CN102410902B

CN102410902B - Ball and disc type tester for measuring elastic fluid frictional force of lubricant

Info

Publication number: CN102410902B
Application number: CN 201110372454
Authority: CN
Inventors: 王燕霜; 曹佳伟; 李璞; 高鹏飞; 承军伟; 杨伯原; 李航; 祝海峰; 张贝; 袁倩倩; 李燕
Original assignee: Henan University of Science and Technology
Current assignee: Qilu University of Technology
Priority date: 2011-11-22
Filing date: 2011-11-22
Publication date: 2013-12-25
Anticipated expiration: 2031-11-22
Also published as: CN102410902A

Abstract

A ball-on-disk tester for testing the elastohydrodynamic friction of lubricants, the tester includes a chassis, an electric spindle A, an electric spindle B, a disc test piece, a ball test piece, a static pressure vertical shaft, and a bracket , a friction sensor and a lever mechanism; the upper surface of the bottom frame vertically fixes the electric spindle A and the electric spindle B, the end of the electric spindle A is fixed to the disk test piece, and the end of the electric spindle B is fixed with a plate corresponding to the disk test piece. The ball test piece; the electric spindle B is fixed at a position higher than the electric spindle A through the bracket in contact with the friction sensor, and the height is adjusted by the static pressure vertical shaft and the lever mechanism; the tester can simulate the friction between the two contact pieces. The state of rolling with sliding and the state of elastohydrodynamic lubrication can accurately measure the friction force of lubricating oil.

Description

A kind of ball disc type tester for measuring elastic fluid frictional force of lubricant

[technical field]

The present invention relates to a kind of tester, especially relate to a kind of ball disc type tester for test lubricant bullet stream friction force.

[background technology]

Known, elastohydrodynamic lubrication is called for short elastohydrodynamic lubrication, it is the hydrodynamic lubrication problem between research dotted line contact Elastic surface, specifically refer in the process be in contact with one another at two solid surface with relative motion, consider the elastic deformation of solid and the liquid lubrication of lubricating oil viscosity variation effect; The driving member such as rolling bearing, gear is in ehl status in most cases, can form one deck elastohydrodynamic lubrication oil film between two contact elements, the bullet of oil film stream rubbing characteristics on the dynamic behavior impact of the driving members such as rolling bearing, gear greatly, as the oil film friction force existed between bearing roller and raceway can cause the excessive slip of rolling body; The inertial load that the excessive slip of rolling body produces has determined the order of severity of rolling body and retainer collision, this has greatly affected kinetic stability and the serviceable life of retainer, if do not controlled, will cause the destruction of retainer, thereby badly influence the serviceable life of rolling bearing; Because different lubricants has different rubbing characteristicss, therefore, carry out according to the frictional behaviour of lubricant slip and the rolling that design bearing can not only be controlled rolling body, and can control to a great extent the stability of retainer, simultaneously the serviceable life of corresponding raising bearing; From the above, lubricant bullet stream friction force is to carry out the driving members such as rolling bearing, gear to design one of requisite significant data, and therefore, the accuracy of lubricant bullet stream friction testing device just seems particularly important;

At present, research to lubricant friction force, that on four ball frictional testing machines, is tested is more, but four ball frictional testing machines can only be simulated the sliding motion between two contact elements, and friction force when it only can the test lubricant boundary lubrication, the companion of the slip between two contact elements rolling condition in reality can not be simulated, ehl status can not be simulated; Secondly, can also to lubricant friction force, be tested by ball disc type lubricating oil friction force testing table, but the loading structure of existing ball disc type lubricating oil friction force testing table is divided into two kinds of hydraulic loaded structure and hinge loading structures, its hydraulic loaded structure has and loads unsettled defect in practical operation, and the swing meeting that the hinge loading structure produces in operation impacts the test of lubricating oil friction force, thereby can't accurately record the friction force of lubricating oil.

[summary of the invention]

In order to overcome the deficiency in background technology, the present invention discloses a kind of ball disc type tester for measuring elastic fluid frictional force of lubricant, described tester can be simulated rolling between two contact elements with sliding mode and ehl status, thereby can accurately record the friction force of lubricating oil.

