CN105014104A - External-adjustable constant-pressure pre-tightening device for motorized spindle - Google Patents

Abstract

The invention discloses an external adjustable constant pressure pretensioning device of an electric spindle. It consists of housing, bearing support system and preload adjustment system; the bearing support system is composed of bearings, inner and outer spacers, bearing housings, linear bearings, fastening bolts, etc.; the preload adjustment system is composed of spring baffles, bolts, connecting plates , Adjusting bolts; the spring baffle is installed inside the shell, and the ears of the spring baffle are connected to the connecting plate through bolts, and the adjusting bolt protrudes from the back cover of the electric spindle through the hole in the connecting plate; it can be adjusted in real time by rotating the adjusting bolt during work. The preload applied to the bearing. The present invention can adjust the axial preload of the electric spindle bearing in real time according to different rotation speeds and different loads by setting an external adjustable constant pressure pretightening force mechanism between the electric spindle shell and the bearing seat, so that the electric spindle can always be at the optimum position. The ideal working condition reduces the heating inside the bearing and prolongs the service life. The pretightening force of the present invention is externally adjustable and convenient to operate, and at the same time avoids the required external complex device in the way of adjusting the pretightening force through electromagnetic or hydraulic pressure.

Description

An External Adjustable Constant Pressure Preloading Device for Electric Spindle

technical field

The present invention relates to the field of mechanical equipment, in particular to an external adjustable constant pressure pretensioning device of an electric spindle.

Background technique

As the key component of CNC machine tools, the electric spindle is widely used. According to the characteristics of CNC machine tools, the electric spindle is required to adapt to high-speed cutting on the one hand. In high-speed cutting, it is generally finishing machining. The cutting amount is small and the speed is high. The spindle is under less force. The spindle bearing can meet the requirements under a small pre-tightening force; on the other hand, the electric spindle must meet the low-speed cutting requirements of the machine tool. At this time, it is often rough machining and the cutting volume is large. Larger cutting force of the machine tool. According to the requirements of the working conditions of the spindle, real-time adjustment of the preload of the electric spindle can improve the internal stress state of the bearing, and can also reduce the heat generation of the bearing and the resulting thermal deformation, thereby prolonging the service life of the bearing.

At present, the preload application methods of electric spindle bearings mainly include positioning preload, constant pressure preload, and preload application through electromagnetic or hydraulic control; positioning preload and constant pressure preload determine the preload of the bearing during the assembly stage. , it cannot be adjusted in real time according to the cutting conditions of different working speeds of the spindle during use; the preload application of electromagnetic control requires an electromagnetic proportional valve and an external power supply, and the preload application of hydraulic control requires a large number of external hydraulic devices; therefore, it is necessary Develop a simple and convenient preloading device that can be adjusted outside the main shaft to improve the internal stress of the bearing to meet the requirements of different working conditions at different speeds.

Contents of the invention

The purpose of the present invention is to overcome the limitations of the traditional electric spindle bearing preload, and provide an external adjustable constant pressure preload device for the electric spindle. The pre-tightening force of the bearing makes the electric spindle adapt to different working conditions and prolongs its service life.

For achieving the above object, technical scheme of the present invention is:

An external adjustable constant pressure preloading device for an electric spindle, including a housing, a rotating shaft, a bearing support system and an external adjustable constant pressure preloading system; it is characterized in that the bearing support system includes a bearing, a fastening nut, Inner spacer, outer spacer, bearing seat and linear bearing, the bearings are a pair of angular contact ball bearings arranged in the same direction facing the middle of the rotating shaft, the two bearings are connected by the inner spacer and the outer spacer and are connected by the shaft shoulder and the fastening screw The cap is fixed; the bearing is placed in the bearing seat, and the bearing seat is placed in the shaft housing through the linear bearing; there is an external adjustable constant pressure preload system including springs, spring baffles, bolts, connecting plates, springs and adjusting bolts, the The spring is a wave spring, and the spring is a ring spring. The four lugs of the spring baffle are placed in the groove of the shaft housing and connected to the connecting plate by bolts. The adjusting bolts pass through the connecting plate in turn, and the spring is connected to the rear cover through threads. When working, the initial preload of the bearing preload spring can be adjusted by rotating the adjusting bolt outside the shaft housing.

Compared with the prior art, the present invention has the following outstanding substantive features and significant progress:

(1) Change the preload exerted by the internal spring baffle of the electric spindle on the preload spring through the external adjustment bolt. When the bearing is working, the constant pressure preload of the spring can ensure the constant pressure preload according to the thermal deformation of the shaft, so as to realize the The external adjustable internal constant pressure preload function of the main shaft.

(2) The external complicated adjustment device and the required supporting power supply or hydraulic system are avoided, and the internal pretightening force can be adjusted in real time only by rotating the external adjustment bolt. The device of the present invention has the characteristics of simplicity and practicality.

Description of drawings

Fig. 1 is a structural schematic diagram of an embodiment of the present invention.

Fig. 2 is a sectional view of the spring stopper in Fig. 1 .

Fig. 3 is a schematic diagram of the connection board in Fig. 1 .

