Exhaust cooling air shaft with self-excited vibration restraining function

Abstract

The exhausting and cooling air shaft comprises a shell, a radial bearing is arranged in the shell, a rotating shaft is arranged in the radial bearing, a hollow rotating shaft is arranged in the rotating shaft, a grinding wheel connecting rod base is arranged at one end of the rotating shaft, an impeller is arranged at the end, away from the grinding wheel connecting rod base, of the rotating shaft, and a cooling device is arranged on the rotating shaft. A thrust bearing is arranged on one side of the grinding wheel connecting rod base, and a silencing ring is arranged on the outer side of the impeller. Airflow is discharged through the impeller at the tail end of the hollow rotating shaft to increase the flowability of the airflow, so that the temperature is reduced; through an air inlet of the thrust bearing, a throttling air nozzle and a closed air cavity, air vibration interferes with air hammer excitation generated between the damping thrust bearing and the flange, and the effects of reducing vibration of the main shaft and improving high-frequency harmonic waves are achieved. The exhaust groove, the exhaust ring groove and the impeller are matched, flowing of airflow in the hollow interior of the rotating shaft is accelerated, the temperature is reduced, and through rotation of the impeller, air in the axis of the rotating shaft can be pumped out for active cooling.

Description

Technical Field

[0001] The invention relates to the technical field of gas shafts, and in particular to an exhaust cooling gas shaft with self-excited vibration suppression function. Background Art

[0002] Most air hydrostatic journal bearings will show self-excited vibration. Currently, the existing hollow shaft is mainly used to reduce the mass and reduce the moment of inertia to improve the rotation speed and rotation performance of the shaft. However, high-speed air flotation grinding and cutting spindles not only have requirements for speed and rigidity, but also have stricter requirements and control on temperature rise, resonance and vortex self-excited instability during operation. The existing air shaft generates high temperature during high-speed operation, and the current cooling means cannot effectively reduce the temperature of the shaft. In addition, during the high-speed rotation of the spindle, the self-excited vibration generated will affect the rotation speed, rotation accuracy and performance of the spindle. The existing technology cannot better reduce the self-excited vibration. Summary of the invention

[0003] In view of the above problems existing in the prior art, the main purpose of the present invention is to provide an exhaust cooling gas shaft with self-excited vibration suppression.

[0004] The technical solution of the present invention is as follows: an exhaust cooling air shaft with self-excited vibration suppression, comprising a shell, a radial bearing is arranged inside the shell, a rotating shaft is arranged inside the radial bearing, the rotating shaft is a hollow rotating shaft, a grinding wheel connecting rod seat is arranged at one end of the rotating shaft, an impeller is arranged at the end of the rotating shaft away from the grinding wheel connecting rod seat, a thrust bearing is arranged on the rotating shaft at one side of the grinding wheel connecting rod seat, and a muffler ring is arranged on the outer side of the impeller;

[0005] The rotating shaft is provided with a rotating shaft radial air hole, and the rotating shaft is provided with a rotating shaft flange closed air cavity on the flange corresponding to the thrust bearing, an air inlet on one side of the rotating shaft flange closed air cavity, and the air inlet and the thrust bearing throttle air nozzle are arranged at the same radius; a throttle air nozzle is arranged on the end face of the thrust bearing, and the closed air cavity air inlet and the thrust bearing throttle air nozzle are at the same radius position, and are connected with the rotating shaft flange closed air cavity through the closed air cavity air inlet;

[0006] The radial bearing is provided with a radial bearing air inlet hole, and a plurality of exhaust grooves are provided on the inner walls on both sides of the throttle air nozzle of the radial bearing. An exhaust ring groove is provided between the radial bearing and the rotating shaft. The radial bearing exhaust ring groove corresponds to the rotating shaft ring groove, and enters the shaft cavity through the radial air hole of the rotating shaft ring, and flows toward the axial hollow hole and is discharged toward the tail.

[0007] As a preferred implementation, the throttle air nozzles are evenly distributed on the thrust bearing, and the upper part of the air cavity closed by the rotating shaft flange is sealed by a sealing top screw.

[0008] As a preferred implementation, the radial air holes of the rotating shaft are inclined holes, and the radial air holes of the rotating shaft are evenly distributed on the rotating shaft.

[0009] As a preferred embodiment, the muffler ring is made of sintered copper powder.

