Embedded counterweight moment balance built-in mechanical on-line dynamic balance device

Abstract

A nested counterweight moment balance built-in mechanical on-line dynamic balance device belongs to the field of on-line dynamic balance of overspeed spindles, and comprises a driving transmission mechanism arranged in an outer side driving cavity, the driving transmission mechanism comprises two direct current motors, the direct current motors are fixedly connected with couplings through speed reducers, the couplings are matched with inner gears, and the inner gears are connected with the outer side driving cavity. The inner gear is connected with the inner-layer and outer-layer counterweight support through the outer gear, the inner-layer and outer-layer counterweight support is connected with the dynamic balance weight, and the inner-layer and outer-layer counterweight support and the stepped mandrel form a nested structure and are matched through two groups of rolling bearings; the position of the balancing weight can be fed back in real time, the problem that the dynamic balancing head moment is unbalanced is solved, and the stability and precision of the balancing process are improved.

Description

Technical Field

[0001] The invention relates to the technical field of main shaft balancing of rotating machinery, and in particular to a nested counterweight moment balancing built-in mechanical online dynamic balancing device. Background Art

[0002] Rotating machinery is widely used in energy, chemical industry, manufacturing equipment and defense industry, such as steam turbines, compressors, machine tool spindles and aircraft engines. During the movement of rotating machinery, due to the existence of mass eccentricity, structural asymmetry, installation error, wear and other problems of the spindle, it will cause trouble to the operation of the spindle and cause vibration of the rotor system. In rotating machines including transmission shafts, the problems of torsional vibration and rotational imbalance are particularly prominent, because in addition to hindering the operation of the rotating machine system, they will also damage the actual structure and components that make up the rotating machine system.

[0003] According to the characteristics of rotor imbalance, it can be divided into original imbalance, gradual imbalance and sudden imbalance. First, with the increase of speed, the originally small and negligible imbalance will also affect the running state of the spindle and interfere with the normal operation of the spindle, which puts higher requirements on the accuracy of dynamic balancing. Second, when the spindle runs at high speed for a long time, gradual imbalance is inevitable due to wear, plastic deformation, material corrosion and other reasons. Third, the spindle will produce a large imbalance due to sudden conditions during operation. To remove these imbalances, it is usually necessary to disassemble and reassemble the rotor system and use a dynamic balancing machine to balance the spindle offline, which will consume more resources. At the same time, during the disassembly and assembly of the spindle, new imbalances will appear due to assembly errors and other reasons. Therefore, the theoretical research on online dynamic balancing and the development of online dynamic balancing equipment have become urgent problems to be solved.

[0004] The motor-type online dynamic balancing device drives the counterweight to move through the motor. When the spindle is in working condition, the combined force of the double counterweight is used to offset the imbalance of the spindle itself, so as to achieve the online balance of the spindle. At present, the double counterweight non-nested structure balancing head structure (publication number: CN104999330A, name: a spindle built-in mechanical online dynamic balancing device; publication number: CN115716138A, name: a built-in mechanical online dynamic balancing device with a counterweight position closed loop) is widely used. The characteristics are that the mass adjustment block and the counterweight are arranged in parallel along the axial direction. This structure is beneficial to the calculation of the mass of the counterweight, but because the balancing forces generated by the two counterweights are not in the same plane, an unbalanced torque that cannot be eliminated will be generated. This unbalanced torque makes the device itself unbalanced, which seriously reduces the overall accuracy of the balancing device. Summary of the invention

[0005] In order to overcome the shortcomings of the above-mentioned prior art, the purpose of the present invention is to provide a nested counterweight torque balancing built-in mechanical online dynamic balancing device, which can provide real-time feedback on the position of the counterweight block, improve positioning accuracy, and overcome the problem of torque imbalance of the non-nested dynamic balancing head itself, thereby improving the stability of the balancing process and the balancing efficiency.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions to achieve it:

[0007] A nested counterweight moment balancing built-in mechanical online dynamic balancing device comprises an outer driving cavity 1, a transmission cavity 2 and a balancing block shaft system 3 which are arranged in sequence:

[0008] The outer driving cavity 1 contains a closed-loop driving mechanism with a central symmetrical position to form a symmetrical power output. The closed-loop driving mechanism includes a symmetrically arranged DC motor 6 with an encoder, and the DC motor 6 is fixed on a reduction box 8; the power output end of the DC motor 6 is connected to the internal gear 10 through the reduction box 8 and the coupling 9, and the reduction box 8 is connected to the motor connecting seat 7; a mass compensation block 11 is connected to the shorter coupling 9.

