阅读说明：本技术 一种滚动轴承预紧力精确加载系统及加载方法 (Rolling bearing pretightening force accurate loading system and loading method ) 是由 吴智恒 罗江龙 郭伟科 黄栋 毛璐瑶 陈启愉 张华伟 于 2020-05-22 设计创作，主要内容包括：本发明涉及一种滚动轴承预紧力精确加载系统及加载方法。该加载系统包括等效装置、加载装置和应变采集装置；具体的加载方法是：先通过等效装置配合应变采集装置获得等效轴承在承受待加载预紧力后外圈的加载应变值；然后通过调节电流大小使两个导电环产生互相吸引的电磁力,牵引对应的轴承压环对两个待加载轴承的外圈施加预紧力。当施加的预紧力致使采集的待加载轴承外圈上应变数值与等效装置中获得的加载应变值在允许的精度区间内时,则完成轴承预紧力的加载。本发明可定量精准施加预紧力,操作过程中加载的预紧力大小调节方便,精度高。(The invention relates to a rolling bearing pretightening force accurate loading system and a loading method. The loading system comprises an equivalent device, a loading device and a strain acquisition device; the specific loading method comprises the following steps: firstly, obtaining a loading strain value of an outer ring of an equivalent bearing after bearing a to-be-loaded pretightening force through the cooperation of an equivalent device and a strain acquisition device; and then the two conducting rings generate mutually attracted electromagnetic force by adjusting the current, and the corresponding bearing compression rings are pulled to apply pretightening force to the outer rings of the two bearings to be loaded. And when the applied pretightening force causes the acquired strain value on the outer ring of the bearing to be loaded and the load strain value obtained in the equivalent device to be within an allowable precision range, the bearing pretightening force is loaded. The invention can quantitatively and accurately apply the pretightening force, and the pretightening force loaded in the operation process is convenient to adjust and has high precision.)

1. The utility model provides an accurate loading system of antifriction bearing pretightning force which characterized in that: the device comprises an equivalent device, a loading device and a strain acquisition device;

the equivalent device comprises a fixed base, a supporting cylinder for supporting the equivalent bearing, a tray and a weight placed on the tray, wherein the supporting cylinder is fixedly installed on the fixed base, and the tray consists of a tray body for placing the weight and a supporting ring fixed on the bottom surface of the tray body;

the loading device comprises a loading cylinder, a loading support seat for mounting the loading cylinder, a support shaft penetrating through the loading cylinder and used for mounting two bearings to be loaded, and two groups of loading assemblies arranged on the support shaft at intervals, wherein a shaft sleeve is arranged between the two bearings to be loaded on the support shaft; the bearing compression ring is formed by combining two semi-ring bodies, each semi-ring body comprises a semi-ring circumferential surface, a bearing outer ring side pressure surface and a conductive ring clamping surface, magnetic leakage gaps are uniformly distributed on the conductive ring clamping surfaces, and each conductive ring is connected with a control circuit capable of adjusting current; the loading cylinder is sleeved on the two bearing press rings and is provided with a threading window;

the strain acquisition device comprises a strain acquisition instrument, a first strain gauge and a second strain gauge, wherein the first strain gauge and the second strain gauge are connected with the strain acquisition instrument, and the first strain gauge and the second strain gauge are respectively adhered to the outer ring circumferential surfaces of the equivalent bearing and the bearing to be loaded.

2. The rolling bearing pre-tightening force accurate loading system according to claim 1, characterized in that: the control circuit comprises an adjustable voltage-stabilized power supply, an adjustable resistor and a control switch, wherein the adjustable voltage-stabilized power supply, the adjustable resistor, the conducting ring and the control switch are connected to form a circuit loop.

3. The rolling bearing pre-tightening force accurate loading system according to claim 2, characterized in that: the semi-ring circumferential surface is uniformly provided with a plurality of strain gage positioning openings, each strain gage positioning opening corresponds to one second strain gage, and the inner wall of the semi-ring circumferential surface is provided with a wire groove.

