High-speed high-precision grinding machine spindle structure

Abstract

The utility model provides a high-speed and high-precision grinding machine main shaft structure which aims at solving the problem that in the prior art, a grinding machine main shaft structure is prone to heating under the working condition of high-speed operation, and consequently precision is reduced. The motor mainly comprises a main shaft shell, a core shaft, a rotor, a stator, two pairs of bearing pack supports, a front end cover, a rear housing, a water inlet and a water outlet, wherein the water inlet and the water outlet are formed in the rear housing; a cooling water channel for connecting the water inlet and the water outlet is distributed in the main shaft shell; compact design is adopted in the radial direction of the main shaft structure, the overall size is small, during high-speed operation, the cooling water channel can effectively dissipate heat, preload is applied to the bearing through the spring to compensate thermal extension of the main shaft, and the overall thermal deformation of the main shaft is small; an angular contact ball bearing combination is selected for bearing pairing, heating is little, axial rigidity and radial rigidity are both considered, 72 series bearings are adopted, the bearing capacity is higher, friction force generated by the taper of a Morse taper shank is used for fixing, and the connecting effect is more stable.

Description

TECHNICAL FIELD

[0001] The utility model relates to lathe main shaft technical field especially is related to a high -speed high -precision grinding machine main shaft structure. BACKGROUND

[0002] The grinding wheel spindle can support the grinding wheel and make it rotate at high speed, thereby ensuring that the distance between the axis of the grinding wheel and the surface of the workpiece and the size of the clamping force have precision and stability, and can be used in the field of high-precision machining such as machining gauges that require mirror surface effect.

[0003] The existing main shaft structure based on the stator and the rotor has the problem of heating during high-speed operation, which easily causes thermal deformation of the whole main shaft, thereby affecting the machining precision. SUMMARY

[0004] The present application provides a high-speed high-precision grinding machine main shaft structure to solve the above-mentioned problems in the prior art, which adopts a compact design and has a small overall volume. The cooling water channel can effectively dissipate heat during high-speed operation, and the bearing is preloaded by means of a spring to compensate for the thermal elongation of the main shaft, so that the overall thermal deformation of the main shaft is small.

[0005] The utility model discloses a technical scheme for solving the above technical problems:

[0006] A high-speed high-precision grinding machine main shaft structure, comprising a main shaft shell and a mandrel arranged at the rotation center, the mandrel is interference fitted with a rotor, the rotor outer ring is fitted with a stator, the front and rear ends of the mandrel are supported by two pairs of bearing sets, the outer side of the front end bearing set is provided with a front end cover, the rear end bearing set is provided with a rear cover shell, the rear cover shell is provided with a water inlet and a water outlet, and the inner part of the main shaft shell is distributed with a cooling water channel connecting the water inlet and the water outlet.

[0007] Further, the main shaft shell is a thin-walled hollow structure, the water inlet of the rear cover shell enters the main shaft shell in two symmetrical branches, the branches are arranged reciprocally from the rear end to the front end of the main shaft shell, and the branches are arranged along the circumference of the main shaft in cross section, and the two branches finally converge to the water outlet for discharge.

[0008] Further, each group of bearing sets comprises two groups of angular contact ball bearings arranged oppositely, and the axial direction between the opposite angular contact ball bearings is spaced by a bearing inner spacer and a bearing outer spacer.

[0009] Further, the inner ring of each group of bearing sets is pre-tightened by a bearing lock nut, the outer ring of the bearing set located at the front end is positioned and pre-tightened by a pressure ring and a front end cover, and the outer ring of the bearing set located at the rear end is pre-tightened by a wave spring.

[0010] Further, the front end of the mandrel is threadedly connected with a grinding rod, and the working end of the grinding rod is connected with a grinding wheel.

[0011] Further, the grinding rod is a Morse taper shank matched with the mandrel.

[0012] Further, the tail end of the rotor is further provided with a rotor tail end spacer, and the bearing seat at the rear end is further provided with a tail end bearing sliding sleeve relative to the main shaft shell, the rear cover shell is provided with a cable socket, and the cable of the cable socket is connected to the stator through the tail end bearing sliding sleeve.

[0013] Further, the air-tight sealing assembly comprises an air inlet provided on the rear cover shell and two air outlets provided on the bearing seats of the front end bearing set, and the air inlet and the air outlets are communicated through an air path provided on the main shaft shell.

[0014] The beneficial effects of the main shaft structure of the utility model relative to the prior art are as follows:

[0015] 1) The main shaft structure of the utility model is designed in a compact radial mode, and has a small overall volume.

[0016] 2) The main shaft structure of the utility model can effectively dissipate heat through the cooling water channel when running at high speed, and the bearing is preloaded by means of a spring to compensate for the thermal elongation of the main shaft, so that the overall thermal deformation of the main shaft is small.