For achieving the above object, the present invention adopts following technical scheme:

A kind of ball disc type tester for measuring elastic fluid frictional force of lubricant, described tester comprises underframe, electric principal axis A, electric main shaft B, dish test specimen, ball test specimen, static pressure vertical shaft, carriage, friction force sensor and leverage; Described underframe upper side is fixedly installed two vertical sleeves; The inside of sleeve A is set with vertical electric principal axis A, and the upper side of sleeve A is fixed with the oil sump box; Upper side and the sealing of the outstanding sleeve A of described electric principal axis A upper end stretch in the oil sump box; Described dish test specimen is fixedly mounted on the termination section of the electric principal axis A that is positioned at oil sump box inside;

The upper and lower two ends of the inwall of described sleeve B fixedly mount respectively a hydrostatic bearing, and two hydrostatic bearings are isometrical; Described static pressure vertical shaft is socketed in sleeve B inside by the mesopore of two hydrostatic bearings, and the upper side of static pressure vertical shaft is higher than the upper side of sleeve B, and the upper side of static pressure vertical shaft is connected with the bottom surfaces center of carriage; Described sleeve B upper side is equipped with the friction force sensor be connected with data collector, and the upper side of friction force sensor contacts with the bottom surfaces of carriage; Described electric main shaft B is skewed and is fixedly mounted on carriage, and the termination sealing that electric main shaft B is positioned at below stretches to the oil sump box; Described ball test specimen is fixedly mounted on the termination section of the electric main shaft B that is positioned at oil sump box inside, and the ball test specimen bottom surfaces be arranged on electric main shaft B is not less than the dish test specimen upper side be arranged on electric principal axis A;

Described leverage comprises lever, briquetting and electromagnet; Described lever is arranged on the below of underframe upper side, and an end of lever is provided with the push rod that upwards runs through the underframe upper side and conflict with static pressure vertical shaft bottom surfaces center, and the other end of lever connects briquetting; Described briquetting is made by the material that can be adsorbed by electromagnet, and the weight of briquetting is greater than the general assembly (TW) of static pressure vertical shaft, carriage and electric main shaft B; Described electromagnet is fixedly mounted on the position of vertical corresponding briquetting upper side on underframe.

Described ball disc type tester for measuring elastic fluid frictional force of lubricant, described oil sump box comprises box body and sealing box cover; Described box body upper side is made as the uncovered of corresponding sealing box cover, and the bottom center of box body is provided with the through hole that extends to middle part in box body, and the inwall upper end, hole of through hole is fixedly installed the O-ring seal A supporting with electric principal axis A upper end head diameter; One lateral body wall upper end of box body is provided with the perforation that is through to box body inside, and the perforation inwall is fixedly installed the O-ring seal B supporting with termination, electric main shaft B below diameter.

Described ball disc type tester for measuring elastic fluid frictional force of lubricant, the diameter of described ball test specimen is 20mm, the diameter of described dish test specimen is 80mm, and the surfaceness of ball test specimen and dish test specimen is 0.02mm, loading range is 10～150N, the rolling speed scope is 10～50m/s, the Film Thickness Ratio λ of bullet stream oil film > 3; Wherein, λ=hmin/ σ, hmin is minimum oil film thickness, σ is ball test specimen and the comprehensive roughness of coiling test specimen.

Described ball disc type tester for measuring elastic fluid frictional force of lubricant, described carriage is the column structure that a middle part is provided with inclined via-hole, the external diameter of the diameter of inclined via-hole and electric main shaft B is supporting, and at least is provided with two fastening screws that connect respectively to inclined via-hole at bracket surface.

Described ball disc type tester for measuring elastic fluid frictional force of lubricant, described fastening screw is perpendicular to inclined via-hole.

Described ball disc type tester for measuring elastic fluid frictional force of lubricant, described electromagnet is to the electromagnetic force of briquetting and the total force of making a concerted effort to equal electric main shaft B, carriage and static pressure vertical shaft of briquetting weight.

Described ball disc type tester for measuring elastic fluid frictional force of lubricant, described carriage upper side fixed installation is useful on the weighted platform that loads counterweight.

Described ball disc type tester for measuring elastic fluid frictional force of lubricant, described friction force sensor is digital sensor.

