A built-in mechanical online dynamic balancing device with a counterweight position closed loop

Abstract

A built-in mechanical online dynamic balancing device with a closed loop of counterweight position comprises an intermediate housing, wherein the intermediate housing contains a driving transmission mechanism with a symmetrical position center to form a symmetrical counterweight adjustment mechanism: the driving transmission mechanism comprises a DC motor, the DC motor and a worm gear assembly can be self-locking when matched, the worm gear assembly and a worm spur gear assembly can be self-locking when matched, the spur gears of the worm spur gear assembly match with driving inner teeth, the driving inner teeth are connected to a sleeve, a motor sleeve is arranged inside the sleeve, the sleeve and the motor sleeve are supported by two needle bearings, the motor sleeve is fixed to the intermediate housing; the outer ring of the sleeve is connected to the counterweight block; the motor sleeve fixes the DC motor position by a top screw, the motor sleeve is fixed to a third end cover, a micro sensor is built in the inner side of the third end cover, and a scale line is contained on the side of the sleeve close to the third end cover; the present invention can provide real-time feedback on the position of the counterweight block, thereby improving the stability and efficiency of the balancing process.

Description

Technical Field

[0001] The invention relates to the technical field of spindle balancing, and in particular to a built-in mechanical online dynamic balancing device with a counterweight position closed loop. Background Art

[0002] High-end CNC machine tools are important "mother machines" for modern machining, and the spindle is one of the key components of high-end CNC machine tools. The quality of machining depends largely on the performance of the spindle. Due to reasons such as spindle manufacturing, installation, and unknown accidents during machining, the spindle usually has a certain amount of imbalance. At high speeds, a small amount of imbalance will manifest as a huge centrifugal force, which will not only affect the quality of machine tool processing, but may even cause more serious safety accidents.

[0003] In order to solve the problem of spindle imbalance, the on-site dynamic balancing technology is now widely used. However, it requires frequent starting and stopping of the machine tool during the balancing process, which not only affects the balancing efficiency and processing efficiency, but also has a greater impact on the processing quality and even affects the life of the machine tool. With the development of science and technology, online dynamic balancing technology for online adjustment of spindle mass distribution and correction of imbalance has gradually developed. This method performs real-time imbalance correction during the operation of the machine tool, which not only does not affect the processing efficiency and quality, but also has a certain adaptability to speed changes. Relying on online dynamic balancing technology, there are currently many types of online dynamic balancing devices: liquid-jet online dynamic balancing device, electromagnetic online dynamic balancing device, piezoelectric online dynamic balancing device, motor online dynamic balancing device, among which the motor online dynamic balancing device is widely used due to its simple drive control, strong self-locking performance, and excellent starting characteristics.

[0004] The motor-type online dynamic balancing device drives two counterweights to make circular motion through a brushless motor. During the operation of the main shaft, the combined force of the two counterweights is used to balance the centrifugal force generated by the imbalance to achieve the balance of the main shaft. The currently widely used balancing method is the double counterweight balancing method (Chinese patent application number CN201510398608.9, title: A spindle built-in mechanical online dynamic balancing device; Chinese patent application number CN201820033878.9, title: A built-in piezoelectric online dynamic balancing execution structure). The double counterweight balancing method includes two steps: phase balance and amplitude balance; there is a trial step process in both steps, that is, at the beginning, a direction is randomly selected to drive the counterweight to move, monitor the change of the imbalance, and then determine the correct adjustment direction of the counterweight. The trial step process may cause a sharp increase in the imbalance, that is, the "misadjustment" problem; since the position of the counterweight block of the built-in motor balancing device is difficult to measure and the counterweight block drive control adopts an open-loop control method, the "misadjustment" problem is difficult to avoid, resulting in the spindle imbalance amount cannot be reduced monotonically, reducing the balancing efficiency. Summary of the invention

[0005] In order to overcome the above-mentioned shortcomings of the prior art, the purpose of the present invention is to provide a built-in mechanical online dynamic balancing device with a counterweight position closed loop, which can provide real-time feedback on the counterweight position, solve the "misadjustment" problem, and improve the stability and efficiency of the balancing process.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is:

[0007] A built-in mechanical online dynamic balancing device with a closed loop of counterweight position, comprising an intermediate housing 1, wherein the intermediate housing 1 contains a driving transmission mechanism with a symmetrical position center to form a symmetrical counterweight adjustment mechanism: the driving transmission mechanism comprises a DC motor 11, the DC motor 11 and a worm gear assembly 13 cooperate to be self-locking, the worm gear assembly 13 and a worm spur gear assembly 12 cooperate to be self-locking, the spur gear of the worm spur gear assembly 12 cooperates with a driving inner tooth 14, the driving inner tooth 14 is connected to a sleeve 2, a motor sleeve 15 is arranged inside the sleeve 2, the sleeve 2 and the motor sleeve 15 are supported by two needle bearings 22, and the motor sleeve 15 is fixed to the intermediate housing 1; the outer ring of the sleeve 2 is connected to a counterweight block 3;

[0008] The motor sleeve 15 fixes the position of the DC motor 11 through the top screw 152. The motor sleeve 15 is fixed to the third end cover 4. The inner side of the third end cover 4 has a built-in micro sensor 41. The side of the sleeve 2 close to the third end cover 4 has a scale line 23.

