CN212551757U - Double-end double-seal mechanical main shaft - Google Patents

Abstract

The application discloses a double-head double-sealing mechanical main shaft which comprises a motor driving mechanism and a double-head main shaft; the main shaft adopts the technical bottleneck that framework oil seals are added at two ends, the conventional air blowing type sealing is adopted, and refrigeration and heat dissipation are adopted, so that the technical bottleneck that oil seals cannot be used when the main shaft of the mechanical industry exceeds 3000 turns is broken; meanwhile, the shaft center adopts a double-lip framework oil seal, and a certain volume of high-temperature-resistant bearing grease can be placed in the concave position of the shaft center, so that the shaft center can achieve lubrication in the sealing process for a long time, the friction coefficient is reduced, the temperature is effectively controlled to increase along with the increase of the rotating speed, and the main shaft is not damaged; the double-lip framework oil seal is mainly used for sealing, and a main shaft with two sealed ends is arranged, so that the potential water can be completely prevented from seeping into the oil seal; the nano ceramic coating is added on the surface of the spindle shaft and polished into a mirror surface, so that the wear resistance is improved, the friction coefficient is further reduced, and a certain effect on controlling the temperature rise is achieved.

Description

Double-end double-seal mechanical main shaft

Technical Field

The application relates to the technical field of double-end main shafts, in particular to a double-end double-sealing mechanical main shaft.

Background

The mechanical main shaft is a product several decades ago, the known main shaft sealing technology mainly comprises two main shaft sealing technologies, one is that the main shaft axis of a low-speed main shaft below 3000 turns can be sealed by adopting a framework oil seal; the other type is a high-speed main shaft, which means more than 3000 turns, so that the super speed is high, the internal pressure of the main shaft is increased by mainly adopting air sealing and oil-gas mixing sealing, the internal pressure is higher than the external pressure, and therefore dust does not enter the main shaft, and various bearing cover labyrinths are arranged to increase the sealing performance of the main shaft. The mounting method of the bearing is also the common knowledge, and can be realized by the skilled person with mechanical common knowledge. The mounting method of the transmission wheel is basically similar. However, the technical bottleneck that oil seals cannot be used when the number of main shafts in the mechanical industry exceeds 3000 turns is not solved by a good method at present, and meanwhile, how to balance the fit of oil seal tolerance in the prior art is also lack of good and effective schemes at present.

Disclosure of Invention

In order to solve the above technical problem, an embodiment of the present application provides a dual-head dual-seal mechanical spindle, including a motor driving mechanism and a dual-head spindle; the motor driving mechanism comprises a main shaft mounting bracket and a servo motor; a servo motor mounting chamber is arranged at the upper part of the main shaft mounting bracket; the servo motor passes through the cavity and is arranged on the motor plate; a waist hole is formed on the side of the motor plate and is fixed with the main shaft mounting bracket through a screw; a synchronous belt wheel is arranged on an output shaft of the servo motor; the synchronous belt wheel comprises a servo motor driving wheel, a synchronous belt and a main shaft mandrel driven wheel; the driving wheel of the servo motor is arranged on an output shaft of the servo motor through an expansion sleeve; a driving wheel of the servo motor is provided with a synchronous belt; the other end of the synchronous belt is connected with a spindle mandrel driven wheel and is used for transmitting power to a mechanical spindle; a dynamic balance adjusting screw hole is formed in the driving wheel of the servo motor;

the double-head main shaft comprises a main shaft shell, a main shaft mandrel and a shell heightening seat; the main shaft shell is fixed on the shell heightening seat through a bolt; the shell heightening seat is arranged at the bottom of the bracket;

the spindle mandrel penetrates through the spindle shell, BT tool handles are mounted at two ends of the spindle mandrel, and two ends of the spindle mandrel extend out of the spindle shell; the main shaft mandrel driven wheel is connected with one end of the main shaft mandrel extending out of the main shaft shell and serves as an input end of the main shaft mandrel to realize synchronous motion;

a bearing inner spacer ring and a bearing outer spacer ring are arranged on the outer side of the middle of the spindle shaft in the spindle shell; a group of matched thrust bearings are arranged on both sides of the bearing by taking the inner and outer spacing rings of the bearing as centers; a handle cap is arranged between the other side of the matched thrust bearing and the flange cover close to the output end of the spindle; flange covers are arranged outside two sides of the main shaft shell; the flange cover is connected with the matched thrust bearing in the main shaft shell; a double-lip framework oil seal is arranged in each flange cover; the middle of the double-lip framework oil seal is concave, and a high-temperature-resistant bearing grease layer is arranged in the concave part; the outer sides of the flange covers are provided with main shaft air seal covers for forming air seals.