Owing to adopting technical scheme as above, the present invention has following beneficial effect:

Ball disc type tester for measuring elastic fluid frictional force of lubricant of the present invention is with respectively Moving plate test specimen and the rotation of ball test specimen by electric principal axis A and electric main shaft B, when the dish test specimen contacts with the ball test specimen, in the oil sump box, lubricating oil to be tested can be entrainmented goal dish contact region, then, adjust respectively the rotating speed of electric principal axis A and electric main shaft B, make the ball test specimen different from the dish linear velocity of test specimen at the contact point place and produce relative sliding, thereby reached purpose that simulating between two contact elements the companion's sliding mode that rolls; Because the diameter of ball test specimen is 20mm, the diameter of dish test specimen is 80mm, and the surfaceness of ball test specimen and dish test specimen is 0.02mm, and loading range is 10～150N, and the rolling speed scope is 10～50m/s, effectively guaranteed the Film Thickness Ratio λ of bullet stream oil film > 3, thereby guaranteed that ball test specimen and the contact region of dish between test specimen are in complete ehl status, wherein, λ=hmin/ σ, hmin is minimum oil film thickness, and σ is ball test specimen and the comprehensive roughness of coiling test specimen; Under the effect of friction force, electric main shaft B and carriage can deflect around the axis of static pressure vertical shaft, thereby reach by carriage, oppress friction force sensor, and utilize friction force sensor related data to be recorded to the purpose of collecting by data collector;

When test, adjust the rotating speed of electric principal axis A or electric main shaft B, can record different sliding rolling than the numerical value of lower lubricating oil bullet stream friction force, change load, electric principal axis A and electric main shaft B speed and, can record the numerical value of lubricating oil bullet stream friction force under different loads, different rolling speed; Because the friction force between static pressure vertical shaft and hydrostatic bearing is far smaller than the friction force between static pressure vertical shaft and general rolling bearing, so when electric main shaft B, carriage and static pressure vertical shaft during around static pressure vertical shaft axis tilt, friction factor between static pressure vertical shaft and hydrostatic bearing is less one more than the order of magnitude than tested friction coefficient of lubricating oil, thereby reach the friction of ignoring between static pressure vertical shaft and hydrostatic bearing, realized accurately recording the purpose of lubricating oil friction force; In addition, can in test process, by effectively adjusting described carriage, control the position of electric main shaft B, thereby reached, control better the ball test specimen and coil contacting between test specimen, the purpose of raising dish test specimen utilization factor; Secondly, the general assembly (TW) of utilizing described leverage can reach in test process to eliminate electric main shaft B, carriage and static pressure vertical shaft contact the impact of normal load on the ball test specimen with the dish test specimen, but also can play in stopped status or effective protection ball test specimen and coil the effect that test specimen is not damaged while cutting off the power supply suddenly; Simultaneously, utilize described leverage and load counterweight, can directly read the numerical value of normal load, having reached and loaded accurately, stablize and simple purpose.

[accompanying drawing explanation]

Fig. 1 is schematic diagram of the present invention;

Fig. 2 is the cut-away view of described oil sump box;

Fig. 3 is another kind of structural representation of the present invention.

In figure: 1, underframe; 2, sleeve A; 3, sleeve B; 4, electric principal axis A; 5, oil sump box; 6, dish test specimen; 7, hydrostatic bearing; 8, static pressure vertical shaft; 9, carriage; 10, friction force sensor; 11, electric main shaft B; 12, ball test specimen; 13, lever; 14, briquetting; 15, electromagnet; 16, push rod; 17, box body; 18, sealing box cover; 19, through hole; 20, O-ring seal A; 21, perforation; 22, O-ring seal B; 23, inclined via-hole; 24, fastening screw; 25, weighted platform.

[embodiment]

Can explain in more detail the present invention by the following examples, disclose purpose of the present invention and be intended to protect all changes and improvements in the scope of the invention, the present invention is not limited to the following examples;

1～2 described a kind of ball disc type tester for measuring elastic fluid frictional force of lubricant by reference to the accompanying drawings, described tester comprises underframe 1, electric principal axis A 4, electric main shaft B 11, dish test specimen 6, ball test specimen 12, static pressure vertical shaft 8, carriage 9, friction force sensor 10 and leverage; Described underframe 1 upper side is fixedly installed two vertical sleeves; The inside of sleeve A 2 is set with vertical electric principal axis A 4, and the upper side of sleeve A 2 is fixed with oil sump box 5; Upper side and the sealing of the outstanding sleeve A 2 of described electric principal axis A 4 upper ends stretch in oil sump box 5, described dish test specimen 6 is fixedly mounted on the termination section of the electric principal axis A 4 that is positioned at oil sump box 5 inside, drive by electric principal axis A 4 dish test specimen 6 rotations that are positioned at oil sump box 5, and electric principal axis A 4 when rotated, the lubricating oil to be measured in oil sump box 5 can not flow out along the outer wall of electric principal axis A 4 yet;

