CN103413486B - The soft monolateral support dynamic balancing machine of a kind of rigid rotator - Google Patents

Abstract

The invention relates to a dynamic balancing machine with soft unilateral support for a rigid rotary body, which is composed of a workbench (1), a vibration meter (2), a power distribution room (3) and a balancing machine, and the balancing machine is installed on the workbench (1). ), the output of the balancing machine is connected to the sensor installed in the cabinet of the workbench (1), and the sensor sends the signal to the vibration meter (2) to complete the signal test. The invention can carry out repeated dynamic balance experiments, so that the obtained dynamic balance data gradually tends to the theoretical value, thereby helping to improve students' hands-on ability and theoretical understanding.

Description

A Rigid Rotary Soft Unilateral Support Dynamic Balancing Machine

technical field

The invention belongs to the technical field of mechanical teaching instruments, in particular to a dynamic balancing machine with soft unilateral support for a rigid rotary body.

Background technique

At present, in order to better improve the teaching quality and actively help and improve the hands-on ability of college students in many science and engineering colleges and universities in our country, the focus is on the cultivation of compound talents, fully combined with the specific teaching situation of the school, and under the conditions of the school's ability. Students create more opportunities and more suitable experimental equipment to help cultivate college students' interest in learning and hands-on ability, and greatly broaden their horizons.

We know that during mechanical operation, the inertial force and inertial force couple generated by each component will cause additional dynamic pressure and friction in each kinematic pair, thereby accelerating the wear of kinematic pair elements, reducing mechanical efficiency and weakening the strength of components. Since the size and direction of the inertial force and the inertial couple change periodically with the movement and rotation of the machine, the machine and its foundation will be forced to vibrate. When the vibration frequency is close to the natural frequency of the mechanical system, it will cause resonance, making it difficult for the machine to operate normally, and in severe cases, it will endanger the safety of surrounding buildings and personnel. Therefore, it is necessary to try to balance or partially balance the inertial force and the inertial couple to minimize its adverse effects, thereby improving the working performance of the machine and extending its service life.

Contents of the invention

The technical problem to be solved by the present invention is to provide a dynamic balancing machine with soft unilateral support for a rigid gyratory body, so as to solve the limitation that the traditional industrial dynamic balancing machine with the original rigid bilateral support is not suitable for teaching in college laboratories question.

A dynamic balancing machine with flexible unilateral support for a rigid rotary body, including a workbench, a vibrometer, and a power distribution room. A vibrometer is fixed on the board, a unilateral support base is fixed on the workbench, a V-shaped support block is installed on the unilateral support base, and a V-shaped support block is installed on the front and rear frames. The central axis of the overall frame is placed parallel to the balance wheel shaft. There are four balance wheels on the balance wheel shaft. Both the front and rear frames include sliders and sliders. The bottom of the left and right frames on one side of the seat is connected to the top of the worktable through the cooperation of the tension spring and the tension spring fixing ring, and a sensor wire is fixed under the left and right frames near the position of the tension spring, and the sensor steel wire passes through the working table vertically downward. The table top is connected with the sensor in the cabinet of the workbench. A motor bracket is fixed on the workbench outside the front and rear frames on one side. The motor base is installed on the motor bracket. The motor base is fixed in the middle cavity of the motor base. The motor base The bottom of one side is connected with the adjustment knob on the motor bracket through a buckle, and the other side of the motor base protrudes above the overall frame to form a clutch lever handle. There is a driven wheel shaft outside the upper end of the clutch lever handle, and the driven wheel shaft is connected to the motor. An abrasive belt is connected between the output shafts.

A front door and a power supply emergency stop switch are installed in front of the power distribution room.

V-shaped support blocks are respectively fixedly installed on the unilateral support base through the unilateral support spring pieces with opposite inclination angles on the left and right sides thereof.

The position of the central axis on the overall frame passes through two pairs of mandrel contact bearings on the left and right frames, and a balance wheel shaft is placed in parallel.

The balance wheel shaft is rested on the mandrel contact bearings by the mandrel raceways at both ends.

The sensor is connected with the vibrometer through a connection line.

A motor base is installed on the motor support through a mounting shaft.

A power cord protrudes from the lower part of the motor.

The outer side of the upper end of the clutch lever handle is fixed with a driven wheel shaft by loosening and adjusting bolts.

Mechanical balance problems can be divided into two categories: the balance of the rotating body (rotor) and the balance of the mechanism. A dynamic balancing machine with soft unilateral support for a rigid rotary body is mainly aimed at the balance of the rotary body (rotor): it refers to the balance of the inertial force and the inertial force couple of the rotating member around a fixed axis. It can be divided into the balance of rigid rotary parts and the balance of flexible rotary parts. The former regards the rotating part as a rigid body and ignores the elastic deformation caused by its inertial force. This balance method is generally applied to medium and low-speed machines; the latter treats the rotating part as a flexible part and must consider the elastic deformation caused by it. Balance factor, this method of balancing is applied to high-speed machinery.

