Method and device for measuring energy consumption coefficient of rolling bearing
阅读说明：本技术 一种测量滚动轴承能耗系数的方法及装置 (Method and device for measuring energy consumption coefficient of rolling bearing ) 是由 吴参 吴蓥伟 李帅帅 夏强 于 2021-07-27 设计创作，主要内容包括：本发明公开了一种测量滚动轴承能耗系数的方法及装置。现有滚动轴承能耗系数测量方式精度低、测量不准确。本发明基于能量转换法的原理,最初通过砝码给予整个装置一个动能,使得轴承套筒带动轴承外圈转动,内圈固定,在转动的过程中,一部分动能转换为轴承的动能,另一部分动能由于轴承内部存在摩擦从而转换为热能；通过测量轴承的动能以及转动的角度,可以计算出能耗系数。本发明突破传统测量摩擦力矩去计算能耗系数的方式,从能量转换法的角度提出一种新的滚动轴承能耗系数测量方法,避免了现有摩擦力矩测量方式误差大的问题,使得测量结果更加精确,且使轴承能耗系数的研究能从一个新的角度获得解决方法。(The invention discloses a method and a device for measuring the energy consumption coefficient of a rolling bearing. The existing rolling bearing energy consumption coefficient measuring mode has low precision and inaccurate measurement. Based on the principle of an energy conversion method, firstly, a kinetic energy is given to the whole device through a weight, so that a bearing sleeve drives a bearing outer ring to rotate, an inner ring is fixed, in the rotating process, one part of the kinetic energy is converted into the kinetic energy of a bearing, and the other part of the kinetic energy is converted into heat energy due to friction in the bearing; the energy consumption coefficient can be calculated by measuring the kinetic energy and the rotating angle of the bearing. The invention breaks through the traditional mode of measuring friction torque to calculate the energy consumption coefficient, provides a new method for measuring the energy consumption coefficient of the rolling bearing from the perspective of an energy conversion method, avoids the problem of large error of the existing friction torque measuring mode, enables the measuring result to be more accurate, and enables the research on the energy consumption coefficient of the bearing to obtain a solution from a new perspective.)
1. A method for measuring the energy consumption coefficient of a rolling bearing is characterized in that: the method comprises the following specific steps:
the method comprises the following steps: connecting a cylinder body of the air cylinder with the base through an axial displacement adjusting mechanism, wherein a piston rod of the air cylinder is horizontally arranged; then, connecting the air cylinder with a pneumatic circuit system, wherein the pneumatic circuit system is connected with a controller; one end of the connecting sleeve is fixed on a piston rod of the cylinder;
step two: fixing the three-jaw chuck on the base through a supporting seat; selecting a mandrel with the diameter of the bearing shaft section being the same as the inner diameter of the measured bearing, and clamping the mandrel on a three-jaw chuck; the inner ring of the bearing to be measured is in transition fit with the supporting shaft section of the mandrel, and a check ring is embedded into a clamping groove formed in the supporting shaft section of the mandrel to axially position the inner ring of the bearing to be measured; then, selecting a bearing sleeve with the inner diameter being the same as the outer diameter of the measured bearing, and carrying out interference fit on the bearing sleeve and the outer ring of the measured bearing;
step three: fixing a photoelectric sensor on a base and aligning to a grating disc fixed at one end face of a bearing sleeve;
step four: two stepped shafts are symmetrically fixed on the outer wall of the bearing sleeve, and the positions of the cylinder and the connecting sleeve along the axial direction of the mandrel are adjusted through an axial displacement adjusting mechanism, so that the connecting sleeve is aligned with the stepped shafts on the bearing sleeve along the axial direction of the mandrel; then, the step shaft of the bearing sleeve is held by hands to be in a horizontal state; then, the controller controls the pneumatic loop system to drive a piston rod of the air cylinder to push out, so that the connecting sleeve is sleeved on the shaft section of the outermost end of the stepped shaft, close to the air cylinder, on the bearing sleeve, and the connecting sleeve is in clearance fit with the shaft section of the outermost end of the stepped shaft; finally, sleeving a rope which is annular and is suspended with weights on the shaft section of the outermost end of the stepped shaft of the bearing sleeve, which is far away from the cylinder;
step five: the controller controls the pneumatic loop system to drive the piston rod of the air cylinder to retract, the weight falls to drive the bearing sleeve, the grating disc and the outer ring of the tested bearing to synchronously rotate, the photoelectric sensor records the number n of pulse signals, and finally the energy consumption coefficient M is calculated.
