Direct drive rotary table with double pistons and working method thereof

Abstract

The present application relates to the technical field of rotary table, especially to a direct drive rotary table with double pistons and its working method, the rotary table comprises: a mounting seat, a stator is arranged inside; a rotating shaft rotates in the mounting seat; a rotor and a brake pad are arranged on the rotating shaft; a fixed brake plate is fixed on the mounting seat; a first cylinder is fixed on the end of the mounting seat; a first oil path is arranged in the first cylinder to communicate with the internal space of the first cylinder; a first piston slides in the first cylinder; the brake pad is located between the fixed brake plate and the first piston; a spring is arranged between the first piston and the fixed brake plate; a second cylinder is fixed on the end of the first cylinder; a second oil path and a third oil path are arranged in the second cylinder; the second oil path communicates with the first oil path and the outside of the first cylinder; the third oil path communicates with the second oil path and the internal space of the second cylinder; a second piston slides in the second cylinder; the first piston and the second piston abut each other. The present application can effectively increase the braking force and ensure the stability of the brake.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of rotary tables, in particular to a direct-drive rotary table with double-piston brakes and a working method thereof. BACKGROUND

[0002] A direct-drive rotary table is a high-precision rotary platform used for fixing and rotating workpieces, and is widely used in the fields of precision numerical control machine tools and intelligent automation processing. The rotary table usually has a brake function, and the principle is to limit the movement of the rotary shaft of the rotary table by the friction generated by the mutual contact between the brake plate and the brake pad. Due to the structural limitations of the rotary table, the brake plate and the brake pad are relatively small in size, and the traditional piston used to push the brake plate and the brake pad closer can only exert limited force. Therefore, in use cases where the rotary shaft of the rotary table is under heavy stress, the brake force generated by the traditional single-piston force- applying structure is too small to stably brake. SUMMARY

[0003] The present application provides a direct-drive rotary table with double-piston brakes and a working method thereof, which can effectively solve the problems in the background art.

[0004] The direct-drive rotary table with double-piston brakes provided by the present application comprises:

[0005] A mounting seat is independently fixedly arranged, and a stator is arranged in the mounting seat;

[0006] A rotary shaft is arranged to rotate in the mounting seat, and a rotor and a brake pad are arranged on the rotary shaft;

[0007] A fixed brake plate is fixedly arranged at the end of the mounting seat;

[0008] A first cylinder is fixedly arranged at the end of the mounting seat, and a first oil passage is arranged in the first cylinder, with one end of the first oil passage being in communication with the internal space of the first cylinder;

[0009] A first piston is arranged to slide in the internal space of the first cylinder, and the outer side of the brake pad extends into the space between the fixed brake plate and the first piston;

[0010] A spring is arranged between the first piston and the fixed brake plate;

[0011] A second cylinder is fixedly arranged at the end of the first cylinder, and a second oil passage and a third oil passage are arranged in the second cylinder; one end of the second oil passage is in communication with the first oil passage, and the other end is in communication with the outside of the first cylinder; one end of the third oil passage is in communication with the second oil passage, and the other end is in communication with the internal space of the second cylinder;

[0012] A second piston is arranged to slide in the internal space of the second cylinder;

[0013] The first piston and the second piston abut against each other.

[0014] Further, when the first piston and the second piston are located farthest from the brake pad, a first interval space is formed between the first piston and the inner end face of the first cylinder, and a second interval space is formed between the second piston and the inner end face of the second cylinder, and the first interval space is larger than the second interval space.

[0015] Further, the second piston end face is provided with a concave hole, the inner end face of the second cylinder is provided with a convex column, and the convex column extends into the concave hole.

[0016] Further, when the first piston is located farthest from the brake pad, an interval space is formed between the brake pad and the fixed brake plate.

[0017] Further, the first cylinder is provided with a guide hole.

[0018] Further, the first cylinder is provided with a guide hole.

[0019] Further, when the first piston and the second piston are located farthest from the brake pad, a first sliding interval space is formed between the first piston and the fixed brake plate, and a second sliding interval space is formed between the second piston and the first cylinder, and the first sliding interval space is larger than the second sliding interval space, and the second sliding interval space is larger than the interval space between the first piston and the brake pad.

