Bearing inner ring and grinding undercut machining method thereof

Abstract

The invention discloses a bearing inner ring and grinding undercut machining method, which comprises the following specific machining steps: step 1, a technician sets working parameters of a PLC (Programmable Logic Controller), estimates I / O (Input / Output) points according to actual application requirements, considers proper allowance and carries out trial operation on a numerical control lathe; secondly, the bar is clamped and fixed through a three-jaw chuck, a milling cutter is controlled by a PLC to cut redundant outer edge materials of the bar, and the outer diameter of the bar is made to be the size needed by the bearing inner ring; thirdly, a shaft hole of the cut bar is axially cut through a numerical control lathe, the hole diameter is the inner diameter of the bearing inner ring, then the bar is radially cut according to the needed size, and a bearing inner ring blank is obtained; and fourthly, the inner ring blank is installed on a five-axis rotary table through a three-jaw chuck. A V-shaped vertical cutter is adopted for hard turning of the grinding undercut between the step face and the bearing inner ring, turning blind areas can be reduced to the maximum extent, and the machining efficiency and quality of the grinding undercut are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of bearing processing, and in particular relates to a bearing inner ring and an overrun groove processing method thereof. Background Art

[0002] Bearings are an important component in contemporary mechanical equipment. Their main function is to support mechanical rotating bodies, reduce the friction coefficient during their movement, and ensure their rotation accuracy. The production process of bearings mainly includes raw material preparation, inner and outer ring processing, steel ball or roller processing, cage processing, and bearing assembly. An overtravel groove is generally provided between the step surface and the inner ring of the bearing inner ring. The overtravel groove of the bearing inner ring is an annular groove cut into a part of the bearing inner ring. This design mainly serves the performance optimization and installation convenience of the bearing. The existence of the overtravel groove can enhance the structural strength of the inner ring, so that it can reduce the possibility of deformation and damage when facing large radial or axial forces. It needs to be produced and prepared through a special bearing inner ring and its overtravel groove processing method.

[0003] The existing bearing inner ring and its overrun groove processing method easily produce turning blind areas during the overrun groove processing, and the overrun groove processing efficiency is low and the quality is poor. It cannot withstand higher radial forces, the anti-deformation effect is not obvious, it is not convenient to operate, and the applicability is poor. Summary of the invention

[0004] The purpose of the present invention is to provide a method for processing a bearing inner ring and an overrun groove thereof, so as to solve the problems of the existing method for processing a bearing inner ring and an overrun groove thereof proposed in the above-mentioned background technology, that the overrun groove is prone to produce a turning blind area during the processing, the processing efficiency of the overrun groove is low and the quality is poor, and it cannot withstand higher radial forces, the anti-deformation effect is not obvious, it is not convenient to operate, and the applicability is poor.

[0005] To achieve the above-mentioned purpose, the present invention provides the following technical solution: a method for processing a bearing inner ring and an overrun groove thereof, wherein the specific processing steps are as follows: Step 1: The technician sets the working parameters of the PLC controller, estimates the number of I / O points according to the actual application requirements, takes into account appropriate margins, and conducts a test run on the CNC lathe; Step 2: The bar is clamped and fixed by a three-jaw chuck, and the milling cutter is controlled by a PLC controller to cut the excess outer edge of the bar so that the outer diameter of the bar is the required size of the inner ring of the bearing; Step 3: Then, the cut bar is axially cut into a shaft hole using a CNC lathe, and the hole diameter is the inner diameter of the bearing inner ring. Then, the bar is radially cut according to the required size to obtain the bearing inner ring blank; Step 4: Install the inner ring blank on the five-axis turntable through a three-jaw chuck, use a D-type end mill to machine steps, raceways and ribs on both sides of the inner ring of the bearing inner ring blank, and use a C-type external cylindrical cutter to machine the outer circle on the outer edge of the step; Step 5: Then use a C-type external cylindrical cutter to turn the end face of the inner ring blank of the bearing, and then turn the outer circle. The tool is automatically adjusted to adjust the size. The Renishaw probe measures the internal teeth to find the tooth position. The gear skiving cutter scrapes the teeth strongly to form a gear groove on one side of the step. Step 6: Finely grind the plane of the inner ring of the bearing in step 5, demagnetize the bearing, and finely grind the outer diameter of the bearing, the inner diameter of the outer ring of the bearing, the rib of the bearing, and the raceway of the bearing in sequence; Step 7: Make the inner diameter of the bearing inner ring contact with the sector surface of the claw, and use a V-shaped vertical tool to hard turn the overrun groove between the step surface and the bearing inner ring. The hard turning processing parameters are: cutting speed of 45m / min, feed rate of 0.02mm / r; Step 8: Place the processed inner ring of the bearing into an ultrasonic cleaner and add solvent for cleaning. After a period of time, take out the inner ring of the bearing and place it on a workbench. Turn on the motor to drive the hard brush to rotate and clean the surface and gap of the inner ring of the bearing. Step 9: Finally, put the cleaned inner ring of the bearing into an ultrasonic cleaner and add clean water for cleaning. The treated semi-finished inner ring of the bearing is dried in a dryer at 65-85°C; Step 10: Use a high-frequency heating furnace to heat the surface of the semi-finished bearing inner ring at a heating rate as fast as possible, generally greater than 580°C / second, and quickly heat to 990°C~1100°C, and quench it; after quenching, the semi-finished bearing ring is naturally cooled to produce a finished bearing inner ring with an overtravel groove.

