WO2020061733A1

WO2020061733A1 - Bearing having force sensor

Info

Publication number: WO2020061733A1
Application number: PCT/CN2018/107247
Authority: WO
Inventors: 关冉; 王爱萍; 黄春亮
Original assignee: 舍弗勒技术股份两合公司
Priority date: 2018-09-25
Filing date: 2018-09-25
Publication date: 2020-04-02

Abstract

Provided is a bearing having force sensor, wherein the bearing (11) has at least one support member, at least one receiving hole is provided on an axial end face of the support member, a force sensor (2) for measuring the load on the support member is provided inside the receiving hole, a force transmitting member (1, 1') arranged between the force sensor (2) and the bottom of the receiving hole is also provided inside the receiving hole, the force transmitting member (1, 1') has two end portions distributed along the extending direction of the receiving hole, that is, a first end portion abutting on the bottom of the receiving hole and a second end portion abutting on the force sensor (2), the force transmitting member (1, 1') can transmit the force received at the first end portion to the force sensor (2).

Description

Bearing with force sensor

Technical field

The invention relates to a bearing, in particular to a bearing having a force sensor.

Background technique

When assembling a bearing or working with a bearing, it is often necessary to determine the amount of load the bearing is subjected to. For example, the bearing clearance of a rolling bearing is a very important parameter. When the bearing is not mounted on a shaft or a housing, it fixes one of its inner or outer ring, and then makes the unfixed side diameter. The amount of movement when moving in the axial or axial direction. When the bearing is running, the clearance has a very important influence on the overall performance of the rolling bearing. One method currently used to determine the clearance of tapered roller bearings is to use a finite element analysis method to calculate the amount of movement and in this case, it is necessary to accurately machine components that cooperate with rolling bearings, such as shafts and housings. However, this is only a theoretical method or a simulation method, and the actual bearing clearance is still unknown. Since there is a corresponding relationship between the bearing clearance and the stress distribution of the bearing, it is considered to derive the bearing clearance based on the stress of each component of the bearing. In addition, when assembling the bearing to the equipment, it is also necessary to ensure that the actual bearing preload is consistent with the design value, thereby ensuring the reliable operation of the bearing. Therefore it is necessary to measure the load on the bearing.

Currently, one measurement solution is to provide a sensor such as a sensor bolt in a bearing to measure the bearing stress. The principle is that when the sensor bolt is tightened in the threaded hole of the bearing component, the bolt body is stretched in the axial direction to reduce the diameter, and the sensor bolt is deformed when the bearing is subjected to a load. Since the strain sensor is assembled in the hole of the bolt body, the tensile force can be measured. In this case, the current sensor bolt is only suitable for a case with a large space, so that sufficient deformation for the sensor measurement can be generated. However, for example, in the fan, when assembling the bearing of the main shaft, a preload is applied by connecting the end cover and the main shaft, and the end cover is in contact with the end surface of the main shaft. At this time, such a sensor bolt cannot be used.

Another measurement solution is the use of strain sensors. The problem is that the strain sensors are very sensitive to the direction of the force. Therefore, especially when the strain sensor is mounted on the inner or outer ring of the rolling bearing, the strain sensor needs to be mounted very accurately in the radial direction. Errors in the mounting direction will result in unstable sensitivity and coupling errors of the strain sensor. In addition, the strain sensor requires a large installation space, which needs to change the current design of the bearing, and the bearing needs to be tested and verified again, so this solution is not suitable for existing bearings. In addition, it is expensive to set up a separate sensor.

Summary of the Invention

Therefore, the technical problem to be solved by the present invention is to be able to provide a bearing capable of measuring the load carried by itself based on the design of the existing bearing, wherein the bearing can be used in the bearing accommodation space, especially the axial accommodation space It is small, and the bearing is easy to install, easy to use, and low in cost.

This technical problem is solved by a bearing, which has at least one support member, and at least one receiving hole is provided on an axial end face of the support member, wherein a force sensor for measuring a load received by the support member is provided in the receiving hole, Wherein, a force transmitting member arranged between the force sensor and the bottom of the receiving hole is also provided in the receiving hole, wherein the force transmitting member has two ends distributed along the extending direction of the receiving hole, that is, abutting against the receiving hole The first end portion of the bottom portion and the second end portion abutting on the force sensor, the force transmitting member can transmit the force received at the first end portion to the force sensor.