The upper and lower two ends of the inwall of described sleeve B 3 fixedly mount respectively a hydrostatic bearing 7, and two hydrostatic bearings 7 are isometrical; Described static pressure vertical shaft 8 is socketed in sleeve B 3 inside by the mesopore of two hydrostatic bearings 7, and static pressure vertical shaft 8 can utilize two hydrostatic bearings 7 to slide up and down in the inside of sleeve B 3; The upper side of static pressure vertical shaft 8 is higher than the upper side of sleeve B 3, and the upper side of static pressure vertical shaft 8 is connected with the bottom surfaces center of carriage 9, thereby reaches the purpose that carriage 9 is moved up and down with static pressure vertical shaft 8 in stressed uniform state; Described sleeve B 3 upper side are equipped with the friction force sensor 10 be connected with data collector, and the upper side of friction force sensor 10 contacts with the bottom surfaces of carriage 9, thereby when ball test specimen 12 contacts with dish test specimen 6, by carriage 9, the power be subject to is passed to friction force sensor 10, and utilizes friction force sensor 10 that related data is recorded and collects by data collector; For making the sensing effect more accurate, friction force sensor 10 is made as to digital sensor;

Described electric main shaft B 11 is skewed and is fixedly mounted on carriage 9, and the termination sealing that electric main shaft B 11 is positioned at below stretches to oil sump box 5, described ball test specimen 12 is fixedly mounted on the termination section of the electric main shaft B 11 that is positioned at oil sump box 5 inside, drive by electric main shaft B 11 ball test specimen 12 rotations that are positioned at oil sump box 5, and electric main shaft B 11 when rotated, the lubricating oil to be measured in oil sump box 5 can not overflow along the outer wall of electric main shaft B 11 yet; For effectively making ball test specimen 12 and dish test specimen 6 come in contact, ball test specimen 12 bottom surfaces that are arranged on electric main shaft B 11 are not less than dish test specimen 6 upper side that are arranged on electric principal axis A 4; Fixedly be skewed electric main shaft B 11 on carriage 9 for being more convenient for, described carriage 9 is the column structure that a middle part is provided with inclined via-hole 23, the external diameter of the diameter of inclined via-hole 23 and electric main shaft B 11 is supporting, and at least be provided with two fastening screws 24 that connect respectively to inclined via-hole 23 on carriage 9 surfaces, thereby be inserted in inclined via-hole 23 at electric main shaft B 11, and, when appropriate location, can to electric main shaft B 11, carry out fastening spacing by the screw of tightening in fastening screw 24; In addition, along the position of the adjusting of centerline of inclined via-hole 23 electricity main shaft B 11, the ball test specimen 12 that can make to be arranged on electric main shaft B 11 ends with dish test specimen 6 in best contact position, thereby the corresponding utilization factor that has improved dish test specimen 6; For further strengthening the fastening position-limiting action of the interior screw of fastening screw 24 to electric main shaft B 11, described fastening screw 24 is all perpendicular to inclined via-hole 23.

Described oil sump box 5 comprises box body 17 and sealing box cover 18; Described box body 17 upper side are made as the uncovered of corresponding sealing box cover 18, the bottom center of box body 17 is provided with the through hole 19 that extends to box body 17 interior middle parts, and the inwall upper end, hole of through hole 19 is fixedly installed the O-ring seal A 20 supporting with electric principal axis A 4 upper end head diameters, thereby guaranteed electric principal axis A 4 when rotated, the lubricating oil to be measured in oil sump box 5 can not flow out along the outer wall of electric principal axis A 4; One lateral body wall upper end of box body 17 is provided with the perforation 21 that is through to box body 17 inside, 21 inwalls of boring a hole are fixedly installed the O-ring seal B 22 supporting with electric main shaft B 11 termination, below diameters, guaranteed electric main shaft B 11 when rotated, the lubricating oil to be measured in oil sump box 5 can not overflow along the outer wall of electric main shaft B 11;