Each symbol in the figure means:

1. Shaft housing 2. Linear bearing

3. Bearing seat 4. Bearing

5. Shaft 6. Inner spacer

7. Outer spacer 8. Fastening nut

9. Spring baffle 10. Spring

11. Bolts 12. Connecting plate

13. Back cover 14. Spring

15. Adjust the bolt.

Implementation

Preferred embodiment of the present invention is described as follows in conjunction with accompanying drawing 1:

Embodiment one:

Referring to Figures 1 to 3, the external adjustable constant pressure preloading device of the electric spindle includes a housing, a rotating shaft 5, a bearing support system and an external adjustable constant pressure preloading system; it is characterized in that: the bearing support The system includes a bearing 4, a fastening nut 8, an inner spacer 6, an outer spacer 7, a bearing housing 3 and a linear bearing 2. The bearing 4 is a pair of angular contact ball bearings arranged in the same direction facing the middle of the rotating shaft. It is connected by the inner spacer 6 and the outer spacer 7 and fixed by the shaft shoulder and the fastening nut 8; the bearing 4 is placed in the bearing seat 3, and the bearing seat 3 is placed in the shaft shell 1 through the linear bearing 2; there is an external adjustable The constant pressure pretensioning system comprises a spring 10, a spring baffle 9, a bolt 11, a connecting plate 12, a spring 14 and an adjusting bolt 15, the spring 10 is a wave spring, the spring 14 is a ring spring, and the four parts of the spring baffle 9 The lugs are placed in the groove of the shaft housing 1 and connected to the connecting plate 12 by bolts 11. The adjusting bolts 15 pass through the connecting plate 12 in turn, and the springs 14 are connected to the rear cover 13 through threads. Bolt to adjust the initial preload of the bearing preload spring.

Embodiment two:

Referring to Fig. 1 to Fig. 3, the external adjustable constant pressure preloading device of the electric spindle is composed of housing, bearing support system, preload adjustment system and other components; the bearing support system consists of bearing 4, inner spacer 6 and outer spacer 7. The bearing seat 3, the linear bearing 2, the fastening bolt 8, etc.; During installation, the bearing seat 3 forms a shoulder at the rear end, and the wave spring 10 is placed on the bearing seat 3. The ears of the spring baffle 9 are placed in the groove of the housing 1, and the spring baffle 9 presses the bearing through the wave spring 10. Seat 3, the ear portion of spring baffle is connected with bolt 11. Bearing seat 3 is placed in housing 1 through linear bearing 2, bearing 4 is placed in bearing seat 3 through inner spacer 6 and outer spacer 7, and rotating shaft 5 is placed in bearing 4 and connected by fastening nut 8. The spring baffle 9 is connected with the connecting plate 12 through the bolt 11, the adjusting bolt 15 passes through the central hole of the connecting plate 12, puts on the annular spring 14 and passes through the central bolt hole of the back cover, and the adjusting bolt 15 has a slot for easy rotation and adjustment Bolt 15.

When it is necessary to adjust the bearing pretightening force, the displacement of the connecting plate 12 can be changed by rotating the adjusting bolt 15 outside the shaft housing, and the spring baffle 9 is driven by the bolt 11 to move to change the pretightening force of the spring 10 on the bearing seat; When the pre-tightening force is large, rotate the adjusting bolt 15 to move the connecting plate 12 toward the rear cover 13, that is, increase the pressing force of the spring baffle 9 on the spring 10; when reducing the pre-tightening force, rotate the adjusting bolt 15 to retract into the shaft housing , The spring 10 pushes the connecting plate 12 to move into the shaft housing to drive the bolt 11 and the spring baffle 9 to move to the middle of the shaft housing, reducing the compression of the spring 10 so as to reduce the pre-tightening force. Therefore, the pretightening force of the internal bearing of the electric spindle is jointly controlled by the adjusting bolt 15 and the wave spring 10 .

The above is only a preferred embodiment of the present invention, and does not limit the present invention in any way, but any simple modifications, changes and equivalent structural changes made by those skilled in the art to the above embodiments according to the essence of the technology of the present invention , all still belong to the protection scope of the technical solution of the present invention.

Claims (1)

1. An external adjustable constant pressure preloading device for an electric spindle, including a housing, a rotating shaft (5), a bearing support system and an external adjustable constant pressure preloading system; it is characterized in that: the bearing support system includes a bearing ( 4), fastening nut (8), inner spacer (6), outer spacer (7), bearing seat (3) and linear bearing (2), the bearing (4) is a pair of angular contact ball bearings Arranged facing the middle of the rotating shaft in the same direction, the two bearings are connected by the inner spacer (6) and the outer spacer (7) and fixed by the shaft shoulder and the fastening nut (8); the bearing (4) is placed in the bearing seat (3) , the bearing seat (3) is placed in the shaft housing (1) through the linear bearing (2); there is an external adjustable constant pressure preload system including springs (10), spring baffles (9), bolts (11), connections Plate (12), spring (14) and adjusting bolt (15), the spring (10) is a wave spring, the spring (14) is a ring spring, and the four lugs of the spring baffle (9) are placed on the shaft housing (1) In the groove and connected to the connecting plate (12) by the bolt (11), the adjusting bolt (15) passes through the connecting plate (12) and the spring (14) in turn to connect to the back cover (13) through threads, During work, the initial preload of the bearing preload spring can be adjusted by rotating the adjusting bolt outside the shaft housing.