4. The rolling bearing pre-tightening force accurate loading system according to claim 1, characterized in that: and the loading support seat is provided with a clamping groove matched with the lower part of the loading cylinder.

5. The rolling bearing pre-tightening force accurate loading system according to any one of claims 1 to 4, characterized in that: the strain acquisition instrument is a multichannel strain acquisition instrument, and the first strain gauge and the second strain gauge are both provided with a plurality of strain acquisition instruments.

6. A loading method of the accurate loading system of the pre-tightening force of the rolling bearing, which is characterized by comprising the following steps:

(1) selecting a bearing with the same model as the bearing to be loaded as an equivalent bearing, pasting a first strain gauge on the equivalent bearing, placing the equivalent bearing on a supporting cylinder, and applying pre-tightening force to be loaded through a tray and a weight; obtaining a loading strain value of an outer ring of the equivalent bearing after bearing a to-be-loaded pretightening force through deformation data of a first strain gauge of the strain acquisition instrument;

(2) 2 bearings to be loaded are arranged on the supporting shaft, and other parts of the loading device are arranged;

(3) and (3) connecting power supplies of the two groups of conducting rings, enabling the two groups of conducting rings to generate electromagnetic force to act on the outer ring of the bearing to be loaded, observing the strain value of the second strain gauge monitored by the strain acquisition instrument, adjusting current through two groups of current-adjustable control circuits respectively, and slowly increasing the electromagnetic force of the two conducting rings to enable the strain value of the second strain gauge and the loading strain value obtained in the step (1) to be within an allowable precision interval, so that accurate loading of the pre-tightening force is completed.

7. The loading method according to claim 6, wherein: the first strain gauge in the step (1) and the second strain gauge in the step (3) are both provided with a plurality of strain gauges, each strain gauge is a multi-channel strain gauge, each multi-channel strain gauge is connected with a data processing device, and the data processing device can respectively calculate and store the equivalent bearing strain mean values obtained by testing of the equivalent device and the loading deviceMean value of strain with bearing to be loadedAll are the same asCan judge whether the accuracy is satisfiedWherein the index meeting the precision is as follows:

。

Technical Field

The invention relates to the technical field of bearing application, in particular to a pre-tightening force loading system and method for a bearing.

Background

The deformation rate gradually decreases as the ball bearing load increases. When the acting load exceeds the inflection point of the load-displacement curve, the proper pre-tightening force is beneficial to reducing the displacement of the bearing. Meanwhile, the bearing is prevented from slipping by applying pretightening force to the bearing, the rotation and positioning precision is improved, and the vibration noise is reduced. However, if the preload of the bearing is too high, the friction temperature of the bearing will rise too high, resulting in early failure. Therefore, the bearing is applied with the static pretightening force, so that the performance and the service life of the bearing are greatly improved.

It is common in engineering to grind the opposite end faces of the bearing and then press the bearing against the shaft. However, this method is highly empirical and complicated to operate, and the preload load is difficult to control, and the load cannot be controlled quantitatively. Patent No. CN205978124U proposes a method of applying bearing preload by means of sleeve temperature rise expansion, but the expansion is nonlinear due to temperature rise of the material, which is difficult to control. In patent No. CN110567626A, the deformation is calculated and the pre-tightening force is applied by using the idea of finite element, but the requirement of finite element simulation on material parameters and boundary conditions is high, and the calculation result has a certain difference in accuracy compared with the experimental test. Some scholars also use vibration signals to monitor to apply pretightening force, but the interference factors are more, and the operation is not facilitated.

Disclosure of Invention

The invention aims to provide a rolling bearing pretightening force accurate loading system and method capable of quantitatively and accurately applying pretightening force. The pre-tightening force loaded in the operation process is convenient to adjust and high in precision.