[0020] The fifth oil path is provided on the guide column, and one end of the fifth oil path is communicated with the end of the guide column close to the first piston, and the other end of the fifth oil path is communicated with the part of the side surface of the guide column corresponding to the first sliding interval space.

[0021] Further, the end of the guide column close to the first piston is provided with a transition section with gradually reduced diameter.

[0022] Further, the end of the second piston is provided with a mounting hole, and one end of the guide column extends into the mounting hole.

[0023] Further, the inside of the first piston is provided with an extension section, and the extension section extends out of the first cylinder and abuts against the second piston.

[0024] The application also provides a working method of a direct drive rotary table of a double-piston brake.

[0025] According to the rotation demand, the power supply to the stator is controlled to rotate the rotor and the rotating shaft.

[0026] After reaching the rotation position, oil is supplied to the second oil path, and the oil supply is stopped when the oil pressure in the second oil path reaches a set value, and the oil pressure is maintained.

[0027] In the next rotation, the maintenance of the oil pressure in the second oil path is released, and the power supply to the stator is controlled to rotate the rotor and the rotating shaft after waiting for a set time.

[0028] The technical scheme of the present application can achieve the following technical effects:

[0029] The special double-piston structure and the special oil path of the rotary table are matched with each other, so that the oil can simultaneously generate pressure on the end faces of the first piston and the second piston during braking, and the clamping force during braking is the superposition of the two pressures, thereby greatly improving the braking force and ensuring stable braking effect in the case of large stress. Moreover, the structure can realize simultaneous action control of the first piston and the second piston through the cooperation between the various oil paths, so that the braking speed is faster and the control difficulty is smaller. BRIEF DESCRIPTION OF DRAWINGS

[0030] In order to more clearly illustrate the technical schemes in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments described in the present application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of these drawings.

[0031] Figure 1 It is a cross-sectional view of the oil path of the direct-drive rotary table of the double-piston brake in the present application.

[0032] Figure 2 It is a state diagram of A in the present application Figure 1 when the brake is not applied.

[0033] Figure 3 It is a state diagram of A in the present application Figure 1 when the brake is applied.

[0034] Figure 4 It is a cross-sectional view of the guide column of the direct-drive rotary table of the double-piston brake in the present application.

[0035] Figure 5 It is a state diagram of B in the present application Figure 4 when the brake pad is not worn.

[0036] Figure 6 It is a state diagram of B in the present application Figure 4 when the brake pad is worn.

[0037] Reference: 1, mounting seat; 2, stator; 3, rotating shaft; 4, rotor; 5, brake pad; 6, fixed brake plate; 7, first cylinder; 7a, first oil path; 7c, first interval space; 7e, first sliding interval; 8, first piston; 8a, extension section; 9, spring; 10, second cylinder; 10a, second oil path; 10b, third oil path; 10c, second interval space; 10d, boss; 10e, second sliding interval; 11, second piston; 12, guide column; 12a, fifth oil path; 12b, transition section. DETAILED DESCRIPTION

[0038] The basic principles and main features of the technical solutions of the present application will be described below in combination with the drawings of the embodiments of the present application. The description will be more intuitive through one or more embodiments, and the described embodiments are only some of the embodiments of the present application, not all the embodiments.

[0039] In the description of the present application, the words indicating the orientation or positional relationship (such as up, down, left, right, etc.) are based on the orientation shown in the drawings or some conventional positional relationship, only for the convenience of describing the present application and simplifying the description, and are not indicative or implied that the features indicated must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application.

[0040] The present application relates to a kind of double-piston brake's direct drive rotary table, as shown in Figures 1-3 The specific structure and mounting position of each component are as follows: mounting seat 1, stator 2, rotating shaft 3, rotor 4, brake pad 5, fixed brake plate 6, first cylinder 7, first piston 8, spring 9, second cylinder 10 and second piston 11.

[0041] Mounting seat 1 is independently fixed to the ground or other fixed ground equipment frame; stator 2 is arranged in mounting seat 1.

