Four-point contact ball bearing test tool for medical robot

Abstract

The application provides a four-point contact ball bearing test tool for medical robots, which comprises a driving assembly, a loading assembly and a mounting seat, the mounting seat is arranged between the driving assembly and the loading assembly, the mounting seat is provided with an inner hole, a test shaft and a plurality of positioning rings, the inner hole extends axially and can be used for rotating the test shaft to pass through, the plurality of positioning rings are detachably connected at both ends of the corresponding inner hole of the mounting seat, the inner wall of the positioning ring is provided with a first positioning groove, one end of the test shaft is provided with an adjusting block, the other end of the test shaft and the adjusting block are respectively provided with a second positioning groove and a third positioning groove, and the second positioning groove and the third positioning groove are used for nesting the inner ring of the test bearing. In view of the defects of the prior art, the four-point contact ball bearing test tool for medical robots can simultaneously test two four-point contact ball bearings with different sizes, and can detect the matching condition between the two four-point contact ball bearings.

Description

Technical Field

[0001] This invention relates to a testing fixture for a four-point contact ball bearing used in medical robots. Background Technology

[0002] Four-point contact ball bearings are a type of angular contact ball bearing. They are named for the four-point contact between the rollers and raceways when bearing no load or only radial load. Four-point contact ball bearings primarily bear axial loads and can also operate well under combined loads with a certain radial load. They also perform well at high speeds, making them widely applicable, such as in medical robots. However, their use in medical robots often requires the use of four-point contact ball bearings of different sizes. Existing testing fixtures for four-point contact ball bearings typically include a drive device and a loading device. The loading device applies an axial load to the four-point contact ball bearing, and the drive device drives the bearing to rotate. However, existing technologies only test individual four-point contact ball bearings and lack fixtures for testing pairs of four-point contact ball bearings, especially those of different sizes. This makes it difficult to accurately simulate the operation and interaction of four-point contact ball bearings in medical robots. Summary of the Invention

[0003] To address the shortcomings of existing technologies, this invention provides a testing fixture for four-point contact ball bearings used in medical robots that can simultaneously test two four-point contact ball bearings of different sizes and specifications, and can detect the fit between the two bearings.

[0004] To achieve the above objectives, the present invention provides a testing fixture for a four-point contact ball bearing used in medical robots, comprising a drive assembly, a loading assembly, and a mounting base. The mounting base is disposed between the drive assembly and the loading assembly. The mounting base has an inner hole, a test shaft, and several positioning rings. The inner hole extends axially and allows the test shaft to rotatably pass through it. The several positioning rings are detachably connected to both ends of the inner hole of the mounting base. The inner wall of each positioning ring has a first positioning groove for positioning with the outer ring of the test bearing. Both ends of the test shaft are connected to the drive assembly and the loading assembly respectively. An adjusting block is detachably disposed at one end of the test shaft. A second positioning groove and a third positioning groove are respectively disposed at the other end of the test shaft and on the adjusting block. Both the second and third positioning grooves are used for the inner ring of the test bearing to be nested therein.

[0005] The advantages of the above technical solution are as follows: By setting a mounting base between the drive assembly and the loading assembly, and setting an inner hole, a test shaft, and several positioning rings on the mounting base, the test shaft rotates through the axially extending inner hole, and the two ends of the test shaft are respectively connected to the drive assembly and the loading assembly for transmission. The two ends of the test shaft are also respectively equipped with a third positioning groove and an adjusting block with a second positioning groove, which can position the inner rings of the two test bearings. The positioning rings are installed at both ends of the inner hole, and the outer rings of the test bearings are positioned using the first positioning groove on the positioning rings. Then, the drive assembly and the loading assembly, in cooperation with the test shaft, can respectively drive the test shaft to rotate and apply loads for testing. Since the adjusting block with the positioning groove and the several positioning rings are detachably connected, while simultaneously testing two test bearings, the adjusting block and positioning rings can be disassembled and replaced according to the size of the test bearing at one end of the test shaft. This achieves the effect of simultaneously testing two four-point contact ball bearings of different sizes and can also detect the fit between the two point contact ball bearings.

