Spindle unit tail end fixing structure

Abstract

This utility model discloses a spindle unit tail end fixing structure, including a housing, a spindle unit, and a tightening cover. The spindle unit is axially rotatably mounted in the housing with a clearance fit. The tightening cover is fixed to the tail end of the housing by a first screw. The tail end of the spindle unit has an outer conical surface near the inner side of the tightening cover, and the inner side of the tightening cover has an inner conical surface that mates with the outer conical surface. This utility model provides sufficient axial and radial clearance between the tightening cover and the housing, reducing the machining accuracy requirements for the spindle unit and housing mounting holes, thus lowering assembly difficulty and processing costs. Furthermore, the mating of the inner and outer conical surfaces ensures that the tightening cover can be reliably pressed onto the tail end of the housing, improving assembly accuracy and preventing deformation caused by the clearance between the spindle unit and the housing during transmission. This reduces mechanical vibration and wear, extending the service life of the spindle unit.

Description

Technical Field

[0001] This utility model relates to the field of machine tool spindle installation technology, and in particular to a spindle unit tail end fixing structure. Background Technology

[0002] Currently, the tail-end mounting of machine tool spindle units on the market typically uses nut locking and pressure cap clamping methods. For example, a spindle mounting structure disclosed in patent CN206882797U has an end cap on one side of the housing, which is fixed to the housing with screws. This fastening method places high demands on the machining of the tail end face and mating inner hole of the housing, requiring precision machining or even scraping of the end face to ensure its flatness and perpendicularity to the axis, which increases production costs for machine tool manufacturers.

[0003] On the other hand, there are also strict requirements for the clearance between the outer circle of the spindle unit and the mounting hole of the housing. Since the tail end of the spindle unit is the power output end of the spindle box, it is usually connected to transmission components such as pulleys or gears. Therefore, the installation structure between the tail end of the spindle unit and the housing has higher requirements. If the clearance between the outer circle of the spindle unit and the mounting hole of the housing is too large, it will cause insufficient rigidity and excessive vibration during machine tool operation, resulting in surface rippling and reduced accuracy during workpiece processing. Furthermore, the vibration of the machine tool will cause premature bearing damage, greatly reducing the service life of the bearings and causing extreme waste. Conversely, if the clearance is too small, it will make it difficult to install the spindle unit during assembly, increasing the difficulty of assembly.

[0004] Therefore, the existing installation and fixing methods of machine tool spindle units and housings need to be improved. Utility Model Content

[0005] The purpose of this invention is to provide a spindle unit tail end fixing structure to solve the problems in the prior art, such as high requirements for spindle and housing machining accuracy, high production cost, short service life, and difficult assembly.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A spindle unit tail end fixing structure includes a housing, a spindle unit, and a tightening cover. The spindle unit is rotatably mounted in the housing along the axial direction and the two are in clearance fit. The tightening cover is fixed to the tail end of the housing by a first screw. The tail end of the spindle unit is provided with an outer conical surface near the inner side of the tightening cover. The inner side of the tightening cover is provided with an inner conical surface that mates with the outer conical surface. In the initial state, there is an axial gap between the tightening cover and the tail end face of the housing. As the first screw is tightened, the axial gap is completely eliminated, so that the tightening cover and the tail end face of the housing fit tightly together.

[0008] Furthermore, the expansion cap includes an annular end cap and a positioning ring disposed inside the annular end cap. The annular end cap has a plurality of through threaded holes spaced apart along the circumferential direction. The inner conical surface is disposed on the inner wall of the positioning ring. The positioning ring has a plurality of slots spaced apart along the circumferential direction.

[0009] Furthermore, the inner diameter of the annular end cap is smaller than the inner diameter of the positioning ring, and a stop portion is formed between the two, which is engaged with the shoulder of the spindle unit.

[0010] Furthermore, the front end of the spindle unit is fixedly connected to the housing by a second screw.

[0011] Furthermore, a transmission component is provided at the tail end of the main spindle unit located on the outside of the housing.

[0012] Compared with the prior art, the beneficial effects of this utility model are:

[0013] The expansion cap of this invention has sufficient axial and radial clearances between itself and the housing, which reduces the machining accuracy requirements for the spindle unit and the housing mounting holes, thereby reducing assembly difficulty and machining costs. Furthermore, the fit between the inner and outer conical surfaces ensures that the expansion cap can be reliably pressed onto the tail end of the housing, improving assembly accuracy and preventing deformation caused by the gap between the spindle unit and the housing during transmission. This reduces mechanical vibration and wear, and extends the service life of the spindle unit. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 This is an axial structural cross-sectional view of the present invention;

[0016] Figure 2 for Figure 1 Enlarged view of the local structure at point A;

[0017] Figure 3 This is a schematic diagram of the end face structure of the expansion and tightening cap in this utility model;

[0018] Figure 4 This is an axial structural cross-sectional view of the expansion and tightening cap in this utility model.