[0042] Rotating shaft 3 rotates in mounting seat 1; one end of rotating shaft 3 extends out of mounting seat 1 and forms a circular table, and the workpiece is placed on the circular table during machining; the middle section of rotating shaft 3 is provided with rotor 4, and rotor 4 cooperates with stator 2 to form a motor structure, to realize the rotating function of rotor 4; the other end of rotating shaft 3 is provided with brake pad 5 which rotates synchronously with rotating shaft 3.

[0043] Fixed brake plate 6 is fixedly arranged at the end of mounting seat 1; spring hole for fixing the position of spring 9 is arranged on fixed brake plate 6.

[0044] First cylinder 7 is fixedly arranged at the end of mounting seat 1; first oil path 7a is arranged in first cylinder 7, and one end of first oil path 7a communicates with the internal space of first cylinder 7.

[0045] The first piston 8 slides within the internal space of the first cylinder 7; sealing rings are provided on both the inner and outer sides of the first piston 8, thereby ensuring tight contact between the first piston 8 and the side wall of the internal space of the first cylinder 7. The outer side of the brake pad 5 extends between the fixed brake plate 6 and the first piston 8.

[0046] A spring 9 is disposed between the first piston 8 and the fixed brake plate 6. The spring 9 is continuously compressed and provides a force that separates the first piston 8 and the fixed brake plate 6 from each other.

[0047] The second cylinder 10 is fixedly installed at the end of the first cylinder 7; the second cylinder 10 is provided with a second oil passage 10a and a third oil passage 10b; one end of the second oil passage 10a is connected to the first oil passage 7a, and the other end is connected to the outside of the first cylinder 7 for oil supply; one end of the third oil passage 10b is connected to the second oil passage 10a, and the other end is connected to the internal space of the second cylinder 10.

[0048] The second piston 11 slides within the internal space of the second cylinder 10; sealing rings are provided on both the inner and outer sides of the second piston 11, so that the second piston 11 is in close contact with the side wall of the internal space of the second cylinder 10.

[0049] Before the brake pads are worn to a set level (i.e., when the turntable is working normally), the first piston 8 and the second piston 11 remain in contact with each other.

[0050] The braking principle of this direct-drive turntable is as follows:

[0051] like Figure 2 As mentioned above, when braking is not required, oil will not be supplied to the oil circuit, that is, there is no oil pressure in each oil circuit. At this time, the spring 9 will push the first piston 8 and the fixed brake plate 6 to separate from each other, the brake pad 5 is not squeezed, so the rotating shaft 3 can rotate freely.

[0052] When braking is required, such as Figure 3 As shown, oil is supplied to the second oil passage 10a. After flowing through the third oil passage 10b and the first oil passage 7a, the oil enters the internal space of the first cylinder 7 and the second cylinder 10, pushing the first piston 8 and the second piston 11 to move simultaneously. This pushes the first piston 8 toward the fixed brake plate 6, ultimately causing the first piston 8 to clamp the brake pad 5 onto the fixed brake plate 6, thus completing the braking process.

[0053] With this structure, during braking, the hydraulic fluid simultaneously exerts pressure on the end faces of the first piston 8 and the second piston 11. The clamping force during braking is the superposition of these two pressures, which greatly enhances the braking force and ensures stable braking performance under high stress. Furthermore, through the coordination between the various hydraulic circuits, this structure can simultaneously control the movement of the first piston 8 and the second piston 11, resulting in faster braking speeds and easier control.

[0054] Because the final brake force of the structure is large, if all the thrusts are applied to the brake pad 5 at a moment, the instantaneous impact force on the brake pad 5 will be very large, which will cause great damage to the brake pad 5. In order to solve the above problem, the rotary table is designed as follows:

[0055] When the first piston 8 and the second piston 11 are both stopped at the position farthest from the brake pad 5, as shown in Figure 2 The end surface of the second piston 11 is provided with a groove corresponding to the outlet of the third oil channel 10b, so that the second piston 11 and the inner end surface of the second cylinder 10 form a second spacing space 10c; and the first piston 8 cannot abut against the inner end surface of the first cylinder 7 due to abutting against the second piston 11, so that the first piston 8 and the inner end surface of the first cylinder 7 form a first spacing space 7c; the first spacing space 7c is larger than the second spacing space 10c.

