Special clamp device for grinding backing bearing

Abstract

The invention relates to a special clamp device for backing bearing grinding, and relates to the technical field of bearing grinding. Comprising a mandrel, a tensioning sleeve, a locking nut, a pressing ring, a left end cover and a right end cover, a shaft ring is arranged in the middle section of the mandrel, the shaft ring is sleeved with the tensioning sleeve, the left end of the tensioning sleeve is pressed against the left shoulder face of the shaft ring through the locking nut, and the right end of the tensioning sleeve is positioned on the right shoulder face of the shaft ring through a screw by means of the pressing ring. A quick-change connector is arranged at the end of the outer side of the oil inlet hole, pressure oil is connected into the oil inlet hole through the quick-change connector, the pressure oil expands the outer cylindrical face of the tensioning sleeve after entering the oil cavity, and an inner hole of the inner ring of the backing bearing is positioned in the radial direction. A left end cover, a positioning device, a right end cover and a clamping device are arranged at the two ends of the mandrel. The outer cylindrical surface of the tensioning sleeve expands under the action of pressure oil, so that radial positioning of the inner hole of the inner ring of the backing bearing is realized, and the inner ring is clamped; and under the action of the positioning device and the clamping device, the outer ring of the backing bearing is clamped so as to realize precise grinding of the backing bearing.

Description

Technical Field

[0001] The invention relates to the technical field of bearing grinding, in particular to a special clamp device for backing bearing grinding. Background Art

[0002] Backing bearings are widely used in various mechanical fields, such as aerospace, automobile, machine tool, metallurgy, mining, etc. In these fields, backing bearings mainly play the role of supporting and protecting rolling or sliding bearings. Backing bearings are key components for bearing and transmission of rolling mills, and their use accuracy and life directly affect the performance of rolling mills. Backing bearings are rolling bearings with particularly thick outer rings. When used, they are installed in groups on stationary shafts to become support rollers. Backing bearings are precision mechanical parts with very high precision requirements for their own parts. They must be accurately grouped and matched during installation to achieve the best operating function, especially the section height from the inner diameter to the outer diameter after eliminating the radial clearance. If the section height is too large, the backing bearings of the row of support rollers will be severely unevenly stressed during rolling, causing vibration and roller fatigue damage, affecting product quality and reducing the service life of the backing bearings. The operation of the rolling mill will cause damage to the outer diameter of the backing bearing, such as dents, flattening and cold work hardening, which requires regrinding the outer diameter of the backing bearing.

[0003] The most widely used grinding method at present is to grind the outer ring of a single backing bearing, which is to disassemble the bearing, take out the rollers, inner ring and accessories, mark them, clean them, grind the outer ring of the bearing on a grinder according to the measured size, and then reassemble them, which is time-consuming and labor-intensive.

[0004] Therefore, it is necessary to grind the outer ring of the bearing without disassembling the bearing. If it is ground directly, since the inner and outer rings of the bearing are movable, the outer ring cannot be ground without a special fixture. Therefore, a special fixture device for outer cylindrical grinding of the backing bearing outer ring is urgently needed. Summary of the invention

[0005] The purpose of the present invention is to address the gaps in the prior art and to provide a special clamp device for backing bearing grinding. A tension sleeve is provided outside the core shaft, an oil chamber is provided inside the tension sleeve, and an oil inlet hole leading to the oil chamber of the tension sleeve is provided inside the core shaft. The pressure oil enters the oil chamber of the tension sleeve through a quick-change joint connected to the oil inlet hole of the core shaft. Under the action of the pressure oil, the outer cylindrical surface of the tension sleeve expands, thereby radially positioning the inner hole of the inner ring of the backing bearing and clamping the inner ring of the backing bearing.