[0006] The present invention can be further configured such that the cross-section of the inner wall of the second positioning groove and the third positioning groove is L-shaped and semi-open, the test shaft is detachably provided with several baffles, the baffles can be fitted and positioned on the test shaft to cover the second positioning groove or the third positioning groove, and the baffles can press the inner ring of the test bearing into the radial inner wall of the second positioning groove or the third positioning groove by abutting fit.

[0007] By further designing the second and third positioning grooves into L-shaped semi-open forms, the installation of the test bearing can be facilitated. Several removable baffles are also installed on the test shaft. After the test bearing is installed on the test shaft, the baffles are then installed on the test shaft, and the inner ring of the test bearing is pressed against the radial inner wall of the second or third positioning groove, which facilitates the installation of the test bearing.

[0008] The present invention can be further configured such that: the plurality of positioning rings include a first positioning ring and a second positioning ring, each of the first positioning ring and the second positioning ring being provided with a first ring portion and a second ring portion, the first ring portion and the second ring portion being sleeved together, the inner edge of the first ring portion being provided with a ring surface and a first stop edge perpendicular to the ring surface, the second ring portion being provided with a second stop edge, the second stop edge being able to slide along the ring surface to the first stop edge as the first ring portion and the second ring portion are sleeved together, and the first positioning groove is composed of a ring surface, a first stop edge and a second stop edge.

[0009] By further designing the positioning rings, two types of positioning rings are respectively set as first positioning rings and second positioning rings. Both types of positioning rings are provided with interlocking first ring parts and second ring parts. The first ring part is provided with a ring surface and a first stop edge, and the second ring part is provided with a second stop edge. The first positioning groove is composed of a ring surface, a first stop edge, and a second stop edge. On the one hand, the first ring part can be installed on the mounting base first, and the second ring part can be installed after the test shaft and test bearing are installed, which is convenient for installation. On the other hand, it also allows the size of the first positioning groove to be adjusted when the interlocking first ring part and the second ring part slide relative to each other.

[0010] The present invention can be further configured such that: the first ring portion and the second ring portion of the first positioning ring are respectively provided with a first bend portion and a second bend portion in an annular shape; the second bend portion and the axial end face of the mounting base form a clamping of the first bend portion; the first bend portion is provided with a first screw hole and a second screw hole near its outer edge; the first screw hole and the second screw hole are arranged alternately and at intervals in a circumferential manner on the first bend portion; and the second bend portion is provided with a limiting recess and a third screw hole at the positions corresponding to the first screw hole and the second screw hole, respectively.

[0011] By further designing the first positioning ring, a first bend and a second bend, forming annular shapes, are respectively provided on the first and second ring portions. A first screw hole and a second screw hole are provided on the first bend, and a limiting recess and a third screw hole are provided on the second bend. When installing the first positioning ring, the first ring portion is first installed on the mounting base through the first screw hole on the first bend. After the test shaft and test bearing are installed, the second ring portion is then inserted into the mounting base. The bolts on the limiting recess and the first screw hole on the second bend form a preliminary limiting and alignment. Finally, bolts are installed on the third and second screw holes to complete the reinforcement of the first ring portion and the connection between the first ring portion and the first ring portion. The installed structure is moved to the axial end face of the mounting base, which is suitable for installing relatively large test bearings.

[0012] The present invention can be further configured such that: the first ring portion of the second positioning ring is inserted into the inner hole, the second ring portion of the second positioning ring is positioned on the first ring portion by screwing, a loading head is provided on the other side of the first ring portion opposite to the second ring portion, a ring-shaped connecting portion is provided at one end of the loading head, the connecting portion is attached to the first ring portion of the second positioning ring and fastened by bolts, and the other end of the loading head is connected to the loading assembly for transmission.

[0013] By further configuring the second positioning ring, the first ring portion is inserted into the inner hole, and the second ring portion is screwed onto the first ring portion to complete the radial limiting of the second positioning ring. The loading head is fixed to the second positioning ring through its connecting part, and its other end is connected to the output end of the loading component for transmission, so that the second positioning ring can move axially under the action of the loading component and apply axial load to both test bearings.

