Main shaft sealing structure, electric main shaft and machine tool

Abstract

The utility model discloses a main shaft seal structure, motorized spindle and machine tool, including machine body and shaft core subassembly, shaft core subassembly is supported in the machine body through bearing, the bearing includes lower bearing, machine body includes the lower end cover of lower bearing outside, the lower end cover is equipped with the first plastic ring of clearance fit with the shaft core subassembly, and the first plastic ring is equipped with the second plastic ring of clearance fit with the shaft core subassembly. A sealing gap is formed between the first plastic ring and the shaft core assembly. According to the technical scheme, the first plastic ring is arranged between the lower end cover and the shaft core assembly and surrounds the periphery of the shaft core assembly, so that a sealing structure between the machine body and the shaft core assembly at the lower end of the main shaft is formed through clearance fit of the first plastic ring and the shaft core assembly, and the hardness of the plastic ring is softer than that of a metal material; therefore, on the premise that the shaft core assembly is not abraded, the sealing gap can be made smaller, impurities can be prevented from entering the main shaft by reducing the sealing gap, and the phenomenon that the main shaft is stuck after friction is effectively prevented.

Description

TECHNICAL FIELD

[0001] The utility model relates to a main shaft field, in particular to a main shaft sealing structure, electric spindle and machine tool. BACKGROUND

[0002] The numerical control machining center machine tool is integrated by mechanical equipment and numerical control system, and is mainly used for industrial manufacturing machining, and is widely applied to the machining of parts in the fields of mould, automobile, ship, aerospace and communication. The numerical control machining center machine tool can be applied to high-efficiency automatic machining equipment of complex parts. The numerical control machining center machine tool has certain advantages in comprehensive machining capacity, and a workpiece can be clamped and fixed once to complete machining of multiple processes, so that the machining precision and efficiency of parts can be effectively improved.

[0003] At present, in the machining process of the machining center mechanical spindle, oil, gas, cooling liquid and machining waste scraps enter the front end of the spindle, so that sundries enter the lubricating grease of the rolling bearing and the lubricating grease is polluted, and the service life of the spindle is reduced. The sealing mode of the prior art generally adopts labyrinth + gas sealing, and the sealing effect of this sealing mode is poor, and the energy consumption is relatively high. UTILITY MODEL CONTENT

[0004] The utility model discloses a main shaft sealing structure, electric spindle and machine tool, and at least one of the technical problems in the prior art is solved.

[0005] The utility model discloses the technical scheme that the technical problem is solved is as follows:

[0006] Firstly, a main shaft sealing structure is provided, which comprises a machine body and a shaft core assembly, the shaft core assembly is supported on the machine body through a bearing, the bearing comprises a lower bearing, the machine body comprises a lower end cover arranged outside the lower bearing, the lower end cover is provided with a first plastic ring in gap cooperation with the shaft core assembly, and a sealing gap is formed between the first plastic ring and the shaft core assembly.

[0007] In combination with the first aspect, in some implementation manners of the first aspect, the sealing gap is between 0.01-0.1 mm.

[0008] In combination with the first aspect and the above implementation manners, in some implementation manners of the first aspect, the lower end cover comprises a lower end cover outer sleeve and a lower end cover inner sleeve, the lower end cover outer sleeve is provided with a shaft hole for the shaft core assembly to pass out, the lower end cover outer sleeve is provided with a flange extending radially to the inside of the shaft hole, the lower end cover inner sleeve is interference-fitted in the shaft hole, and the first plastic ring is axially pressed and fitted on the flange, the radial gap between the inner circumferential surface of the first plastic ring and the outer circumferential surface of the shaft core assembly forms the sealing gap, and the radial gaps between the lower end cover inner sleeve and the shaft core assembly and between the flange and the shaft core assembly are all greater than the sealing gap.

[0009] In combination with the first aspect and the above-described implementations, in some implementations of the first aspect, the inner circumferential surface of the first plastic ring is provided with a first annular groove.

[0010] In combination with the first aspect and the above-mentioned implementation methods, in some implementation methods of the first aspect, the inner circumferential surface of the lower end cover inner sleeve is provided with a second annular groove, and the lower end cover outer sleeve and the lower end cover inner sleeve are provided with air supply holes communicating with the second annular groove.

[0011] In combination with the first aspect and the above-described implementations, in some implementations of the first aspect, the bearing includes an upper bearing, the body includes an upper bearing housing, the upper bearing is disposed in the upper bearing housing, the shaft core assembly is provided with a sealing end cap extending to the outside of the upper bearing housing, the upper bearing housing is provided with a third annular groove, the sealing end cap is provided with a convex ring, the convex ring is embedded in the third annular groove, and a labyrinth sealing structure is formed between the upper bearing housing and the sealing end cap.