[0006] In order to achieve the above-mentioned purpose, the present invention provides a special fixture device for backing bearing grinding, including a core shaft, a tension sleeve, a locking nut, a pressure ring, a left end cover and a right end cover, wherein the left end of the core shaft is provided with a left end cover, the right end is provided with a right end cover, the middle section of the core shaft is provided with a shaft ring, the tension sleeve is sleeved on the outer side of the core shaft shaft ring, the left end of the core shaft is provided with an external thread 1, and the right end is provided with an external thread 2, the left end of the tension sleeve is pressed against the left shoulder surface of the core shaft shaft ring through the cooperation of the external thread 1 and the locking nut, and the tension sleeve is tightened by the screw through the pressure ring to tighten the right end of the tension sleeve The end is positioned on the right shoulder surface of the core shaft collar, an oil chamber is provided in the tensioning sleeve, an oil inlet hole leading to the oil chamber is provided in the core shaft, and a quick-change joint for entering pressure oil is provided at the end of the oil inlet hole on the outer side of the core shaft. The pressure oil enters the oil chamber through the quick-change joint and the oil inlet hole to expand the outer cylindrical surface of the tensioning sleeve, thereby radially positioning the inner hole of the inner ring of the backing bearing; a left rotary positioning device is provided on the outer side of the left end cover, and a right rotary clamping device is provided on the outer side of the right end cover, and the axial positioning and clamping of the outer ring of the backing bearing are realized by the left rotary positioning device and the right rotary positioning device.

[0007] Furthermore, a reinforcing rib is provided in the middle section of the inner hole of the tension sleeve to divide the oil chamber into two parts, left and right.

[0008] Furthermore, an O-ring four is provided between the left side of the core shaft collar and the tension sleeve, and an O-ring two is provided between the right side of the core shaft collar and the tension sleeve, for sealing the pressure oil in the oil cavity of the tension sleeve.

[0009] Furthermore, an inner conical surface is provided on the inner side of the pressure ring, and an outer conical surface is provided on the outer side of the right end of the tensioning sleeve. Under the action of the screw, the tensioning sleeve moves axially, the inner conical surface of the pressure ring presses the outer conical surface of the tensioning sleeve, and enables the inner hole on the right side of the tensioning sleeve and the core shaft ring to achieve better circumferential positioning.

[0010] Furthermore, the left rotation positioning device includes a tapered roller bearing, a left transition cover, a left elastic retaining ring and a left bearing cover. The left end cover is provided with a left elastic retaining ring, and the tapered roller bearing is fixed to the left end cover by the left elastic retaining ring. The left bearing cover is radially positioned on the left end cover by the left transition cover and the tapered roller bearing, and the left end cover is connected to the core shaft by an external thread.

[0011] Furthermore, the right rotary clamping device includes a second tapered roller bearing, a right transition cover, a right elastic retaining ring and a right bearing cover. The right end cover is provided with a right elastic retaining ring, and the second tapered roller bearing is fixed to the right end cover by the right elastic retaining ring; the right bearing cover is positioned on the right end cover by the right transition cover and the second tapered roller bearing, and the right end cover is connected to the core shaft by an external thread two.

[0012] Furthermore, the two ends of the tapered roller bearing one are provided with a Y-type sealing ring one and a Y-type sealing ring two for sealing the tapered roller bearing one; the two ends of the tapered roller bearing two are provided with a Y-type sealing ring three and a Y-type sealing ring four for sealing the tapered roller bearing two.

[0013] Furthermore, the left transition cover is provided with a lubricating oil nozzle 1 for lubricating the tapered roller bearing 1; the right transition cover is provided with a lubricating oil nozzle 2 for lubricating the tapered roller bearing 2.

[0014] Furthermore, a left center hole and a right center hole are provided at both ends of the mandrel, which are used for positioning the mandrel on the headstock and tailstock of the machine tool during grinding.

[0015] Furthermore, a rotating handle is provided on the core shaft to prevent the core shaft from rotating when the left end cover and the right end cover are installed; a flat-end stop screw is provided in the locking nut to prevent the locking nut from loosening.