[0017] 3) On the basis of ensuring high-speed operation, the rigidity is high. The bearing of the utility model is combined by selecting angular contact ball bearings, has less heat generation, and has axial and radial rigidity, has higher bearing capacity by using 72 series bearings, and is fixed by using the friction force generated by the Morse taper shank taper, and the connection effect is more stable. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 It is a first perspective three-dimensional structure schematic view of the utility model;

[0019] Figure 2 It is a second perspective three-dimensional structure schematic view of the utility model;

[0020] Figure 3 It is a main shaft shell structure schematic view of the utility model;

[0021] Figure 4 It is an internal structure schematic view of the utility model;

[0022] Figure 5 It is a structure schematic view of the rear cover shell in the utility model;

[0023] Figure 6 It is a structure schematic view of the front end cover in the utility model;

[0024] Figure 7 It is a sectional view of the front end cover in the utility model.

[0025] Wherein: 1, main shaft shell; 2, mandrel; 3, rotor; 4, stator; 5, bearing group; 6, front end cover; 7, rear cover; 8, water inlet; 9, water outlet; 10, bearing inner spacer; 11, bearing outer spacer; 12, bearing lock nut; 13, pressure ring; 14, wave spring; 15, grinding rod; 16, grinding wheel; 17, rotor tail end spacer; 18, tail end bearing sliding sleeve; 19, cable socket; 20, air inlet; 21, air outlet. DETAILED DESCRIPTION

[0026] The specific implementation of the utility model will be described below in combination with the drawings.

[0027] The utility model provides a kind of high-speed high-precision grinding machine main shaft structure, to solve the problem of the grinding machine main shaft structure of prior art in high-speed operation condition is easy to heat, to cause precision to reduce.

[0028] As Figures 1 to 7 Indicated, the utility model includes main shaft shell 1 and is arranged in the mandrel 2 of rotation center, the rotor 3 is interference fit on the mandrel 2, the stator 4 is cooperated with the outer circle of rotor 3, the front and rear ends of mandrel 2 are supported by two pairs of bearing group 5, the bearing group 5 outside of front end is provided with front end cover 6, the rear end of bearing group 5 is provided with rear cover 7, the rear cover 7 is provided with water inlet 8 and water outlet 9, the inside of main shaft shell 1 is distributed with the cooling water channel of connecting water inlet 8 and water outlet 9.

[0029] In an embodiment of the utility model, main shaft shell 1 is thin-walled hollow structure, the water inlet 8 of rear cover 7 is divided into two symmetrical branch paths on main shaft shell 1, the branch path is reciprocatingly arranged from the rear end to the front end of main shaft shell 1, and the branch path is arranged along the circumference of main shaft in cross section, and the two branch paths are finally converged to water outlet 9 and discharged.

[0030] In an embodiment of the utility model, each bearing group includes two pairs of angular contact ball bearings arranged oppositely, and the axial direction between the opposite angular contact ball bearings is separated by bearing inner spacer 10 and bearing outer spacer 11.

[0031] In an embodiment of the utility model, the inner ring of each bearing group 5 is pre-tightened by bearing lock nut 12, the outer ring of bearing group 5 located at the front end is positioned and pre-tightened by pressure ring 13 and front end cover 6, and the outer ring of bearing group 5 located at the rear end is pre-tightened by wave spring 14.

[0032] In an embodiment of the utility model, the front end of mandrel 2 is threadedly connected with grinding rod 15, and the working end of grinding rod 15 is connected with grinding wheel 16.

[0033] In an embodiment of the utility model, the grinding rod 15 is a Morse taper shank matched with the mandrel 2.

[0034] In an embodiment of the utility model, the tail end of the rotor 3 is further provided with a rotor tail end spacer 17, and the bearing seat at the rear end is further provided with a tail end bearing sliding sleeve 18 between the main shaft shell 1, the rear cover shell 7 is provided with a cable socket 19, and the cable of the cable socket 19 is connected to the stator 4 through the tail end bearing sliding sleeve 18.

[0035] In an embodiment of the utility model, further include airtight seal assembly, the airtight seal assembly includes the air inlet 20 of setting on the rear cover shell 7 and the two air outlets 21 of setting on the bearing seat of the front end bearing set 5, the air inlet 20 is communicated with the air outlet 21 through the air path of setting on the main shaft shell 1.

[0036] The specific structure and working principle of the utility model are as follows:

[0037] The main shaft structure provided by the utility model adopts front 2 rear 2 angular contact ball bearing pairing, the front and rear 2 groups of bearings are assembled on the mandrel 2, are separated by a spacer in the middle, the inner ring is pre-tightened by a lock nut, the outer ring of the front end bearing set 5 is positioned and pre-tightened by using a pressing ring 13 and a front end cover 6, the rear end bearing set 5 is pre-tightened by using a wave spring 14, the grinding rod 15 is connected on the mandrel 2 by screwing, the grinding rod 15 is matched with the mandrel 2 by a Morse taper shank, and the grinding wheel 16 is fixed on the grinding rod 15. The rotor 3 is interference-fitted on the mandrel 2 and opposite to the stator 4. The stator 4 coil shell and the front end bearing seat adopt integrated design, the tail end bearing sliding sleeve 18 of the rear bearing seat is slidable, the water pipe and the gas pipe interface are connected into the rear cover shell 7, the rear cover shell 7 is provided with a hole in the middle, the mandrel 2 can be conveniently disassembled by fixing the mandrel 2 by using the inner hexagon in the center. Through the above technical scheme, the tail end bearing sliding sleeve 18 is slidable, the wave spring 14 is matched to apply pre-load to the bearing set 5 to compensate for the thermal elongation of the main shaft, so that the overall thermal deformation of the main shaft is small.