In order to realize the purpose, the utility model discloses a technical scheme is: the utility model provides an accurate loading system of antifriction bearing pretightning force which characterized in that: the device comprises an equivalent device, a loading device and a strain acquisition device; the equivalent device comprises a fixed base, a supporting cylinder for supporting the equivalent bearing, a tray and a weight placed on the tray, wherein the supporting cylinder is fixedly installed on the fixed base, the inner diameter and the outer diameter of the supporting cylinder are matched with the inner diameter and the outer diameter of the outer ring of the equivalent bearing, the tray is composed of a tray body for placing the weight and a supporting ring fixed on the bottom surface of the tray body, and the inner diameter and the outer diameter of the supporting ring are matched with the inner diameter and the outer diameter of the inner ring of the equivalent bearing; the loading device comprises a loading cylinder, a loading support seat for mounting the loading cylinder, a support shaft penetrating through the loading cylinder and used for mounting two bearings to be loaded, and two groups of loading assemblies arranged on the support shaft at intervals, wherein a shaft sleeve is arranged between the two bearings to be loaded on the support shaft; the bearing compression ring is formed by combining two semi-ring bodies, each semi-ring body comprises a semi-ring circumferential surface, a bearing outer ring side pressure surface and a conductive ring clamping surface, magnetic leakage gaps are uniformly distributed on the conductive ring clamping surfaces, and each conductive ring is connected with a control circuit capable of adjusting current; the loading cylinder is sleeved on the two bearing press rings and is provided with a threading window; the strain acquisition device comprises a strain acquisition instrument, a first strain gauge and a second strain gauge, wherein the first strain gauge and the second strain gauge are connected with the strain acquisition instrument, and the first strain gauge and the second strain gauge are respectively adhered to the outer ring circumferential surfaces of the equivalent bearing and the bearing to be loaded. Preferably, the strain in the circumferential direction of the bearing outer ring is measured at the center of the circumferential surface of the outer ring.

Furthermore, the control circuit comprises an adjustable voltage-stabilized power supply, an adjustable resistor and a control switch, and the adjustable voltage-stabilized power supply, the adjustable resistor, the conducting ring and the control switch are connected to form a circuit loop.

Furthermore, a plurality of strain gage positioning openings are uniformly distributed on the circumferential surface of the semi-ring, each strain gage positioning opening corresponds to one second strain gage, and a wire groove is formed in the inner wall of the circumferential surface of the semi-ring.

Furthermore, a clamping groove matched with the lower part of the loading cylinder is formed in the loading supporting seat.

Further, the strain acquisition instrument is a multichannel strain acquisition instrument, and the first strain gauge and the second strain gauge are both provided with a plurality of strain acquisition instruments.

The invention also discloses a loading method of the accurate loading system by utilizing the pretightening force of the rolling bearing, which is characterized by comprising the following steps of: (1) selecting a bearing with the same model as the bearing to be loaded as an equivalent bearing, pasting a first strain gauge on the equivalent bearing, placing the equivalent bearing on a supporting cylinder, and applying pre-tightening force to be loaded through a tray and a weight; obtaining a loading strain value of an outer ring of the equivalent bearing after bearing a to-be-loaded pretightening force through deformation data of a first strain gauge of the strain acquisition instrument; (2) 2 bearings to be loaded are arranged on the supporting shaft, and other parts of the loading device are arranged; (3) and (3) connecting power supplies of the two groups of conducting rings, enabling the two groups of conducting rings to generate electromagnetic force to act on the outer ring of the bearing to be loaded, observing the strain value of the second strain gauge monitored by the strain acquisition instrument, adjusting current through two groups of current-adjustable control circuits respectively, and slowly increasing the electromagnetic force of the two conducting rings to enable the strain value of the second strain gauge and the loading strain value obtained in the step (1) to be within an allowable precision interval, so that accurate loading of the pre-tightening force is completed.