[0016] The beneficial effects of the present invention are:

[0017] In the present invention, a tension sleeve is arranged outside the core shaft, an oil chamber is arranged inside the tension sleeve, and an oil inlet hole leading to the oil chamber of the tension sleeve is arranged inside the core shaft. The pressure oil enters the oil chamber of the tension sleeve after passing through a quick-change joint connected to the oil inlet hole of the core shaft. Under the action of the pressure oil, the outer cylindrical surface of the tension sleeve expands, thereby radially positioning the inner hole of the inner ring of the backing bearing and clamping the inner ring of the backing bearing; the pressure oil is unloaded through the quick-change joint, and the outer cylindrical surface of the tension sleeve returns to its original size, thereby separating the inner hole of the inner ring of the backing bearing from the outer cylindrical surface of the tension sleeve and releasing the inner ring of the backing bearing. The two ends of the core shaft pass through the left end cover and the right end cover respectively, and a left rotary positioning device is arranged outside the left end cover, and a right rotary clamping device is arranged outside the right end cover. By adjusting the positions of the left rotary positioning device and the right rotary clamping device on the core shaft, the axial positioning and clamping of the outer ring of the backing bearing are realized, ensuring effective grinding of the outer cylindrical surface of the outer ring of the backing bearing. An O-ring is set between the mandrel and the tension sleeve to ensure that the hydraulic oil does not leak out. Y-rings are set on both sides of the rolling bearings in the left rotary positioning device and the right rotary clamping device to prevent the entry of dirt such as grinding chips that affect the life of the bearings during grinding, thereby extending the service life of the bearings. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 The structure of the present invention is schematically shown Figure 1 ;

[0019] Figure 2 The structure of the present invention is schematically shown Figure 2 .

[0020] Among them, in the figure:

[0021] 1- spindle; 2- tension sleeve; 3- locking nut; 4- left end cover; 5- Y-type seal ring 1; 6- tapered roller bearing 1; 7- left transition cover; 8- left elastic retaining ring; 9- Y-type seal ring 2; 10- left bearing cover; 11- backing bearing; 12- right bearing cover; 13- Y-type seal ring 3; 14- right elastic retaining ring; 15- tapered roller bearing 2; 16- right transition cover; 17- Y-type seal ring 4; 18- pressure ring; 19- right end cover; 20- quick-change connector; 21- O-ring seal Sealing ring one; 22-O-ring two; 23-O-ring three; 24-screw; 27-lubricating nozzle two; 28-O-ring four; 30-driving screw; 31-O-ring five; 32-lubricating nozzle one; 34-flat end stop screw; 35-rotating handle; 101-left top hole; 102-right top hole; 103-oil inlet hole; 104-external thread one; 105-external thread two; 201-oil chamber; 202-reinforcement rib; 111-inner ring; 112-outer ring. DETAILED DESCRIPTION

[0022] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequential order. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present application described here. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0024] In the present application, the terms "upper", "lower", "left", "right", "front", "back", "top", "bottom", "inner", "outer", "middle", "vertical", "horizontal", "lateral", "longitudinal" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings. These terms are mainly used to better describe the present application and its embodiments, and are not used to limit the indicated devices, elements or components to have a specific orientation, or to be constructed and operated in a specific orientation.

[0025] In addition, some of the above terms may be used to express other meanings in addition to indicating orientation or positional relationship. For example, the term "on" may also be used to express a certain dependency or connection relationship in some cases. For those of ordinary skill in the art, the specific meanings of these terms in this application can be understood according to specific circumstances.