Within the scope of the present invention, the receiving hole, the force sensor, and the force transmitting member collectively constitute a force measurement module for measuring a load received by a supporting member of the bearing capacity measurement module. Able to install at least one force measurement module on the bearing. If necessary, two or more sets of force measurement modules can be set on the bearing to meet the needs of measuring the load. When two or more sets of force measurement modules are provided, the force measurement modules can be provided on the same support member or on different support members.

The bearing can be a rolling bearing or a plain bearing. The force measurement module can be provided at a plurality of positions of the bearing, that is, the receiving holes can be provided at different positions of each support member of the bearing. If the bearing is designed as a sliding bearing, the receiving hole can be provided on the axial end face of the bearing shell of the sliding bearing, and the receiving hole can also be provided on the axial end face of the journal. If the bearing is designed as a rolling bearing, the receiving hole can be provided on the axial end face of the bearing ring and / or on the axial end face of the roller. In this case, the bearing ring is a substantially annular component of a bearing having a roller raceway, such as an annular outer ring, an annular inner ring, a tapered outer ring, and a tapered inner ring. Rollers are rollers with a defined axis of rotation, such as cylindrical rollers that are generally cylindrical and tapered rollers that are generally circular truncated cones. The extending direction of the receiving hole, that is, the longitudinal direction of the receiving hole, corresponds to the depth of the hole. The receiving hole can be a hole already existing on the bearing component, such as a hoisting hole on a bearing ring, or it can be a hole machined for a force measurement module. Advantageously, the receiving hole is a cylindrically shaped cavity as a whole. Of course, the accommodating hole can also have other shapes, preferably an axisymmetric shape. Therefore, the bearing support member can uniformly apply the load to the force transmission member.

The force sensor is capable of measuring a force in an extending direction of the receiving hole. The force sensor can be a sensor using a different sensing principle. For example, a force sensor made of a strain gauge, a piezoelectric sensor, a piezomagnetic sensor, or a piezoresistive sensor can be used. Preferably, the strain sensor uses a strain gage with a temperature compensation structure, because such a sensor technology is mature and inexpensive. The force sensor also includes, but is not limited to, a data transmission unit and a power supply unit. The force sensor can have a wireless transmission function for transmitting measurement data. In this case, the load of the bearing can be measured in real time without being limited to the position of the force measurement module and the timing of the load measurement (during assembly or work). Alternatively, a relatively low-cost solution can be adopted, that is, transmission of measurement data by wire. In this case, if the load needs to be measured in real time, the force measurement module can be set on a relatively fixed support member of the bearing, such as the outer ring of a rolling bearing, and the transmission line is always connected to the force sensor so that it can be read at any time Measurement data. If the force measurement module is set on a part of the bearing that rotates relatively during operation, such as a roller of a rolling bearing, it is not appropriate to measure the working load of the bearing in order to prevent the transmission line from winding non-ideally. In this case, it can be used in assembly At this time, the transmission line is temporarily connected to the force sensor to obtain information such as preload.

The force transmitting member according to the present invention has two end portions distributed along the extending direction of the receiving hole, that is, a first end portion abutting the bottom of the receiving hole and a second end portion abutting on the force sensor. When the bearing is deformed by the bearing, the receiving hole presses the first end portion of the force transmitting member, so that the force transmitting member has acceleration along the extending direction of the receiving hole, and is transmitted to the second end portion of the force transmitting member to The force sensor is used to obtain measurement data on the force in the direction of the receiving hole extension. Since the position of the receiving hole on the support member and its extension direction are known, and the structure of the bearing, especially the geometric size and relative position of each support member are also known, the bearing data can be derived from the measured data obtained. Centripetal (radial load) and / or thrust (axial load). Therefore, for thrust bearings and radial thrust bearings, such as tapered roller bearings and angular contact bearings, etc., the preload and working load can be measured according to the present invention. For radial bearings, such as cylindrical roller bearings, spherical roller bearings and deep groove ball bearings, etc., the working load can be measured according to the present invention. Therefore, in the present invention, a force sensor can be used instead of a strain sensor to measure the bearing load, which overcomes the problem that the strain sensor cannot be used in the prior art because there may not be enough strain space. In addition, since the force sensor is insensitive to mounting tolerances and force directions, it is easy to install and use. In addition, the force measurement module can be directly integrated with the existing bearing, and there is no major change in the design of the existing bearing, which realizes good interchangeability with traditional bearings.

