CN204603915U - Ball screw integral bearing mechanism - Google Patents

Abstract

The utility model discloses an integral bearing mechanism for a ball screw, which comprises: a screw, the end of which is provided with a shaft shoulder, and the shaft shoulder is provided with a threaded part; hole, the step-shaped through hole is composed of large and small round holes, and the large and small round holes are coaxially arranged; the bearing group is composed of at least two bearings of the same type, and the bearing group is installed in the large round hole; Cover, which is a disc-shaped structure with a shaft hole in the center of the circle. A cylindrical boss is provided at one end of the gland. The end face fits; the lock nut is matched and installed with the threaded part of the screw rod; wherein, the inner end surface of the bearing group fits with the stepped surface formed by the large and small round holes, and the inner end surface of the lock nut Fitted with the outer end surface of the gland. The utility model greatly enhances the bearing contact rigidity and high-precision and stable gyration performance, and the stability of the positioning accuracy is good.

Description

Integral bearing mechanism for ball screw

technical field

The utility model relates to a screw rod supporting device, in particular to an integral bearing mechanism for a ball screw rod.

Background technique

The ball screw pair is a mechanical element composed of screw, nut, ball and other parts. It is a screw transmission element with balls as the rolling body between the screw and the nut. The ball screw pair is the most commonly used transmission element on precision machine tools. It is an ideal product for converting the rotary motion of the screw into the linear motion of the nut, or converting the linear motion of the nut into the rotary motion of the screw. At the same time, it has high Characterized by precision, reversibility and high efficiency.

In order to obtain high transmission accuracy for the feed system of precision machine tools, in addition to the rigidity requirements of the ball screw itself, the correct installation and support mechanism of the ball screw should not be underestimated. In the existing machine tools, there are generally four ways to install and fix the ball screw: (1) "fixed-fixed" type, the two ends of this form are respectively restrained by a pair of bearings in the axial and radial degrees of freedom, and the load is controlled by two sets of bearings. The bearing pairs are shared, and the bearing pairs at both ends can also bear the reverse pre-tension force, thereby improving the transmission rigidity, which is suitable for high-speed and high-precision occasions; (2) "fixed-swimming" type, one end of which is composed of a pair of The axial and radial degrees of freedom are constrained by bearings, and the radial degree of freedom is constrained by a single bearing at the other end. The load is borne by a pair of bearing pairs. The single floating bearing can prevent the deflection of the cantilever and absorb the stress caused by thermal changes. It is suitable for For occasions with medium speed and high precision; (3) "Support-support" type, a bearing is arranged at both ends of this form to bear radial force and single-direction axial force respectively. With the change of load direction, two bearings are respectively provided The bearing alone bears the force in a certain direction, which is suitable for occasions with medium speed and medium precision; (4) "fixed-free" type, one end of which is constrained by a pair of bearings in the axial and radial degrees of freedom, and the other end is suspended in the air to form a free State and load are borne by the same pair of bearings, and it is necessary to overcome the bending moment caused by the centrifugal force of the screw rotation. It is suitable for occasions with low speed, medium precision and short axial length. The utility model is mainly elaborated on the "fixed-fixed" installation method.

The overall rigidity of the ball screw pair using the "fixed-fixed" installation method is mainly affected by factors such as the inherent stiffness of the screw, bearing stiffness, bearing clearance, and the clearance between the bearing and the bearing sleeve. Since the inherent rigidity of the screw and the rigidity of the bearing are fixed and immutable, the overall rigidity of the ball screw can only be improved by eliminating or reducing the clearance between the bearing and the clearance between the bearing and the bearing sleeve. In the final analysis, it depends on the preload of the bearing. way of applying force.

At present, the assembly of the ball screw support bearings of the various motion axes of domestic CNC machine tools is carried out at the assembly site. Due to improper adjustment of the bearing clearance, when the bearing is installed in the bearing sleeve, the end face of the outer ring of the bearing and the end face of the bearing sleeve, the end face of the inner ring of the bearing and the ball The step surface of the screw shaft is prone to gaps, and the dimensional accuracy and position accuracy of the end face of the gland are poor, so it is easy to generate heat and shaft movement during the movement of each axis of the machine tool, resulting in reduced rotation accuracy, rigidity, and anti-vibration vibration cutting performance of the ball screw. , the temperature rise and thermal deformation increase, which in turn affects the precision and surface quality of the processed parts.

Utility model content

In view of the deficiencies in the above-mentioned technologies, the purpose of this utility model is to provide an integral bearing mechanism for a ball screw, which can eliminate or reduce bearing clearance, bearing outer The gap between the end face of the ring and the end face of the bearing sleeve, the gap between the end face of the inner ring of the bearing and the step surface of the ball screw shaft, so that the ball screw pair can maintain a relatively stable working state under different working conditions.

