High-rigidity knife rest spindle structure

Abstract

The invention relates to the field of machine tools, in particular to a high-rigidity tool rest spindle structure which comprises a spindle body, bearings, end face keys and a shell, the spindle body comprises a front-end spindle and a rear-end spindle, the shell comprises a front-end shell and a rear-end shell which are connected, the front-end spindle is assembled with the front-end shell through the bearings, and the rear-end spindle is assembled with the rear-end shell through the bearings. The front-end main shaft and the rear-end main shaft are coaxial and are radially positioned and connected through an end face key, and a gap is reserved between the rear-end main shaft and the front-end main shaft. By the adoption of the technical scheme, the problems that heat affects machining precision, and machining and maintaining difficulty is large can be solved at the same time.

Description

Technical Field

[0001] The invention relates to the field of machine tools, and in particular to a high-rigidity tool holder spindle structure. Background Art

[0002] At present, the shell and spindle structure of the commonly used tool holder structure are both integral, which has great limitations in the structural design, processing and assembly process. For example, it is difficult to ensure the accuracy during processing, and the processing cost is relatively high; it is inconvenient to repair the tool holder at a later time, including replacing bearings and repairing the motor; and the heat generated by the motor of the integral spindle during processing will have a negative impact on the machining accuracy of the machine tool. For example, the heat transferred to the front end of the spindle will affect the spindle stiffness and cause deformation, or cause the spindle to expand thermally, causing the length and diameter of the spindle to change, or high temperature will cause the material properties of the bearing to change, such as reduced hardness and strength.

[0003] In order to solve the problem of negative impact of heat generated by motors on machine tool processing, a patent for a spindle unit for a machine tool with publication number CN102389987B discloses heat dissipation through a gap between the fitting surface and the supporting surface to avoid mechanical stress caused by heat, but it still fails to comprehensively solve the aforementioned problems. Summary of the invention

[0004] The present invention aims to provide a high-rigidity tool holder spindle structure to comprehensively solve the problems of heat affecting machining accuracy and high difficulty in machining and maintenance.

[0005] To achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a high-rigidity tool holder spindle structure, including a spindle body, a bearing, an end face key and a shell, the spindle body including a front end spindle and a rear end spindle, the shell including a connected front end shell and a rear end shell, the front end spindle is assembled with the front end shell through a bearing, the rear end spindle is assembled with the rear end shell through a bearing, the front end spindle and the rear end spindle are coaxial and radially positioned and connected by an end face key, and a gap is left between the rear end spindle and the front end spindle.

[0006] The technical effect of this solution is: the spindle body and the shell are divided into two parts, a gap is left between the rear end spindle and the front end spindle so that they are not in direct contact, the motor on the rear end spindle generates heat, and when the heat energy is transferred along the rear end spindle to the gap between the rear end spindle and the front end spindle, the air layer between the rear end spindle and the front end spindle blocks the transfer of heat energy, thereby isolating the influence of the heat energy on the front end spindle, because it is mainly the front end spindle that bears the cutting force during gear hobbing, thereby improving the rigidity of the tool holder spindle to meet the machining accuracy of gear hobbing.

[0007] This solution is different from the existing solution of setting a gap on the shell to dissipate heat to solve the problem of heat transfer in the motor. The existing technology does not provide a technical solution or technical inspiration for "broken shaft". This solution divides the main shaft body and the shell into two parts, and also takes into account the following technical effects in one fell swoop:

[0008] Reduce the deflection of the front-end spindle: The deflection generated during the rotation of the spindle body will also have a negative impact on the machining accuracy of the machine tool. This solution effectively reduces the deflection of the front-end spindle by dividing the spindle body into two, which is also beneficial to improving the machining accuracy of gear hobbing.

[0009] Saving rear-end spindle material: Since the large end diameter of the front-end spindle is larger and the diameter of the rear-end spindle is smaller, and the spindle body is usually forged from bar stock, in order to meet the material requirements of the front-end spindle, the blank material of the spindle body will increase, resulting in material waste; after the spindle body is divided into two parts, the rear-end spindle can be formed with small-diameter bar stock, which can save the blank of the rear-end spindle and thus reduce costs.