Described leverage comprises lever 13, briquetting 14 and electromagnet 15, described lever 13 is arranged on the below of underframe 1 upper side, one end of lever 13 is provided with the push rod 16 that upwards runs through underframe 1 upper side and contact with static pressure vertical shaft 8 bottom surfaces centers, can utilize by the action of adjusting lever 13 push rod 16 to control the knee-action of adjusting static pressure vertical shaft 8, the other end of lever 13 is connected with the briquetting 14 of being made by the material that can be adsorbed by electromagnet 15, and the weight of briquetting 14 is greater than static pressure vertical shaft 8, the general assembly (TW) of carriage 9 and electric main shaft B 11, in addition, described electromagnet 15 is fixedly mounted on the position of vertical corresponding briquetting 14 upper side on underframe 1, utilized the weight of briquetting 14 to guarantee without test operation the time, ball test specimen 12 can not come in contact with dish test specimen 6, and when test operation, by the absorption affinity of adjusting 15 pairs of briquettings 14 of electromagnet, effectively control ball test specimen 12 and coil contacting between test specimen 6, eliminated electric main shaft B 11 simultaneously, the general assembly (TW) of carriage 9 and static pressure vertical shaft 8 contacts the impact of normal load on ball test specimen 12 and dish test specimen 6, control the acting force between electromagnet 15 and briquetting 14 for being more convenient for, the electromagnetism absorption affinity of 15 pairs of briquettings 14 of described electromagnet and the total force of making a concerted effort to equal electric main shaft B 11, carriage 9 and static pressure vertical shaft 8 of briquetting 14 weight.

While implementing ball disc type tester for measuring elastic fluid frictional force of lubricant of the present invention, first in oil sump box 5, inject appropriate tested lubricating oil, make again electric principal axis A 4 and electric main shaft B 11 be with respectively Moving

plate test specimen

6 and 12 rotations of ball test specimen, thereby make the tested lubricating oil in oil sump box 5 be entrainmented goal dish contact region, the counterweight that then utilizes the absorption affinity of 15 pairs of briquettings 14 of electromagnet and load corresponding weight on carriage 9 makes ball test specimen 12 and coils test specimen 6 and accurately contact; Now, because the counterweight weight loaded is the normal load between ball test specimen 12 and dish test specimen 6, while therefore operating described tester, not only load accurately, and easy to operate; In practical operation, load counterweight for being more convenient for, with reference to accompanying drawing 3, can be useful on the weighted platform 25 that loads counterweight in described carriage 9 upper side fixed installations;

Under the effect of normal load, ball test specimen 12 contacts and certain elastic deformation occurs with dish test specimen 6, can form one deck elastic fluid dynamic pressure oil film between ball dish contact region, now, by adjusting the rotating speed of two electric main shafts, make between ball test specimen 12 and dish test specimen 6 surface in contacts and produce relative sliding, the stream of the bullet between two surface in contacts oil film will produce friction force to ball test specimen 12 and dish test specimen 6; Under the friction force effect, electric main shaft B 11 and carriage 9 are deflected around the axis of static pressure vertical shaft 8, thereby compressing friction force sensor 10, be converted to digital signal to force signal by friction force sensor 10, and record the related data of collecting friction force by data collector; Electromagnet 15 outages when test finishes, static pressure vertical shaft 8 is by push rod 16 jack-up on lever 13, and ball test specimen 12 is thrown off with dish test specimen 6, realizes unloading.

Part not in the detailed description of the invention is prior art, therefore the present invention is not described in detail.

Claims

1. a ball-on-disk type lubricant elastohydrodynamic friction tester, is characterized in that: described tester comprises underframe (1), electric spindle A (4), electric spindle B (11), disc test piece ( 6), ball test piece (12), static pressure vertical shaft (8), bracket (9), friction sensor (10) and lever mechanism; The upper surface of the underframe (1) is fixedly provided with two vertical sleeve; the sleeve A (2) is fitted with a vertical electric spindle A (4), and the upper surface of the sleeve A (2) is fixed with an oil pool box (5); the electric spindle A (4 ) protrudes from the upper surface of the sleeve A (2) and seals into the oil pool box (5); the disc test piece (6) is fixedly installed on the electric spindle A located inside the oil pool box (5) (4) the end of the head;