2. A method for measuring the coefficient of energy consumption of a rolling bearing according to claim 1, characterized in that: the energy consumption coefficient M of the measured bearing is calculated as follows:
because the vertical whereabouts of weight, the weight whereabouts in-process, the distance of rope and bearing sleeve the central axis is unchangeable, and the weight breaks away from the bearing sleeve when establishing the bearing sleeve and rotate gamma angle, then gamma's computational formula is:
l is the distance between the shaft shoulder of the outermost shaft section of the stepped shaft for hanging the weight and the central axis of the bearing sleeve, L is the length of the outermost shaft section of the stepped shaft for hanging the weight, and r is the radius of the outermost shaft section of the stepped shaft for hanging the weight;
after simplification, obtaining:
after the formula (1) is deformed, the following components are obtained:
if phi is the included angle from the point on the excircle of the central axis of the stepped shaft of the suspended weight and the outer circle of the end face of the outermost end of the stepped shaft to the perpendicular line of the central axis of the mandrel, phi satisfies:
substituting formula (2) and formula (3) into formula (1) to obtain:
namely:
thereby obtaining:
when the angle theta rotated by the bearing sleeve meets the condition that theta is more than 0 degrees and less than gamma, the following steps are carried out:
wherein x is the distance from the intersection point of the central axes of the rope and the stepped shaft of the hanging weight to the shaft shoulder of the outermost end shaft section of the stepped shaft of the hanging weight;
the torque formula of the weight to the bearing sleeve when the bearing sleeve rotates by the angle theta is as follows:
T＝mgcosθ(L+x-rtanθ) (5)
wherein m is the weight of the weight, g is the gravity acceleration, and g is 9.8m/s2；
Substituting the formula (4) into the formula (5) and simplifying to obtain:
T＝mg(L-rsinθ)
the work W of the weight on the bearing sleeve in the whole process that the bearing sleeve rotates by the angle gamma is as follows:
the calculation formula of the energy consumption coefficient M of the measured bearing is as follows:
wherein alpha is the angle rotated by the tested bearing from the beginning to the stop;
α＝nβ (8)
wherein, beta is a grating disk corner corresponding to two continuous pulses recorded by the photoelectric sensor;
and (6) and (8) are substituted into formula (7), so that the energy consumption coefficient M of the tested bearing is as follows:
3. the utility model provides a measure antifriction bearing coefficient of energy consumption's device, includes base, axial displacement adjustment mechanism and cylinder, its characterized in that: the device also comprises a connecting sleeve and a measuring mechanism; the axial displacement adjusting mechanism comprises a bearing seat, a ball screw, a linear guide rail and a workbench; a screw rod of the ball screw is supported on a bearing seat through a bearing, and the bearing seat is fixed on the base; the workbench is fixed with a nut block of the ball screw; a slide block of the linear guide rail is fixed with the workbench, and a slide rail of the linear guide rail is fixed on the base; the cylinder body of the cylinder is fixed on the workbench; one end of the connecting sleeve is fixed on a piston rod of the air cylinder; a piston rod of the cylinder is horizontally arranged, and the cylinder is connected with the pneumatic loop system; the pneumatic circuit system is controlled by a controller; the measuring mechanism comprises a mandrel, a supporting seat, a three-jaw chuck, a bearing sleeve, a weight and a photoelectric sensor; the three-jaw chuck is fixed on the base through the supporting seat; the mandrel is clamped and fixed by a three-jaw chuck; two stepped shafts which are symmetrically arranged are fixed on two sides of the outer wall of the bearing sleeve, and a grating disc is fixed on the end face of one end of the bearing sleeve; the photoelectric sensor is fixed on the base and aligned with the grating disc; the signal output end of the photoelectric sensor is connected with the controller; the weight is hung on the annular rope.