[0010] Reduce the difficulty of shell processing: The shell is divided into two parts, which can reduce the difficulty of processing and save costs. First, the selection of processing machine tools is wider. When the shell is a whole, a large processing machine tool is required. After disassembling, a smaller machine tool can be used for processing, and the energy consumption of the equipment is reduced, that is, the processing cost is reduced; secondly, after the shell is separated, a through hole is made, which reduces the step hole processing of the overall shell, reduces the difficulty of processing, and also reduces the cost.

[0011] Reduce the difficulty of maintenance: the spindle body and the housing are divided into two parts, which is convenient for assembly and later maintenance. When disassembling for maintenance, the front housing and the rear housing are pulled apart, so that the front spindle and the rear spindle can be separated, and the bearing on the front spindle can be replaced separately. This is more convenient than removing the bearing on the rear spindle before removing the bearing on the front spindle.

[0012] Preferably, as an improvement, the end faces of the front end spindle and the rear end spindle close to one end are both provided with positioning grooves in the circumferential direction, the end face keys are located in the positioning grooves, and the end face keys are fixed to the front end spindle.

[0013] Preferably, as an improvement, a gap is also left between the end face key and the rear end spindle.

[0014] Preferably, as an improvement, an outer spacer sleeve is provided between the bearing on the front main shaft and the bearing on the rear main shaft for supporting the outer ring of the bearing.

[0015] Preferably, as an improvement, two sets of bearings are provided on the front main shaft, and an outer spacer is provided between the two sets of bearings; and an inner spacer is provided between the two sets of bearings for supporting the inner rings of the bearings.

[0016] Preferably, as an improvement, a locking member is provided at a group of bearings on the front end spindle close to the rear end spindle, the locking member includes a locking screw and a locking ring, the locking ring sleeve is arranged on the front end spindle, a ring groove is provided on the front end spindle, an elastic retaining ring is installed at the ring groove, the locking ring is provided with a chamfer at the ring groove, the elastic retaining ring and the chamfer contact the axial limiting locking ring, an inner spacer is also provided between the locking ring and the bearing, the set screw is connected to the locking ring bolt, and the set screw contacts the inner spacer.

[0017] The technical effect of this solution is: the locking ring is limited by the elastic retaining ring, so that the end face of the set screw threadedly connected to the locking ring pushes the inner spacer to tighten the inner ring load of the bearing.

[0018] Preferably, as an improvement, the inner end surfaces of the front end housing and the rear end housing are both provided with steps for supporting the outer ring of the bearing.

[0019] Preferably, as an improvement, the front end spindle is made of alloy steel material, and the rear end spindle is made of ordinary steel material.

[0020] The technical effect of this solution is: since the front spindle is subjected to a large cutting force, the rear spindle mainly serves to support the motor, so the front spindle can be made of better alloy steel material and the rear spindle can be made of general steel to save costs.

[0021] Preferably, as an improvement, the bearings on the front end spindle and the rear end spindle are complete sets of bearings.

[0022] Preferably, as an improvement, it also includes screws, the connection between the front end shell and the rear end shell is tightened by a bearing on the rear end main shaft, the front end shell and the rear end shell are connected by screws, and the screws are located below the front end shell and the rear end shell.

[0023] The technical effect of this scheme is: the front end housing is tightened by the bearing on the rear end spindle to facilitate the positioning and assembly of the front end housing; in addition, the front end housing and the rear end housing are locked and connected with screws at the bottom, while ensuring that the front end housing and the rear end housing are fixedly connected, the remaining contact positions of the front end housing and the rear end housing have the possibility of slight relative movement; even if the rear end spindle is in the process of slight deflection, the front end housing is driven by the bearing on the rear end spindle to produce corresponding deflection, so that the front end housing drives the front end spindle and the rear end spindle to maintain the same deflection, ensuring that the front end spindle and the rear end spindle remain coaxial, so as to improve the machining accuracy of gear rolling; because if the front end housing does not assist the front end spindle to produce corresponding deflection, and only relies on the end face key to drive the front end spindle to produce deflection, the timeliness of the front end spindle movement may be affected, thereby affecting the coaxiality of the front end spindle and the rear end spindle, and then affecting the machining accuracy of gear rolling. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1is a cross-sectional view of an embodiment of the present invention;