The upper and lower ends of the inner wall of the sleeve B (3) are respectively fixed with a static pressure bearing (7), and the two static pressure bearings (7) are equal in diameter; the static pressure vertical shaft (8) passes through two static pressure The middle hole of the bearing (7) is socketed inside the sleeve B (3), the upper surface of the static pressure vertical shaft (8) is higher than the upper surface of the sleeve B (3), and the upper surface of the static pressure vertical shaft (8) is in line with the The lower surface of the bracket (9) is centrally connected; the upper surface of the sleeve B (3) is equipped with a friction sensor (10) connected to the data acquisition device, and the upper surface of the friction sensor (10) is connected to the bracket The lower surface of (9) is in contact; the electric spindle B (11) is fixedly installed on the bracket (9) in an inclined shape, and the end seal of the electric spindle B (11) at the bottom extends into the oil pool box ( 5) inside; the ball test piece (12) is fixedly installed on the end of the electric spindle B (11) inside the oil sump box (5), and the ball test piece installed on the electric spindle B (11) (12) The lower surface is not lower than the upper surface of the disc test piece (6) installed on the electric spindle A (4);

Described lever mechanism comprises lever (13), briquetting block (14) and electromagnet (15); Described lever (13) is installed below the upper surface of chassis (1), and one end of lever (13) is provided with The push rod (16) that penetrates the upper surface of the chassis (1) upwards and conflicts with the center of the lower surface of the static pressure vertical shaft (8), and the other end of the lever (13) is connected to the briquetting block (14); the briquetting block (14) Made of substances that can be adsorbed by electromagnets (15), and the weight of the briquetting block (14) is greater than the total weight of the static pressure vertical shaft (8), bracket (9) and electric spindle B (11); Iron (15) is fixedly installed on the bottom frame (1) and vertically corresponds to the position of the upper surface of briquetting block (14).

2. ball-on-disk type lubricant elastohydrodynamic friction tester according to claim 1, is characterized in that: described oil sump box (5) comprises box body (17) and sealing box cover (18); The upper surface of the box body (17) is set as the opening of the corresponding sealed box cover (18), and the center of the bottom surface of the box body (17) is provided with a through hole (19) extending to the middle part of the box body (17), and the through hole The upper end of the inner wall of the hole of (19) is fixedly provided with a seal ring A (20) matching the diameter of the upper end of the electric spindle A (4); the upper end of the side wall of the box body (17) is provided with a Inside the perforation (21), the inner wall of the perforation (21) is fixedly provided with a sealing ring B (22) matching the diameter of the lower end of the electric spindle B (11).

3. The ball-on-disk lubricant elastohydrodynamic friction tester according to claim 1, characterized in that: the diameter of the ball test piece (12) is 20 mm, and the diameter of the disc test piece (6) is 80 mm , and the surface roughness of the ball specimen (12) and disc specimen (6) is 0.02mm, the loading range is 10-150N, the rolling speed range is 10-50m/s, and the film thickness ratio of the elastodynamic oil film λ>3 ; where λ=hmin/σ, hmin is the minimum oil film thickness, and σ is the comprehensive roughness of the ball specimen (12) and disc specimen (6).

4. The ball-on-disk lubricant elastohydrodynamic friction tester according to claim 1, characterized in that: the bracket (9) is a cylindrical structure with an inclined through hole (23) in the middle, and the inclined The diameter of the through hole (23) matches the outer diameter of the electric spindle B (11), and at least two fastening screw holes (24) respectively penetrating to the inclined through hole (23) are provided on the surface of the bracket (9).

5. The ball-on-disk lubricant elastohydrodynamic friction tester according to claim 4, characterized in that: said fastening screw hole (24) is perpendicular to the inclined through hole (23).

6. The ball-on-disk type lubricant elastohydrodynamic friction tester according to claim 1, is characterized in that: the electromagnetic force of the described electromagnet (15) to the briquetting block (14) and the weight of the briquetting block (14) The resultant force is equal to the total gravity of the electric spindle B (11), the bracket (9) and the static pressure vertical shaft (8).

7. The ball-on-disk lubricant elastohydrodynamic friction tester according to any one of claims 1, 4 or 6, characterized in that: the upper surface of the bracket (9) is fixedly installed with a loading device for loading weights platform (25).

8. The ball-on-disk lubricant elastohydrodynamic friction tester according to claim 1, characterized in that: the friction sensor (10) is a digital sensor.