In order to achieve these objects and other advantages according to the present utility model, an integral bearing mechanism for a ball screw is provided, comprising:

The screw rod is a cylindrical rod-shaped structure, the end of the screw rod is provided with a shaft shoulder, and the shaft shoulder is provided with a threaded part;

The flange type bearing sleeve is a combined structure of a cylinder and a flange plate. The inside of the flange type bearing sleeve has a stepped through hole. The stepped through hole is composed of a large and a small round hole. The size The round holes are coaxially connected, the large round hole is opened on the end face of the flange, and the small round hole is opened on the end face of the cylinder;

A bearing set, which is composed of at least two bearings of the same type, and the bearing set is installed in the large circular hole;

Gland, which is a disc-shaped structure, with a through-axis hole in the center of the circle. A cylindrical boss is provided at one end of the gland, and the boss is installed in the large hole and connected to the bearing set Fitting of the outer end surface;

A lock nut, which is matched and installed with the threaded part of the screw rod;

Wherein, the inner end surface of the bearing group fits with the stepped surface formed by the large and small round holes, the end of the screw rod passes through the small round hole, the bearing group and the gland in turn, and the shaft The shoulder protrudes from the end surface of the flange of the bearing sleeve, and the inner end surface of the locking nut fits the outer end surface of the gland.

Using the support mechanism with the above structure, the axial force of the screw rod acting on the gland can be set by adjusting the position of the compression nut on the shoulder of the screw shaft, so that the axial force of the bearing can be adjusted under different working conditions. To the preload and screw pretension force.

As a further improvement of the utility model, an inner spacer and an outer spacer with a circular cylindrical structure can be provided, the outer diameter of the spacer is slightly smaller than the radius of the small circular hole, and the inner diameter is the same as the radius of the shoulder of the screw shaft. Similarly, the inner spacer is installed between the small round hole and the screw shaft shoulder, and the outer spacer is installed between the gland and the screw shaft shoulder. The use of the spacer device can facilitate the installation of each component and the application of axial pre-tightening force.

As a further improvement of the utility model, an inner sealing ring and an outer sealing ring with a circular structure can be provided, the inner sealing ring is installed on the inner spacer, and the outer sealing ring is installed on the outer spacer put on. The sealing ring can prevent water or dust from entering the bearing during long-term work.

Preferably, the utility model also includes a machine tool fixing seat, a number of A-type bolt holes are arranged on the flange type bearing sleeve, and the flange type bearing sleeve is installed and fixed with the machine tool fixing base through the A-type bolts, and the gland is provided with There are several B-type bolt holes, and the gland can be installed and fixed with the flanged bearing sleeve through B-type bolts.

Compared with the prior art, the utility model has the beneficial effects of:

The axial force of the screw acting on the gland can be set by adjusting the position of the compression nut on the shoulder of the screw shaft, so that the axial preload of the bearing and the screw shaft can be adjusted under different working conditions. Pre-stretch force can eliminate or reduce the bearing clearance, the clearance between the end surface of the bearing outer ring and the end surface of the bearing sleeve, the clearance between the end surface of the bearing inner ring and the step surface of the ball screw shaft, so that the ball screw pair can remain relatively stable under different working conditions working status;

Its backlash, screw vibration, and ball screw motion noise are significantly reduced;

The machining accuracy of the machine tool and the service life of the ball screw pair are improved;

Bearings can withstand higher loads while maintaining the same working life.

Description of drawings

Fig. 1 is a structural schematic diagram of an integral bearing mechanism for a ball screw of the present invention.

Detailed ways

The utility model will be described in further detail below in conjunction with the accompanying drawings, so that those skilled in the art can implement it by referring to the description.

It should be understood that terms such as "having", "comprising" and "including" as used herein do not entail the presence or addition of one or more other elements or combinations thereof.

Fig. 1 shows a kind of implementation form according to the present utility model, comprises:

Screw rod 5, which is a cylindrical rod-shaped structure, the end of the screw rod 5 is provided with a shaft shoulder, and the shaft shoulder is provided with a threaded portion;

The flanged bearing sleeve 1 is a combined structure of a cylinder and a flange. The flanged bearing sleeve 1 has a stepped through hole inside, and the stepped through hole is composed of a large and a small round hole. The large and small round holes are coaxially connected, the large round hole is opened on the end face of the flange, and the small round hole is opened on the end face of the cylinder;

A bearing set 2, which is composed of at least two bearings of the same type, and the bearing set 2 is installed in the large circular hole;

Gland 3, which is a disc-shaped structure, with a through-axis hole in the center of the circle. One end of the gland 3 is provided with a cylindrical boss, and the boss is inserted into the large hole and connected to the bearing. The outer end face of group 2 is bonded;

A lock nut 4, which is matched with the threaded part of the screw rod for installation;

Wherein, the inner end surface of the bearing group 2 fits with the stepped surface formed by the large and small round holes, and the end of the screw rod passes through the small round hole, the bearing group 2 and the gland 3 in sequence, The shoulder protrudes from the end face of the flange of the flanged bearing sleeve 1 , and the inner end face of the locking nut 4 fits the outer end face of the gland 3 .