4. A device for measuring the coefficient of energy consumption of a rolling bearing according to claim 3, wherein: and a hand wheel is fixed at one end of the ball screw.
5. A device for measuring the coefficient of energy consumption of a rolling bearing according to claim 3, wherein: a piston rod of the air cylinder is provided with threads; one end of the connecting sleeve is provided with an integrally formed end plate, a central hole formed in the end plate is sleeved on a piston rod of the air cylinder, and the nut is in threaded connection with the piston rod of the air cylinder and tightly presses the end plate of the connecting sleeve.
6. A device for measuring the coefficient of energy consumption of a rolling bearing according to claim 3, wherein: the diameter of the supporting shaft section of the mandrel and the inner diameter of the bearing sleeve are provided with various specifications.
7. The apparatus for measuring the coefficient of energy consumption of a rolling bearing according to any one of claims 3 to 6, wherein: the pneumatic loop system comprises a three-way joint, a speed regulating valve, a three-position four-way electromagnetic reversing valve, a hose, a two-position three-way electromagnetic reversing valve and an air pump; a working opening where a piston rod of the air cylinder is located is connected with a first connector of the three-way connector through a hose; one working port and an air outlet of the two-position three-way electromagnetic directional valve are respectively connected with the other working port of the air cylinder and a second interface of the three-way joint; the third interface of the three-way joint is connected with a working port of the three-position four-way electromagnetic directional valve; the air inlet of the three-position four-way electromagnetic reversing valve is connected with the air pump through a hose; the air inlet and the air outlet of the speed regulating valve are respectively connected with the other working port of the three-position four-way electromagnetic reversing valve and the air inlet of the two-position three-way electromagnetic reversing valve through hoses; the speed regulating valve, the three-position four-way electromagnetic reversing valve and the two-position three-way electromagnetic reversing valve are all controlled by the controller.
Technical Field
The invention belongs to the technical field of rolling bearings, and particularly relates to a method and a device for measuring the energy consumption coefficient of a rolling bearing, which are simple in structure and high in precision.
Background
The rolling bearing is an essential part in the mechanical industry, is often applied to various fields such as agricultural machinery, industrial equipment, household appliances and the like, and has the characteristics of easy starting, small friction, stable performance, easy maintenance, simple and convenient maintenance and the like.
With the development of advanced equipment at present, high efficiency, high speed and long service life are the main goals pursued by mechanical equipment. The system performance of the whole mechanical equipment is determined by the performance of the rolling bearing to a great extent, the running accuracy and the running stability of the mechanical equipment are greatly influenced by the performance of the rolling bearing, the rolling bearing is used as a component for providing rotary support in a mechanical system and comprises five parts, namely an outer ring, an inner ring, a steel ball, a sealing ring, a retainer and the like, and the five parts are in mutual contact friction in the rotating process and have certain energy consumption. If the energy loss inside the bearing is too large in the process, the abrasion of the components inside the bearing is increased, and the running precision of the rolling bearing is reduced; and on the other hand, excessive energy loss converted into heat can cause internal temperature to rise, thereby causing the rolling bearing lubricant to fail due to exceeding the applicable temperature, and finally causing the rolling bearing to be damaged due to surface burn of internal components. Therefore, the coefficient of energy consumption is one of the key parameters of the performance, and determines the key technical performance such as internal abrasion, heat generation and service life of the rolling bearing during operation.
The existing testing method is to calculate and obtain the energy consumption coefficient through the measurement and conversion of the friction torque, but because the friction torque value of the bearing is small, the bearing is easily interfered by external conditions and is limited by the measurement precision problem of a sensor, the existing friction torque measurement has large fluctuation and randomness, and the precision is difficult to be identified. Therefore, the method and the device capable of accurately measuring the energy consumption coefficient of the rolling bearing are designed, and are the hot topics of the bearing industry.