[0012] In combination with the first aspect and the above-described implementations, in some implementations of the first aspect, the upper bearing housing has a fourth annular groove on the wall surface facing the sealing end cover, and the fourth annular groove has a second plastic ring that is clearance-fitted with the sealing end cover.

[0013] In combination with the first aspect and the above-described implementations, in some implementations of the first aspect, the sealing end cap is connected to the shaft core assembly and axially locks the inner ring of the upper bearing.

[0014] In a second aspect, an electric spindle includes the spindle sealing structure described in any implementation of the first aspect.

[0015] Thirdly, a machine tool comprising an electric spindle of any implementation of the second aspect.

[0016] One of the above technical solutions has at least one of the following advantages or beneficial effects: In the technical solution of this utility model, a first plastic ring is provided between the lower end cover and the spindle assembly. The first plastic ring surrounds the outer circumference of the spindle assembly, thereby forming a sealing structure between the machine body and the spindle assembly at the lower end of the spindle through a clearance fit between the first plastic ring and the spindle assembly. The plastic ring is softer than metal materials, thus allowing for a smaller sealing gap while ensuring that the spindle assembly is not worn. This reduces the sealing gap, preventing impurities from entering the spindle and effectively preventing spindle jamming after friction. Furthermore, the small gap achieves a "pressure holding" effect and reduces energy consumption. The technical solution of this utility model reduces energy consumption and solves the technical defects of poor spindle sealing effect and short spindle service life in CNC machine tools.

[0017] The additional aspects and advantages of the present application will be in part apparent and in part pointed out hereinafter in the description of embodiments in which reference will be made to the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0018] The above and / or additional aspects and advantages of the present application will become apparent and be readily appreciated from the following description of embodiments, taken in conjunction with the accompanying drawings, in which:

[0019] Figure 1 is a sealing structure schematic view between the lower end cover and the shaft core assembly of one embodiment of the present application;

[0020] Figure 2 is a first plastic ring structure schematic view of one embodiment of the present application;

[0021] Figure 3 is a sealing structure schematic view between the sealing end cover and the upper bearing seat of one embodiment of the present application. DETAILED DESCRIPTION

[0022] This part will describe the specific embodiments of the present application in detail, the preferred embodiments of the present application are shown in the drawings, the role of the drawings is to supplement the description of the text part with figures, so that people can intuitively and visually understand each technical feature and the overall technical scheme of the present application, but it cannot be understood as the limitation of the protection scope of the present application.

[0023] In the present application, if the direction (up, down, left, right, front and back) is described, it is only for the convenience of describing the technical scheme of the present application, and is not intended to indicate or imply that the technical features referred to must have a specific orientation, structure and operation, therefore it cannot be understood as the limitation of the present application.

[0024] In the present application, the meaning of "several" is one or more, the meaning of "multiple" is two or more, "greater than", "less than", "more than" and the like are not included in the number; "above", "below", "within" and the like are included in the number. In the description of the present application, if "first" and "second" are described, they are only used for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features or implicitly indicating the sequence of indicated technical features.

[0025] In the utility model, unless otherwise explicitly limited, the words such as ''set'', ''install'', ''connect'' should be understood in a broad sense, for example, it can be directly connected, and it can also be indirectly connected through an intermediate medium, it can be fixedly connected, and it can also be detachably connected, and it can also be integrally formed, it can be mechanically connected, and it can also be electrically connected or capable of intercommunication, it can be the communication inside two elements or the interaction relationship of two elements, and the person skilled in the art can determine the specific meaning of the above words in the utility model in combination with the specific content of the technical scheme.

[0026] Wherein, Figure 1 、 Figure 3 The reference direction coordinate system of the embodiment of the utility model is given, and the embodiment of the utility model is explained below in combination with the direction shown in the drawings. Figure 1 、 Figure 3

[0027] Referring to Figure 1 , a main shaft sealing structure, comprising a machine body 100 and a shaft core assembly 200, the shaft core assembly 200 is supported on the machine body 100 through a bearing, the bearing comprises a lower bearing (not shown in the drawing), the lower end of the main shaft is used for connecting a cutter, the lower end is closer to a machining position relative to the upper end of the main shaft, and the lower end is more susceptible to the influence of oil, air, coolant, machining waste and the like, the machine body 100 comprises a lower end cover arranged outside the lower bearing, the lower end cover is provided with a first plastic ring 300 in gap cooperation with the shaft core assembly 200, and a sealing gap is formed between the first plastic ring 300 and the shaft core assembly 200.

[0028] The first plastic ring 300 can adopt existing plastic materials such as polytetrafluoroethylene.