[0010] Compared with the prior art, the advantages and positive effects of the present invention are:

[0011] 1. The exhaust gas from the air-floating main shaft can be transported to the hollow shaft through the radial air holes of the shaft, and then the airflow is pumped out through the impeller at the tail end of the hollow shaft to increase the fluidity of the airflow and thus reduce the temperature;

[0012] 2. Exhaust gas through the thrust bearing throttle nozzle, and part of the gas is directly discharged to the air inlet on the shaft flange surface corresponding to the equal radius and enters the closed air cavity of the connected shaft flange. During the rotation process, when the thrust bearing throttle nozzle and the air inlet of the closed air cavity of the shaft flange are exactly corresponding, the pressure is the largest, and the gas inside the air cavity is slightly compressed. When the gas is staggered, the gas in the cavity is discharged again to generate air flow vibration. The damping force generated by the gas vibration interferes with the air hammer excitation generated between the thrust bearing and the flange, thereby reducing the vibration of the main shaft and improving the high-frequency harmonics.

[0013] 3. The exhaust groove, the exhaust ring groove and the impeller cooperate to exhaust the air in the hollow shaft cavity when the hollow shaft rotates, accelerate the flow of air inside the bearing, reduce the temperature, and accelerate the exhaust of air in the shaft cavity through the rotation of the impeller to actively cool down. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 The present invention provides a schematic diagram of the overall structure of an exhaust cooling gas shaft with self-excited vibration suppression;

[0015] Figure 2 A schematic diagram of the structure of an exhaust cooling gas shaft with self-excited vibration suppression is provided for the present invention;

[0016] Figure 3 A schematic diagram of the radial air hole positions of a rotating shaft of an exhaust cooling air shaft for suppressing self-excited vibration is provided for the present invention;

[0017] Figure 4 A schematic diagram of the position of an exhaust ring groove of an exhaust cooling gas shaft with self-excited vibration suppression is provided for the present invention;

[0018] Figure 5 A schematic diagram of the position of an impeller with an exhaust cooling air shaft for suppressing self-excited vibration is provided for the present invention.

[0019] Legend: 1. Housing; 2. Radial bearing; 21. Radial bearing air inlet; 22. Exhaust ring groove; 3. Rotating shaft; 4. Hollow rotating shaft; 41. Radial air hole of rotating shaft; 42. Air cavity closed by rotating shaft flange; 43. Air inlet of closed air cavity; 5. Grinding wheel connecting rod seat; 6. Impeller; 7. Thrust bearing; 71. Throttle air nozzle; 8. Muffler ring. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. The components of the embodiments of the present invention generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0021] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0022] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0023] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0024] Example

[0025] An exhaust cooling air shaft with self-excited vibration suppression includes a housing 1, a radial bearing 2 is arranged inside the housing 1, a rotating shaft 3 is arranged inside the radial bearing 2, a hollow rotating shaft 4 is arranged inside the rotating shaft 3, a grinding wheel connecting rod seat 5 is arranged at one end of the rotating shaft 3, an impeller 6 is arranged at the end of the rotating shaft 3 away from the grinding wheel connecting rod seat 5, a thrust bearing 7 is arranged on the rotating shaft 3 at one side of the grinding wheel connecting rod seat 5, and a muffler ring 8 is arranged outside the impeller 6;

[0026] The rotating shaft 3 is provided with a rotating shaft radial air hole 41, and air enters the hollow rotating shaft 4 from the rotating shaft radial air hole 41. As the hollow rotating shaft 4 rotates inside the housing 1, the air is discharged in a spiral motion, which increases the flow of airflow, thereby reducing the temperature. The change in the inertia of the air flow increases the damping force of the rotating shaft, effectively reducing the resonance and self-excited instability amplitude, and significantly improving the dynamic performance of the main shaft. The rotating shaft radial air hole 41 is an inclined hole opened along the rotation direction. The rotating shaft radial air hole 41 can also be a normal-centered straight hole or an eccentric hole. The port of the inclined hole is chamfered, so that the air intake is smoother and whistling sound is avoided.

[0027] On the rotating shaft 3, the end face of the throttle air nozzle 71 of the thrust bearing 7 corresponds to the rotating shaft flange with the rotating shaft flange closed air cavity 42, and a closed air cavity air inlet 43 is provided on one side of the rotating shaft flange closed air cavity 42; a throttle air nozzle 71 is provided in the thrust bearing 7, and the throttle air nozzle 71 is connected with the rotating shaft flange closed air cavity 42 through the closed air cavity air inlet 43; the throttle air nozzle 71 and the closed air cavity air inlet 43 are distributed on the circumference with equal radius, and when the throttle air nozzle 71 and the closed air cavity air inlet 43 correspond to each other, the closed air cavity pressure is the largest, and the gas inside the rotating shaft flange closed air cavity 42 is slightly compressed, and the staggered When the gas in the closed air cavity 42 of the rotating shaft flange is discharged, vibration is generated. The gas vibration damping force interferes with and suppresses the air hammer excitation generated between the thrust bearing and the flange, thereby reducing the vibration of the main shaft and improving the high-frequency harmonic effect; when the thrust bearing 7 rotates, it drives the throttle air nozzle 71 to rotate. When the throttle air nozzle 71 corresponds to the air inlet 43 of the closed air cavity, the compressed air at the extrusion layer will be pressed into the closed air cavity 42 of the rotating shaft flange again, so that an independent damping air chamber is completed, and a damping force is generated when the air flows in and out, thereby eliminating the unstable state of the air-floating thrust bearing;