Disclosure of Invention
The invention provides a method and a device for measuring the energy consumption coefficient of a rolling bearing, which have high precision and simple structure and aim to solve the problems that the existing rolling bearing energy consumption coefficient measuring mode is low in precision, inaccurate in measurement and difficult to accurately measure.
The technical scheme adopted by the invention is as follows:
based on the principle of an energy conversion method, firstly, a kinetic energy is given to the whole device through a weight, so that a bearing sleeve drives a bearing outer ring to rotate, an inner ring is fixed, in the rotating process, one part of the kinetic energy is converted into the kinetic energy of a bearing, and the other part of the kinetic energy is converted into heat energy due to friction in the bearing; the energy consumption coefficient can be calculated by measuring the kinetic energy and the rotating angle of the bearing. The method breaks through the traditional mode of calculating the energy consumption coefficient by measuring the friction torque, so that the research on the energy consumption coefficient of the bearing can obtain a solution from a new angle.
The invention relates to a method for measuring the energy consumption coefficient of a rolling bearing, which comprises the following steps:
the method comprises the following steps: connecting a cylinder body of the air cylinder with the base through an axial displacement adjusting mechanism, wherein a piston rod of the air cylinder is horizontally arranged; then, connecting the air cylinder with a pneumatic circuit system, wherein the pneumatic circuit system is connected with a controller; one end of the connecting sleeve is fixed on a piston rod of the cylinder.
Step two: fixing the three-jaw chuck on the base through a supporting seat; selecting a mandrel with the diameter of the bearing shaft section being the same as the inner diameter of the measured bearing, and clamping the mandrel on a three-jaw chuck; the inner ring of the bearing to be measured is in transition fit with the supporting shaft section of the mandrel, and a check ring is embedded into a clamping groove formed in the supporting shaft section of the mandrel to axially position the inner ring of the bearing to be measured; and then, selecting a bearing sleeve with the inner diameter being the same as the outer diameter of the measured bearing, and carrying out interference fit on the bearing sleeve and the outer ring of the measured bearing.
Step three: and fixing the photoelectric sensor on the base and aligning to the grating disc fixed at the end face of one end of the bearing sleeve.
Step four: two stepped shafts are symmetrically fixed on the outer wall of the bearing sleeve, and the positions of the cylinder and the connecting sleeve along the axial direction of the mandrel are adjusted through an axial displacement adjusting mechanism, so that the connecting sleeve is aligned with the stepped shafts on the bearing sleeve along the axial direction of the mandrel; then, the step shaft of the bearing sleeve is held by hands to be in a horizontal state; then, the controller controls the pneumatic loop system to drive a piston rod of the air cylinder to push out, so that the connecting sleeve is sleeved on the shaft section of the outermost end of the stepped shaft, close to the air cylinder, on the bearing sleeve, and the connecting sleeve is in clearance fit with the shaft section of the outermost end of the stepped shaft; finally, the rope which is annular and is suspended with the weight is sleeved on the shaft section of the outermost end of the stepped shaft of the bearing sleeve, which is far away from the cylinder.
Step five: the controller controls the pneumatic loop system to drive the piston rod of the air cylinder to retract, the weight falls to drive the bearing sleeve, the grating disc and the outer ring of the tested bearing to synchronously rotate, the photoelectric sensor records the number n of pulse signals, and finally the energy consumption coefficient M is calculated.
Preferably, the calculation process of the energy consumption coefficient M of the measured bearing is as follows:
because the vertical whereabouts of weight, the weight whereabouts in-process, the distance of rope and bearing sleeve the central axis is unchangeable, and the weight breaks away from the bearing sleeve when establishing the bearing sleeve and rotate gamma angle, then gamma's computational formula is:
l is the distance between the shaft shoulder of the outermost shaft section of the stepped shaft for hanging the weight and the central axis of the bearing sleeve, L is the length of the outermost shaft section of the stepped shaft for hanging the weight, and r is the radius of the outermost shaft section of the stepped shaft for hanging the weight;
after simplification, obtaining:
after the formula (1) is deformed, the following components are obtained:
if phi is the included angle from the point on the excircle of the central axis of the stepped shaft of the suspended weight and the outer circle of the end face of the outermost end of the stepped shaft to the perpendicular line of the central axis of the mandrel, phi satisfies:
substituting formula (2) and formula (3) into formula (1) to obtain:
namely:
thereby obtaining:
when the angle theta rotated by the bearing sleeve meets the condition that theta is more than 0 degrees and less than gamma, the following steps are carried out:
wherein, x is the distance that the nodical to the ladder shaft outermost end shaft section shoulder of hanging the weight of rope and the ladder shaft central axis of hanging the weight.