[0009] The worm gear assembly 13 is connected to a first bearing 131 and a first end cover 133, and is supported on the intermediate housing 1 through the first bearing 131, and the first bearing 131 and the intermediate housing 1 are interference fit; the worm gear assembly 13 and the first end cover 133 are connected through a third bearing 132, and the third bearing 132, the first end cover 133 and the worm gear assembly 13 are all interference fit.

[0010] The worm gear spur gear assembly 12 is connected to a second bearing 121 and a second end cover 123, and is supported on the intermediate housing 1 through the second bearing 121, and the first bearing 121 and the intermediate housing 1 are interference fit; the worm gear spur gear assembly 12 and the first end cover 123 are connected through a fourth bearing 122, and the fourth bearing 122, the first end cover 123 and the worm gear spur gear assembly 12 are all interference fit.

[0011] The DC motor 11, the worm gear assembly 13, the worm gear spur gear assembly 12 and the driving internal teeth 14 together constitute the driving mechanism of the counterweight block 3, and the mechanism reduction ratio is 12700.

[0012] The material of the counterweight block 3 is tungsten alloy.

[0013] The micro sensor 41 is a laser displacement sensor, which will respond when it passes through the scale line 23 on the sleeve 2. During the dynamic balancing process, when the counterweight 3 rotates forward or reversely, the micro sensor 41 monitors the number of scale advances and retreats of the sleeve 2 in real time, and feeds back to the control system. The control system obtains the real-time position of the counterweight 3, and then issues the next action instruction to the counterweight 3, forming a closed-loop control of the counterweight position.

[0014] The DC motor 11 driving power supply and the laser displacement sensor input and output signals from the outside through high-speed slip rings.

[0015] The beneficial effects of the present invention are:

[0016] The present invention adopts a micro laser displacement sensor to monitor the position of the counterweight block, realizes closed-loop control of the built-in mechanical online dynamic balancing device, can accurately identify the position of the counterweight block, avoid the "misadjustment" problem, and improve the stability and balancing efficiency of the online dynamic balancing of the spindle. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of the present invention.

[0018] Figure 2 It is a partial schematic diagram of the motor sleeve of the present invention.

[0019] Figure 3 It is a schematic diagram of the central transmission structure of the present invention.

[0020] Figure 4 It is a schematic diagram of the structure of the transmission component of the present invention.

[0021] Figure 5 It is a partial schematic diagram of the counterweight block of the present invention. DETAILED DESCRIPTION

[0022] The present invention is described in detail below with reference to the accompanying drawings and embodiments.

[0023] Reference Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5A built-in mechanical online dynamic balancing device with a closed loop of counterweight position comprises an intermediate housing 1, wherein the intermediate housing 1 contains a driving transmission mechanism with a symmetrical position center to form a symmetrical counterweight adjustment mechanism: the driving transmission mechanism comprises a DC motor 11 as a driving source, the DC motor 11 cooperates with a worm gear assembly 13 to be self-locking, the worm gear assembly 13 cooperates with a worm spur gear assembly 12 to be self-locking, the spur gear of the worm spur gear assembly 12 cooperates with a driving inner tooth 14, the driving inner tooth 14 is connected to a sleeve 2 by a first bolt 21, a motor sleeve 15 is provided inside the sleeve 2, the sleeve 2 and the motor sleeve 15 are supported by two needle bearings 22, and the motor sleeve 15 is fixed to the intermediate housing 1 by a second bolt 151; the outer ring of the sleeve 2 is connected to the counterweight block 3 by a third bolt 31;

[0024] Reference Figure 2 , Figure 5 The motor sleeve 15 fixes the position of the DC motor 11 through a top screw 152, and the motor sleeve 15 is fixed to the third end cover 4 through a fourth bolt 42. A micro sensor 41 is built into the inner side of the third end cover 4, and a scale line 23 is included on the side of the sleeve 2 close to the third end cover 4.

[0025] Reference Figure 4 The worm gear assembly 13 is connected to a first bearing 131 and a first end cover 133, and is supported on the intermediate housing 1 through the first bearing 131, and the first bearing 131 and the intermediate housing 1 are interference fit; the worm gear assembly 13 and the first end cover 133 are connected through a third bearing 132, and the third bearing 132, the first end cover 133 and the worm gear assembly 13 are all interference fit.

[0026] The worm gear spur gear assembly 12 is connected to a second bearing 121 and a second end cover 123, and is supported on the intermediate housing 1 through the second bearing 121, and the first bearing 121 and the intermediate housing 1 are interference fit; the worm gear spur gear assembly 12 and the first end cover 123 are connected through a fourth bearing 122, and the fourth bearing 122, the first end cover 123 and the worm gear spur gear assembly 12 are all interference fit.

[0027] The DC motor 11, the worm gear assembly 13, the worm gear spur gear assembly 12 and the driving internal teeth 14 together constitute the driving mechanism of the counterweight block 3, and the mechanism reduction ratio is 12700.