[0026] In addition, the terms "installed", "set", "provided with", "connected", "connected", and "socketed" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection, or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be an internal connection between two devices, elements, or components. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0027] like Figure 1-2 As shown, the present invention provides a special fixture device for backing bearing grinding, including a spindle 1, a tensioning sleeve 2, a locking nut 3, a pressure ring 18, a left end cover 4 and a right end cover 19. The left end of the spindle 1 is provided with a left end cover 4, the right end is provided with a right end cover 19, the middle section of the spindle 1 is provided with a shaft ring, the tensioning sleeve 2 is sleeved on the outer side of the shaft ring of the spindle 1, the left end of the spindle 1 is provided with an external thread 104, and the right end is provided with an external thread 2 105. The left end of the tensioning sleeve 2 is pressed against the left shoulder surface of the shaft ring of the spindle 1 through the cooperation of the external thread 104 and the locking nut 3, the tensioning sleeve 2 is positioned on the right shoulder surface of the shaft ring of the spindle 1 by the screw 24 relying on the pressure ring 18, and the tensioning sleeve 2 is provided with an oil chamber 201 An oil inlet hole 103 leading to the oil chamber 201 is provided in the core shaft 1, and a quick-change joint 20 for entering pressure oil is provided at the end of the oil inlet hole 103 on the outer side of the core shaft 1. The pressure oil enters the oil chamber 201 through the quick-change joint 20 and the oil inlet hole 103 to expand the outer cylindrical surface of the tension sleeve 2, thereby radially positioning the inner hole of the inner ring 111 of the backing bearing 11. When disassembling, the pressure oil is removed, and the outer cylindrical surface of the tension sleeve 2 returns to its original size, thereby radially loosening the inner hole of the inner ring 111 of the backing bearing 11; a left rotary positioning device is provided on the outer side of the left end cover 4, and a right rotary clamping device is provided on the outer side of the right end cover 19. The axial positioning of the outer ring 112 of the backing bearing 11 is achieved by the left rotary positioning device and the right rotary clamping device.

[0028] To further optimize the technical solution, a reinforcing rib 202 is provided in the middle section of the inner hole of the tension sleeve 2, dividing the oil chamber 201 into two parts, left and right. Since the structures of the left and right ends of the tension sleeve 2 are different, the reinforcing rib 202 is provided so that the tension sleeve 2 can be uniformly expanded under the action of the pressure oil in the oil chamber 201, so as to achieve uniform radial positioning of the inner hole of the inner ring 111 of the backing bearing 11, making the radial positioning more reliable.

[0029] To further optimize the technical solution, an O-ring four 28 and an O-ring five 31 are provided between the left side of the core shaft 1 shaft ring and the tensioning sleeve 2, an O-ring two 22 is provided between the right side of the core shaft 1 shaft ring and the tensioning sleeve 2, an O-ring one 21 is provided between the right shoulder surface of the core shaft 1 shaft ring and the pressure ring 18, and an O-ring three 23 is provided between the pressure ring 18 and the right end surface of the tensioning sleeve 2, which are used to seal the pressure oil in the oil chamber 201 of the tensioning sleeve 2 and prevent dirt such as grinding fluid from entering the space between the core shaft 1 and the tensioning sleeve 2; at the same time, the pressure ring 18 is positioned on the core shaft 1 through the circumference of the step surface on the core shaft 1.

[0030] To further optimize the technical solution, an inner conical surface is provided on the inner side of the pressure ring 18, and an outer conical surface is provided on the outer side of the right end of the tensioning sleeve 2. Under the action of the screw 24, the tensioning sleeve 2 moves axially, and the inner conical surface of the pressure ring 18 presses the outer conical surface of the tensioning sleeve 2, so that the inner hole on the right side of the tensioning sleeve 2 and the shaft ring of the core shaft 1 can achieve better circumferential positioning.

[0031] The left rotation positioning device includes a tapered roller bearing 6, a left transition cover 7, a left elastic retaining ring 8 and a left bearing cover 10. The left end cover 4 is provided with a left elastic retaining ring 8, and the tapered roller bearing 6 is fixed to the left end cover 4 through the left elastic retaining ring 8. The left bearing cover 10 is radially positioned on the left end cover 4 through the left transition cover 7 and the tapered roller bearing 6. The left end cover 4 is connected to the core shaft 1 through an external thread 104 and fixed on the core shaft 1. The left end cover 4 and the right end surface of the left bearing cover 10 are in the same plane.