[0006] Furthermore, the specific machine tool model in the step one is the Hermle C52U five-axis linkage machining center, and the specific Renishaw probe model in the step five is MH20i, which is suitable for the repeatable positioning measuring seat of the TP20 probe module.

[0007] Furthermore, in the step 2, the cutting speed is 90-100 m / min and the feed speed is 0.08-0.1 mm / r.

[0008] Furthermore, in step three, the cutting speed is 60-70 m / min and the feed speed is 0.02-0.03 mm / r.

[0009] Furthermore, in step eight, the semi-finished bearing inner ring is placed in an ultrasonic cleaner, and the solvent is added and it takes 4 minutes to clean. In step nine, the semi-finished bearing inner ring is placed in an ultrasonic cleaner, and clean water is added and it takes 5 minutes to clean. The time for brushing the substrate surface with a hard brush is preferably 2 to 3 minutes.

[0010] Furthermore, the temperature of heating the surface of the semi-finished bearing inner ring in step ten must exceed the temperature range of the austenite region, that is, 723°C to 830°C.

[0011] Furthermore, in the step 10, the quenching treatment adopts a spray quenching medium crystallization annealing for 50 to 80 minutes and then multiple unidirectional rolling forming, and the equivalent effect variable of each unidirectional rolling is 1.8 to 3.

[0012] Compared with the prior art, the present invention has the following beneficial effects: (1) A method for processing a bearing inner ring and its overrun groove uses a D-type end mill to machine steps, raceways and ribs on both sides of the inner ring of a bearing inner ring blank without clamping the workpiece multiple times. The double-sided steps can increase the bearing inner ring's ability to withstand higher radial forces and have a significant anti-deformation effect. Powerful gear skiving is an efficient gear processing method that combines the two processes of hobbing and gear shaping, allowing high-speed continuous cutting on a five-axis machine tool. Its main advantages are its high productivity and flexibility, which improves the production efficiency of the bearing inner ring. The resulting bearing inner ring is quenched to achieve grain refinement, obtain high-strength properties, greatly improve yield strength, not easy to deform, and be durable, effectively extending the service life of the bearing ring.

[0013] (2) A method for machining a bearing inner ring and its overrun groove. Renishaw probes are well-known for their high precision and repeatability. They can measure at multiple angles and recall positions without recalibration, thereby saving operation time and improving measurement accuracy. The gear grooves produced are convenient for use with active bevel gears, expanding the scope of use. A V-shaped vertical tool is used to hard-turn the overrun groove between the step surface and the bearing inner ring, which can minimize the turning blind area and improve the machining efficiency and quality of the overrun groove. Before quenching, the surface and gap of the bearing inner ring are cleaned with an ultrasonic cleaner, which has a high cleaning effect and prevents surface metal particles from adhering to the workpiece surface at high temperature, affecting product quality. The overall production steps are easy to operate, highly creative, and suitable for widespread promotion and use. DETAILED DESCRIPTION

[0014] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. 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 making creative work are within the scope of protection of the present invention.