[0029] In combination with Figure 1 , in the technical scheme of the utility model, the first plastic ring 300 is arranged between the lower end cover and the shaft core assembly 200, the first plastic ring 300 surrounds the outer periphery of the shaft core assembly 200, so that the sealing structure between the machine body 100 and the shaft core assembly 200 at the lower end of the main shaft is formed through the gap cooperation between the first plastic ring 300 and the shaft core assembly 200, the plastic ring is softer relative to the hardness of metal material, so that the sealing gap can be made smaller under the premise that the shaft core assembly 200 is not abraded, so that impurities can be prevented from entering the main shaft by reducing the sealing gap, and the phenomenon of main shaft jamming after friction can be effectively prevented. And through the small gap, the effect of ''pressure maintaining'' is achieved, and the energy consumption is reduced. The technical scheme of the utility model reduces the use energy consumption, and solves the technical defect problems such as poor sealing effect of the main shaft of the numerical control machining machine tool and short service life of the main shaft.

[0030] ​In some embodiments, by selecting the first plastic ring 300 as a sealing component in a clearance fit with the shaft core assembly 200, the sealing gap between the first plastic ring 300 and the shaft core assembly 200 can be set to between 0.01-0.1 mm, so that the sealing gap can be made smaller, that is, by reducing the sealing gap to prevent impurities from entering the main shaft, and improve the sealing effect of the lower end of the main shaft.

[0031] In some embodiments, the plastic ring grinding tolerance can reach +0.01-+0.04. The outer circle tolerance of the shaft core assembly 200 is 0-0.01. Thus, by reducing the sealing gap, impurities can be prevented from entering the main shaft, and the "pressure retention" effect can be achieved through a small gap, and energy consumption can be reduced.

[0032] The first plastic ring 300 can be installed on the lower end cover by slotting or setting fasteners on the lower end cover.

[0033] Further, in some embodiments, referring to Figure 1 , the lower end cover includes a lower end cover outer sleeve 101 and a lower end cover inner sleeve 102, the lower end cover outer sleeve 101 is provided with a shaft hole for the shaft core assembly 200 to pass out, the lower end cover outer sleeve 101 is provided with a flange 103 extending radially inward of the shaft hole, the lower end cover inner sleeve 102 is interference fitted in the shaft hole, and the first plastic ring 300 is axially pressed onto the flange 103, the radial gap between the inner circumferential surface of the first plastic ring 300 and the outer circumferential surface of the shaft core assembly 200 forms a sealing gap, and the radial gap between the lower end cover inner sleeve 102 and the shaft core assembly 200 and the radial gap between the flange 103 and the shaft core assembly 200 are all greater than the sealing gap, so that the plastic ring has space to deform and prevent the phenomenon of being stuck after friction.

[0034] In some embodiments, referring to Figure 1 , Figure 2 , the inner circumferential surface of the first plastic ring 300 is provided with one or more first ring grooves 104, in this embodiment, by providing the first ring grooves 104 on the inner circumferential surface of the first plastic ring 300, on the one hand, a plurality of annular cavities 105 can be formed between the first plastic ring 300 and the shaft core assembly 200, forming a multi-layer seal, and on the other hand, the fitting area between the first plastic ring 300 and the shaft core assembly 200 can be reduced, and the assembly precision requirement of the first plastic ring 300 and the shaft core assembly 200 can be reduced.

[0035] In some embodiments, referring to Figure 1 , the inner circumferential surface of the lower end cover inner sleeve 102 is provided with a second ring groove 106, and the lower end cover outer sleeve 101 and the lower end cover inner sleeve 102 are provided with a gas hole 107 communicating with the second ring groove 106. In use, referring to Figure 1The main shaft introduces the gas flow into the second annular groove 106 through the gas supply hole 107 in the direction of the arrow, and the gas flow is blown out through the gap between the lower end cover inner sleeve 102 and the shaft core assembly 200 after being uniformly distributed in the second annular groove 106, so as to form a gas seal between the main shaft assembly and the lower end cover inner sleeve 102, and further improve the sealing effect of the lower end of the main shaft on the basis of the gap sealing of the first plastic ring 300.

[0036] In some embodiments, referring to Figure 3 The bearing includes an upper bearing 400, the machine body 100 includes an upper bearing seat 107, the upper bearing 400 is arranged in the upper bearing seat 107, the shaft core assembly 200 is provided with a sealing end cover 201 extending to the outside of the upper bearing seat 107, the upper bearing seat 107 is provided with a third annular groove 108, the sealing end cover 201 is provided with a convex ring 202, the convex ring 202 is embedded in the third annular groove 108, and a labyrinth seal structure is formed between the upper bearing seat 107 and the sealing end cover 201. The labyrinth seal structure is formed between the upper bearing seat 107 and the sealing end cover 201, and the upper end of the main shaft is sealed.