[0019] Figure label:

[0020] 1-Box body, 2-Main spindle unit, 21-Outer conical surface, 3-Tightening cover, 31-Inner conical surface, 32-Annular end cover, 33-Positioning ring, 34-Threaded hole, 35-Slot, 36-Stop part, 4-First screw, 5-Second screw, 6-Transmission component. Detailed Implementation

[0021] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0022] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in this utility model embodiment are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0023] Furthermore, the use of terms such as "first" and "second" in this utility model is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features.

[0024] In the description of the embodiments, unless otherwise expressly specified and limited, the terms "set," "connect," etc., should be interpreted broadly. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or a connection through an intermediate medium, or it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0025] like Figure 1 As shown, the spindle unit tail end fixing structure in this embodiment includes a housing 1, a spindle unit 2, and a shrinking cover 3. The spindle unit 2 is rotatably disposed in the housing 1 along the axial direction and the two are in clearance fit. The clearance fit facilitates the assembly of the spindle unit 2 into the housing 1, and also reduces the machining accuracy requirements of the outer circle of the spindle unit 2 and the mounting hole of the housing 1, which helps to reduce machining costs.

[0026] In this embodiment, the spindle unit 2 is a conventional technical means in the field, which integrates structures such as spindle, bearing, and transmission device. For example, the electric spindle commonly used in the field can also be considered as a spindle unit.

[0027] The expansion cap 3 is fixedly installed at the tail end of the housing 1 by the first screw 4. The housing at the front end of the main shaft unit 2 is fixedly connected to the housing 1 by the second screw 5. The main shaft unit 2 is provided with a transmission component 6 at the position outside the housing 1 at the tail end. The transmission component 6 includes, but is not limited to, structures such as pulleys, gears or sprockets.

[0028] like Figure 2 As shown, the tail of the spindle unit 2 is provided with an outer conical surface 21 near the inner side of the expansion and tightening cover 3, and the inner side of the expansion and tightening cover 3 is provided with an inner conical surface 31 that cooperates with the outer conical surface 21.

[0029] like Figure 3-4 As shown, the expansion and tightening cover 3 includes an annular end cover 32 and a positioning ring 33 disposed inside the annular end cover 32. The annular end cover 32 is provided with a plurality of through threaded holes 34 spaced along the circumferential direction. The first screw 4 passes through the threaded holes 34 and connects to the outer wall of the housing 1.

[0030] The inner conical surface 31 is provided on the inner wall of the positioning ring 33, and the positioning ring 33 is provided with multiple slots 35 at intervals along the circumferential direction.

[0031] The inner diameter of the annular end cap 32 is smaller than the inner diameter of the positioning ring 33, and a stop portion 36 is formed between the two. The stop portion 36 is engaged with the shoulder of the spindle unit 2.

[0032] like Figure 2 As shown, in the initial state, there is an axial gap L between the expansion cap 3 and the tail end face of the box 1. As the first screw 4 is tightened, the axial gap L is completely eliminated, so that the expansion cap 3 and the tail end face of the box 1 fit tightly together.

[0033] As the expansion cap 3 moves inward toward the housing 1, the outer conical surface 21 and the inner conical surface 31 engage with each other. Because the positioning ring 33 has multiple slots 35, it undergoes moderate deformation. Through the engagement of the two conical surfaces, the spindle unit 2 is securely fixed within the mounting hole of the housing 1. This method improves assembly accuracy and prevents deformation caused by gaps between the spindle unit 2 and the housing 1 during transmission, thereby reducing mechanical vibration and wear and extending the service life of the spindle unit 2.

[0034] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this utility model should be included within the protection scope of this utility model. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the protection scope claimed by this utility model.

Claims

1. A tail end fixing structure for a spindle unit, characterized in that: The device includes a housing, a main spindle unit, and a tightening cover. The main spindle unit is rotatably mounted in the housing with a clearance fit. The tightening cover is fixed to the tail end of the housing by a first screw. The tail end of the main spindle unit has an outer conical surface near the inner side of the tightening cover. The inner side of the tightening cover has an inner conical surface that mates with the outer conical surface. Initially, there is an axial gap between the tightening cover and the tail end face of the housing. As the first screw is tightened, the axial gap is completely eliminated, making the tightening cover fit tightly against the tail end face of the housing.

2. The spindle unit tail end fixing structure according to claim 1, characterized in that: The expansion and tightening cap includes an annular end cap and a positioning ring disposed inside the annular end cap. The annular end cap has a plurality of through threaded holes spaced apart along the circumferential direction. The inner conical surface is disposed on the inner wall of the positioning ring. The positioning ring has a plurality of slots spaced apart along the circumferential direction.

3. The spindle unit tail end fixing structure according to claim 2, characterized in that: The inner diameter of the annular end cap is smaller than the inner diameter of the positioning ring, and a stop portion is formed between the two. The stop portion is engaged with the shoulder of the spindle unit.

4. The spindle unit tail end fixing structure according to claim 1, characterized in that: The front end of the spindle unit is fixedly connected to the housing by a second screw.

5. The spindle unit tail end fixing structure according to claim 1, characterized in that: The main spindle unit has a transmission component located at the tail end of the outer side of the housing.

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