33 results about "Ball diameter" patented technology

A method of designing a ball bearing includes providing a value of a shaft outside diameter and a load. An inside diameter of a bearing inner ring is determined based on the value of the shaft outside diameter. A ball size having a specific ball diameter is selected and a number of the balls of the selected standard ball size required to support the load is determined. A pitch diameter of a pitch circle of the ball bearing is determined based on the determined number of balls of the selected ball size. A suitability factor is calculated for the particular value of the pitch diameter and the particular pitch diameter is validated as suitable when the suitability factor is between calculated upper and lower limits.

The invention provides a method for determining the ball diameter and grading of an ore grinding medium in fine grinding operation, which adopts two or more ore grinding medium ball diameter theoretical calculation methods, and comprises the following steps: calculating the theoretical ball diameter of the ore grinding medium of each size fraction of materials to be ground, and preliminarily determining the ball diameter and ball ratio of a mill by referring to the granularity composition and mass fraction of the materials to be ground; and then verifying and optimizing through an ore grinding test, and finally determining the technical scheme of reasonable initial ball loading and accurate ball supplementing and adding of the mill. The method comprises the steps of size fraction analysis and grouping of the materials to be ground, theoretical ball diameter calculation, ore grinding test verification, determination of the initial ball loading scheme of the mill and determination of the ball supplementing and adding scheme of the mill, theoretical calculation and test verification optimization are included, the implementation method is simple, the application range is wide, and the process effect is good.

A linear guide (10) comprises: a guide rail (1) having a raceway groove (3) on a side surface; a slider (2) assembled to the guide rail (1) and having a raceway groove (7) facing the raceway groove (3); and a plurality of rolling elements disposed rollably in a rolling element rolling path (23), which is composed of a load rolling path (22) formed by the raceway grooves (3, 7), and a no-load rolling path (21) provided on the slider (2) and communicating between one end and the other end of the load rolling path (22). One of the guide rail (1) and the slider (2) moves relative to the other as the rolling elements roll. The plurality of rolling elements are constituted by a plurality of steel balls (6), and a plurality of spacer balls (16) smaller than the steel balls (6) and having elasticity. At least one spacer ball (16) is always present in the no-load rolling path (21). The length of a gap in which neither the steel balls (6) nor the spacer balls (16) are present in the rolling element rolling path (23) is 50% or less of the diameter of the steel balls (6), regardless of the position of the rolling elements. Consequently, it is possible to provide a rolling guide device that is easy to assemble and has good operability and excellent repeated positioning accuracy.

An angular contact ball bearing has: an inner ring having a cross-sectional circular-arc-shaped inner ring raceway groove on an outer peripheral surface; an outer ring having a cross-sectional circular-arc-shaped outer ring raceway groove on an inner peripheral surface; and a plurality of balls disposed freely rolling between the inner ring raceway groove and the outer ring raceway groove. A ratio (Ri) of a groove curvature radius of the inner ring raceway groove to a ball diameter is 54 to 58%, a ratio (Ro) of a groove curvature radius of the outer ring raceway groove to the ball diameter is 51 to 58%, and Ri-Ro is 0% or more, and at least the inner ring raceway groove has a maximum surface pressure of 4.7 to 6.0 GPa when a sum of permanent deformations of the ball and the inner ring raceway groove at a center of a contact portion of the ball and the inner ring raceway groove is one ten-thousandth of the ball diameter. Thus, an angular contact ball bearing capable of reducing a heat generation amount and suppressing damage caused by an external impact load at a standstill is provided.