[0056] When braking under the above structure, after the oil passes through the third oil channel 10b and the first oil channel 7a, it will flow into the first spacing space 7c and the second spacing space 10c respectively. Because the first spacing space 7c is larger than the second spacing space 10c, the second spacing space 10c will be filled first to push the second piston 11 to move and push the first piston 8 to move, and at this time the first spacing space 7c is not yet filled and cannot generate pressure on the first piston 8, so that the total pressure on the brake pad 5 at this time is only the thrust provided by the oil in the second spacing space 10c, so that the impact force of the first piston 8 on the brake pad 5 in the initial stage of contact is small.

[0057] When the first piston 8 abuts against the brake pad 5, the first piston 8 and the second piston 11 will stop moving, that is, the first spacing space 7c and the second spacing space 10c will not be enlarged, and with the oil gradually filling the first spacing space 7c and generating pressure, the pressure generated by the two piston combinations will begin to gradually increase, and finally reach a large brake force.

[0058] Preferably, a recess is arranged on the end surface of the second piston 11; a boss 10d is arranged on the inner end surface of the second cylinder 10, and the boss 10d extends into the recess; and one end of the third oil channel 10b is located on the boss 10d. In this way, a large gap can be ensured between the first spacing space 7c and the second spacing space 10c in the initial stage of movement of the two pistons, so as to ensure the smooth realization of the above functions. When the first piston 8 abuts against the brake pad 5, the boss 10d will be separated from the recess, so that the oil can reach the entire end surface of the second piston 11, the contact area of the oil is increased, and the thrust on the second piston 11 is increased.

[0059] Preferably, when the first piston 8 is located at the position farthest from the brake pad 5, there is a gap between the brake pad 5 and the fixed brake plate 6, that is, the brake pad 5 and the fixed brake plate 6 are not in contact in the non-braking state, so as to avoid the friction between the brake pad 5 and the fixed brake plate 6 affecting the rotation during the rotation of the rotating shaft 3; when the first piston 8 moves against the brake pad 5 during braking, the brake pad 5 will be elastically deformed and then pushed onto the fixed brake plate 6, so that when the first piston 8 moves away after the brake is released, the brake pad 5 will be reset elastically and separated from the fixed brake plate 6 again.

[0060] In order to improve the stability and force transmission effect of the first piston 8 and the second piston 11 during movement, the following structure is designed for the turntable:

[0061] The first cylinder 7 is provided with a guide hole;

[0062] Further comprising a guide column 12 sliding in the guide hole, and the guide column 12 extends out of the guide hole at both ends, and the two ends of the guide column 12 abut against the first piston 8 and the second piston 11 respectively during normal operation of the turntable. The guide column 12 is aligned with the outside of the brake pad 5 in the direction of the axis of the turntable as much as possible, so that the pressure of the second piston 11 can directly act on the outside of the brake pad 5 through the guide column 12, thereby improving the clamping effect on the brake pad 5.

[0063] With the use of the turntable, the outside of the brake pad 5 will become thin due to wear, and when the outside of the brake pad 5 is too thin, the brake pad 5 will not be able to withstand too much braking force, resulting in deformation or even breakage of the brake pad 5, which has a great safety hazard. In order to avoid the above problems, the following structure is designed for the turntable as shown in the drawings: Figures 4-6

[0064] When the first piston 8 and the second piston 11 are located at the position farthest from the brake pad 5, the first sliding gap 7e is formed between the first piston 8 and the fixed brake plate 6, and the second sliding gap 10e is formed between the second piston 11 and the first cylinder 7, the first sliding gap 7e is greater than the second sliding gap 10e, and the second sliding gap 10e is greater than the gap between the first piston 8 and the brake pad 5;

[0065] The fifth oil channel 12a is arranged on the guide column 12; one end of the fifth oil channel 12a communicates with the end face of the guide column 12 close to the first piston 8, and the other end communicates with the part of the side surface of the guide column 12 corresponding to the first sliding gap 7e.