[0009] The transmission cavity 2 contains an internal gear meshing mechanism with a central symmetry, forming a symmetrical transmission structure; the transmission structure includes a first external gear 13 and a second external gear 14 meshing with the two internal gears 10, the second external gear 14 is connected to the inner counterweight support 21, the first external gear 13 is connected to the outer end cover 23, and the outer end cover 23 is connected to the outer counterweight support 22;

[0010] The balancing block shaft system 3 contains counterweight balancing blocks nested inside and outside, including a stepped spindle 15, which is supported in an inner counterweight support 21 through a first bearing 16 and a second bearing 18, and the end of the inner counterweight support 21 is connected to an inner end cover 24, which is pressed against the second bearing 18; the inner counterweight support 21 is connected to an outer counterweight support 22 through a third bearing 19, and the end of the outer counterweight support 22 is matched with the stepped spindle 15 through a fourth bearing 20, and the end of the stepped spindle 15 is connected to an end cover 4, which is in contact with the fourth bearing 20; the inner counterweight support 21 is connected to an inner counterweight 25 and an inner counterweight balancing block 26, and the outer counterweight support 22 is connected to an outer counterweight 27 and an outer counterweight balancing block 28.

[0011] The internal gear 10 , the first external gear 13 and the second external gear 14 form a multi-stage reduction fit through the reduction box 8 and are self-locking.

[0012] The driving motor 6 can realize a position closed loop.

[0013] The reduction box 8 and the coupling 9 are interference fit, and the coupling 9 and the internal gear 10 are interference fit, and there is no gap between the fitting end faces.

[0014] The outer driving cavity 1 and the stepped spindle 15 are in interference fit.

[0015] The DC motor 6, the reduction box 8, the internal gear 10, the first external gear 13 and the second external gear 14 together form a driving mechanism, and the reduction ratio of the mechanism is 1470.

[0016] The inner layer counterweight 25, the outer layer counterweight 27, the inner layer counterweight balance block 26 and the outer layer counterweight balance block 28 are made of tungsten alloy.

[0017] The inner layer counterweight 25 and the inner layer counterweight balance block 26, the outer layer counterweight 27 and the outer layer counterweight balance block 28 are inner and outer nested structures with the same length. The angle of the inner layer counterweight 25 is 180°, and the angle of the outer layer counterweight 27 is 75.046°.

[0018] The transmission ratio of the DC motor 6, the outer counterweight 27 and the inner counterweight 25 is

[0019] Compared with the prior art, the present invention has the following advantages:

[0020] The present invention adopts double-layer nested matching, which eliminates the problem of unbalanced torque of ordinary mechanical balancing heads; each layer of counterweights is equipped with corresponding counterweight balance blocks, which eliminates the force imbalance caused by bolt connections and different mass radii; an encoded motor is adopted, and stable and controllable motor position and speed can be achieved through control methods such as PWM and PID, avoiding the problem of "misadjustment" and also improving the balancing efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a structural schematic diagram of the present invention.

[0022] Figure 2 It is a schematic diagram of the outer driving cavity part of the present invention.

[0023] Figure 3 It is a schematic diagram of the transmission structure of the present invention.

[0024] Figure 4 It is a schematic diagram of the inner and outer layer shaft system support of the present invention.

[0025] Figure 5 It is a schematic diagram of the distribution of counterweight blocks of the present invention. DETAILED DESCRIPTION

[0026] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments.