The application discloses a bearing steel ball grinding tool, a parameter design method and a use method, and mainly relates to the bearing machining technical field. The bearing steel ball grinding tool comprises a fixed grinding disc and a movable grinding disc arranged at the bottom of the fixed grinding disc. The top of the movable grinding disc and the bottom of the fixed grinding disc are both provided with annular V-shaped grooves. The angle of the tip of the V-shaped groove is 90 degrees. Circular arc grooves are arranged on the two inner walls of the V-shaped groove. The center point of the circular arc groove is a pure rolling point of the steel ball. The bisector of the angle formed by the connecting line of the center points of the two circular arc grooves and the center of the steel ball coincides with the center line of the V-shaped groove. The application can effectively improve the coverage of the grinding tool grinding track network on the surface of the steel ball, effectively reduce the spherical deviation and the spherical diameter variation of the steel ball after grinding, and improve the final grinding precision.

To provide a ball bearing which can optimize the diameters of a plurality of balls with different sizes as a roller and which can contribute to reduction in rotation torque and increase in acceptable load.SOLUTION: A representative configuration of a ball bearing 100 includes: an outer ring 110; an inner ring 120; and a plurality of balls that roll between the outer ring and the inner ring. As the balls, balls with different diameters are regularly aligned. When a parameter γ representing an internal configuration of the bearing is indicated by the following formula: γ=(Da / PCD)*cosα (where Da is the diameter of the ball, PCD is a pitch circle diameter, and α is a contact angle), a maximum ball diameter difference ΔDa between a ball with the largest diameter (largest-diameter ball 132) and a ball with the smallest diameter (smallest-diameter ball 134) is within a range of (7.52×10-4γ+8.91×10-4)*Da≤ΔDa≤(6.43×10-3γ+7.62×10-3)*Da when γ≤0.09, and (-9.65×10-4γ+1.05×10-3)*Da≤ΔDa≤(-8.25×10-3γ+8.98×10-3)*Da when γ>0.09.SELECTED DRAWING: Figure 2

The invention discloses hub bearing ball double-channel assembling equipment, and belongs to the field of assembling equipment. Comprising a workbench, a mounting cover is arranged on the workbench, and the mounting cover is provided with an auxiliary plate; the feeding assembly is arranged on the auxiliary plate; the rotating assembly is arranged on the workbench; the moving assembly is arranged on the workbench; and the adjusting assembly is arranged on the supporting part, and the adjusting assembly is arranged on the supporting part. According to the hub bearing ball double-channel assembling equipment, through double-channel feeding of the feeding assembly, the conveying part and the sensing part, efficient conveying of balls is achieved; the rotating assembly drives the holder to stably rotate, and the moving assembly accurately positions the material conveying part; the adjusting assembly dynamically adjusts the assembling clearance, the fine adjustment part controls the distance, the difference value between the distance and the ball diameter is reduced, vibration is restrained, ball deviation is reduced, manual adjustment is not needed, intervention is reduced, and the assembling efficiency and precision are improved.

An apparatus for picking up, holding and transporting one or more balls. The apparatus has two rectangular frame members positioned parallel and opposite each other. Tensioning arrangement connect between corresponding corner segments of the frame members. In an unstretched position of the tensioning arrangement the frame members are distanced a distance that is smaller than a ball diameter. When picking up a ball, the frame members are distanced a distance that is equal to the ball diameter, and, after picking up the ball, the frame members are distanced a distance that is smaller than the ball diameter and larger than the unstretched distance, and, the ball is retained within the apparatus.

The utility model discloses a cleaning device, which is used for cleaning grinding balls after quenching and before tempering, and comprises a plate body, one or more first channel sections allowing the grinding balls to pass through are arranged on the obliquely arranged plate body, a plurality of first channel sections are arranged in parallel, and a plurality of corners are arranged in the first channel sections. The plate body is provided with a ball inlet groove body communicated with inlets above all the first channel sections and a ball outlet groove body directly or indirectly communicated with outlets below all the first channel sections, the plate body is provided with a first containing groove section, an opening is formed in the lower portion of the first containing groove section, and a plurality of balls are arranged in the first containing groove section in an array mode. The column spacing of the plurality of balls is matched with the passing of the grinding balls, the line spacing of the plurality of balls is smaller than the diameter of the grinding balls, and a first channel section is formed between any two adjacent columns of balls. The device can effectively remove quenching media on the surfaces of the grinding balls and reduce tempering oil smoke.