[0066] The specific principle of the above structure is as follows:

[0067] When the brake pad 5 has not been worn, as shown in the drawings: Figure 5 ​As shown, the movable range of the first piston 8 is relatively small. After the first piston 8 contacts the brake pad 5, there is still a certain space in the second sliding interval 10e, that is, the second piston 11 can continue to move towards the brake pad 5, so that the first piston 8 and the second piston 11 always remain in contact. In this way, the end of the guide post 12 will always stick to the end face of the first piston 8, and the oil cannot enter the fifth oil passage 12a. At this time, the second piston 11 and the first piston 8 are both pushed by the oil from left to right, that is, the maximum braking force is generated on the brake pad 5 at this time.

[0068] When the wear of brake pad 5 exceeds a certain limit, such as Figure 6 As shown, even though the second piston 11 has moved to the far right, the first piston 8 still needs to move further to the right to touch the brake pad 5. This causes the end of the guide post 12 to separate from the end face of the first piston 8. The oil in the first gap space 7c will then enter the second sliding gap 10e through the fifth oil passage 12a. At this time, the second piston 11 is simultaneously subjected to oil pressure from both the left and right sides, which can eliminate the thrust generated by the second piston 11 and allow the oil to fill the space between the first piston 8 and the second piston 11, avoiding the creation of a vacuum area. The first piston 8 is subjected to the thrust of the oil from left to right. In summary, only the first piston 8 exerts thrust on the brake pad 5, thereby reducing the braking force. If a decrease in braking stability is detected at this time, it can be identified that the brake pad 5 has experienced significant wear and needs to be replaced promptly.

[0069] Preferably, a transition section 12b with a gradually decreasing diameter is provided at the end of the guide post 12 near the first piston 8. In this way, the oil in the first gap space 7c will always generate a leftward thrust on the guide post 12, avoiding the first piston 8 and the guide post 12 from being too tightly fitted, which would prevent them from being unable to separate and affect the function of automatically reducing braking force when the brake pad 5 wears.

[0070] Preferably, a mounting hole is provided at the end of the second piston 11, and one end of the guide post 12 extends into the mounting hole, thereby improving the movement stability of the guide post 12 and the second piston 11.

[0071] Preferably, an extension section 8a is provided inside the first piston 8. The extension section 8a extends out of the first cylinder 7 and abuts against the second piston 11. The extension section 8a can increase the local thickness of the first piston 8, thereby preventing the first piston 8 from flipping when moving, so that it can apply force more evenly when it is in contact with the brake pad 5, and ensure the stability of braking.

[0072] This invention also relates to a method for operating a direct-drive turntable with dual-piston brakes, for use in a direct-drive turntable with dual-piston brakes as described above, the steps of which include:

[0073] Power is supplied to the stator 2 according to the rotation requirements, so that the rotor 4 rotates and drives the shaft 3 to rotate.

[0074] After reaching the rotating position, oil is supplied to the second oil passage 10a, and the oil supply is continued until the oil pressure in the second oil passage 10a reaches a set value, and then the oil supply is stopped, and the oil pressure is maintained;

[0075] At the next rotation, the maintenance of the oil pressure in the second oil passage 10a is released, and a certain waiting time is required to reset the brake structure inside the turntable, and the length of the waiting time is set according to the specific situation, and then power is supplied to the stator 2 to drive the rotor 4 and the rotating shaft 3 to rotate.

[0076] The above shows and describes the basic principles, main features and advantages of the present application. Those skilled in the art should understand that the present application is not limited to the above embodiments, and the above embodiments and descriptions in the specification are only to illustrate the principles of the present application, and various changes and improvements can be made without departing from the spirit and scope of the present application, and these changes and improvements all fall within the scope of the claimed present application. The scope of protection of the present application is defined by the appended claims and their equivalents.