[0028] The material of the counterweight block 3 is tungsten alloy.

[0029] The micro sensor 41 is a laser displacement sensor, which will respond when it passes through the scale line 23 on the sleeve 2. During the dynamic balancing process, when the counterweight 3 rotates forward or reversely, the micro sensor 41 monitors the number of scale advances and retreats of the sleeve 2 in real time, and feeds back to the control system. The control system obtains the real-time position of the counterweight 3, and then issues the next action instruction to the counterweight 3, forming a closed-loop control of the counterweight position.

[0030] The DC motor 11 driving power supply and the laser displacement sensor input and output signals from the outside through high-speed slip rings.

[0031] The working principle of the present invention is:

[0032] A built-in mechanical online dynamic balancing device with a closed loop of counterweight position is built into the inner hole of the main shaft through a transition fit, and the third end cover 4 is locked with the main shaft by bolts; in the initial state, the micro sensor 41 on the third end cover 4 coincides with a special scale line 23 on the sleeve 2. When the unbalanced state of the main shaft is detected, the unbalanced vector and phase are obtained, and the current position of the counterweight block 3 is compared, and the DC motor 11 is driven to drive the internal teeth 14 to rotate through the worm gear assembly 13 and the worm gear spur gear assembly 12, so that the counterweight block 3 rotates and adjusts Mass distribution, and then complete the imbalance correction of the spindle; at the same time, the micro sensor 41 feeds back the rotation angle of the sleeve 2, that is, the position information of the counterweight 3, in real time, and the control system records the position information of the counterweight 3. When the spindle is detected to be unbalanced again, the position information of the counterweight 3 recorded by the control system is used to drive the counterweight 3 to move in the correct direction during the online dynamic balancing of the spindle, avoiding the trial step process of the double counterweight balancing method, thereby avoiding the "misadjustment" problem, improving the stability and efficiency of the balancing process, and allowing the spindle to quickly reach balance.

Claims

1. A built-in mechanical online dynamic balancing device with a counterweight position closed loop, comprising an intermediate housing (1), characterized in that: The intermediate housing (1) contains a driving transmission mechanism with a central symmetry, forming a symmetrical counterweight adjustment mechanism: the driving transmission mechanism includes a DC motor (11), the DC motor (11) and the worm gear assembly (13) cooperate to be self-locking, the worm gear assembly (13) and the worm gear spur gear assembly (12) cooperate to be self-locking, the spur gear of the worm gear spur gear assembly (12) cooperates with the driving inner teeth (14), the driving inner teeth (14) are connected to the sleeve (2), a motor sleeve (15) is provided inside the sleeve (2), the sleeve (2) and the motor sleeve (15) are supported by a needle bearing (22), and the motor sleeve (15) is fixed to the intermediate housing (1); the outer ring of the sleeve (2) is connected to the counterweight block (3); The motor sleeve (15) fixes the position of the DC motor (11) via a top screw (152), the motor sleeve (15) is fixed to the third end cover (4), a micro sensor (41) is built into the inner side of the third end cover (4), and a scale mark (23) is included on one side of the sleeve (2) close to the third end cover (4); The micro sensor (41) is a laser displacement sensor. When the laser displacement sensor passes through the scale line (23) on the sleeve (2), a response is generated. During the dynamic balancing process, while the counterweight (3) rotates forward or reversely, the micro sensor (41) monitors the number of scales of the sleeve (2) that advance or retreat in real time, and feeds back to the control system. The control system obtains the real-time position of the counterweight (3), and then issues the next action instruction to the counterweight (3), thereby forming a closed-loop control of the counterweight position.

2. The device according to claim 1, characterized in that: The worm gear assembly (13) is connected to a first bearing (131) and a first end cover (133), and is supported on the intermediate housing (1) via the first bearing (131), and the first bearing (131) and the intermediate housing (1) are in an interference fit; the worm gear assembly (13) and the first end cover (133) are connected via a third bearing (132), and the third bearing (132), the first end cover (133) and the worm gear assembly (13) are in an interference fit.

3. The device according to claim 1, characterized in that: The worm gear spur gear assembly (12) is connected to a second bearing (121) and a second end cover (123), and is supported on the intermediate housing (1) via the second bearing (121), and the second bearing (121) and the intermediate housing (1) are in an interference fit; the worm gear spur gear assembly (12) and the second end cover (123) are connected via a fourth bearing (122), and the fourth bearing (122), the second end cover (123) and the worm gear spur gear assembly (12) are in an interference fit.

4. The device according to claim 1, characterized in that: The DC motor (11), the worm gear assembly (13), the worm gear spur gear assembly (12) and the driving internal teeth (14) together form a counterweight (3) driving mechanism, and the mechanism reduction ratio is 12700.

5. The device according to claim 1, characterized in that: The material of the counterweight block (3) is tungsten alloy.

6. The device according to claim 1, characterized in that: The DC motor (11) driving power supply and the laser displacement sensor input and output signals from the outside via a high-speed slip ring.

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