Furthermore, the first strain gauge in the step (1) and the second strain gauge in the step (3) are respectively provided with a plurality of strain acquisition instruments, each strain acquisition instrument is a multichannel strain acquisition instrument, the multichannel strain acquisition instruments are connected with a data processing device, and the data processing device can respectively calculate and store the strain mean values of the equivalent bearing obtained by the test of the equivalent device and the loading deviceMean value of strain with bearing to be loadedAt the same time, whether the accuracy is satisfied or not can be judgedWherein the index meeting the precision is as follows:

。

the invention has the beneficial effects that: the invention can quantitatively and accurately apply the pretightening force, and the pretightening force loaded in the operation process is convenient to adjust and has high precision. The method comprises the following steps: firstly, obtaining a loading strain value of an outer ring of an equivalent bearing after bearing a to-be-loaded pretightening force through the cooperation of an equivalent device and a strain acquisition device; and then the two conducting rings generate mutually attracted electromagnetic force by adjusting the current, and the corresponding bearing compression rings are pulled to apply pretightening force to the outer rings of the two bearings to be loaded. And when the applied pretightening force causes the acquired strain value on the outer ring of the bearing to be loaded and the load strain value obtained in the equivalent device to be within an allowable precision range, the bearing pretightening force is loaded.

Because the equivalent bearing is strictly contrasted with the supporting bearing, the influence of factors such as friction in the pretightening force transmission is avoided, and the current can be accurately controlled, so that the pretightening force can be quantitatively and accurately applied, and the device is convenient to adjust, high in precision and strong in feasibility.

The invention is suitable for the same type of bearings used in pairs such as angular contact ball bearings. The suction force or the repulsion force can be generated by controlling the current directions of the two conducting rings, the two-way bearing back-to-face installation and the two-way bearing back-to-back installation can be respectively applied to two modes, the applicability is strong, the loading is simple and feasible, and the operation is convenient.

Drawings

FIG. 1 is a schematic block diagram of a rolling bearing pre-tightening force accurate loading system according to the present invention;

FIG. 2 is a perspective view of an equivalent device of the present invention;

FIG. 3 is a schematic cross-sectional view of an equivalent apparatus according to the present invention;

FIG. 4 is a perspective view of a loading device according to the present invention;

FIG. 5 is an exploded view of FIG. 4;

FIG. 6 is a top view of the loading device of the present invention;

FIG. 7 is a sectional view taken along line A-A of FIG. 6;

FIG. 8 is a schematic view of the structure of the bearing clamping ring according to the present invention;

FIG. 9 is a circuit diagram illustrating control of the conductive ring according to the present invention.

Detailed Description

The present invention will be described in detail with reference to the accompanying drawings.

As shown in fig. 1, the rolling bearing pretightening force accurate loading system of the present invention comprises an equivalent device 1, a loading device 2 and a strain acquisition device 3; the strain acquisition device 3 comprises a strain acquisition instrument 31, and a first strain gauge 32 and a second strain gauge 33 which are connected with the strain acquisition instrument 31. Preferably, the strain acquisition instrument is a multichannel strain acquisition instrument, and the first strain gauge 32 and the second strain gauge 33 are both provided with a plurality of strain acquisition instruments.

As shown in fig. 2 and 3, the equivalent device 1 comprises a fixed base 11, a supporting cylinder 13 for supporting the equivalent bearing 12, a tray 14 and a weight 15 placed on the tray. The support cylinder 13 is fixedly mounted on the stationary base 11. Preferably, the inner diameter and the outer diameter of the supporting cylinder 13 are matched with the inner diameter and the outer diameter of the outer ring 121 of the equivalent bearing; the tray 14 is composed of a tray body 141 for placing the weight and a support ring 142 fixed on the bottom surface of the tray body, and the inner and outer diameters of the support ring 142 are adapted to the inner and outer diameters of the inner ring 122 of the equivalent bearing. The first strain gauge 32 is bonded to the center of the outer circumferential surface of the outer ring 121 of the dummy bearing. By the design, the outer ring 121 of the equivalent bearing is just supported by the supporting cylinder 13, then the weight 15 matched with the pre-tightening force to be loaded is selected and placed on the tray 14, the pre-tightening force is applied to the inner ring 122 of the equivalent bearing through the supporting ring 142, and the loading strain value with high precision can be obtained.