Further, the main shaft shell is a one-piece casting; one end of the main shaft shell close to the driven wheel of the main shaft mandrel is provided with a plurality of threaded holes for installing evenly distributed bolts, and the threaded holes are used for fixing the flange cover; the other end of the main shaft shell, which is far away from the driven wheel of the main shaft mandrel, is provided with a thread which is coaxial with the shell; the flange cover is rotationally locked into the main shaft shell through threads; the flange cover is provided with a threaded hole for installing a top bolt to be fixed on the main shaft shell; the bottom of the main shaft shell is a high-precision mounting plane which is parallel to the cylindrical inner hole of the inner cavity of the shell.

Further, the spindle housing is a trapezoidal cube, the top of the trapezoid is semicircular, the bottom of the trapezoid is provided with a clearance position, and the bottom of the spindle housing is provided with a plurality of threaded mounting holes for being fixed at the bottom of the spindle mounting bracket through bolts.

Further, the surface of the spindle mandrel is provided with a nano ceramic coating.

Furthermore, inner holes at two ends of the spindle mandrel are inner taper holes, the inner taper holes are manufactured into BT series 7:24, and threaded holes are formed in the two bottoms of the inner taper holes.

Furthermore, the tolerance range of the matching of the outer diameter of the spindle mandrel and the oil seal of the double-lip framework is-0.5-0.8 MM.

Furthermore, the driven wheel of the spindle mandrel is fixed on the side surface of the spindle end of the spindle by uniformly distributed bolts, and the precision positioning of the synchronous belt wheel is based on the cylindricity and the step verticality of the spindle mandrel;

the servo motor driving wheel and the main shaft mandrel driven wheel are made of high-strength aluminum alloy; the servo motor driving wheel and the spindle mandrel are provided with high-precision shaft positioning steps, and one side of the driving wheel and one side of the driven wheel are provided with a circle of dynamic balance adjusting bolt holes.

Furthermore, an O-shaped sealing ring groove is formed in the outer side of one end of the flange cover and used for sealing with the main shaft shell, and a framework oil seal installation cavity is formed in the inner side of the flange cover; the flange cover is provided with an air seal blowing connecting hole.

Furthermore, the motor plate is ground on two sides and can be independently disassembled; a motor plate adjusting steel bar is arranged at the top of the servo motor plate; the motor plate adjusting steel bar is locked with the end face of the main shaft mounting bracket through a transverse screw; the motor plate adjusting steel bar is tightly hung at the top of the motor plate through a top screw.

Further, the main shaft mounting bracket is an integral casting part and is molded into a special shape; a plurality of clearance-avoiding weight-reducing positions are erected on the main shaft mounting support, hexahedron processing is adopted in a processing mode, all mounting surfaces are processed in a fine grinding mode, and the verticality flatness is within 0.01 MM.

In the embodiment of the application, the main shaft adopts the technical bottleneck that framework oil seals are added at two ends, the conventional air blowing type sealing is adopted, and refrigeration is used for heat dissipation, so that the technical bottleneck that oil seals cannot be used when the number of main shafts of the mechanical industry exceeds 3000 is broken; meanwhile, the shaft center adopts the double-lip framework oil seal, and the concave part in the oil seal can be filled with high-temperature-resistant bearing grease with certain volume, so that the lubricating effect is achieved for a long time in the sealing process, the friction coefficient is reduced, the temperature is effectively controlled to increase along with the increase of the rotating speed, and the main shaft is not damaged.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a schematic view of an overall structure of a mechanical spindle provided in an embodiment of the present application;

FIG. 2 is a schematic view of the back angle configuration of FIG. 1;