[0015] A method for processing a bearing inner ring and an overrun groove thereof, wherein the specific processing steps are as follows: Step 1: The technician sets the working parameters of the PLC controller, estimates the number of I / O points according to the actual application requirements, takes into account appropriate margins, and conducts a test run on the CNC lathe; Step 2: The bar is clamped and fixed by a three-jaw chuck, and the milling cutter is controlled by a PLC controller to cut the excess outer edge of the bar so that the outer diameter of the bar is the required size of the inner ring of the bearing; Step 3: Then, the cut bar is axially cut into a shaft hole using a CNC lathe, and the hole diameter is the inner diameter of the bearing inner ring. Then, the bar is radially cut according to the required size to obtain the bearing inner ring blank; Step 4: Install the inner ring blank on the five-axis turntable through a three-jaw chuck, use a D-type end mill to machine steps, raceways and ribs on both sides of the inner ring of the bearing inner ring blank, and use a C-type external cylindrical cutter to machine the outer circle on the outer edge of the step; Step 5: Then use a C-type external cylindrical cutter to turn the end face of the inner ring blank of the bearing, and then turn the outer circle. The tool is automatically adjusted to adjust the size. The Renishaw probe measures the internal teeth to find the tooth position. The gear skiving cutter scrapes the teeth strongly to form a gear groove on one side of the step. Step 6: Finely grind the plane of the inner ring of the bearing in step 5, demagnetize the bearing, and finely grind the outer diameter of the bearing, the inner diameter of the outer ring of the bearing, the rib of the bearing, and the raceway of the bearing in sequence; Step 7: Make the inner diameter of the bearing inner ring contact with the sector surface of the claw, and use a V-shaped vertical tool to hard turn the overrun groove between the step surface and the bearing inner ring. The hard turning processing parameters are: cutting speed of 45m / min, feed rate of 0.02mm / r; Step 8: Place the processed inner ring of the bearing into an ultrasonic cleaner and add solvent for cleaning. After a period of time, take out the inner ring of the bearing and place it on a workbench. Turn on the motor to drive the hard brush to rotate and clean the surface and gap of the inner ring of the bearing. Step 9: Finally, put the cleaned inner ring of the bearing into an ultrasonic cleaner and add clean water for cleaning. The treated semi-finished inner ring of the bearing is dried in a dryer at 65-85°C; Step 10: Use a high-frequency heating furnace to heat the surface of the semi-finished bearing inner ring at a heating rate as fast as possible, generally greater than 580°C / second, and quickly heat to 990°C~1100°C, and quench it; after quenching, the semi-finished bearing ring is naturally cooled to produce a finished bearing inner ring with an overtravel groove.

[0016] Among them, the specific machine tool model in step 1 is the Hermle C52U five-axis linkage machining center, and the specific Renishaw probe model in step 5 is MH20i, which is suitable for the repeatable positioning measuring seat of the TP20 probe module.

[0017] Wherein; in the step 2, the cutting speed is 90-100 m / min, and the feed speed is 0.08-0.1 mm / r.

[0018] Wherein; in step three, the cutting speed is 60-70 m / min, and the feed speed is 0.02-0.03 mm / r.

[0019] Among them, in step eight, the semi-finished bearing inner ring is placed in an ultrasonic cleaner, and the solvent is added and it takes 4 minutes to clean. In step nine, the semi-finished bearing inner ring is placed in an ultrasonic cleaner, and clean water is added and it takes 5 minutes to clean. The time for brushing the substrate surface with a hard brush is preferably 2 to 3 minutes.

[0020] Wherein, the temperature of heating the surface of the semi-finished bearing inner ring in step 10 must exceed the temperature range of the austenite region, that is, 723°C to 830°C.

[0021] Wherein, the quenching treatment in step ten adopts spray quenching medium crystallization annealing for 50 to 80 minutes and then multiple unidirectional rolling forming, and the equivalent effect variable of each unidirectional rolling is 1.8 to 3.

[0022] When the present invention is working: a D-type end mill is used to machine steps, raceways and ribs on both sides of the inner ring of the bearing inner ring blank, without the need to clamp the workpiece multiple times. The double-sided steps can increase the ability of the bearing inner ring to resist higher radial forces, and the anti-deformation effect is significant. Powerful gear skiving is an efficient gear processing method, which combines the two processes of rolling milling and gear shaping, allowing high-speed continuous cutting on a five-axis machine tool. Its main advantages are its high productivity and great flexibility, which improves the production efficiency of the bearing inner ring. The resulting bearing inner ring is quenched to achieve grain refinement, obtain high-strength characteristics, greatly improve yield strength, is not easy to deform, is durable, and effectively extends the service life of the bearing ring. Renishaw probes are renowned for their high precision and repeatability. They can measure at multiple angles and recall positions without recalibration, saving operating time and improving measurement accuracy. The gear grooves produced are easy to use with active bevel gears, expanding the scope of use. The use of a V-shaped vertical tool to hard-turn the overrun groove between the step surface and the inner ring of the bearing can minimize the turning blind area and improve the machining efficiency and quality of the overrun groove. The surface and gaps of the inner ring of the bearing are cleaned with an ultrasonic cleaner before quenching, which has a high cleaning effect and prevents surface metal particles from adhering to the workpiece surface at high temperatures, affecting product quality. The overall production process is easy to operate, highly creative, and suitable for widespread promotion and use.