As shown in fig. 4-6, the loading device 2 includes a loading cylinder 21, a loading support seat 22 for mounting the loading cylinder, a support shaft 24 passing through the loading cylinder and for mounting two bearings 23 to be loaded, and two sets of loading assemblies disposed on the support shaft at intervals. A shaft sleeve 25 is mounted on the support shaft 24 at a position between the two bearings 23 to be loaded, and both sides of the shaft sleeve 25 are respectively in contact with the inner rings 232 of the two bearings to be loaded. The loading assembly comprises a conducting ring 26, a magnetism isolating ring 27 and a bearing press ring 28, wherein the conducting ring 26, the magnetism isolating ring 27 and the corresponding bearing 23 to be loaded are arranged in the bearing press ring 28, and the magnetism isolating ring 27 is arranged between the conducting ring 26 and the corresponding bearing outer ring 231 to be loaded. After the two groups of loading assemblies are installed, the two corresponding conducting rings 26 are located between the two bearings to be loaded and are arranged oppositely. One end of the supporting shaft 24 is a shaft shoulder 241, and the other end is in threaded connection with a fastening nut 242, so that the two bearings 23 to be loaded are fixed on the supporting shaft 24 in a limiting manner.

As shown in fig. 7 and 8, the bearing compression ring 28 is formed by combining two half ring bodies, each half ring body includes a half ring circumferential surface 281, a bearing outer ring lateral surface 282 and a conductive ring clamping surface 283, and magnetic leakage gaps 284 are uniformly distributed on the conductive ring clamping surface 283. Preferably, a plurality of strain gage positioning openings 285 are uniformly distributed on the circumferential surface 281 of the half ring, a wire casing 286 is arranged on the inner wall of the circumferential surface of the half ring, and the wire casing 286 is communicated with the plurality of strain gage positioning openings 285. The second strain gauge 33 is adhered to the bearing outer ring to be loaded corresponding to each strain gauge positioning hole 285, and the lead wire of the second strain gauge 33 is placed in the wire slot 286 and finally penetrates out through the lead wire hole 287. A lead-out notch 288 of the conductive ring power line is further formed in the middle of each half ring body close to one side of the conductive ring clamping surface 283. Through setting up foil gage location mouth 285, can mark on waiting to load the bearing outer lane, then carry out pasting of second foil gage 33 again, can guarantee the equipartition setting of foil gage.

Each conducting ring 26 is connected to a current-adjustable control circuit; specifically, the control circuit may adopt a circuit, as shown in fig. 9, which includes an adjustable voltage-stabilized power supply 291, an adjustable resistor 292, and a control switch 293, where the adjustable voltage-stabilized power supply 291, the adjustable resistor 292, the conductive ring 26, the control switch 294, and a fuse 295 are connected to form a circuit loop. Thus, the current passing through the conductive rings can be changed by the matching adjustment of the adjustable voltage-stabilized power supply 291 and the adjustable resistor 292, so as to obtain different electromagnetic forces, because the two conductive rings 26 attract each other, the conductive ring clamping surface 283 of the bearing ring is pressed, the bearing outer ring side pressure surface 282 of the bearing ring is driven to extrude the outer ring 231 of the bearing to be loaded, that is, the horizontal axial pre-tightening force is applied to the outer ring of the bearing to be loaded, and finally, the strain value of the monitored second strain gauge is matched, so as to finish the accurate application of the pre-tightening force.

Further, as shown in fig. 5, the loading cylinder 21 is sleeved on the two bearing press rings, and a threading window 221 is formed in the loading cylinder 21. The wire passing window 221 is used for the wire of the lead wire of the second strain gauge and the conducting ring to pass through.

Specifically, a clamping groove 221 is formed in the loading support seat 22, and the lower portion of the loading cylinder 21 is accommodated in the clamping groove 221 and clamped.