The present invention makes it possible to realize a bearing that can be applied under high-speed rotation conditions. In this ball bearing, when Da represents the ball diameter, D represents the bearing outer diameter, d represents the bearing inner diameter, and PCD represents the pitch circle diameter of a ball (5), the minimum wall thickness t in the axial direction of an annular part (11) at the bottom of a pocket (12) is 15-30% of the ball diameter Da, the bearing inner diameter d is 25-55 mm, the bearing outer diameter D is 50-90 mm, the bearing width H is 10-20 mm, the ball diameter Da is 7 / 32 inches or less, and the ratio of the value that is specified by 1 / 2 of the difference between the pitch circle diameter PCD and the bearing inner diameter d with respect to the bearing inner diameter d is 10-20%.

A groove curvature radius ratio Ri of the inner ring raceway groove to a ball diameter is 54% to 58%, a groove curvature radius ratio Ro of an outer ring raceway groove of an outer ring to the ball diameter is 51% to 58%, and Ri−Ro≥0 points. At least an inner ring raceway groove of an inner ring has a maximum surface pressure of 4.7 GPa to 6.0 GPa when a sum of permanent deformation amounts of the ball and the inner ring raceway groove at a center of a contact portion between a ball of an angular ball bearing and the inner ring raceway groove is 1 / 10,000 of the ball diameter. Accordingly, it is possible to provide the angular ball bearing that can reduce the heat generation amount, and that can reduce the damage caused by the external impact load in the stationary state.

To provide a ball screw design method and a ball screw that can secure smooth ball movement and cope with high speed movement.SOLUTION: In a ball screw design method, when a ball diameter is represented as Da, the length of a straight line between two curved lines as L, a ball pitch angle on the curved line as θb, and a central angle of the curved line as θr in the case where there exists a straight line between the two curved lines whose radiuses are the same as a central line of a circuit, an angle ratio of the curved lines is defined as θr / θb, and the θr / θb is determined as (A) θr / θb≒n+0.25 (n being an optional integer), or (B) when θr / θb≒n+0.25 is not satisfied, the value of L is set so as to satisfy formulas (1) and (2): (1) L / Da+θr / θb≒n+0.5 (n being an integer), (2) L≒(n+0.5-(θr / θb))×Da.SELECTED DRAWING: Figure 4

The invention provides a falling ball testing device, and the device comprises an objective table which is used for bearing a to-be-detected object; the lifting part is connected with the objective table; the ball falling mechanism comprises a placing table and a supporting frame, the supporting frame is installed on the lifting part, and the placing table is arranged above the objective table through the supporting frame; wherein the placing table comprises a placing surface used for bearing the falling balls, and the placing table is movably installed on the supporting frame so as to release the falling balls. According to the falling ball testing device provided by the invention, the placement surface of which the bottom is used for supporting the falling balls is adopted, so that the falling balls made of various materials such as magnetic and non-magnetic materials can be compatible, and the defect that an electromagnetic adsorption mode is limited for testing the materials is overcome; after falling balls with different diameters are placed through the placing surface, the impact heights of the falling balls relative to the objective table are consistent, so that test errors caused by diameter changes of the falling balls are eliminated; therefore, the accuracy, the applicability and the reliability of the test are improved.