[0032] The right rotary clamping device includes a tapered roller bearing 15, a right transition cover 16, a right elastic retaining ring 14 and a right bearing cover 12. The right end cover 19 is provided with a right elastic retaining ring 14, and the tapered roller bearing 15 is fixed to the right end cover 19 through the right elastic retaining ring 14; the right bearing cover 12 is positioned on the right end cover 19 through the right transition cover 16 and the tapered roller bearing 15, and the right end cover 19 is connected to the core shaft 1 through the external thread 105 and fixed on the core shaft 1.

[0033] A driving device is provided in the radial direction of the left bearing cover. The grinding head frame rotates the driving device and the outer ring of the backing bearing together through the driving device, so that the grinding wheel grinds the outer cylindrical surface of the outer ring of the backing bearing. The driving device can be a driving screw 30 or a disc, as long as the driving device on the head frame can drive the left rotary positioning device and the left end cover 4 to achieve relative rotary motion after being connected thereto. The rotation of the grinding head frame rotates the driving screw 30 and the outer ring 112 of the backing bearing 11 together through the driving device, so that the grinding wheel grinds the outer ring 112 of the backing bearing 11.

[0034] In order to achieve reliable axial positioning and clamping of the outer ring 112 of the backing bearing 11, after the left bearing cover 10 and the right bearing cover 12 contact the end faces on both sides of the outer ring 112 of the backing bearing 11, a certain gap is left between the right side of the tensioning sleeve 2 and the right end face of the inner ring 111 of the backing bearing 11, so as to avoid the outer ring 112 of the backing bearing 11 not being clamped tightly and being unable to effectively drive the outer ring 112 of the backing bearing 10 and the driving device to rotate synchronously.

[0035] To further optimize the technical solution, the two ends of the tapered roller bearing 6 are provided with a Y-type sealing ring 1 5 and a Y-type sealing ring 2 9 to seal the tapered roller bearing 1 6; the two ends of the tapered roller bearing 2 15 are provided with a Y-type sealing ring 3 13 and a Y-type sealing ring 4 17 to seal the tapered roller bearing 2 15.

[0036] To further optimize the technical solution, the left transition cover 7 is provided with a lubricating oil nozzle 32 for lubricating the tapered roller bearing 6; the right transition cover 16 is provided with a lubricating oil nozzle 27 for lubricating the tapered roller bearing 15.

[0037] To further optimize the technical solution, the two ends of the mandrel 1 are provided with a left center hole 101 and a right center hole 102, which are used to position the mandrel 1 on the headstock and tailstock of the machine tool during grinding. Preferably, the left end face of the mandrel 1 is provided with a 60° center hole 101, and the right end face is provided with a 60° center hole 102, which are used to fix the entire fixture on the grinding machine for grinding.

[0038] To further optimize the technical solution, a rotating handle 35 is provided on the core shaft 1 to prevent the core shaft 1 from rotating when the left end cover 4 and the right end cover 19 are installed; a flat-end stop screw 34 is provided in the locking nut 3 to prevent the locking nut 3 from loosening.