In a preferred embodiment, the central axis of the receiving hole coincides with or is parallel to the central axis of the support provided with the receiving hole. That is, for example, when the receiving hole is provided on the roller of the rolling bearing, the receiving hole can extend along the central axis of the roller, and when the receiving hole is provided on the bearing ring, the central axis of the receiving hole is parallel to the central axis of the bearing ring. Therefore, it is convenient to manufacture the receiving hole and calculate the load.

In an advantageous embodiment, the first end of the force transmitting member is designed to be spherical, and the bottom of the receiving hole is conical, and the first end of the force transmitting member abuts the conical surface of the receiving hole. More specifically, the first end portion of the force transmission member is designed as a part of a sphere, so that the first end portion of the force transmission member can achieve a good contact with the receiving hole and transmit the force more effectively. Therefore, the force acting on the force transmission member includes a component force perpendicular to the extension direction of the accommodation hole and a component force along the extension direction of the accommodation hole. Therefore, when the force transmission member acts on the force sensor, it can be estimated from the data measured by the force sensor. Radial and axial loads on bearings. In addition, the bottom of the tapered accommodating hole can be directly obtained by a conventional process when making a hole, thereby saving steps and facilitating manufacturing.

Alternatively or additionally, the first end of the force transmitting member abuts the side of the receiving hole. That is, the first end of the force transmitting member abuts the side of the receiving hole that defines the hole width. Preferably, the receiving hole is substantially cylindrical, and the first end portion of the force transmitting member abuts the circumferential surface of the cylinder, so that when the receiving hole is deformed toward the direction, the force transmitted through the force transmitting member is increased.

In another advantageous embodiment, the force transmitting member is a rigid member, and the surface of the force transmitting member is hardened. For example, the force transmitting member is made of steel. Therefore, the force transmitting member has sufficient rigidity to transmit the force received at the first end portion to the force sensor. In addition, at least the surface of the first end portion is hardened to reduce wear and increase the service life of the force transmitting member.

Advantageously, the force transmitting member has a hole extending in the extension direction of the receiving hole. The hole can be a blind hole or a through hole. When the force transmitting member is a rotary body, the hole is preferably a central through hole. This saves material and reduces weight. In an advantageous embodiment, a holding device for holding the force sensor is provided in the receiving hole, and the holding device is connected to the receiving hole in a form-fitting manner. Thereby, the force sensor can be fixedly held in the receiving hole.

Particularly advantageously, the holding device is designed as a hollow bolt. The hollow bolt has no bolt head and is similar to a set screw in this respect. The force sensor is housed in the cavity of the hollow bolt, and the side of the force sensor opposite the force transmitting member is stopped by the axial end face of the hollow bolt. By adjusting the tightening degree or tightening torque of the hollow bolt, the critical contact position of the force transmitting member relative to the force sensor can be easily found during assembly, that is, there is no gap between the force transmitting member and the force sensor, and once the receiving hole is deformed, the force transmitting member The applied force can be converted to the force sensor. This makes it easy to determine the initial parameters at zero load, which is good for calibrating the force measurement module.

Advantageously, a through hole for a connection line of the force sensor is provided on the holding device. Conducive to the transmission line arrangement in the wired data transmission scheme.

Advantageously, the retaining device stops the second end of the force transmitting member in the radial direction. For example, the second end portion of the force transmitting member can partially extend into the cavity of the holding device that accommodates the force sensor, so that the holding device has a guiding effect on the force transmitting member.

In another advantageous embodiment, the receiving hole is arranged in an end face region of a component of the bearing which is recessed in the direction of extension of the receiving hole. This ensures that the force measurement module, especially the force sensor and its holding device, will not protrude from the end face, preventing collision with other parts of the bearing.