In the balance of a rigid rotating body, the rotor shown in Figure 9, d is the diameter, the width is b, m ₁ and m ₂ are the unbalanced masses, and the intersection point O of the axis of rotation and the main inertial axis of the center, when the rotor is equal to When the angular velocity ω rotates, the inertial force generated by each point on the rotor can be simplified as an inertial force F and an inertial moment M passing through the center of mass C.

F＝F ₁ +F ₂

M＝F ₁ l ₁ +F ₂ l ₂

when When , due to the large width b, the unevenness of mass distribution is often not in the same plane, and the moment of inertia M cannot be ignored, such as engine crankshafts, motor rotors, etc. are typical examples of such rotors. The centrifugal force generated when the rotor rotates is not a plane force system, but a space force system. Even if the total center of mass of this type of rotor is on the axis of rotation, the imbalance of the moment of inertia will appear during rotation, so the balance of this type of rotor is dynamic balance. Dynamic balance can be the balance of inertial force and inertial moment.

Beneficial effect

The one-step experimental results of the industrial dynamic balancing machine cannot satisfy the students to understand the slow process of gradual correction of the dynamic balance. However, the present invention is different from the rigid double-support experiment of the industrial dynamic balancing machine during the experiment. Repeated dynamic balance experiments on a piece of experimental equipment by hand, so that the obtained dynamic balance data gradually tends to the theoretical value, and the experiment tends to be gradually completed, so that students can have a process of gradually understanding and understanding, and have a more gradual experiment The time was also successfully completed within the controlled experimental class time, and the effect of such an enlightening experiment is very obvious.

Description of drawings

Fig. 1 is a schematic view of the overall appearance of the present invention from a right perspective.

Fig. 2 is a left schematic diagram of the dynamic balancing machine of the present invention.

Fig. 3 is a schematic diagram of a balance wheel and a mandrel of the present invention.

Fig. 4 is a schematic diagram of the non-working state on the left side of the dynamic balancing machine of the present invention.

Fig. 5 is a schematic diagram of bearings installed on the balance wheel mandrel shaft of the dynamic balancing machine of the present invention.

Fig. 6 is a schematic diagram of the left rear side of the dynamic balancing machine of the present invention.

Fig. 7 is a schematic diagram of the right rear side of the dynamic balancing machine of the present invention.

Fig. 8 is a schematic diagram of the overall working state of the present invention from the left perspective.

Fig. 9 is a balance moment diagram of the rotor body.

Fig. 10 is a schematic diagram of the present invention.

Fig. 11 is a schematic diagram of the dynamic balance of the unbalanced rotary body.

detailed description

Below in conjunction with specific embodiment, further illustrate the present invention. It should be understood that these examples are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the teachings of the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of the present application.

Example 1

As shown in Figures 1 to 8, a dynamic balancing machine with flexible unilateral support for a rigid rotary body includes a workbench 1, a vibration meter 2, a power distribution room 3, a power plug 4, a front door 5, and a power emergency stop switch 6 , front and rear frame 7, unilateral support spring leaf 8, unilateral support base 9, left and right frame 10, balance wheel 11, balance wheel shaft 12, mandrel raceway 13, slide bar 14, slide block 15, core Shaft contact bearing 16, mounting shaft 17, clutch lever handle 18, tightness adjustment bolt 19, adjustment knob 20, motor bracket 21, motor power cord 22, driven wheel shaft 23, abrasive belt 24, motor base 25, motor 26, Motor output shaft 27, V-shaped support block 28, tension spring 29, tension spring fixing ring 30, sensor steel wire 31, vibration meter panel 32, connecting wire 33, sensor 34, and the above-mentioned power distribution room 3 is a workbench 1 , one side of the workbench 1 protrudes a support plate outwards, a vibrometer 2 is fixed on the support plate, a unilateral support base 9 is fixed on the workbench 1, and a V-shaped support block is installed on the unilateral support base 9 28. An integral frame consisting of front and rear frames 7 and left and right frames 10 is installed on the V-shaped support block 28. The central axis of the overall frame is placed parallel to the balance wheel shaft 12, and there are four balancing wheels on the balance wheel shaft 12. Wheel 11, front and rear frame 7 all comprise slide bar 14 and slide block 15, and slide block 15 is strung on slide bar 14, is fixed by extension spring 29 and extension spring below the left and right frame 10 near support base 9 one side. The ring 30 is connected to the top of the workbench 1, and a sensor steel wire 31 is fixed below the left and right frame 10 near the position of the extension spring 29. The sensor steel wire 31 passes through the workbench 1 and the cabinet of the workbench 1 vertically downward. The sensor 34 is connected, wherein a motor support 21 is fixed on the workbench 1 outside the front and rear frame 7 on one side, a motor base 25 is installed on the motor support 21, and a motor 26 is fixed in the middle cavity of the motor base 25. The bottom of one side of the seat 25 is connected with the adjustment knob 20 on the motor bracket 21 through buckles, and the other side of the motor base 25 protrudes above the overall frame to form a clutch lever handle 18. There is a driven lever handle 18 on the outside of the upper end of the clutch lever handle. A wheel shaft 23, an abrasive belt 24 is connected between the driven wheel shaft 23 and the motor output shaft 27.