[0039] In the present invention, a tension sleeve is arranged outside the core shaft, an oil chamber is arranged inside the tension sleeve, and an oil inlet hole leading to the oil chamber of the tension sleeve is arranged inside the core shaft. The pressure oil enters the oil chamber of the tension sleeve after passing through a quick-change joint connected to the oil inlet hole of the core shaft. Under the action of the pressure oil, the outer cylindrical surface of the tension sleeve expands, thereby radially positioning the inner hole of the inner ring of the backing bearing and clamping the inner ring of the backing bearing; the pressure oil is unloaded through the quick-change joint, and the outer cylindrical surface of the tension sleeve returns to its original size, thereby separating the inner hole of the inner ring of the backing bearing from the outer cylindrical surface of the tension sleeve and releasing the inner ring of the backing bearing. The two ends of the core shaft pass through the left end cover and the right end cover respectively, and a left rotary positioning device is arranged outside the left end cover, and a right rotary clamping device is arranged outside the right end cover. By adjusting the positions of the left rotary positioning device and the right rotary clamping device on the core shaft, the axial positioning and clamping of the outer ring of the backing bearing are realized, ensuring effective grinding of the outer cylindrical surface of the outer ring of the backing bearing. An O-ring is set between the mandrel and the tension sleeve to ensure that the hydraulic oil does not leak out. Y-rings are set on both sides of the rolling bearings in the left rotary positioning device and the right rotary clamping device to prevent the entry of dirt such as grinding chips that affect the life of the bearings during grinding, thereby extending the service life of the bearings.

[0040] Working principle of the present invention:

[0041] First, the head and tailstock centers of the machine tool support the mandrel 1 through the left center hole 101 and the right center hole 102 of the mandrel 1.

[0042] Secondly, the pressure oil enters the oil chamber 201 through the quick-change joint 20 and the oil inlet hole 103 to expand the outer cylindrical surface of the tension sleeve 2, thereby radially positioning the inner hole of the backing bearing 11; when disassembling, the pressure needs to be released through the quick-change joint 20, and the outer cylindrical surface of the tension sleeve 2 returns to its original size, thereby radially loosening the inner hole of the backing bearing 11.

[0043] Next, the position of the left end cover 4 on the mandrel 1 is adjusted through the external thread 104, and the left bearing cover 10 outside the left end cover 4 is axially positioned with respect to the outer ring 112 of the backing bearing 11. The position of the right end cover 19 on the mandrel 1 is adjusted through the external thread 2 105, and the right bearing cover 12 outside the right end cover 19 is axially clamped with respect to the outer ring 112 of the backing bearing 11 on the right side of the outer ring 112 of the backing bearing 11.

[0044] Finally, under the action of the head frame driving device, the left bearing cover 10, the outer ring 112 of the backing bearing 11 and the right bearing cover 12 are driven to rotate by the driving screw 30 to achieve the grinding of the outer cylindrical surface of the outer ring 112 of the backing bearing 11.

[0045] The above description is only a preferred embodiment of the present invention and does not limit the technical scope of the present invention. Therefore, any slight modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A special fixture device for backing bearing grinding, characterized in that: The invention comprises a core shaft (1), a tension sleeve (2), a locking nut (3), a pressure ring (18), a left end cover (4) and a right end cover (19), wherein the left end of the core shaft (1) is provided with a left end cover (4), the right end is provided with a right end cover (19), the middle section of the core shaft (1) is provided with a shaft ring, the tension sleeve (2) is sleeved on the outer side of the shaft ring of the core shaft (1), the left end of the core shaft (1) is provided with an external thread (104), and the right end is provided with an external thread (105), the left end of the tension sleeve (2) is pressed against the left shoulder surface of the shaft ring of the core shaft (1) by the cooperation of the external thread (104) and the locking nut (3), and the right end of the tension sleeve (2) is fixed on the right shoulder surface of the shaft ring of the core shaft (1) by the pressure ring (18) through the screw (24). The tension sleeve (2) is provided with an oil chamber (201), the core shaft (1) is provided with an oil inlet hole (103) leading to the oil chamber (201), and the end of the oil inlet hole (103) outside the core shaft (1) is provided with a quick-change joint (20) for feeding pressure oil. The pressure oil enters the oil chamber (201) through the quick-change joint (20) and the oil inlet hole (103) to expand the outer cylindrical surface of the tension sleeve (2), thereby radially positioning the inner hole of the inner ring (111) of the backing bearing (11); the outer side of the left end cover (4) is provided with a left rotary positioning device, and the outer side of the right end cover (19) is provided with a right rotary clamping device, and the axial positioning and clamping of the outer ring (112) of the backing bearing (11) are realized by the left rotary positioning device and the right rotary clamping device.