[0014] The present invention can be further configured such that: the loading component includes a hydraulic cylinder and a force sensor, one end of the force sensor is axially positioned with the output of the hydraulic cylinder, the other end of the force sensor is provided with a protrusion with a radial through hole, the other end of the loading head is provided with a cylindrical body, the protrusion extends into the body and is connected by a pin that passes through the two.

[0015] By further configuring the loading assembly, a hydraulic cylinder and a force sensor are installed. The hydraulic cylinder provides the driving force, and the force sensor displays the load intuitively, facilitating the test. A protrusion is installed on the force sensor, and a cylindrical body is installed at the other end of the loading head. The protrusion passes through the body, and the two are positioned by a pin. This method is effective and easy to disassemble and adjust.

[0016] The present invention can be further configured such that the drive assembly includes a servo motor, a drive shaft and a coupling, one end of the drive shaft is connected to the output shaft of the servo motor, and the other end of the drive shaft is connected to the other end of the test shaft through the coupling.

[0017] With further configuration, a servo motor, a drive shaft, and a coupling are set in the drive assembly. The drive shaft is connected to the output shaft of the servo motor, and then connected to the other end of the test shaft through the coupling. During operation, the servo motor provides driving force, which drives the test shaft to rotate through the drive shaft.

[0018] The present invention can be further configured such that: the drive assembly includes a transmission chamber and a plurality of ball bearings, the transmission shaft passes through the transmission chamber, the plurality of ball bearings are axially spaced in the transmission chamber, and the outer ring and inner ring of the ball bearings are respectively positioned on the inner wall of the transmission chamber and on the transmission shaft.

[0019] By further configuring the drive assembly, a transmission chamber and several ball bearings are installed, allowing the drive shaft to pass through the transmission chamber. The outer and inner rings of the ball bearings are positioned on the inner wall of the transmission chamber and on the drive shaft, respectively, to ensure the smooth operation of the test shaft during the test. Attached Figure Description

[0020] Figure 1 This is a perspective view of an embodiment of the present invention;

[0021] Figure 2 This is a top view of an embodiment of the present invention;

[0022] Figure 3 This is an embodiment of the present invention. Figure 2 Sectional view at point AA;

[0023] Figure 4 This is an embodiment of the present invention. Figure 3 An enlarged view of part a;

[0024] Figure 5 This is an embodiment of the present invention. Figure 3 Enlarged view of section b;

[0025] Figure 6 This is a schematic diagram illustrating the fit between the mounting base and the test shaft in an embodiment of the present invention. Figure 1 ;

[0026] Figure 7 This is a schematic diagram illustrating the fit between the mounting base and the test shaft in an embodiment of the present invention. Figure 2 ;

[0027] Figure 8 This is a schematic diagram of the structure of the first positioning ring in an embodiment of the present invention;

[0028] Figure 9 This is a schematic diagram of the structure of the second positioning ring in an embodiment of the present invention;

[0029] Figure 10 This is a schematic diagram of the fit between the test shaft and the test bearing in an embodiment of the present invention;

[0030] The components include: drive assembly 1; servo motor 11; drive shaft 12; coupling 13; transmission chamber 14; ball bearing 15; loading assembly 2; loading head 21; connecting part 211; main body 212; hydraulic cylinder 22; force sensor 23; protrusion 231; mounting base 3; inner hole 31; test shaft 4; adjusting block 41; third positioning groove 411; second positioning groove 42; baffle 43; positioning ring 5; first positioning groove 51; first positioning ring 5a; second positioning ring 5b; first ring part 52; ring surface 521; first stop 522; second ring part 53; second stop 531; first bending part 54; first screw hole 541; second screw hole 542; second bending part 55; limiting recess 551; third screw hole 552; and test bearing 6. Detailed Implementation