FIG. 3 is a schematic diagram of the exploded structure of FIG. 1;

FIG. 4 is a left side view of FIG. 1;

FIG. 5 is a right side view of FIG. 1;

FIG. 6 is a rear view of FIG. 1;

FIG. 7 is a schematic sectional view of the spindle portion;

FIG. 8 is a schematic cross-sectional view of the left side flange cover of FIG. 7;

FIG. 9 is a schematic view of the right side flange cover of FIG. 7;

FIG. 10 is a schematic cross-sectional view of the right side flange cover of FIG. 7

FIG. 11 is a front view of the air cap;

FIG. 12 is a front view of the driven wheel;

fig. 13 is a front view of the drive pulley.

The meaning of the reference symbols in the figures:

101-servo motor, 102-spindle mounting bracket, 103-motor plate adjusting steel bar, 104-motor plate, 105-driving wheel, 106-expansion sleeve, 107-synchronous belt, 108-driven wheel, 201-housing heightening base, 202-spindle housing, 203-BT handle, 204-air sealing cover, 205-flange cover, 206-handle cap, 207-thrust bearing, 208-bearing inner and outer spacing ring, 209-spindle mandrel, 301-air inlet hole, 302-transverse through hole, 303-framework oil seal, 304-waist hole, 305-top screw hole, 306-dynamic balance adjusting bolt hole, 307-mounting hole, 308-O type sealing ring groove, 309-framework oil seal mounting cavity and 310-bolt.

Detailed Description

In order to make the purpose, features and advantages of the present application more obvious and understandable, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the embodiments described below are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

The invention is further elucidated with reference to the drawings and the embodiments.

In the description of the present application, it is to be understood that the terms "upper", "lower", "top", "bottom", "inner", "outer", and the like, indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, are only for convenience in describing the present application and simplifying the description, and do not indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and thus, are not to be construed as limiting the present application.

The double-head double-sealing mechanical spindle shown in the figure can comprise two parts, namely a motor driving mechanism and a double-head spindle.

The motor drive mechanism includes a spindle mounting bracket 102 and a servo motor 101.

The spindle mounting bracket 102 is cast as a complete machine. The innovative purpose of the bracket 102 is to obtain higher processing precision, and to facilitate hexahedron processing, six surfaces can be milled and ground, so that the complete bracket has higher precision and is more convenient to install.

The upper part of the spindle mounting bracket 102 is provided with a servo motor mounting chamber, and the servo motor 101 passes through the chamber and is mounted on the motor plate 104.

The top of motor board 104 is provided with motor board regulation billet 103, through the side screw locking on main shaft installing support 102, rethread top screw hangs tight motor board 104, makes to fix on motor board 104 the motor not drop in the work, can conveniently adjust the elasticity of hold-in range 107 wheel simultaneously.

Be equipped with the waist hole on the motor board 104, rethread top screw hangs tight motor board 104, can adjust mobile motor board 104 distance, can conveniently adjust the elasticity of hold-in range 107 wheel simultaneously.

The synchronous belt 107 wheel is installed on the motor shaft through the expansion sleeve 106, and the motor shaft is not provided with a groove due to elimination of a flat key on the motor, so that the coaxiality and the roundness are better, the dynamic balance is better during high-speed rotation, and the synchronous wheel is provided with a dynamic balance adjusting screw hole, so that the common rotating speed can be adjusted to the optimal state in real time through a dynamic balancing instrument on line.

The double-ended spindle comprises a spindle housing 202 and a spindle mandrel 209, as shown in an exploded structural diagram in fig. 3, the spindle mandrel 209 penetrates through the spindle housing 202, wherein both ends of the spindle mandrel 209 extend out of the spindle housing 202, and both ends are provided with BT tool shanks 203, so that the output of the double-ended spindle is realized. The spindle driven pulley 108 is coupled to an end of the spindle 209 extending out of the spindle housing 202, and serves as an input end of the spindle 209 to achieve synchronous movement.