Described power distribution room 3 fronts are equipped with front door 5, power supply emergency stop switch 6.

V-shaped support blocks 28 are respectively fixedly installed on the unilateral support base 9 through the unilateral support spring pieces 8 with opposite inclination angles on the left and right sides thereof.

The central axis position on the overall frame passes through two pairs of mandrel contact bearings 16 on the left and right frames 10 to place the balance wheel shaft 12 in parallel.

The balance wheel shaft 12 is rested on the mandrel contact bearing 16 by the mandrel raceway 13 at its two ends.

The sensor 34 is connected to the vibrometer 2 through a connection line 33 .

A motor base 25 is installed on the motor bracket 21 through the installation shaft 17 .

A power cord 22 protrudes from the bottom of the motor 26 .

The outside of the upper end of the clutch lever handle 18 is fixed with a driven wheel shaft 23 by loosening and adjusting bolts 19 .

A rigid rotary body soft unilateral support dynamic balancing machine is a method for dynamic balancing of rigid rotors, and it is a soft support dynamic balance in this method (when the rotor is balanced, the rotational angular speed is higher than that of the rotor and its supporting system. Natural frequency ω>3ω).

The dynamic balance experiment of the rotary body is carried out by using the soft unilateral support dynamic balancing machine. Figure 10 is the schematic diagram of the balancing machine device. The frame is connected to the frame through the cross elastic support, and the frame, the test piece and the spring form a vibration system. When the frame is subjected to external force (rotor unbalanced inertial force), it must vibrate around the cross elastic support axis A-A, and its amplitude is recorded faithfully by the vibrometer. Among them, the speed sensor uses the principle of electromagnetic induction to convert the vibration speed of the frame caused by the unbalanced inertial force into a voltage signal and transmit it to the vibrometer. There is an integrating circuit in the vibrometer to restore the speed signal to a displacement signal to obtain an amplitude signal.

From the dynamic balance principle of the rotary member, we know that when each part of an unbalanced rotary member, due to the centrifugal inertial force generated by the unbalanced weight, it can always be decomposed into two parallel forces. Figure 11 is an unbalanced rotary body The schematic diagram of the dynamic balance, the planes I-I and II-II in the figure are two randomly selected planes parallel to each other and perpendicular to the axis of rotation, and PII in the figure is the inertial force decomposed in the plane II-II. In plane I-I there will be an unbalanced inertial force PI. In this way, PI and PII are statically balanced in the I-I and II-II planes, so that Among them, G1 and G2 are respectively equivalent to the unbalanced weights of the inertial forces PI and PII on the planes I-I and II-II, are the radius of _gyration of _unbalanced weight; Respectively, their radius of gyration, at this time, the component reaches dynamic balance.

The experimental device of the soft unilateral support dynamic balancing machine can measure the unbalanced weight-diameter product in two planes respectively and The size and direction of the test piece to achieve dynamic balance. Place the rotor II-II plane on the AA axis, so that when the rotor rotates, the unbalanced inertial force on the I-I plane produces a vibration moment M ₁ =P _u1 cos(ωt) around the AA axis, so that the frame system is Axis AA generates forced vibrations. When its vibration frequency is the same as the natural frequency of the frame system itself, resonance occurs. At this time, the maximum amplitude A of the steady state vibration is proportional to the value of the exciting force.

In the same way, the balance test can also be carried out on the II-II plane.

1. Experiment of dynamic balancing machine with soft unilateral support for rigid rotary body

(1) Turn on the power and preheat the instrument for 10 minutes; place the function selection knob of the vibrometer 2 on the X (f>1) position, and set the range switch on the 300μ position.