[0023] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for machining a bearing inner ring and an overrun groove thereof, characterized in that: The specific processing steps are as follows: Step 1: The technician sets the working parameters of the PLC controller, estimates the number of I / O points according to the actual application requirements, takes into account appropriate margins, and conducts a test run on the CNC lathe; Step 2: The bar is clamped and fixed by a three-jaw chuck, and the milling cutter is controlled by a PLC controller to cut the excess outer edge of the bar so that the outer diameter of the bar is the required size of the inner ring of the bearing; Step 3: Then, the cut bar is axially cut into a shaft hole using a CNC lathe, and the hole diameter is the inner diameter of the bearing inner ring. Then, the bar is radially cut according to the required size to obtain the bearing inner ring blank; Step 4: Install the inner ring blank on the five-axis turntable through a three-jaw chuck, use a D-type end mill to machine steps, raceways and ribs on both sides of the inner ring of the bearing inner ring blank, and use a C-type external cylindrical cutter to machine the outer circle on the outer edge of the step; Step 5: Then use a C-type external cylindrical cutter to turn the end face of the inner ring blank of the bearing, and then turn the outer circle. The tool is automatically adjusted to adjust the size. The Renishaw probe measures the internal teeth to find the tooth position. The gear skiving cutter scrapes the teeth strongly to form a gear groove on one side of the step. Step 6: Finely grind the plane of the inner ring of the bearing in step 5, demagnetize the bearing, and finely grind the outer diameter of the bearing, the inner diameter of the outer ring of the bearing, the rib of the bearing, and the raceway of the bearing in sequence; Step 7: Make the inner diameter of the bearing inner ring contact with the sector surface of the claw, and use a V-shaped vertical tool to hard turn the overrun groove between the step surface and the bearing inner ring. The hard turning processing parameters are: cutting speed of 45m / min, feed rate of 0.02mm / r; Step 8: Place the processed inner ring of the bearing into an ultrasonic cleaner and add solvent for cleaning. After a period of time, take out the inner ring of the bearing and place it on a workbench. Turn on the motor to drive the hard brush to rotate and clean the surface and gap of the inner ring of the bearing. Step 9: Finally, put the cleaned inner ring of the bearing into an ultrasonic cleaner and add clean water for cleaning. The treated semi-finished inner ring of the bearing is dried in a dryer at 65-85°C; Step 10: Use a high-frequency heating furnace to heat the surface of the semi-finished bearing inner ring at a heating rate as fast as possible, generally greater than 580°C / second, and quickly heat to 990°C~1100°C, and quench it; after quenching, the semi-finished bearing ring is naturally cooled to produce a finished bearing inner ring with an overtravel groove.

2. A method for machining a bearing inner ring and an overrun groove thereof according to claim 1, characterized in that: The specific machine tool model in step 1 is a Hermle C52U five-axis linkage machining center, and the specific Renishaw probe model in step 5 is MH20i, which is suitable for the repeatable positioning measuring seat of the TP20 probe module.

3. A method for machining a bearing inner ring and an overrun groove thereof according to claim 1, characterized in that: In the step 2, the cutting speed is 90-100 m / min, and the feed speed is 0.08-0.1 mm / r.

4. A method for machining a bearing inner ring and an overrun groove thereof according to claim 1, characterized in that: In the step three, the cutting speed is 60-70 m / min, and the feed speed is 0.02-0.03 mm / r.

5. A method for machining a bearing inner ring and an overrun groove thereof according to claim 1, characterized in that: In step eight, the semi-finished inner ring of the bearing is placed in an ultrasonic cleaner and the solvent is added for cleaning for 4 minutes. In step nine, the semi-finished inner ring of the bearing is placed in an ultrasonic cleaner and clean water is added for cleaning for 5 minutes. The time for brushing the surface of the substrate with a hard brush is preferably 2 to 3 minutes.

6. A bearing inner ring and a method for processing an overrun groove thereof according to claim 1, characterized in that: In the step 10, the temperature at which the surface of the semi-finished inner ring of the bearing is heated must exceed the temperature range of the austenite region, i.e., 723° C. to 830° C.

7. A bearing inner ring and a method for machining an overrun groove thereof according to claim 1, characterized in that: In the step 10, the quenching treatment adopts spraying quenching medium for crystallization annealing for 50 to 80 minutes and then multiple unidirectional rolling forming, and the equivalent effect variable of each unidirectional rolling is 1.8 to 3.