[0037] Further, in some embodiments, referring to Figure 3 The wall surface of the upper bearing seat 107 towards the sealing end cover 201 is provided with a fourth annular groove, and the fourth annular groove is provided with a second plastic ring 500 in gap cooperation with the sealing end cover 201. The second plastic ring 500 protrudes from the fourth annular groove, and the second sealing ring is in gap cooperation with the sealing end cover 201 to form a gap seal, further improving the sealing performance of the upper end of the main shaft. By selecting the second plastic ring in gap cooperation with the shaft core assembly 200 as the sealing part, the sealing gap between the second plastic ring 500 and the shaft core assembly 200 can be set to be between 0.01-0.05mm, so that the sealing gap can be smaller, that is, impurities are prevented from entering the main shaft by reducing the sealing gap, and the sealing effect of the lower end of the main shaft is improved.

[0038] In combination with the first aspect and the above implementation manners, in some implementation manners of the first aspect, the sealing end cover 201 is connected to the shaft core assembly 200 and locks the inner ring of the upper bearing 400 in the axial direction. In this embodiment, the sealing end cover 201 realizes the function of locking the upper bearing 400 by being locked to the shaft core assembly 200 while realizing the sealing in cooperation with the upper bearing seat 107.

[0039] The embodiment of the utility model provides a kind of electric spindle, including the main shaft sealing structure in any one of the above embodiments.

[0040] The embodiment of the utility model further provides a kind of machine tool, including the electric spindle in any one of the above embodiments.

[0041] In the description of the present specification, the description referring to the terms "example", "embodiment" or "some embodiments" or the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0042] Of course, the present application is not limited to the above-described embodiments, and those skilled in the art can make equivalent modifications or substitutions without departing from the spirit of the present application, and these equivalent modifications or substitutions are included in the scope defined by the claims of the present application.

Claims

1. A spindle seal structure, characterized by, The main shaft sealing structure comprises a main body and a shaft core assembly, the shaft core assembly is supported by a bearing on the main body, the bearing comprises a lower bearing, the main body comprises a lower end cover arranged outside the lower bearing, the lower end cover is provided with a first plastic ring in clearance fit with the shaft core assembly, and a sealing gap is formed between the first plastic ring and the shaft core assembly.

2. The spindle seal structure of claim 1, wherein, The sealing gap is between 0.01mm and 0.1mm.

3. The spindle seal structure of claim 1, wherein, The lower end cover comprises a lower end cover outer sleeve and a lower end cover inner sleeve, the lower end cover outer sleeve is provided with a shaft hole through which the shaft core assembly passes, the lower end cover outer sleeve is provided with a flange extending radially towards the inside of the shaft hole, the lower end cover inner sleeve is interference-fitted in the shaft hole, and the first plastic ring is axially pressed on the flange, the radial gap between the inner circumferential surface of the first plastic ring and the outer circumferential surface of the shaft core assembly forms the sealing gap, and the radial gaps between the lower end cover inner sleeve and the shaft core assembly and between the flange and the shaft core assembly are all greater than the sealing gap.

4. The spindle seal structure of claim 3, wherein, The inner circumferential surface of the first plastic ring is provided with a first ring groove.

5. The spindle seal structure of claim 3, wherein, The inner circumferential surface of the lower end cover inner sleeve is provided with a second ring groove, and the lower end cover outer sleeve and the lower end cover inner sleeve are provided with a gas supply hole communicating with the second ring groove.

6. The spindle seal structure of claim 1, wherein, The bearing comprises an upper bearing, the main body comprises an upper bearing seat, the upper bearing is arranged in the upper bearing seat, the shaft core assembly is provided with a sealing end cover extending outside the upper bearing seat, the upper bearing seat is provided with a third ring groove, the sealing end cover is provided with a convex ring, the convex ring is embedded in the third ring groove, and a labyrinth sealing structure is formed between the upper bearing seat and the sealing end cover.

7. The spindle seal structure of claim 6, wherein, The wall surface of the upper bearing seat towards the sealing end cover is provided with a fourth ring groove, and the fourth ring groove is provided with a second plastic ring in clearance fit with the sealing end cover.

8. The spindle seal structure of claim 6, wherein, The sealing end cover is connected to the shaft core assembly and axially locks the inner ring of the upper bearing.

9. An electric spindle, characterized by The main shaft sealing structure comprises any one of claims 1-8.

10. A machine tool, characterized by The electric main shaft comprises claim 9.

Images