BRIEF DESCRIPTION OF THE DRAWINGS

The preferred embodiments of the present invention will be schematically described below with reference to the accompanying drawings. The drawings are:

Fig. 1 is a schematic sectional view of a part of a wind turbine equipped with a bearing according to a preferred embodiment of the present invention,

Fig. 2 is a front view of the bearing according to Fig. 1,

FIG. 3 is a partially enlarged view of the front surface of the bearing according to FIG. 2,

4 is a sectional view of a roller of the bearing according to FIG. 2,

Fig. 5 is a partially enlarged view of a cross-section of the roller according to Fig. 4,

6 is a sectional view of a roller of a bearing according to another embodiment, and

FIG. 7 is a partially enlarged view of a cross-section of the roller according to FIG. 6.

detailed description

FIG. 1 shows a schematic sectional view of a part of a fan equipped with a bearing according to a preferred embodiment of the present invention. As shown in the figure, the fan has two tapered roller bearings 11 as main bearings, and the tapered roller bearings 11 are bearings of a standard design. The tapered roller bearing is supported between the main shaft 13 and the housing 14. During the assembly process of the tapered roller bearing, a predetermined preload is used to ensure the bearing assembly gap or bearing clearance. In this case, the axial preload of the tapered roller bearing is applied by assembling the end cover 12, wherein the end cover 12 abuts on the axial end surface of the main shaft 13, and the end cover 12 is connected to the main shaft 13 by a plurality of bolts. connection.

FIG. 2 shows a front view of a tapered roller bearing according to FIG. 1. As shown, the tapered roller bearing 11 has a tapered roller (labeled 6 in FIG. 3), an outer ring 5 and an inner ring 4. The cage of the bearing is not shown here, but the invention is also applicable to a bearing having a cage.

FIG. 3 shows a partial enlarged view of the front side of the bearing according to FIG. 2, that is, a partial enlarged view of the A area. As shown in the figure, the tapered roller bearing 11 has a force measurement module, and in this embodiment, the force measurement module is provided on the tapered roller 6 of the tapered roller bearing 11 having a substantially circular truncated cone shape. The tapered roller 6 is the best carrier for the force sensor 2, because in the assembly process of FIG. 1, all tapered rollers have the same load. The tapered roller bearing does not need to rotate, and the measured force is the tapered roller 6. Of force. Of course, in other embodiments, the force measurement module can be assembled with other components of the bearing. In addition, the hollow bolt 3 for holding the force sensor in the force measurement module can be clearly seen.

FIG. 4 shows a sectional view of a tapered roller of the tapered roller bearing according to FIG. 2. As shown in the figure, the tapered roller 6 is provided with a receiving hole for a force measurement module extending along its rotation axis. The receiving hole is provided on a large-diameter end surface of the circular truncated roller. The accommodating hole is a threaded hole, and is made of the positioning hole of the tapered roller through processes such as reaming and tapping.

FIG. 5 shows a partially enlarged view of the tapered roller according to FIG. 4, that is, a partially enlarged view of a region B. FIG. It can be clearly seen that the force measurement module includes a receiving hole in the form of a threaded hole, a force transmitting member 1, a force sensor 2, and a hollow bolt 3. The end of the receiving hole is a tapered structure formed by the shape of a drilling tool. The force sensor 2 has a strain gage having a temperature compensation structure. The force transmission member 1 has two ends along the axial direction of the receiving hole, wherein the first end portion of the force transmission member 1 is designed as a part of a sphere, and the rest of the force transmission member 1 is cylindrical. The force transmission member 1 is made of steel, and its surface is hardened. The first end portion of the force transmitting member 1 is in contact with the conical bottom surface of the receiving hole through its spherical surface. The circular bottom surface of the second end portion of the force transmitting member 1 is in contact with the force sensor 2. Hollow bolt 3 is used to hold force sensor 2. Hollow bolt 3 has no bolt head, similar to set screws. The force sensor 2 is accommodated in a central hole forming a cavity of the hollow bolt 3 and is stopped at one end (on the right side in the figure) by the axial end surface of the hollow bolt 3 at the force sensor 2. The external thread of the hollow bolt 3 is matched with the internal thread of the receiving hole, so that the force sensor can be fixed in the receiving hole. The diameter of the center hole of the hollow bolt 3 is slightly larger than the diameter of the cylinder of the second end portion of the force transmitting member 1. The second end portion of the force transmission member 1 can partially extend into the center hole, so that the force transmission member 1 can move in the axial direction of the receiving hole. The assembled hollow bolt 3 does not protrude from the axial end face of the opposite tapered roller 6 to prevent collision with other parts of the equipment. The axial end surface of the hollow bolt 3 is provided with an opening 7 through which the electrical connection line of the force sensor 2 passes, so that the transmission line can be temporarily connected to the force sensor 2 during assembly to obtain measurement data on the preload.