Externally mounted ball screw, featuring: • a spindle shaft (10), • a screw nut (20) which can be placed on the spindle shaft (10) and is provided with a through hole (24) with an opening edge (241) which is continuously connected by a ball path (T1) which is arranged between the screw nut (20) and the spindle shaft (10), • several bearing balls (30) which can roll along the ball path (T1), wherein the diameters of the bearing balls (30) are defined as ball diameters (BD), and • a rotating component (40) connected to the screw nut (20) and provided with a running groove (41) which is continuously connected to the through hole (24) and is formed with a pivot segment (411) connected thereto, wherein the end of the pivot segment (411) connected to the through hole (24) is formed with a coupling edge (411A) which presses against the opening edge (241), wherein the connection of the opening edge (241) to the coupling edge (411A) is not arranged tangentially, wherein the pivot segment (411) can rotate about a reference point (A) and the outer wall surface (411B) of the pivot segment (411) is arc-shaped with this reference point (A) as the center of a circle, which is located away from the outer wall surface (411B) by a radius of curvature (R), wherein the radius of curvature (R) is greater than or equal to the 1.2 times the diameter of a sphere (BD) or less than or equal to 1.5 times the diameter of a sphere (BD).

This invention discloses a table tennis serving device, characterized by comprising a pair of compression wheels arranged side-by-side at the end of the ball delivery channel. The middle of the compression wheels is positioned directly opposite the center of the ball delivery channel. The compression wheels are connected to a compression motor and can be driven to rotate outwards relative to each other, forming a launch port on the outer side of the compression wheels. The distance between the side-by-side compression wheels is smaller than the diameter of the table tennis ball, and the difference between the two is smaller than the compression deformation limit of the compression wheels and the table tennis ball. This method relies on the relative rotation of the compression wheels to impart launch speed to the table tennis ball, achieving a mechanical serving effect without noise or interference from airflow, avoiding the drawbacks of pneumatic serving and making it more suitable for live ball training.

Provided are a ball screw designing method and a ball screw capable of ensuring smooth movement of balls and of accommodating an increase in speed. This ball screw designing method involves, in a case where a straight line exists between two curves having equal radii as the center line of a circulation path, setting the value of L so as to satisfy formulae (1) and (2) where Da represents the ball diameter, L represents the length of the straight line between the two curves, θb represents the ball pitch angle on the curves, θr represents the center angle of the curves, and the angle ratio of the curves is defined as θr / θb, when (A) θr / θb ≈ n+0.25 (n is an arbitrarily-defined integer) is satisfied or (B) θr / θb ≈ n+0.25 is not satisfied.　(1): L / Da+θr / θb ≈ n+ 0.5 (n is an integer) (2): L ≈ (n+0.5-(θr / θb))×Da

The utility model belongs to the technical field of steel ball detection, and particularly relates to a wear-resistant steel ball diameter rapid measuring device which comprises an objective table, a distance measuring assembly, a blanking assembly and a storage assembly, the distance measuring assembly is arranged on the objective table, the feeding end of the blanking assembly is communicated with the objective table, and the storage assembly is communicated with the discharging end of the blanking assembly; the distance measuring assembly comprises a fixed plate, a movable plate and a distance sensor embedded in the fixed plate, the fixed plate and the movable plate are oppositely arranged on the two sides of a steel ball to be measured, and the movable plate is movably connected with the objective table through a guide rail pair.

A ball bearing having a pair of raceways composed of an inner race and an outer race, a plurality of balls interposed between raceway surfaces of the pair of raceways, and a retainer that retains the plurality of balls between the pair of raceways, the ball bearing being used in a liquefied gas. The retainer is guided by the inner race, the retainer is rotated by bringing an inner diameter surface of the retainer into sliding contact with an outer diameter surface of the inner race in a manner that a radial gap is determined, and the guide gap of the outer diameter surface of the inner race from the inner diameter surface of the retainer is 3% to 10% of a diameter of the ball, i.e., a ball diameter.