[0027] Reference Figure 1A nested counterweight moment balance built-in mechanical online dynamic balancing device, comprising an outer driving cavity 1, a transmission cavity 2 and a balance block shaft system 3 arranged in sequence, an end cover 4 is provided at the head of the whole device, an electromagnetic slip ring 5 is provided outside the connection between the tail and the main shaft, and the electromagnetic slip ring 5 leads to the device wiring:

[0028] Reference Figure 2 The outer driving cavity 1 contains a closed-loop driving mechanism with a symmetrical position center to form a symmetrical power output. The closed-loop driving mechanism includes a symmetrically arranged DC motor 6 with an encoder, and the DC motor 6 is fixed on a reduction box 8; the power output end of the DC motor 6 is connected to the internal gear 10 through the reduction box 8 and the coupling 9, and the reduction box 8 is connected to the motor connecting seat 7; a mass compensation block 11 is connected to the shorter coupling 9.

[0029] Reference Figure 3 , Figure 4 The transmission cavity 2 contains an internal tooth meshing mechanism with a central symmetry, forming a symmetrical transmission structure; the transmission structure includes a first external gear 13 and a second external gear 14 meshing with the two internal gears 10, the second external gear 14 is connected to the inner counterweight support 21, the first external gear 13 is connected to the outer end cover 23, and the outer end cover 23 is connected to the outer counterweight support 22.

[0030] Reference Figure 4 , Figure 5 The balance block shaft system 3 contains inner and outer nested counterweight balance blocks, including a stepped spindle 15, which is supported in an inner counterweight support 21 through a first bearing 16 and a second bearing 18. The end of the inner counterweight support 21 is connected to an inner end cover 24 through bolts, and the inner end cover 24 is pressed against the second bearing 18; the inner counterweight support 21 is connected to an outer counterweight support 22 through a third bearing 19, and the end of the outer counterweight support 22 is matched with the stepped spindle 15 through a fourth bearing 20, and the end of the stepped spindle 15 is connected to an end cover 4, which is in contact with the fourth bearing 20; the inner counterweight support 21 is connected to an inner counterweight 25 and an inner counterweight balance block 26, and the outer counterweight support 22 is connected to an outer counterweight 27 and an outer counterweight balance block 28.

[0031] Reference Figure 2 and Figure 3 The internal gear 10, the first external gear 13, the second external gear 14 and the gear box 8 form a multi-stage reduction fit and are capable of self-locking.

[0032] The driving motor 6 can realize a position closed loop.

[0033] The reduction box 8 and the coupling 9 are interference fit, and the coupling 9 and the internal gear 10 are interference fit, and there is no gap between the fitting end faces.

[0034] The outer driving cavity 1 and the stepped spindle 15 are in interference fit.

[0035] The DC motor 6, the reduction box 8, the internal gear 10, the first external gear 13 and the second external gear 14 together form a driving mechanism, and the reduction ratio of the mechanism is 1470.

[0036] Reference Figure 4 The inner layer counterweight 25, the outer layer counterweight 27, the inner layer counterweight balance block 26 and the outer layer counterweight balance block 28 are made of tungsten alloy.

[0037] Reference Figure 5 The inner counterweight 25 and the inner counterweight balance block 26, the outer counterweight 27 and the outer counterweight balance block 28 are inner and outer nested structures with the same length. The angle of the inner counterweight 25 is 180°, and the angle of the outer counterweight 27 is 75.046°.

[0038] Reference Figure 2 and Figure 3 The transmission ratio of the DC motor 6, the outer counterweight 27 and the inner counterweight 25 is

[0039] The DC motor 6 inputs and outputs signals from the outside through a high-speed slip ring.

[0040] The working principle of the present invention is:

[0041] The nested counterweight moment balancing built-in mechanical online dynamic balancing device is built into the inner hole of the main shaft by overfitting, and the electromagnetic slip ring 5 is locked with the main shaft by bolts. After the power is turned on, the encoder records the current position of the balancing block. When the spindle imbalance is detected, the spindle imbalance amount and phase are extracted by measuring and calculating the spindle vibration signal, and the DC motor 6 is gradually driven to drive the inner and outer counterweight blocks for trial weighting. The control system records the position information of the inner counterweight 25 and the outer counterweight 27, and finds the position that minimizes the unbalanced vibration vector through the corresponding algorithm, and controls the inner counterweight balancing block 26 and the outer counterweight balancing block 28 to move to this position; since the nested counterweight system itself does not have torque imbalance, the control system with a position closed loop can more accurately control the position of the inner counterweight balancing block 26 and the outer counterweight balancing block 28, thereby avoiding the "misadjustment" problem, improving the stability of the balancing process, and improving the balancing efficiency.