2. A special fixture device for backing bearing grinding as claimed in claim 1, characterized in that: A reinforcing rib (202) is provided in the middle section of the inner hole of the tension sleeve (2) to divide the oil chamber (201) into two parts, left and right.

3. A special fixture device for backing bearing grinding as claimed in claim 1 or 2, characterized in that: An O-ring four (28) is provided between the left side of the core shaft (1) shaft ring and the tension sleeve (2), and an O-ring two (22) is provided between the right side of the core shaft (1) shaft ring and the tension sleeve (2), for sealing the pressure oil in the oil chamber (201) of the tension sleeve (2).

4. A special fixture device for backing bearing grinding as claimed in claim 3, characterized in that: The inner side of the pressure ring (18) is provided with an inner conical surface, and the outer side of the right end of the tension sleeve (2) is provided with an outer conical surface. Under the action of the screw (24), the tension sleeve (2) moves axially, and the inner conical surface of the pressure ring (18) presses the outer conical surface of the tension sleeve (2), so that the inner hole on the right side of the tension sleeve (2) and the shaft ring of the core shaft (1) can achieve better circumferential positioning.

5. A special fixture device for backing bearing grinding as claimed in claim 1, characterized in that: The left rotation positioning device comprises a tapered roller bearing (6), a left transition cover (7), a left elastic retaining ring (8) and a left bearing cover (10); a left elastic retaining ring (8) is provided on the left end cover (4); the tapered roller bearing (6) is fixed to the left end cover (4) by the left elastic retaining ring (8); the left bearing cover (10) is radially positioned on the left end cover (4) by the left transition cover (7) and the tapered roller bearing (6); and the left end cover (4) is connected to the core shaft (1) by an external thread (104).

6. A special fixture device for backing bearing grinding as claimed in claim 5, characterized in that: The right-turning clamping device comprises a second tapered roller bearing (15), a right transition cover (16), a right elastic circlip (14) and a right bearing cover (12); a right elastic circlip (14) is provided on a right end cover (19); the second tapered roller bearing (15) is fixed to the right end cover (19) by the right elastic circlip (14); the right bearing cover (12) is positioned on the right end cover (19) by the right transition cover (16) and the second tapered roller bearing (15); the right end cover (19) is connected to the core shaft (1) by an external thread (105).

7. A special fixture device for backing bearing grinding as claimed in claim 6, characterized in that: The two ends of the tapered roller bearing one (6) are provided with a Y-shaped sealing ring one (5) and a Y-shaped sealing ring two (9) for sealing the tapered roller bearing one (6); the two ends of the tapered roller bearing two (15) are provided with a Y-shaped sealing ring three (13) and a Y-shaped sealing ring four (17) for sealing the tapered roller bearing two (15).

8. A special fixture device for backing bearing grinding as claimed in claim 6 or 7, characterized in that: The left transition cover (7) is provided with a lubricating oil nozzle (32) for lubricating the tapered roller bearing (6); the right transition cover (16) is provided with a lubricating oil nozzle (27) for lubricating the tapered roller bearing (15).

9. A special fixture device for backing bearing grinding as claimed in claim 1, characterized in that: The two ends of the mandrel (1) are provided with a left center hole (101) and a right center hole (102), which are used for positioning the mandrel (1) on the headstock and tailstock of the machine tool during grinding.

10. A special fixture device for backing bearing grinding as claimed in claim 1, characterized in that: The spindle (1) is provided with a rotating handle (35) for preventing the spindle (1) from rotating when the left end cover (4) and the right end cover (19) are installed; a flat-end stop screw (34) is provided in the locking nut (3) to prevent the locking nut (3) from loosening.

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