[0031] An example of an embodiment of the present invention: a test fixture for a four-point contact ball bearing for a medical robot. Figure 1-10As shown: The device includes a drive assembly 1, a loading assembly 2, and a mounting base 3. The mounting base 3 is positioned between the drive assembly 1 and the loading assembly 2. The mounting base 3 has an inner hole 31, a test shaft 4, and several positioning rings 5. The inner hole 31 extends axially and allows the test shaft 4 to rotatably pass through it. The positioning rings 5 ​​are detachably connected to the two ends of the mounting base 3 corresponding to the inner hole 31. The inner wall of each positioning ring 5 has a first positioning groove 51 for positioning with the outer ring of the test bearing 6. The two ends of the test shaft 4 are respectively connected to the drive assembly 1 and the loading assembly 2. An adjusting block 41 is detachably mounted on one end of the test shaft 4. A second positioning groove 42 and a third positioning groove 411 are respectively provided on the other end of the test shaft 4 and the adjusting block 41. Both the second positioning groove 42 and the third positioning groove 411 are used for the inner ring of the test bearing 6 to be nested within them.

[0032] The cross-section of the inner wall of the second positioning groove 42 and the third positioning groove 411 is L-shaped and semi-open. The test shaft 4 is detachably provided with several baffles 43. The baffles 43 can be fitted and positioned on the test shaft 4 to cover the second positioning groove or the third positioning groove. In this embodiment, the inner hole size of the several baffles 43 is the same, which is convenient for installation on the test shaft 4. Only the outer edge size of the baffles 43 is different, which is convenient for accommodating test bearings 6 of different sizes. The baffles 43 can press the inner ring of the test bearing 6 into the radial inner wall of the second positioning groove 42 or the third positioning groove 411 by abutting fit.

[0033] In this embodiment, the positioning ring 5 includes a first positioning ring 5a and several second positioning rings 5b of different sizes. The first positioning ring 5a and the second positioning ring 5b are each provided with a first ring portion 52 and a second ring portion 53. The first ring portion 52 and the second ring portion 53 are sleeved together. The inner edge of the first ring portion 52 is provided with a ring surface 521 and a first stop edge 522 perpendicular to the ring surface. The second ring portion 53 is provided with a second stop edge 531. The second stop edge 531 can slide along the ring surface 521 toward the first stop edge 522 as the first ring portion 52 and the second ring portion 53 are sleeved together. The first positioning groove 51 is composed of the ring surface 521, the first stop edge 522 and the second stop edge 531.

[0034] The first positioning ring 5a has a first bend 54 and a second bend 55 arranged in annular shape on the first ring portion 52 and the second ring portion 53, respectively. The second bend 55 and the axial end face of the mounting base 3 form a clamping effect on the first bend 54. The first bend 54 has a first screw hole 541 and a second screw hole 542 near its outer edge. The first screw hole 541 and the second screw hole 542 are arranged alternately and at intervals in a circumferential manner on the first bend 54. The second bend 54 has a limiting recess 551 and a third screw hole 552 respectively at the positions corresponding to the first screw hole 541 and the second screw hole 542.

[0035] The first ring portion 52 of the second positioning ring 5b is inserted into the inner hole 31, and the second ring portion 53 of the second positioning ring 5b is positioned on the first ring portion 52 by screwing. The loading assembly 2 includes a loading head 21, a hydraulic cylinder 22, and a force sensor 23. The loading head 21 is located on the other side of the first ring portion 52 opposite to the second ring portion 53. One end of the loading head 21 is provided with an annular connecting portion 211, which is attached to the first ring portion 52 of the second positioning ring 5b and fastened with bolts. One end of the force sensor 23 is axially positioned with the output of the hydraulic cylinder 22, and the other end of the force sensor 23 is provided with a protrusion 231 with a radial through hole. The other end of the loading head 21 is provided with a cylindrical body 212, and the protrusion 231 extends into the body 21 and is connected by a pin that passes through the two.

[0036] The drive assembly 1 includes a servo motor 11, a drive shaft 12, and a coupling 13. One end of the drive shaft 12 is connected to the output shaft of the servo motor 11, and the other end of the drive shaft 12 is connected to the other end of the test shaft 3 through the coupling 13.

[0037] The drive assembly 1 includes a transmission chamber 14 and a plurality of ball bearings 15. The transmission shaft 12 passes through the transmission chamber 14. The plurality of ball bearings 15 are axially spaced in the transmission chamber 14, and the outer ring and inner ring of the ball bearings 15 are respectively positioned on the inner wall of the transmission chamber 14 and on the transmission shaft 12.