The invention relates to the technical field of turning devices, and provides a turning device for a part with an inner spherical surface and an outer spherical surface, which can realize processing operation of a spherical cavity, is better in applicability, more flexible in cutting operation, simpler in tool replacement, quicker in sphere diameter adjustment of the spherical cavity and better in practicability, and comprises a tool rest and a lathe bed, a left power box and a right power box are arranged at the left end and the right end of the lathe bed respectively, a left chuck is installed on the left power box, a left power structure used for driving the left chuck is installed in the left power box, an inner spherical surface turning assembly is installed on the left chuck and comprises a clamping frame, and the clamping frame is installed in the left chuck in a clamped mode. A centrifugal frame is rotationally connected into the clamping frame, an adjusting arm is installed on the centrifugal frame, a round-edge cutter is connected into the adjusting arm through an inserting rod frame, and a double-positioning piece is installed in the adjusting arm and used for auxiliary positioning of the round-edge cutter in the adjusting arm and auxiliary positioning of the adjusting arm relative to the centrifugal frame.

A ball seat assembly (2) for a downhole tool comprises a collet (6) having a collet shank (8) with an inner collet shank wall (36) and an outer collet shank wall, and collet fingers (10) arranged around a central axis (12) of the collet shank (8) and 5 attached to an uphole end (14) of the collet shank (8); an inner sleeve (34) configured to be axially movable along the inner collet shank wall (36), the inner sleeve (34) having a ball seat (40) and a central flow channel (42) extending through the ball seat (40); wherein the collet fingers (10) have a neutral position creating an uphole opening (26) having a first diameter (D1) and are expandable to 10 a second diameter (D2) larger than the first diameter (D1); wherein in a run-in state of the downhole tool, the inner sleeve (34) is in a first axial position relative to the collet shank (8), in which first position the inner sleeve (34) urges the collet fingers (10) to expand to the second diameter (D2) to allow a ball (44) having a ball diameter (d) less than the second diameter (D2) and larger than the first diameter 15 (D1) to pass through the uphole opening (26) of the collet (6); wherein the inner sleeve (34) is configured to move into a second axial position upon a fluid pressure applied uphole and acting against the ball (44) covering the ball seat (40) and the central flow channel (42), and wherein the ball seat assembly (2) is configured to let the collet fingers (10) snap back into the neutral position, thereby preventing the 20 ball (44) from leaving the collet (6).

Device for setting up a loudspeaker housing, comprising (a) an elongated foot bar (1) which can be attached to the front and rear walls of the loudspeaker enclosure. (b) Fastening means (4) which force-fit the foot bolt to the front and rear wall and optionally provide a positive engagement in a transverse groove (3) of the front and / or rear wall, (c) wherein the fastening means engage screw-typely on countermeasures arranged in the housing structure, in particular on (i) a transverse nut (5) in the side wall of the housing, and / or (ii) Threaded inserts or counter-screw parts in the front or rear panel, (d) a threaded stud (6) with external thread which is screwed into a fine-thread internal bore of the foot bolt and which is adjustable from above by means of a drive engagement, (e) wherein the threaded pin has a conical surface (6a) on its outer side as a contact surface and a ball sleeve (7) inserted into the base is arranged below the pin, which accommodates three balls (8) on a circumferential circle with 120° divisions, (f) wherein each sphere is in contact with the conical surface, a base support of the sphere sleeve and a cylindrical inner wall of the sphere sleeve, (g) wherein the ball sleeve (7) is encapsulated and sealed and forms a lubricant reservoir (10), (h) wherein the force flow into the foot rail, when loads occur about the transverse axis, passes through the side walls, provided that the countermeasures of the foot rail fixing screws include a transverse nut in the side wall. (i) wherein the ball sleeve has an outer diameter D in the range of 10 mm to 20 mm and the ball diameters d K are chosen proportionally to D with a ratio of 0.30 ≤ d K / D ≤ 0.35 (j) and wherein the threaded pin has an axial internal thread for receiving a countersunk screw of nominal size M3 to M5 (11) acting from above, by which the pin is clamped against the foot bolt.