During the assembly process, a preload is applied to the tapered roller bearing 11, so that the tapered roller 6 has a base pressure, which causes the receiving hole to deform. The tapered bottom surface of the receiving hole presses the spherical surface of the first end of the force transmitting member 1. The force transmitting member 1 transmits the force it receives at the first end to the force sensor 2, so that the force sensor measures the measurement data about the force along the axial direction of the receiving hole. Then, the magnitude of the preload is calculated by inverse calculation based on the known structural dimension information of the tapered roller bearing. Therefore, by adjusting the tightening degree or tightening torque of the hollow bolt, the critical contact position of the force transmitting member relative to the force sensor at the factory can be determined to calibrate the force measurement module.

Fig. 6 shows a sectional view of a roller of a bearing according to another embodiment. As shown in the figure, in this embodiment, the design of the force measurement module is basically consistent with the embodiments shown in FIGS. 1 to 5. The difference lies in the structure and dimensions of the force transmission member 1 ', which will only be explained below in this regard.

FIG. 7 shows a partially enlarged view of a cross-section of the roller according to FIG. 6, that is, a partially enlarged view of a region C. FIG. It can be clearly seen that the first end portion of the force transmission member 1 'is basically a part of a sphere, but the diameter of the sphere is increased, so the first end portion of the force transmission member 1' can directly abut the circumferential surface of the receiving hole on. Of course, the first end portion of the force transmission member 1 'preferably abuts on a smooth section seen on the circumferential surface, rather than on a section having an internal thread. In this case, when the receiving hole is deformed, the circumferential surface of the receiving hole presses the spherical surface of the first end portion of the force transmitting member 1 ', increasing the axial force converted from the radial force by the force transmitting member. In addition, the force transmitting member 1 'also has a through hole extending along its central axis, thereby saving material and reducing weight.

Although possible embodiments are exemplarily described in the above description, it should be understood that there are still a large number of variations of the embodiments through all known and further combinations of technical features and implementations easily conceivable by those skilled in the art. In addition, it should also be understood that the exemplary embodiment is only an example, and such an embodiment in no way limits the scope, application, and configuration of the present invention. The foregoing description is more to provide a technical person with technical guidance for transforming at least one exemplary embodiment, wherein various changes can be made without departing from the scope of protection of the claims, especially with respect to the described Changes in function and structure of components.

Reference list

1,1 ’force transmission

2 Force sensor

3 hollow bolts

4 inner circle

5 outer circle

6 rollers

7 opening

8 recess

9 hole

11 Bearing

12 end caps

13 Axis

14 Shell

Claims

A bearing, wherein the bearing (11) has at least one supporting member, and at least one receiving hole is provided on an axial end surface of the supporting member, wherein the receiving hole is provided for measuring the bearing received by the supporting member. Load force sensor (2),

It is characterized in that a force transmitting member (1, 1 ') arranged between the force sensor (2) and the bottom of the receiving hole is further provided in the receiving hole, wherein the force transmitting member (1 1,1 ') has two end portions distributed along the extending direction of the receiving hole, that is, a first end portion abutting on the bottom of the receiving hole and a first portion abutting on the force sensor (2) At two ends, the force transmitting member (1, 1 ') can transmit the force received at the first end to the force sensor (2).
The bearing according to claim 1, wherein the support member is an outer ring (5), an inner ring (4), or a roller (6) of the bearing.
The bearing according to claim 1, wherein a central axis of the receiving hole coincides with or is parallel to a central axis of the support member.
The bearing according to claim 1, wherein a first end portion of the force transmitting member (1, 1 ') is designed to be spherical, and a bottom of the receiving hole is conical, and the force transmitting member The first end of (1,1 ') abuts the conical surface of the receiving hole.
The bearing according to claim 1, wherein the force transmitting member (1, 1 ') is a rigid member, and a surface of the force transmitting member (1, 1') is hardened.
The bearing according to claim 1, characterized in that the force transmitting member (1, 1 ') has a hole (9) extending in the extending direction.
The bearing according to claim 1, wherein a holding device (3) for holding the force sensor (2) is provided in the receiving hole, and the holding device (3) and the receiving hole shape Mating connection.
The bearing according to claim 7, characterized in that the retaining device (3) is designed as a hollow bolt.
The bearing according to claim 7, characterized in that the holding device (3) is provided with an opening (7) through which the connection line of the force sensor (1, 1 ') passes.
The bearing according to claim 1, wherein the receiving hole is arranged in an end surface region of the support member that is recessed in the axial direction.