The torque formula of the weight to the bearing sleeve when the bearing sleeve rotates by the angle theta is as follows:
T＝mgcosθ(L+x-rtanθ) (5)
wherein m is the weight of the weight, g is the gravity acceleration, and g is 9.8m/s2。
Substituting the formula (4) into the formula (5) and simplifying to obtain:
T＝mg(L-rsinθ)
the work W of the weight on the bearing sleeve in the whole process that the bearing sleeve rotates by the angle gamma is as follows:
the calculation formula of the energy consumption coefficient M of the measured bearing is as follows:
wherein alpha is the angle rotated by the bearing to be measured from the beginning to the stop of the rotation.
α＝nβ (8)
Where β is the grating disk rotation angle corresponding between two consecutive pulses recorded by the photosensor.
And (6) and (8) are substituted into formula (7), so that the energy consumption coefficient M of the tested bearing is as follows:
the invention relates to a device for measuring the energy consumption coefficient of a rolling bearing, which comprises a base, an axial displacement adjusting mechanism, a cylinder, a connecting sleeve and a measuring mechanism, wherein the axial displacement adjusting mechanism is arranged on the base; the axial displacement adjusting mechanism comprises a bearing seat, a ball screw, a linear guide rail and a workbench; a screw rod of the ball screw is supported on a bearing seat through a bearing, and the bearing seat is fixed on the base; the workbench is fixed with a nut block of the ball screw; a slide block of the linear guide rail is fixed with the workbench, and a slide rail of the linear guide rail is fixed on the base; the cylinder body of the cylinder is fixed on the workbench; one end of the connecting sleeve is fixed on a piston rod of the air cylinder; a piston rod of the cylinder is horizontally arranged, and the cylinder is connected with the pneumatic loop system; the pneumatic circuit system is controlled by a controller; the measuring mechanism comprises a mandrel, a supporting seat, a three-jaw chuck, a bearing sleeve, a weight and a photoelectric sensor; the three-jaw chuck is fixed on the base through the supporting seat; the mandrel is clamped and fixed by a three-jaw chuck; two stepped shafts which are symmetrically arranged are fixed on two sides of the outer wall of the bearing sleeve, and a grating disc is fixed on the end face of one end of the bearing sleeve; the photoelectric sensor is fixed on the base and aligned with the grating disc; the signal output end of the photoelectric sensor is connected with the controller; the weight is hung on the annular rope.
Preferably, a hand wheel is fixed at one end of the ball screw.
Preferably, a piston rod of the air cylinder is provided with threads; one end of the connecting sleeve is provided with an integrally formed end plate, a central hole formed in the end plate is sleeved on a piston rod of the air cylinder, and the nut is in threaded connection with the piston rod of the air cylinder and tightly presses the end plate of the connecting sleeve.
Preferably, the diameter of the bearing shaft section of the mandrel and the inner diameter of the bearing sleeve are provided with various specifications.
Preferably, the pneumatic circuit system comprises a three-way joint, a speed regulating valve, a three-position four-way electromagnetic reversing valve, a hose, a two-position three-way electromagnetic reversing valve and an air pump; a working opening where a piston rod of the air cylinder is located is connected with a first connector of the three-way connector through a hose; one working port and an air outlet of the two-position three-way electromagnetic directional valve are respectively connected with the other working port of the air cylinder and a second interface of the three-way joint; the third interface of the three-way joint is connected with a working port of the three-position four-way electromagnetic directional valve; the air inlet of the three-position four-way electromagnetic reversing valve is connected with the air pump through a hose; the air inlet and the air outlet of the speed regulating valve are respectively connected with the other working port of the three-position four-way electromagnetic reversing valve and the air inlet of the two-position three-way electromagnetic reversing valve through hoses; the speed regulating valve, the three-position four-way electromagnetic reversing valve and the two-position three-way electromagnetic reversing valve are all controlled by the controller.