The main shaft shell 202 is an integral casting part, mainly aiming at reducing the deformation of the main shaft shell 202, and in addition, in order to achieve better grinding machine processing effect, a scheme that the shell is separated from a heightening seat is adopted, because shafts of common knowledge are all barrel-shaped shells, because the barrel-shaped shells are easier to process on an inner circular grinding machine, a central frame can be additionally arranged on the grinding machine to ensure that a workpiece does not drop when the workpiece is rotationally processed, but a main shaft hoop needs to be added in the installation process of the barrel-shaped main shaft shell to be fixed on a machine, the installation precision is lost in the process of adding the hoop, and the self weight and the volume are increased.

In order to break through the technical bottleneck, the main shaft is smaller, the rigidity is better, the precision is higher, the main shaft shell 202 is made of a trapezoidal special-shaped type, and the processing mode of the internal grinding machine can be processed only by adopting the design of a special tool. In order to reduce the rotating centrifugal force of the shell in the grinding process of the grinding machine, the spindle shell 202 is divided into two layers, the heightening seat is independently processed, and the outer side of the shell is as close to the rotating circle center as possible, so that a better processing effect is achieved.

The purpose of independently processing the main shaft shell heightening seat 201 can be achieved by double-face hemp grinding of a surface grinding machine, and the mounting precision of two faces is higher. The general knowledge in the mechanical industry is that the spindle housing 202 similar to the non-standard non-circular spindle housing generally adopts boring processing to bore a hole by taking a base as a reference, but the boring and milling processing precision is difficult to reach within 0.003 MM. In order to achieve higher precision, a shell split grinding process is adopted.

A bearing inner and outer spacer 208 is provided on the intermediate outer side of the spindle shaft 209 in the spindle case 202. A set of paired thrust bearings 207 are provided on both sides of the bearing inner and outer spacers 208. A cap 206 is provided between the other side of the mating thrust bearing 207 near the output end of the spindle mandrel 209 and the flange cover 205. Both sides of the spindle case 202 are provided with flange covers 205.

The flange covers 205 at both ends of the main shaft housing 202 are used for pressing the main shaft bearing so that the main shaft bearing does not move in a moving process, but in an actual production process, tolerance exists in finish machining of each workpiece, and accumulated errors generated in assembly and combination are difficult to eliminate. In order to achieve better prepressing strength of the bearing, the flange cover 205 at one end is fixed, the installation depth cannot be adjusted and is also used as a reference side, the flange cover 205 at the other end is screwed in the threaded manner, and the flange cover 205 can be rotated to achieve prepressing strength when a small amount of time exists in the process of threaded matching between the flange cover 205 and the shell. After the flange cover 205 is well adjusted, a top bolt is additionally arranged through a threaded hole formed in the flange cover 205 for fixing, so that looseness is prevented.

A double-lip framework oil seal 303 is arranged in each flange cover 205. The middle of the double-lip framework oil seal 303 is concave, and a high-temperature-resistant bearing grease layer is arranged in the concave. The outer side of the flange cover 205 is provided with a spindle gas seal cover 204 for forming a gas seal.

An air inlet hole 301 is respectively provided on both ends of the top surface of the side surface of the main shaft housing 202, a transverse through hole 302 is provided on both ends of the main shaft housing 202, and is communicated with the air blowing hole, and the other side is communicated with the flange cover 205. After passing through the air blowing holes, the air flow sequentially passes through the transverse through holes 302, is blocked when meeting the main shaft air sealing cover 204 after passing through the flange cover 205, and forms air pressure with the outer side of the framework oil seal 303 along the inner surface of the main shaft air sealing cover 204, and because a rotating gap of 0.2-0.5MM is arranged between the air sealing cover 204 and the main shaft mandrel 209, air pressure gas is sprayed out from the matching gap, so that the dustproof, refrigerating and cooling effects are achieved.