When in use, the axial force of the screw acting on the gland 3 can be set by adjusting the position of the compression nut 4 on the shoulder of the screw shaft, so that the axial presetting of the bearing can be adjusted under different working conditions. Tightening force and screw pre-tensioning force.

In the present utility model, the inner spacer 32 and the outer spacer 31 of circular cylindrical structure can be set, the outer diameter of the spacer is slightly smaller than the radius of the small circular hole, and the inner diameter is the same as the radius of the shoulder of the screw shaft , the inner spacer 32 is installed between the small round hole and the screw shaft shoulder, and the outer spacer 31 is installed between the gland and the screw shaft shoulder. The use of the spacer device can facilitate the installation of each component and the application of axial pre-tightening force.

In the present utility model, an inner sealing ring 34 and an outer sealing ring 33 of an annular structure can also be set, the inner sealing ring is installed on the inner spacer 32, and the outer sealing ring is installed on the outer spacer. Set 31 on. The sealing ring can prevent water or dust from entering the bearing during long-term work.

The utility model also includes a machine tool fixing base 6, a number of A-type bolt holes 10 are arranged on the flange bearing sleeve 1, and the flange bearing sleeve is installed and fixed with the machine tool fixing base 6 through the A-type bolts, and a number of A-type bolt holes 10 are arranged on the gland 3 The B-type bolt holes 30, the gland 3 can be installed and fixed with the flanged bearing sleeve 1 through the B-type bolts.

Working principle: Install the overall bearing mechanism on the machine tool fixing base 6, install the ball screw pair, tighten the overall bearing mechanism with A-shaped bolts, and calibrate the ball screw pair with sliders, detection rods, and dial gauges to ensure The ball screw pair displayed by the dial gauge is within 0.01 mm of parallelism to the guide rail of the machine tool in both vertical and horizontal directions. According to the calculated pre-tightening force, use the lock nut 4 to tighten the ball screw with the overall bearing mechanism.

Although the embodiment of the utility model has been disclosed as above, it is not limited to the use listed in the specification and implementation, it can be applied to various fields suitable for the utility model, and for those familiar with the art, it can be Further modifications can readily be effected, so the invention is not limited to the specific details and examples shown and described herein without departing from the general concept defined by the claims and their equivalents.

Claims (6)

1. a ball screw integral bearing mechanism, is characterized in that, comprising:

Screw mandrel, it is cylinder rod-like structure, and the end of described screw mandrel arranges shaft shoulder portion, and described shaft shoulder portion arranges threaded portion;

Flange form bearing holder (housing, cover), it is the combining structure of cylinder and ring flange, described flange form bearing holder (housing, cover) inside has step-like through hole, described step-like through hole is made up of small one and large one circular hole, described size circular hole coaxial is communicated with setting, described big hole is opened at ring flange end face, and described small sircle hole is opened at cylinder end face;

Bearing group, it is made up of the bearing of at least two same models, and described bearing group is arranged in described big hole;

Gland, it is disc-shaped structure, and the center of circle has through axial bore, and described gland one end is provided with a columned boss, and described boss is encased in described big hole and with the outer face of described bearing group and fits;

Locking nut, the threaded portion Matching installation of itself and described screw mandrel;

Wherein, the step surface that the inner face of described bearing group and described size circular hole are formed fits, described screw mandrel end is successively through described small sircle hole, described bearing group and described gland, the described shaft shoulder stretches out the end face of described bearing holder (housing, cover) ring flange, and the inner face of described locking nut and the outer face of described gland fit.

2. ball screw integral bearing mechanism as claimed in claim 1, it is characterized in that, comprise inner spacing collar and the outer separator of annulus column structure, described spacer external diameter is slightly less than described small sircle hole radius, and internal diameter is identical with described screw axis shoulder radii, described inner spacing collar is installed between described small sircle hole and the described screw mandrel shaft shoulder, and described outer separator is installed between described gland and the described screw mandrel shaft shoulder.

3. ball screw integral bearing mechanism as claimed in claim 2, it is characterized in that, comprise inner seal ring and the exterior seal ring of circular ring, described inner seal ring is arranged on described inner spacing collar, and described exterior seal ring is arranged on described outer separator.

4. ball screw integral bearing mechanism as claimed in claim 1, it is characterized in that, described flange form bearing holder (housing, cover) is provided with some A type bolts hole.

5. ball screw integral bearing mechanism as claimed in claim 4, is characterized in that, comprise lathe holder, and described flange form bearing holder (housing, cover) is installed fixing by A type bolt and described lathe holder.

6. ball screw integral bearing mechanism as claimed in claim 5, it is characterized in that, described gland is provided with some Type B bolts hole, and described gland is installed fixing by Type B bolt and described flange form bearing holder (housing, cover).