Compared with the prior art, the invention has the following beneficial results:
1. the invention breaks through the traditional mode of measuring friction torque to calculate the energy consumption coefficient, provides a new method for measuring the energy consumption coefficient of the rolling bearing from the perspective of an energy conversion method, and avoids the problem of large error of the existing friction torque measuring mode, so that the measuring result is more accurate.
2. The invention adopts a pneumatic loop system, realizes the purposes of speed regulation and speed reduction of the process of the cylinder and acceleration of the return stroke, and avoids the interference of the manual return stroke on the bearing sleeve.
3. The invention adopts the connecting sleeve to lead the piston rod of the cylinder to be concentric with the stepped shaft, thereby leading the weight hung on the stepped shaft at the other end to be in a horizontal state.
4. The invention has simple integral structure, convenient operation, simple test condition, good test repeatability and stable obtained data.
Drawings
FIG. 1 is a perspective view of the overall construction of the device of the present invention;
FIG. 2 is a schematic diagram of a pneumatic circuit system of the present invention;
fig. 3 is a schematic view of the position of the weight disengaged from the bearing sleeve in the present invention.
Fig. 4 is a schematic view of a state during rotation of the bearing sleeve according to the present invention.
Fig. 5 is a schematic view showing another state during the rotation of the bearing sleeve in the present invention.
Detailed Description
The technical solution in the embodiments of the present invention is clearly and completely described below with reference to the accompanying drawings.
As shown in fig. 1 and 3, a method for measuring the energy consumption coefficient of a rolling bearing specifically comprises the following steps:
the method comprises the following steps: connecting a cylinder body of a cylinder 8 with the base 1 through an axial displacement adjusting mechanism, wherein a piston rod of the cylinder 8 is horizontally arranged; then, the air cylinder 8 is connected with a pneumatic circuit system, and the pneumatic circuit system is connected with a controller; one end of the connecting sleeve 10 is fixed to the piston rod 9 of the cylinder.
Step two: fixing a three-jaw chuck 13 on the base 1 through a supporting seat 12; selecting a mandrel 11 with the diameter of a supporting shaft section being the same as the inner diameter of a measured bearing 15 and clamping the mandrel 11 on a three-jaw chuck 13; the inner ring of the measured bearing 15 is in transition fit with the supporting shaft section of the mandrel 11, and a check ring is embedded into a clamping groove formed in the supporting shaft section of the mandrel 11 to axially position the inner ring of the measured bearing 15; then, a bearing sleeve 14 with the inner diameter the same as the outer diameter of the measured bearing 15 is selected, and the bearing sleeve 14 is in interference fit with the outer ring of the measured bearing 15.
Step three: the photosensor 17 is fixed to the base 1 in alignment with the grating disk fixed at the end face of one end of the bearing sleeve 14.
Step four: two stepped shafts are symmetrically fixed on the outer wall of the bearing sleeve 14, and the positions of the cylinder and the connecting sleeve 10 along the axial direction of the mandrel 11 are adjusted through an axial displacement adjusting mechanism, so that the stepped shafts on the connecting sleeve 10 and the bearing sleeve 14 are aligned along the axial direction of the mandrel 11; then, the stepped shaft of the bearing sleeve 14 is held by hand, so that the stepped shaft of the bearing sleeve 14 is in a horizontal state; then, the controller controls the piston rod 9 of the pneumatic loop system driving cylinder to push out (the pushing speed is slower), so that the connecting sleeve 10 is sleeved into the shaft section at the outermost end of the stepped shaft close to the cylinder on the bearing sleeve 14, and the connecting sleeve 10 is in clearance fit with the shaft section at the outermost end of the stepped shaft; finally, a rope in the form of a ring and suspended with a weight 16 is looped over the outermost shaft section of the stepped shaft of the bearing sleeve 14 remote from the cylinder 8.