In the application, the main shaft adopts the technical bottleneck that the framework oil seal 303 is added at two ends, the conventional air blowing type sealing is adopted, the refrigeration and the heat dissipation are adopted, and the oil seal can not be used when the main shaft of the mechanical industry exceeds 3000 turns. Meanwhile, the main shaft is applied at a high speed within 20000 revolutions through the following technical innovations:

the shaft center adopts the double-lip framework oil seal 303, the middle of the double-lip framework oil seal 303 is concave, and high-temperature-resistant bearing grease with certain capacity can be placed in the concave part, so that the lubricating effect can be achieved for a long time in the sealing process, the friction coefficient is reduced, the temperature is effectively controlled to increase along with the increase of the rotating speed, and the main shaft is not damaged. The double-lip framework oil seal 303 is mainly used for sealing, a main shaft with two sealed ends can completely and potentially prevent water from seeping into water, but the temperature of the sealing between a main shaft core and the oil seal, which generates friction, is very difficult to control, the smoothness of the shaft core is mechanically defined as roughness, which is a technical key point for generating temperature rise, and how to achieve high roundness, and the ultrahigh mirror finish is a key point. In the prior art, the spindle axis is subjected to heat treatment and then is subjected to finish machining to be ground into a mirror surface, which is a commonly used technical means of common machinery manufacturers, and in the application, a nano ceramic coating is added on the surface of the spindle axis 209 and is ground and polished into the mirror surface. Not only increases the wear resistance, but also further reduces the friction coefficient, and plays a certain role in controlling the temperature rise.

The tolerance matching of the conventional oil seal is that under the normal condition of a shaft diameter of 45MM, the mechanical parameters which can be found in the known mechanical field are that the available h11 of the shaft is-0.16, and the tolerance of the maximum available h13 is-0.39, but in actual years of experiments, the rotating speed exceeds 3000 revolutions, the temperature rise is very obvious, and when the rotating speed reaches 5000 revolutions, the oil seal, the spindle shaft 209 and the bearing can be directly damaged. In order to solve the technical bottleneck, the application adopts 3 means for ensuring that the oil seal can not be filled with oil and controlling the temperature rise by the friction between the oil seal and the shaft:

1) the roughness of the shaft excircle is reduced, so that the shaft excircle is smoother, the friction coefficient is smaller, and the wear resistance of the shaft excircle is improved; 2) a certain amount of grease can be stored in the oil seal by using a better oil seal, so that the lubricating effect is achieved; 3) the axle center is reduced to enable the axle center to be just in contact with an oil seal, but the axle center is not tight and loose and can not leak oil, the tolerance between the outer diameter of the spindle shaft 209 and the oil seal in the application is set to be-0.5 MM-0.8 MM and matched with the air seal pressure, the temperature rise due to friction can be well controlled, the cooling effect is increased by high-pressure air blowing, and the entering of external oil and dust can be effectively controlled.

Although the preferred embodiments of the present invention have been described in detail, the present invention is not limited to the details of the foregoing embodiments, and various equivalent changes (such as number, shape, position, etc.) may be made to the technical solution of the present invention within the technical spirit of the present invention, and the equivalents are protected by the present invention.

Claims (10)

1. A double-head double-sealing mechanical main shaft is characterized by comprising a motor driving mechanism and a double-head main shaft;

the motor driving mechanism comprises a main shaft mounting bracket and a servo motor; a servo motor mounting chamber is arranged at the upper part of the main shaft mounting bracket; the servo motor penetrates through the cavity and is installed on the motor plate; a waist hole is formed in the side of the motor plate and is fixed with the main shaft mounting bracket through a screw; a synchronous belt pulley is arranged on an output shaft of the servo motor; the synchronous belt pulley comprises a servo motor driving wheel, a synchronous belt and a main shaft mandrel driven wheel; the driving wheel of the servo motor is arranged on an output shaft of the servo motor through an expansion sleeve; a synchronous belt is arranged on the driving wheel of the servo motor; the other end of the synchronous belt is connected with a driven wheel of a spindle mandrel and is used for transmitting power to a mechanical spindle; a dynamic balance adjusting screw hole is formed in the driving wheel of the servo motor;

the double-head spindle comprises a spindle shell, a spindle mandrel and a shell heightening seat; the spindle shell is fixed on the shell heightening seat through a bolt; the shell heightening seat is arranged at the bottom of the bracket; the spindle mandrel penetrates through the spindle shell, BT cutter handles are mounted at two ends of the spindle mandrel, and two ends of the spindle mandrel extend out of the spindle shell; the main shaft mandrel driven wheel is connected with one end, extending out of the main shaft shell, of the main shaft mandrel and serves as an input end of the main shaft mandrel to realize synchronous motion;