Claims

1. A direct-drive turntable with dual-piston brakes, characterized in that, include: Mounting base (1), independently fixed; stator (2) is provided inside the mounting base (1); A rotating shaft (3) rotates in the mounting base (1); a rotor (4) and a brake pad (5) are mounted on the rotating shaft (3); The brake plate (6) is fixedly mounted at the end of the mounting base (1); A first cylinder (7) is fixedly disposed at the end of the mounting base (1); a first oil passage (7a) is provided inside the first cylinder (7), and one end of the first oil passage (7a) is connected to the internal space of the first cylinder (7); The first piston (8) slides within the internal space of the first cylinder (7); the outer side of the brake pad (5) extends between the fixed brake plate (6) and the first piston (8); A spring (9) is disposed between the first piston (8) and the fixed brake plate (6); The second cylinder (10) is fixedly disposed at the end of the first cylinder (7); the second cylinder (10) is provided with a second oil passage (10a) and a third oil passage (10b); one end of the second oil passage (10a) is connected to the first oil passage (7a), and the other end is connected to the outside of the first cylinder (7); one end of the third oil passage (10b) is connected to the second oil passage (10a), and the other end is connected to the internal space of the second cylinder (10); The second piston (11) slides within the internal space of the second cylinder (10); The first piston (8) and the second piston (11) abut against each other. When the first piston (8) and the second piston (11) are located at the position furthest from the brake pad (5), a first gap space (7c) is formed between the first piston (8) and the inner end face of the first cylinder (7), and a second gap space (10c) is formed between the second piston (11) and the inner end face of the second cylinder (10). The first gap space (7c) is larger than the second gap space (10c). An extension section (8a) is provided on the inner side of the first piston (8), the extension section (8a) extends out of the first cylinder (7) and abuts against the second piston (11).

2. The direct-drive turntable with dual-piston brakes according to claim 1, characterized in that, The second piston (11) has a concave hole on its end face; the second cylinder (10) has a boss (10d) on its inner end face, and the boss (10d) extends into the concave hole; one end of the third oil passage (10b) is located on the boss (10d).

3. The direct-drive turntable with dual-piston brakes according to claim 1, characterized in that, When the first piston (8) is located at the position furthest from the brake pad (5), there is a gap between the brake pad (5) and the fixed brake plate (6).

4. The direct-drive turntable with dual-piston brakes according to claim 1, characterized in that, The first cylinder (7) is provided with a guide hole; It also includes a guide post (12) that slides within the guide hole, with both ends of the guide post (12) extending out of the guide hole.

5. The direct-drive turntable with dual-piston brakes according to claim 4, characterized in that, When the first piston (8) and the second piston (11) are at the position furthest from the brake pad (5), a first sliding interval (7e) is formed between the first piston (8) and the fixed brake plate (6), and a second sliding interval (10e) is formed between the second piston (11) and the first cylinder (7). The first sliding interval (7e) is greater than the second sliding interval (10e), and the second sliding interval (10e) is greater than the interval between the first piston (8) and the brake pad (5). A fifth oil passage (12a) is provided on the guide post (12); one end of the fifth oil passage (12a) is connected to the end face of the guide post (12) near the first piston (8), and the other end is connected to the part of the side of the guide post (12) corresponding to the first sliding interval (7e).

6. The direct-drive turntable with dual-piston brakes according to claim 5, characterized in that, The guide post (12) has a transition section (12b) with a gradually decreasing diameter at one end near the first piston (8).

7. The direct-drive turntable with dual-piston brakes according to claim 4, characterized in that, The second piston (11) has a mounting hole at its end, and one end of the guide post (12) extends into the mounting hole.

8. A method for operating a direct-drive turntable with dual-piston brakes, characterized in that, A direct-drive turntable for a dual-piston brake as described in any one of claims 1 to 7, comprising the following steps: Power is supplied to the stator (2) according to the rotation requirements, so that the rotor (4) rotates and drives the shaft (3) to rotate; After reaching the rotation position, oil is supplied to the second oil circuit (10a) and the oil supply continues until the oil pressure in the second oil circuit (10a) reaches the set value, then the oil supply stops and the oil pressure is maintained. When rotating again, the maintenance of the oil pressure in the second oil circuit (10a) is released, and after waiting for the set time, the stator (2) is powered to drive the rotor (4) and the shaft (3) to rotate.

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