[0025] Figure 2 for Figure 1 A partial enlarged view of point A in the middle. DETAILED DESCRIPTION

[0026] The following is further described in detail through specific implementation methods:

[0027] The figure marks in the drawings of the specification include: front end spindle 1, connecting plate 2, bearing 3, inner spacer 4, front end housing 5, outer spacer 6, end face key 7, set screw 8, locking ring 9, rear end housing 10, rear end spindle 11, and motor 12.

[0028] The embodiment is basically as shown in the attached Figure 1 , 2 As shown: Figure 1 , 2 A high-rigidity tool holder spindle structure shown in the figure includes a spindle body, a bearing 3, an end face key 7 and a shell, the spindle body includes a front end spindle 1 and a rear end spindle 11, the front end spindle 1 is made of alloy steel material, and the rear end spindle 11 is made of ordinary steel material; the shell includes a front end shell 5 and a rear end shell 10, and the front end face of the front end shell 5 is installed with a receiving plate 2; the front end spindle 1 is assembled with the front end shell 5 through two sets of set bearings 3, and the rear end spindle 11 is also assembled with the rear end shell 10 through two sets of set bearings 3; among which the two sets of set bearings 3 on the rear end spindle 11 mainly introduce the structure of the left set of set bearings 3, and the structure of the right set of set bearings 3 is mainly the supporting structure of the set bearing 3 and the end cover sealing structure.

[0029] It should be emphasized that the front and rear ends of this scheme and the existing patent are not the same concept. The front end of the prior art is equivalent to the general term for the front end and the rear end in this scheme, and the rear end of the prior art is equivalent to the supporting structure of the right set of bearings 3 in this scheme. Therefore, the prior art does not provide any inspiration for dividing the main shaft body and the housing into two parts.

[0030] The front end spindle 1 and the rear end spindle 11 are coaxial, and four positioning grooves are opened in the circumferential direction of the end faces of the front end spindle 1 and the rear end spindle 11 close to each other. The end face key 7 is located in the positioning groove for radial positioning and connects the front end spindle 1 and the rear end spindle 11 to transmit torque, and a gap is left between the rear end spindle 11 and the front end spindle 1; the end face key 7 is fixed to the front end spindle 1 by screws, and a gap is also left between the end face key 7 and the rear end spindle 11.

[0031] An outer spacer sleeve 6 is provided between the bearing 3 on the front end main shaft 1 and the bearing 3 on the rear end main shaft 11 for supporting the outer ring of the bearing 3; an outer spacer sleeve 6 is also provided between the two groups of bearings 3 on the front end main shaft 1, and an inner spacer sleeve 4 is also provided between the two groups of bearings 3 for supporting the inner ring of the bearing 3; the bearings 3 are installed back to back.

[0032] A locking part is provided at a group of bearings 3 on the right side of the front end main shaft 1, and the locking part includes a locking screw and a locking ring 9. The locking ring 9 is sleeved on the front end main shaft 1. A ring groove is opened on the front end main shaft 1, and an elastic retaining ring is installed at the ring groove. The locking ring 9 is provided with a chamfer at the ring groove, and the elastic retaining ring and the chamfer contact the axial limiting locking ring 9. An inner spacer 4 is also provided between the locking ring 9 and the bearing 3. The set screw 8 is bolted to the locking ring 9, and the set screw 8 contacts the inner spacer 4 to push the inner spacer 4 to tighten the inner ring load of the bearing 3.

[0033] The inner end surfaces of the front housing 5 and the rear housing 10 are both provided with steps for supporting the outer ring of the bearing 3. The connection between the front housing 5 and the rear housing 10 is tightened by the bearing 3 on the rear spindle 11, the concentricity between the spindle body and the housing is assembled and positioned by the bearing 3 on the front housing 5 and the rear spindle 11, and the front housing 5 and the rear housing 10 are axially tightened by screw connection, and the screws are located below the front housing 5 and the rear housing 10.