Step five: the controller controls the piston rod 9 of the pneumatic loop system driving cylinder to retract (the retraction speed is high), then the weight 16 falls to drive the bearing sleeve 14, the grating disc and the outer ring of the tested bearing 15 to synchronously rotate, the photoelectric sensor 17 records the number n of pulse signals, and finally the energy consumption coefficient M is calculated.
Preferably, the calculation process of the energy consumption coefficient M of the measured bearing is as follows:
as shown in fig. 3, because the weight falls vertically, the distance between the rope and the central axis of the bearing sleeve is unchanged during the falling process of the weight, and the weight is separated from the bearing sleeve when the bearing sleeve rotates by an angle of gamma, so that the calculation formula of gamma is as follows:
l is the distance between the shaft shoulder of the outermost shaft section of the stepped shaft for hanging the weight and the central axis of the bearing sleeve, L is the length of the outermost shaft section of the stepped shaft for hanging the weight, and r is the radius of the outermost shaft section of the stepped shaft for hanging the weight;
after simplification, obtaining:
after the formula (1) is deformed, the following components are obtained:
if phi is the included angle from the point on the excircle of the central axis of the stepped shaft for hanging the weights and the outer circle of the end face of the outermost end of the stepped shaft to the perpendicular line of the central axis of the mandrel 11, phi satisfies:
substituting formula (2) and formula (3) into formula (1) to obtain:
namely:
thereby obtaining:
as shown in fig. 4 and 5, when the bearing sleeve is rotated by an angle θ satisfying 0 ° < θ < γ, there are:
wherein, x is the distance that the nodical to the ladder shaft outermost end shaft section shoulder of hanging the weight of rope and the ladder shaft central axis of hanging the weight.
The torque formula of the weight to the bearing sleeve when the bearing sleeve rotates by the angle theta is as follows:
T＝mgcosθ(L+x-rtanθ) (5)
wherein m is the weight of the weight, g is the gravity acceleration, and g is 9.8m/s2。
Fig. 4 is a schematic view of a position during rotation of the bearing sleeve still at x < l, fig. 5 is a schematic view of a position during rotation of the bearing sleeve at x > l, and for the positions of fig. 4 and 5, both equations (4) and (5) apply.
Substituting the formula (4) into the formula (5) and simplifying to obtain:
T＝mg(L-rsinθ)
because the work done by the torque is the product of the torque and the angle, the work W done by the weight on the bearing sleeve in the whole process of the bearing sleeve rotating through the angle γ is:
the calculation formula of the energy consumption coefficient M of the measured bearing is as follows:
wherein alpha is the angle rotated by the bearing to be measured from the beginning to the stop of the rotation.
α＝nβ (8)
Where β is the grating disk rotation angle corresponding between two consecutive pulses recorded by the photosensor.
And (6) and (8) are substituted into formula (7), so that the energy consumption coefficient M of the tested bearing is as follows:
as shown in fig. 1, a device for measuring the energy consumption coefficient of a rolling bearing comprises a base 1, an axial displacement adjusting mechanism, a cylinder 8, a connecting sleeve 10 and a measuring mechanism; the axial displacement adjusting mechanism comprises a bearing seat 3, a ball screw 4, a linear guide rail 5 and a workbench 6; a screw rod of the ball screw 4 is supported on a bearing seat 3 through a bearing, and the bearing seat 3 is fixed on the base 1; the workbench 6 is fixed with the nut block of the ball screw 4; a slide block of the linear guide rail 5 is fixed with the workbench 6, and a slide rail of the linear guide rail 5 is fixed on the base 1; the cylinder body of the cylinder 8 is fixed with the baffle 7, and the baffle 7 is fixed on the workbench 6; one end of the connecting sleeve 10 is fixed on the piston rod 9 of the cylinder; a piston rod 9 of the cylinder is horizontally arranged, and the cylinder 8 is connected with a pneumatic loop system; the pneumatic circuit system is controlled by the controller; the measuring mechanism comprises a mandrel 11, a supporting seat 12, a three-jaw chuck 13, a bearing sleeve 14, a weight 16 and a photoelectric sensor 17; the supporting seat 12 is fixed on the base 1; the three-jaw chuck 13 is fixed on the supporting seat 12; the mandrel 11 is clamped and fixed by a three-jaw chuck 13; two symmetrically arranged stepped shafts are fixed on two sides of the outer wall of the bearing sleeve 14, and a grating disc is fixed on the end face of one end; the photoelectric sensor 17 is fixed on the base 1 and aligned with the grating disk; the signal output end of the photoelectric sensor 17 is connected with the controller; when the grating disk rotates by an angle, the photoelectric sensor 17 generates a pulse signal and transmits the pulse signal to the controller; the weight 16 is suspended from a string in the form of a loop.