(2) Press the clutch lever handle 18 of the dynamic balancing machine, the motor 26 rotates, and the balance wheel 11 rotates through the abrasive belt 24, and the rotating speed is higher than the natural frequency of the vibration system; (note: the abrasive belt can lightly touch the balance wheel 11 )

(3) After the speed of the balance wheel 11 is stable, slowly lift the clutch lever handle 18 of the dynamic balancing machine, the balance wheel 11 will rotate freely due to the inertia, and the speed of the balance wheel 11 will gradually decrease from fast to slow due to the friction. When the speed is close to the resonance area , the instrument pointer on the panel 32 changes dynamically, and the students can record the data of the vibrometer 2 (repeated three times).

(4) Perform balance tests on planes I-I and II-II respectively.

The first balance is carried out in the above steps, the precision can generally reach 5μ, and the residual unbalance is 5gmm. In order to improve the accuracy, a second balance can be carried out on this basis, and the range switch of the vibrometer 2 is set to the 10 μ position. At this time, the measurement accuracy is increased by 30 times. Since the balance wheel 11 has tended to be close to balance, G _t should not be too large. Take G _t =0.2--0.3g, and repeat the steps for the first balance.

(5) After the test, remove the balance wheel shaft 12 and turn off the power.

Claims (9)

1. A dynamic balancing machine with flexible unilateral support for a rigid rotary body, comprising a workbench (1), a vibrometer (2), and a power distribution room (3), characterized in that: the power distribution room (3) On the top is the workbench (1), one side of the workbench (1) protrudes a support plate, the vibrometer (2) is fixed on the support plate, and a unilateral support base (9) is fixed on the workbench (1). ), a V-shaped support block (28) is installed on the unilateral support base (9), and a whole body consisting of front and rear frames (7) and left and right frames (10) is installed on the V-shaped support block (28) Frame, the central axis position on the overall frame is parallel to be placed with balance axle (12), and four balance wheels (11) are arranged on the balance axle (12), and front and rear frame (7) all comprise slide bar (14) and slide bar (14). Block (15), slide block (15) is strung on the slide bar (14), passes extension spring (29) and extension spring fixing ring (30) below the left and right frame (10) near support base (9) one side. ) is connected to the top of the workbench (1), a sensor steel wire (31) is fixed below the left and right frame (10) near the tension spring (29), and the sensor steel wire (31) passes through the workbench vertically downward. (1) face is connected with the sensor (34) in the cabinet of workbench (1), and described workbench (1) is fixed with motor support (21), and described motor support (21) is positioned at front and rear frame (7) ), the motor base (25) is installed on the motor bracket (21), the motor base (25) is fixed with a motor (26) in the middle cavity of the motor base (25), and one side of the motor base (25) The bottom is connected with the adjustment knob (20) on the motor bracket (21) through a buckle, and the other side of the motor base (25) protrudes above the overall frame to form a clutch lever handle (18), and the upper end of the clutch lever handle (18) There is a driven wheel shaft (23) in the outside, and the abrasive belt (24) is connected between the driven wheel shaft (23) and the motor output shaft (27). 2. A dynamic balancing machine with rigid gyratory soft unilateral support according to claim 1, characterized in that: a front door (5), a power emergency stop switch (6) are installed in front of the power distribution room (3) ). 3. A dynamic balancing machine with flexible unilateral support for a rigid rotary body according to claim 1, characterized in that: on the unilateral support base (9), there is a single side with two inclination angles on the left and right relative to it. The side support springs (8) are fixedly equipped with V-shaped support blocks (28) respectively. 4. A dynamic balancing machine with rigid gyratory soft unilateral support according to claim 1, characterized in that: the position of the central axis on the overall frame passes through two pairs of cores on the left and right frames (10) The shaft contact bearing (16) is placed in parallel with a balance wheel shaft (12). 5. A dynamic balancing machine with flexible unilateral support for a rigid rotary body according to claim 4, characterized in that: said balance wheel shaft (12) is rested on the core by the mandrel raceways (13) at both ends thereof on the shaft contact bearing (16). 6. A dynamic balancing machine with soft unilateral support for a rigid rotary body according to claim 1, characterized in that: the sensor (34) is connected to the vibrometer (2) through a connection line (33). 7. A dynamic balancing machine with rigid gyratory soft unilateral support according to claim 1, characterized in that: the motor base (25) is installed on the motor bracket (21) through the installation shaft (17) . 8. A dynamic balancing machine with flexible unilateral support for a rigid rotary body according to claim 1, characterized in that: a power cord (22) protrudes from the lower part of the motor (26). 9. A dynamic balancing machine with flexible unilateral support for a rigid rotary body according to claim 1, characterized in that: the outer side of the upper end of the clutch lever handle (18) is fixed with a loosening adjustment bolt (19) Follower shaft (23).