a bearing inner spacer ring and a bearing outer spacer ring are arranged on the outer side of the middle of the spindle shaft in the spindle shell; a group of matched thrust bearings are arranged on both sides of the bearing by taking the inner and outer space rings of the bearing as centers; a handle cap is arranged between the other side of the matched thrust bearing and the flange cover close to the output end of the spindle; flange covers are arranged outside two sides of the main shaft shell; the flange cover is connected with the matched thrust bearing in the main shaft shell; the flange covers are internally provided with double-lip framework oil seals; the middle of the double-lip framework oil seal is concave, and a high-temperature-resistant bearing grease layer is arranged in the concave part; and the outer sides of the flange covers are provided with main shaft air seal covers for forming air seals.

2. The dual head dual seal mechanical spindle of claim 1,

the main shaft shell is an integral casting; one end of the main shaft shell close to the driven wheel of the main shaft mandrel is provided with a plurality of threaded holes for installing evenly distributed bolts, and the threaded holes are used for fixing the flange cover; the other end of the main shaft shell, which is far away from the main shaft mandrel driven wheel, is provided with a thread which is coaxial with the shell; the flange cover is rotationally locked into the spindle shell through threads; the flange cover is provided with a threaded hole for installing a top bolt to be fixed on the main shaft shell; the bottom of the spindle shell is a high-precision mounting plane and is parallel to a cylindrical inner hole of an inner cavity of the shell.

3. The dual head dual seal mechanical spindle of claim 2,

the spindle housing is a trapezoidal cube, the top of the trapezoid is semicircular, the bottom of the trapezoid is provided with a vacancy avoiding position, and the bottom of the spindle housing is provided with a plurality of threaded mounting holes for being fixed at the bottom of the spindle mounting bracket through bolts.

4. The dual head dual seal mechanical spindle of claim 1,

the surface of the spindle mandrel is provided with a nano ceramic coating.

5. The dual head dual seal mechanical spindle of claim 1,

the inner holes at two ends of the spindle mandrel are inner taper holes which are manufactured into BT series 7:24, and threaded holes are formed in the two bottoms of the inner taper holes.

6. The dual head dual seal mechanical spindle of claim 1,

the tolerance range of the outer diameter of the spindle mandrel matched with the double-lip framework oil seal is-0.5-0.8 MM.

7. The dual head dual seal mechanical spindle of claim 1,

the driven wheel of the spindle mandrel is fixed on the side surface of the spindle end of the spindle mandrel through uniformly distributed bolts, and the precision positioning of the synchronous belt wheel is based on the cylindricity of the spindle mandrel and the perpendicularity of steps;

the servo motor driving wheel and the main shaft mandrel driven wheel are made of high-strength aluminum alloy; the servo motor driving wheel and the spindle mandrel driven wheel are provided with high-precision shaft positioning steps, and one side of the driving wheel and one side of the driven wheel are provided with a circle of dynamic balance adjusting bolt holes.

8. The dual head dual seal mechanical spindle of claim 1,

the outer sides of one ends of the two flange covers are respectively provided with an O-shaped sealing ring groove for sealing with the main shaft shell, and the inner sides of the two flange covers are provided with a framework oil seal installation cavity; and the flange cover is provided with an air seal blowing connecting hole.

9. The dual head dual seal mechanical spindle of claim 1,

the motor plate is ground on two sides and can be independently disassembled; a motor plate adjusting steel bar is arranged at the top of the servo motor plate; the motor plate adjusting steel bar is locked with the end face of the main shaft mounting bracket through a transverse screw; the motor plate adjusting steel bar is tightly hung at the top of the motor plate through a top screw.

10. The dual head dual seal mechanical spindle of claim 1,

the main shaft mounting bracket is an integral casting and is molded into a special shape; the main shaft mounting bracket is provided with a plurality of clearance-avoiding weight-reducing positions, the processing mode adopts hexahedron processing, all mounting surfaces adopt accurate grinding processing, and the verticality flatness is within 0.01 MM.

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