Preferably, a hand wheel 2 is fixed to one end of the ball screw 4.
Preferably, the piston rod 9 of the cylinder is provided with a thread; one end of the connecting sleeve 10 is provided with an integrally formed end plate, a central hole formed in the end plate is sleeved on the piston rod 9 of the cylinder, and the nut is connected with the thread of the piston rod 9 of the cylinder and tightly presses the end plate of the connecting sleeve 10.
Preferably, the support shaft section diameter of the mandrel 11 and the inner diameter of the bearing sleeve 14 are each provided with a variety of specifications to accommodate different bearing measurements.
Preferably, as shown in fig. 2, the pneumatic circuit system comprises a three-way joint 18, a speed regulating valve 19, a three-position four-way electromagnetic directional valve 20, a hose 21, a two-position three-way electromagnetic directional valve 22 and an air pump 23; a working port where a piston rod of the air cylinder 8 is located is connected with a first connector of the three-way connector 18 through a hose 21; one working port (port A) and an air outlet T of the two-position three-way electromagnetic directional valve 22 are respectively connected with the other working port of the air cylinder 8 and a second port of the three-way joint 18; the third interface of the three-way joint 18 is connected with a working port (port B) of the three-position four-way electromagnetic directional valve 20; an air inlet P of the three-position four-way electromagnetic directional valve 20 is connected with an air pump 23 through a hose 21; an air inlet and an air outlet of the speed regulating valve 19 are respectively connected with the other working port (port A) of the three-position four-way electromagnetic directional valve 20 and an air inlet P of the two-position three-way electromagnetic directional valve 22 through a hose 21; the speed regulating valve 19, the three-position four-way electromagnetic directional valve 20 and the two-position three-way electromagnetic directional valve 22 are all controlled by a controller. The push stroke of the cylinder adopts a speed regulating valve 19 for speed regulation, and the return stroke adopts differential quick return: when the three-position four-way electromagnetic directional valve is positioned at a left position (the port P is communicated with the port A), and the two-position three-way electromagnetic directional valve is also positioned at the left position (the port P is communicated with the port A), airflow enters from the port P and the port A of the three-position four-way electromagnetic directional valve, enters the cylinder through the speed regulating valve and the two-position three-way electromagnetic directional valve, a piston rod of the cylinder is pushed out, gas in a cavity where the piston rod is positioned is communicated with outside gas through the port B and the port T of the three-position four-way electromagnetic directional valve to form a speed regulating loop, and the speed of the process of the cylinder is regulated through the speed regulating valve; when the three-position four-way electromagnetic directional valve is positioned at the right position (the port P is communicated with the port B), and the two-position three-way electromagnetic directional valve is also positioned at the right position (the port T is communicated with the port A), airflow enters the cylinder from the port P and the port B of the three-position four-way electromagnetic directional valve, a piston rod of the cylinder retracts, and air at the left end of the cylinder is communicated with the entering air at the three-way joint through the port A and the port T of the two-position three-way electromagnetic directional valve to form a differential loop, so that the piston rod of the cylinder can retract quickly.
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