The invention also discloses a loading method of the accurate loading system by utilizing the pretightening force of the rolling bearing, which comprises the following steps:

(1) selecting a bearing with the same model as the bearing to be loaded as an equivalent bearing, pasting a first strain gauge on the equivalent bearing, placing the equivalent bearing on a supporting cylinder, and applying pre-tightening force to be loaded to the inner ring of the equivalent bearing through the gravity of a tray and a weight; and obtaining a loading strain value of the outer ring of the equivalent bearing after bearing the to-be-loaded pretightening force through the deformation data of the first strain gauge of the strain acquisition instrument. Wherein, each part of the equivalent device meets the corresponding horizontal precision and roughness requirement in the test process.

(2) The 2 bearings to be loaded are mounted face to face on the support shaft and the mounting of the other parts of the loading device is completed.

(3) And (2) connecting power supplies of the two groups of conducting rings, connecting anisotropic initial currents to the two conducting rings, enabling the two groups of conducting rings to generate attraction electromagnetic forces, driving the bearing pressing rings to extrude the outer rings of the bearings to be loaded, observing the strain values of the second strain gauges monitored by the strain acquisition instrument, adjusting the currents through the two groups of control circuits with adjustable currents, and slowly increasing the electromagnetic forces of the two conducting rings to enable the strain values of the second strain gauges and the loading strain values obtained in the step (1) to be within an allowable precision range, so that accurate loading of the pre-tightening force is completed.

Further, the first strain gauge in the step (1) and the step (3)The second strain gauges in (1) are all provided with a plurality of strain acquisition instruments which are multi-channel strain acquisition instruments. Specifically, in the step (1), a plurality of loading strain values acquired by the multi-channel strain acquisition instrument during the test of the equivalent device are stored by a computer and then calculated to obtain a strain mean value of the equivalent bearing. In the step (3), a plurality of strain values acquired by the multi-channel strain acquisition instrument during the test of the loading device are stored by a computer and then calculated to obtain a strain mean value of the bearing to be loadedWhen the accuracy is satisfiedWhen required, the experiment was stopped. Wherein, the index that satisfies the precision is:

。

wherein, the quantity of first foil gage 32 is n (n value is according to bearing size reasonable value 6-10), obtains the strain value through strain acquisition instrument 31:. Recording by a data processing device, and calculating a strain mean value of the equivalent bearing:。

in this application of force, 5 foil gage locating openings of equipartition on the half ring body of every bearing clamping ring 28, bearing clamping ring 28 that two half ring body make up has 10 foil gage locating openings, pastes 10 second foil gages promptly on treating the outer lane of loading the bearing.

When the conducting ring is electrified to apply horizontal pretightening force, strain values of 10 second strain gauges on the outer ring of the bearing to be loaded are detected through the strain detectorStoring in a data processing device and calculating the strain mean value of the support bearing. The current in the circuit is debugged by an adjustable stabilized voltage power supply 291 and a variable resistor 292 in the control circuit so as to control the size of the pretightening force; the fuse 30 in the circuit can protect the circuit, and an appropriate power supply and an upper limit of the pre-tightening force can be selected according to actual requirements.

In addition, when the working environment of the 2 bearings to be loaded needs to be installed back to back, in the loading method, in the step (2), the 2 bearings to be loaded are correspondingly installed on the supporting shaft in a face-to-face mode, and the installation of other parts of the loading device is completed. And in the step (3), the two conducting rings are connected with the same-direction initial current, so that the two groups of conducting rings generate repulsive electromagnetic force, the repulsive electromagnetic force acts on the magnetism isolating ring and is transmitted to the outer side of the bearing to be loaded, and pretightening force is applied in a back-to-back installation mode.

The embodiments have been specifically described above with reference to the drawings, but the present invention is not limited to the above embodiments, and those skilled in the art can adopt other embodiments without departing from the spirit of the present invention.