This invention provides a multi-stage ball-drop optimization method and apparatus, belonging to the field of oil and gas reservoir fracturing. The method first obtains perforation diameter variation curves and perforation friction variation curves experimentally. Then, it uses these curves to determine the optimized number of ball-drop stages, the number of balls dropped, and the diameter of the temporary plugging ball. This invention effectively solves the problem of insufficient optimization methods for the number of plugging stages, the number of balls dropped, and the diameter of the temporary plugging ball in ball-drop temporary plugging fracturing, thus helping to improve the effectiveness of ball-drop temporary plugging fracturing.

The efficient grinding equipment comprises an equipment bottom plate, fixing plate bodies are fixed to the two sides of the top of the equipment bottom plate correspondingly, one ends of supporting rods are fixed to the front ends and the rear ends of the tops of the fixing plate bodies correspondingly, an equipment top plate is fixed to the other ends of the supporting rods, and a first telescopic cylinder body is installed at the top of the equipment top plate; a piston rod at the bottom of the first telescopic cylinder body penetrates through the equipment top plate to be fixedly provided with a concave plate body, an electromagnetic rod is fixed in the concave plate body, and a plurality of moving blocks penetrate through the outer portion of the electromagnetic rod, the multiple grinding pieces are arranged and can work on multiple ball joint welded junctions of the ball joint handrail at the same time, and the single-side and double-side grinding pieces are matched to synchronously grind the single-side and double-side ball joint welded junctions; the efficiency is greatly improved; the movable block is matched with the electromagnetic rod to flexibly adjust the position of the polishing piece to meet the polishing requirements of welded junctions at different positions; the grinding part is of a special structure to form a stepped elastic grinding tool and can adapt to the sphere diameter and the curved surface of a welded junction, the grinding consistency and quality are guaranteed, and the structure can generate micro-vibration to assist chip removal.

The application provides an outer circulation type ball screw, which comprises a screw shaft, a nut sleeve set on the screw shaft, the nut has at least one through hole, the through hole has an open end edge, a backflow assembly is combined with the nut, the backflow assembly has a rotation groove, the rotation groove comprises a rotation section and a continuation section, one end of the rotation section is communicated with the through hole, the other end of the rotation section is connected with the continuation section, one end of the rotation section connected with the through hole has an abutment end edge, the abutment end edge is abutted to the open end edge, the rotation section rotates around a reference point, the outer wall surface of the rotation section is arc-shaped and takes the reference point as the center, the distance between the outer wall surface of the rotation section and the reference point is a rotation radius, the length of the rotation radius is greater than or equal to 1.2 times the ball diameter, the length of the rotation radius is less than or equal to 1.5 times the ball diameter, and the abutment end edge and the open end edge are abutted in a non-tangent manner.

The invention provides a ball bearing which is light in weight, and has specified rated dynamic load, track ring strength and bearing life. A ball bearing (1) is provided with an inner ring (2), an outer ring (3) provided on the outside in the radial direction of the inner ring (2), and a plurality of balls (4) disposed between the inner ring (2) and the outer ring (3), the diameter of the balls (4) being Dw, the minimum thickness in the radial direction of the inner ring (2) being Hi, and the minimum thickness in the radial direction of the outer ring (3) being Ho. And the value of the ratio Dw / (Hi + Ho) of the ball diameter Dw to the sum Hi + Ho of the two wall thicknesses is in the range of 1.55-2.4 (inclusive).

The utility model relates to the technical field of steel structures, in particular to a welding ball net rack positioning device for a large-span steel structure building, which comprises a ball diameter adjusting mechanism, a height adjusting mechanism and a bottom supporting mechanism, the ball diameter adjusting mechanism comprises a circular self-positioning circle center mechanism and at least three ball supporting supports; the at least three ball supporting supports are annularly distributed at the top of the circular self-positioning circle center mechanism by taking the center of the circular self-positioning circle center mechanism as a circle center; the ball supporting support is movably matched with the circular self-positioning circle center mechanism and gets close to or away from the center of the circular self-positioning circle center mechanism in the radial direction so as to support welding balls of different diameters. The bottom of the height adjusting mechanism is connected with the bottom supporting mechanism, and the top of the height adjusting mechanism is connected with the circular self-positioning circle center mechanism and used for adjusting the height of the ball diameter adjusting mechanism. By means of the positioning device, the assembling efficiency of the welded ball net rack can be effectively improved, and the positioning and supporting precision is improved.

