2) and the hydraulic cylinder body (5); a seal ring IV (16) is arranged on the joint surface between the lower surface of the hydraulic cylinder assembly (4) and the hydraulic cylinder body (5); a seal ring II (10) is installed on the joint surface between the top surface of the guide sleeve (6) and the piston (2); a seal ring III (12) and a guide ring (13) are installed between the outer circumference of the guide sleeve (6) and the hydraulic cylinder body (5).

5. The adjustable braking device for a direct drive rotary shaft according to claim 1, characterized in that, The limit plate (1) is in an L shape, the notch of the limit plate (1) faces the piston (2), and there is a gap in the vertical direction with the step surface on the upper part of the piston (2).

6. The adjustable braking device for a direct drive rotary shaft according to claim 1, wherein, The brake pad (3) is a rotating body, the inner ring part of the brake pad (3) is fixedly connected to the rotary shaft (20), and the outer ring part of the brake pad (3) is located below the piston (2).

7. The adjustable braking device for a direct drive rotary shaft according to claim 4, characterized in that, The guide ring (13) is made of polytetrafluoroethylene material and is used to maintain a small gap between the guide sleeve (6) and the hydraulic cylinder body (5).

8. The adjustable braking device of the direct drive rotary shaft according to any one of claims 1-4, characterized in that A vent hole (17) and a liquid injection hole (18) are arranged at the bottom of the hydraulic cylinder body (5), and the hydraulic cavity (11) is externally connected to the machine tool liquid injection mechanism through the liquid injection hole (18) and a hydraulic conduit (21); a seal (22) is arranged at the outlet end of the vent hole (17).

9. Adjustable braking method for a direct drive rotary shaft, using the adjustable braking device for a direct drive rotary shaft according to claim 8, characterized in that, It is implemented according to the following steps: 1) When braking is implemented, part or even all of the hydraulic medium in the hydraulic chamber (11) is discharged from the liquid injection hole (18), the disc spring (7) freely releases and deforms to press down the guide sleeve (6) downward, the guide sleeve (6) moves downward to pull the piston (2), and the piston (2) presses downward so that the outer annular part of the brake pad (3) contacts the upper surface of the hydraulic cylinder assembly (4), realizing the braking of the rotating shaft (20); 2) When braking is released, hydraulic medium is injected into the hydraulic chamber (11) from the liquid injection hole (18), the piston (2) moves upward to release the pressing on the brake pad (3), so that the outer annular part of the brake pad (3) separates from the upper surface of the hydraulic cylinder assembly (4) or reduces the pressing force under the action of its own elastic force, and the braking state of the rotating shaft (20) is released or the braking force is reduced.

Images