[0034] During assembly, the bearing 3, the inner spacer 4, and the outer spacer 6 are installed on the front end main shaft 1, and the inner ring of the bearing 3 on the front end main shaft 1 is locked with the inner spacer 4, the set screw 8, and the locking ring 9. After this part is assembled, it is installed as a whole into the front end housing 5; then the bearing 3 is assembled to the rear end main shaft 11. The stator of the motor 12 has been pre-installed in the rear end housing 10, and then the rear end main shaft 11 is installed as a whole into the rear end housing 10, and finally the rotor of the motor 12 is installed. After this part is assembled, when the above two parts are combined, it is necessary to grind the outer spacer 6 at the locking piece, and finally the front end housing 5 and the rear end housing 10 are screwed and tightened.

[0035] The above is only an embodiment of the present invention, and the common knowledge such as the known specific technical solutions and / or characteristics in the solution is not described in detail here. It should be pointed out that for those skilled in the art, without departing from the technical solution of the present invention, several modifications and improvements can be made, which should also be regarded as the protection scope of the present invention, and these will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. A high-rigidity tool holder spindle structure, characterized in that: It includes a spindle body, bearings, end keys and a shell. The spindle body includes a front end spindle and a rear end spindle. The shell includes a front end shell and a rear end shell that are connected. The front end spindle is assembled with the front end shell through a bearing. The rear end spindle is assembled with the rear end shell through a bearing. The front end spindle and the rear end spindle are coaxial and radially positioned and connected by an end key. A gap is left between the rear end spindle and the front end spindle.

2. The high-rigidity tool holder spindle structure according to claim 1, characterized in that: The end faces of the front spindle and the rear spindle close to one end are both provided with positioning grooves in the circumferential direction, the end face keys are located in the positioning grooves, and the end face keys are fixed to the front spindle.

3. The high rigidity tool holder spindle structure according to claim 2, characterized in that: There is also a gap between the end key and the rear end spindle.

4. The high rigidity tool holder spindle structure according to claim 3, characterized in that: An outer spacer is arranged between the bearing on the front main shaft and the bearing on the rear main shaft for supporting the outer ring of the bearing.

5. The high rigidity tool holder spindle structure according to claim 4, characterized in that: Two sets of bearings are arranged on the front main shaft, and an outer spacer is arranged between the two sets of bearings; and an inner spacer is arranged between the two sets of bearings for supporting the inner rings of the bearings.

6. The high rigidity tool holder spindle structure according to claim 5, characterized in that: A locking piece is provided at a group of bearings on the front end spindle close to the rear end spindle, and the locking piece includes a locking screw and a locking ring. The locking ring sleeve is arranged on the front end spindle, and a ring groove is provided on the front end spindle. An elastic retaining ring is installed at the ring groove, and a chamfer is provided at the ring groove of the locking ring. The elastic retaining ring and the chamfer contact the axial limiting locking ring, and an inner spacer is also provided between the locking ring and the bearing. The set screw is connected with the locking ring bolt, and the set screw contacts the inner spacer.

7. The high rigidity tool holder spindle structure according to claim 6, characterized in that: The inner end surfaces of the front end housing and the rear end housing are both provided with steps for supporting the outer ring of the bearing.

8. The high rigidity tool holder spindle structure according to claim 7, characterized in that: The front spindle is made of alloy steel, and the rear spindle is made of ordinary steel.

9. The high rigidity tool holder spindle structure according to claim 8, characterized in that: The bearings on the front and rear spindles are complete sets of bearings.

10. A high rigidity tool holder spindle structure according to any one of claims 1 or 9, characterized in that: It also includes screws. The connection between the front end housing and the rear end housing is tightened through the bearing on the rear end main shaft. The front end housing and the rear end housing are connected by screws, and the screws are located below the front end housing and the rear end housing.

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