[0038] The above examples are merely one preferred embodiment of the present invention. Ordinary variations and substitutions made by those skilled in the art within the scope of the technical solution of the present invention are all included within the protection scope of the present invention.

Claims

1. A four-point contact ball bearing test fixture for medical robots, comprising a drive assembly and a load assembly, characterized in that: The device includes a mounting base disposed between a drive assembly and a loading assembly. The mounting base has an inner bore, a test shaft, and several positioning rings. The inner bore extends axially and allows the test shaft to rotatably pass through it. The positioning rings are detachably connected to both ends of the inner bore of the mounting base. The inner wall of each positioning ring has a first positioning groove for positioning with the outer ring of a test bearing. Both ends of the test shaft are connected to the drive assembly and the loading assembly, respectively. An adjusting block is detachably mounted at one end of the test shaft. A second positioning groove and a third positioning groove are respectively provided on the other end of the test shaft and the adjusting block. Both the second and third positioning grooves are for the inner ring of the test bearing to be nested within them. The cross-section of the inner walls of both the second and third positioning grooves is L-shaped and semi-open. The test shaft is detachably equipped with several baffles. The baffles can be fitted and positioned on the test shaft to cover the second or third positioning groove. The baffles can press the inner ring of the test bearing against the radial inner wall of the second or third positioning groove through abutment. Several positioning rings include a first positioning ring and a second positioning ring. The first and second positioning rings are each provided with a first ring portion and a second ring portion. The first ring portion and the second ring portion are fitted together. The inner edge of the first ring portion is provided with a ring surface and a first stop edge perpendicular to the ring surface. The second ring portion is provided with a second stop edge. The second stop edge can slide along the ring surface to the first stop edge as the first and second ring portions are fitted together. The first positioning groove is composed of a ring surface, a first stop edge, and a second stop edge.

2. The four-point contact ball bearing test fixture for medical robots of claim 1, wherein: The first positioning ring has a first bend and a second bend that are respectively provided on the first ring portion and the second ring portion. The second bend and the axial end face of the mounting base form a clamping effect on the first bend. The first bend has a first screw hole and a second screw hole near its outer edge. The first screw hole and the second screw hole are arranged circumferentially on the first bend, alternating and spaced apart. The second bend has a limit recess and a third screw hole respectively at the positions of the first screw hole and the second screw hole.

3. The four-point contact ball bearing test fixture for medical robots of claim 1, wherein: The first ring portion of the second positioning ring is inserted into the inner hole, and the second ring portion of the second positioning ring is positioned on the first ring portion by screwing. A loading head is provided on the other side of the first ring portion opposite to the second ring portion. A ring-shaped connecting portion is provided at one end of the loading head. The connecting portion is attached to the first ring portion of the second positioning ring and fastened by bolts. The other end of the loading head is connected to the loading assembly for transmission.

4. The four-point contact ball bearing test fixture for medical robots of claim 3, wherein: The loading assembly includes a hydraulic cylinder and a force sensor. One end of the force sensor is axially positioned with the output of the hydraulic cylinder, and the other end of the force sensor is provided with a protrusion with a radial through hole. The other end of the loading head is provided with a cylindrical body. The protrusion extends into the body and is connected by a pin that passes through the two.

5. The four-point contact ball bearing test fixture for medical robots according to claim 1 or 2 or 3 or 4, characterized in that: The drive assembly includes a servo motor, a drive shaft, and a coupling. One end of the drive shaft is connected to the output shaft of the servo motor, and the other end of the drive shaft is connected to the other end of the test shaft via the coupling.

6. The four-point contact ball bearing test fixture for medical robots of claim 5, wherein: The driving assembly comprises a transmission bin and a plurality of ball bearings, the transmission shaft is arranged in the transmission bin, the plurality of ball bearings are arranged in the transmission bin in axial direction, and the outer ring and the inner ring of the ball bearings are positioned at the inner wall of the transmission bin and the transmission shaft respectively.

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