[0038] It should be noted that the bearing pairing of the utility model selects angular contact ball bearing combination, has less heat generation and considers axial and radial rigidity, adopts 72 series bearing with higher bearing capacity, and is further fixed by using the friction force generated by the Morse taper shank, so that the connection effect is more stable.

[0039] Cooling water channel design and principle: since the main shaft shell 1 adopts thin-wall design, the hollow pipeline inside the shell is used for cooling water channel design, two water pipe interfaces are symmetrically designed on the rear cover shell 7, the water pipe interfaces are connected to the water pipe, and the water pipe is connected to the water tank. Figures 4-6As shown, the water inlet 8 and the water outlet 9 are respectively arranged, four water holes and four groups of waist-shaped holes are arranged on the end face of the rear cover 7, and six groups of waist-shaped holes are arranged on the end face of the front end cover 6, so that three cooling water channels capable of reciprocating through the main shaft shell 1 are formed, which are water channel A1, water channel A2 and water channel A3 in sequence. First, the cooling water enters the water inlet 8, directly passes through the pipeline penetrating the shell and then passes through the front end cover 6, and then flows back to the next pipeline through the waist-shaped groove of the front end cover 6 and then flows back to the rear cover 7. After three cycles, the two loops meet at the water outlet 9 and are discharged out of the rear cover 7.

[0040] Structure and principle of the air-tight sealing assembly: as shown, the air inlet 20 is arranged on the rear cover 7, and the gas enters the hollow pipeline in the main shaft shell 1 from the air inlet 20 and is sprayed from the two opposite air outlets 21 arranged on the inner side of the front bearing seat corresponding to the front end cover 6, so that the front bearing seat is air-tightly sealed.

[0041] The above description is an explanation of the utility model, not a limitation of the utility model, and the scope defined by the utility model is referred to the claims. Within the protection scope of the utility model, any form of modification can be made.

Claims

1. A high-speed, high-precision grinding machine spindle structure, characterized in that: The spindle housing (1) includes a spindle housing (1) and a spindle (2) located at the center of rotation. A rotor (3) is interference-fitted on the spindle (2). A stator (4) is fitted on the outer ring of the rotor (3). The front and rear ends of the spindle (2) are supported by two pairs of bearing assemblies (5). A front cover (6) is provided on the outer side of the bearing assembly (5) at the front end. A rear cover (7) is provided on the bearing assembly (5) at the rear end. A water inlet (8) and a water outlet (9) are provided on the rear cover (7). Cooling water channels connecting the water inlet (8) and the water outlet (9) are distributed inside the spindle housing (1).

2. The high-speed, high-precision grinding machine spindle structure as described in claim 1, characterized in that: The main shaft housing (1) is a thin-walled hollow structure. The water inlet (8) of the rear cover (7) enters the main shaft housing (1) through two symmetrical branches. The branches are arranged back and forth from the rear end to the front end of the main shaft housing (1), and the branches are arranged circumferentially along the main shaft in the cross section. The two branches eventually converge to the outlet (9) for discharge.

3. The high-speed, high-precision grinding machine spindle structure as described in claim 1, characterized in that: Each bearing group (5) includes two sets of angular contact ball bearings arranged opposite each other, with the axial spacing between the opposite angular contact ball bearings being the inner spacer (10) and the outer spacer (11).

4. The high-speed, high-precision grinding machine spindle structure as described in claim 1, characterized in that: The inner ring of each bearing assembly (5) is pre-tightened by the bearing lock nut (12), the outer ring of the bearing assembly (5) at the front end is pre-tightened by the pressure ring (13) and the front end cover (6), and the outer ring of the bearing assembly (5) at the rear end is pre-tightened by the wave spring (14).

5. The high-speed, high-precision grinding machine spindle structure as described in claim 1, characterized in that: The front end of the mandrel (2) is threadedly connected to a grinding rod (15), and the working end of the grinding rod (15) is connected to a grinding wheel (16).

6. The high-speed, high-precision grinding machine spindle structure as described in claim 5, characterized in that: The grinding rod (15) is a Morse taper shank that fits with the mandrel (2).

7. The high-speed, high-precision grinding machine spindle structure as described in claim 1, characterized in that: The rotor (3) is also provided with a rotor tail end spacer (17) at the tail end, and a tail end bearing sleeve (18) is provided between the rear bearing seat and the main shaft housing (1). A cable socket (19) is provided on the rear cover (7), and the cable of the cable socket (19) is connected to the stator (4) through the tail end bearing sleeve (18).

8. The high-speed, high-precision grinding machine spindle structure as described in claim 1, characterized in that: It also includes an air seal assembly, which includes an air inlet (20) on the rear cover (7) and two air outlets (21) on the bearing seat of the front bearing assembly (5). The air inlet (20) and the air outlets (21) are connected by an air passage on the spindle housing (1).

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