Claims

1. A nested counterweight moment balancing built-in mechanical online dynamic balancing device, characterized in that: It comprises an outer driving cavity (1), a transmission cavity (2) and a balancing block shaft system (3) which are arranged in sequence: The outer driving cavity (1) contains a closed-loop driving mechanism with a symmetrical position center to form a symmetrical power output. The closed-loop driving mechanism includes a symmetrically arranged DC motor (6) with an encoder. The DC motor (6) is fixed on a reduction box (8). The power output end of the DC motor (6) is connected to an internal gear (10) via a reduction box (8) and a coupling (9). The reduction box (8) is fixed on a motor connecting seat (7). A mass compensation block (11) is connected to the shorter coupling (9). The transmission cavity (2) contains an internal tooth meshing mechanism with a central symmetry, forming a symmetrical transmission structure; the transmission structure includes a first external gear (13) and a second external gear (14) meshing with the two internal gears (10), the second external gear (14) is connected to the inner counterweight support (21), the first external gear (13) is connected to the outer end cover (23), and the outer end cover (23) is connected to the outer counterweight support (22); The balance block shaft system (3) contains a counterweight balance block nested inside and outside, including a stepped mandrel (15), the stepped mandrel (15) is supported in an inner counterweight support (21) through a first bearing (16) and a second bearing (18), the inner counterweight support (21) is connected to an inner end cover (24) at the end, and the inner end cover (24) is pressed against the second bearing (18); the inner counterweight support (21) is connected to the outer counterweight support (21) through a third bearing (19) and an outer counterweight support (18). The outer layer counterweight support (22) is connected with the outer layer counterweight support (22), the end of the outer layer counterweight support (22) is matched with the stepped spindle (15) through the fourth bearing (20), the end of the stepped spindle (15) is connected with the end cover (4), and the end cover (4) is in contact with the fourth bearing (20); the inner layer counterweight support (21) is connected with the inner layer counterweight (25) and the inner layer counterweight balance block (26), and the outer layer counterweight support (22) is connected with the outer layer counterweight (27) and the outer layer counterweight balance block (28).

2. According to claim 1, a nested counterweight moment balancing built-in mechanical online dynamic balancing device is characterized in that: The internal gear (10), the first external gear (13) and the second external gear (14) form a multi-stage reduction fit through a reduction box (8) and are capable of self-locking.

3. The nested counterweight moment balancing built-in mechanical online dynamic balancing device according to claim 1, characterized in that: The driving motor (6) can realize a position closed loop.

4. The nested counterweight moment balancing built-in mechanical online dynamic balancing device according to claim 1, characterized in that: The reduction box (8) and the coupling (9) are interference fit, and the coupling (9) and the internal gear (10) are interference fit, and there is no gap between the fitting end faces.

5. The nested counterweight moment balancing built-in mechanical online dynamic balancing device according to claim 1, characterized in that: The outer driving cavity (1) and the stepped spindle (15) are in interference fit.

6. The nested counterweight moment balancing built-in mechanical online dynamic balancing device according to claim 1, characterized in that: The DC motor (6), the reduction box (8), the internal gear (10), the first external gear (13) and the second external gear (14) together form a driving mechanism, and the mechanism reduction ratio is 1470.

7. The nested counterweight moment balancing built-in mechanical online dynamic balancing device according to claim 1, characterized in that: The inner layer counterweight (25), the outer layer counterweight (27), the inner layer counterweight balance block (26) and the outer layer counterweight balance block (28) are made of tungsten alloy.

8. The nested counterweight moment balancing built-in mechanical online dynamic balancing device according to claim 1, characterized in that: The inner layer counterweight (25) and the inner layer counterweight balance block (26), the outer layer counterweight (27) and the outer layer counterweight balance block (28) are of an inner and outer nested structure, with the same length, the inner layer counterweight (25) having an angle of 180°, and the outer layer counterweight (27) having an angle of 75.046°.

9. The nested counterweight moment balancing built-in mechanical online dynamic balancing device according to claim 1, characterized in that: The transmission ratio of the DC motor (6), the outer counterweight (27) and the inner counterweight (25) is:

Images