A ball bearing includes an inner ring (1), an outer ring (2), and a ball (3). The inner ring (1) has an inner ring groove curvature radius Ri. The outer ring (2) has an outer ring groove curvature radius Re. The ball (3) has a ball diameter Dw. The ratio of the outer ring groove curvature radius Re to the ball diameter Dw satisfies: Re / Dw≥0.5275; and / or the ratio of inner ring groove curvature radius Ri to the ball diameter Dw satisfies: 0.5175≤Ri / Dw≤0.55. The ball bearing may be accommodated in a housing, thereby forming a ball bearing assembly.

To provide a ball bearing capable of actualizing good rotation even under an extremely low temperature where the dimensional shrinkage of bearing components is caused.SOLUTION: The ball bearing which is used in liquefied gas includes a pair of raceway rings consisting of an inner ring and an outer ring, a plurality of balls mounted between the raceway surfaces of the pair of raceway rings, and a cage for holding the plurality of balls between the pair of raceway rings. The cage is an inner ring guide where the cage is rotated by the slide contact of the inner diameter surface of the cage and the outer diameter surface of the inner ring with each other at a determined radial space. A guide space between the outer diameter surface of the inner ring and the inner diameter surface of the cage is 3-10% of a ball diameter as the diameter of the ball.SELECTED DRAWING: Figure 1

Provided is a low-cost long-life angular contact ball bearing with which it is possible to reduce the amount of heat generation and to suppress the occurrence of inclusion starting point peeling even when the surface pressure of a contact section increases. An angular contact ball bearing is provided with: an inner ring having an inner ring raceway groove having an arc-shaped cross-section on the outer peripheral surface; an outer ring having an outer ring raceway groove having an arc-shaped cross-section on the inner circumferential surface; and the plurality of balls are arranged between the inner ring raceway groove and the outer ring raceway groove in a free rolling manner. The inner ring raceway groove has a groove curvature radius ratio (Ri) of 54%-57% with respect to the ball diameter, the outer ring raceway groove has a groove curvature radius ratio (Ro) of 51%-58% with respect to the ball diameter, and in at least the inner ring and the outer ring, the alloy steel contains 0.85%-1.15% by mass of C, 0.40%-0.90% by mass of Si, 0.55%-1.20% by mass of Mn, and 1.30%-1.90% by mass of Cr, with the balance being Fe and unavoidable impurities. The steel sheet is characterized by containing 0.30% by mass or less of Mo, 0.30% by mass or less of Ni, 0.20% by mass or less of Cu, 0.025% by mass or less of S, 0.020% by mass or less of P, 15 ppm by mass or less of O, and the balance of Fe and unavoidable impurities.

The utility model relates to the technical field of placing racks, in particular to a ball placing rack. The device comprises a base, a rectangular frame and a grooved block are fixedly connected to the upper end of the base, supporting rods are connected to the inner wall of the rectangular frame in a sliding mode, a round frame is fixedly connected to one side of each supporting rod, the supporting rods slide on the inner wall of the grooved block, and a fixing assembly is arranged between the supporting rods of the rectangular frame. An adjusting assembly is arranged on one side of the supporting rod, the fixing assembly comprises a T-shaped hole formed in the supporting rod, plug pins are slidably connected to the two sides of the inner wall of the T-shaped hole, a first piston is fixedly connected to one side of each plug pin, and a plurality of evenly-distributed fixing grooves are formed in the two sides of the rectangular frame. The problem that due to the fact that the sizes of the rubber balls needing to be stored are different, when the diameters of the stored rubber balls are larger than the distance between the two round frames, the rubber balls cannot be placed in the round frames, and then the rubber balls cannot be stored is solved.