[0028] A radial bearing small hole throttling exhaust hole 21 is provided on the radial bearing 2, and a plurality of exhaust grooves are provided on the inner wall of the radial bearing 2. An exhaust ring groove 22 is provided between the radial bearing 2 and the rotating shaft 3 to correspond to the radial bearing throttling exhaust hole 21. The radial bearing throttling exhaust hole 21 is discharged to the exhaust ring groove 22 through the working surface (extrusion layer); the gas discharged from the radial bearing working surface (extrusion layer) enters the radial air hole 41 of the rotating shaft through the exhaust ring groove 22, and is then discharged through the hollow channel of the hollow rotating shaft 4 through the impeller fan 6. The impeller 6 fan installed at the tail of the shaft controls the exhaust volume of different bearing parts and the air pressure at the exhaust port end by adjusting the number and size of the radial exhaust holes in various parts of the hollow rotating shaft 4 and the size of the shaft end fan and the number of blades, so as to suppress the vibration of the rotating shaft.

[0029] The throttle air nozzles 71 are evenly distributed on the thrust bearing 7, and the upper part of the air cavity 42 enclosed by the rotating shaft flange is sealed by a sealing top screw, so as to form a sealed space and realize an instantaneous increase in pressure.

[0030] The radial air holes 41 of the rotating shaft are inclined holes. The radial air holes 41 of the rotating shaft are evenly distributed on the rotating shaft 3. The inclined holes are more conducive to the flow of gas.

[0031] The silencer ring 8 is made of sintered copper powder, which is low in cost, simple to manufacture, and has a good silencer effect. It can also be made of sintered lightweight porous materials such as ceramics, graphite, etc., which has better high-speed performance.

[0032] Finally, it should be noted that the above-described embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some or all of the technical features thereof may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An exhaust gas cooling shaft with self-excited vibration suppression, comprising a housing (1), characterized in that: A radial bearing (2) is provided inside the housing (1), a rotating shaft (3) is provided inside the radial bearing (2), a hollow rotating shaft (4) is provided inside the rotating shaft (3), a grinding wheel connecting rod seat (5) is provided at one end of the rotating shaft (3), an impeller (6) is provided at the end of the rotating shaft (3) away from the grinding wheel connecting rod seat (5), a thrust bearing (7) is provided on one side of the grinding wheel connecting rod seat (5) on the rotating shaft (3), and a muffler ring (8) is provided on the outer side of the impeller (6); The rotating shaft (3) is provided with a rotating shaft radial air hole (41); the rotating shaft (3) is provided with a rotating shaft flange closed air cavity (42) on a flange corresponding to the thrust bearing (7); a closed air cavity air inlet (43) is provided on one side of the rotating shaft flange closed air cavity; a throttle air nozzle (71) is provided in the thrust bearing (7); the closed air cavity air inlet (43) and the thrust bearing throttle air nozzle (71) are at equal radial positions and are connected to the rotating shaft flange closed air cavity (42) via the closed air cavity air inlet (43); The radial bearing (2) is provided with a radial bearing air inlet hole (21), a plurality of exhaust grooves are provided on the inner wall of the radial bearing (2), an exhaust ring groove (22) is provided between the radial bearing (2) and the rotating shaft (3), and the radial bearing air inlet hole (21) is discharged to the exhaust ring groove (22) through a throttle air nozzle via the rotating shaft (3) and the radial bearing (2).

2. The exhaust gas cooling shaft with self-excited vibration suppression according to claim 1, characterized in that: The throttling air nozzles (71) are evenly distributed on the thrust bearing (7), and the upper part of the rotating shaft flange closed air cavity (42) is sealed by a sealing top screw.

3. The exhaust gas cooling shaft with self-excited vibration suppression according to claim 1, characterized in that: The radial air holes (41) of the rotating shaft are inclined holes, and the radial air holes (41) of the rotating shaft are evenly distributed on the rotating shaft (3).

4. The exhaust gas cooling shaft with self-excited vibration suppression according to claim 1, characterized in that: The muffler ring (8) is made by sintering copper powder.

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