Method and device for turning a bearing outer ring groove based on pure electroplastic effect

Abstract

The application discloses a bearing outer ring raceway turning method and device based on pure electroplastic effect, belongs to the field of bearing ring manufacturing, and aims at solving the problem of low machining quality caused by work hardening in the traditional bearing outer ring raceway turning process.The method is characterized by injecting pulse current into the bearing outer ring during the turning process of the bearing outer ring raceway, and the pulse current is used to generate pure electroplastic effect in the bearing outer ring.The device for realizing the method comprises a conductive rod, a bearing outer ring, a turning tool holder, a lathe chuck, a lathe workbench and a pulse power supply; the conductive rod, the turning tool holder and the pulse power supply are fixedly arranged on the lathe workbench; the positive and negative poles of the pulse power supply are respectively connected with the tail ends of the conductive rod and the turning tool holder; the bearing outer ring is fixed on the lathe chuck; the head ends of the conductive rod and the turning tool holder are respectively in contact with the inner circular surface of the bearing outer ring; the turning tool holder is used for turning the bearing outer ring; and the conductive rod is used for injecting the pulse current output by the pulse power supply into the bearing outer ring.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of bearing ring manufacturing. BACKGROUND

[0002] As a key component of an aero-engine, the manufacturing level of bearings directly affects the development of aircraft. Bearings are mainly composed of rings, retainers and rolling elements, among which the rings include inner and outer rings. The groove, as the core part of the ring, directly determines the service life of the entire bearing after processing.

[0003] The concept of electroplastic effect was first proposed by scientist O.T.Troitskii in the 1960s. Modern research believes that when a pulsed current field is applied to a plastically deformed metal material, it mainly exhibits Joule heating effect and electroplastic effect. The mechanism of electroplastic effect is that the introduction of pulsed current makes the dislocation receive an additional electronic wind force, helping the dislocation overcome the sliding resistance and enhancing the dislocation movement ability, thereby reducing the deformation resistance of the material.

[0004] During the traditional turning process of the bearing outer ring groove, the internal dislocation movement of the metal exists mutual penetration, which causes the dislocation to be entangled or the grain boundary to be accumulated to produce work hardening phenomenon. Moreover, with the continuous turning, the deformation resistance of the material gradually increases, the turning resistance becomes larger, causing local overheating. At the same time, due to the use of cutting fluid in the turning process, the bearing ring is locally subjected to secondary quenching phenomenon, resulting in quality problems such as burn, micro-cracks and the like in the outer ring groove. SUMMARY

[0005] In view of the problem that the machining quality is not high due to the work hardening phenomenon in the traditional turning process of the bearing outer ring groove, the present application provides a bearing outer ring groove turning method and device based on pure electroplastic effect. The electroplastic effect is used to reduce the deformation resistance of the material, reduce the heat generated by the material during turning, control the inner groove temperature of the ring below the critical temperature of quenching, avoid the secondary quenching phenomenon, and thereby reduce the occurrence of quality problems such as burn and micro-cracks.

[0006] The bearing outer ring groove turning method based on pure electroplastic effect provided by the present application is as follows: a pulsed current is injected into the bearing outer ring during the turning process of the bearing outer ring groove, and the pulsed current is used to generate pure electroplastic effect in the bearing outer ring.

[0007] Preferably, the conductive rod for injecting the pulsed current rotates with the bearing outer ring during the turning process, and the conductive rod is in contact with the bearing outer ring at all times during the rotation.

[0008] Preferably, the pulsed current parameters are as follows: effective current 1-2 A, duty cycle 1%, pulse width 100 μs, pulse spacing 9900 μs, and peak current density at cutting position 1000-2000 A / mm 2.

[0009] The application also provides another technical solution, a bearing outer ring raceway turning device based on pure electroplastic effect, which is used for realizing the method, and comprises a conductive rod 1, a bearing outer ring 2, a turning tool holder 3, a lathe chuck 4, a lathe workbench 6 and a pulse power supply 8.

[0010] The conductive rod 1, the turning tool holder 3 and the pulse power supply 8 are fixedly arranged on the lathe workbench 6; the positive and negative poles of the pulse power supply 8 are respectively connected to the ends of the conductive rod 1 and the turning tool holder 3.

[0011] The bearing outer ring 2 is fixed on the lathe chuck 4; the first ends of the conductive rod 1 and the turning tool holder 3 are respectively in contact with the inner circular surface of the bearing outer ring 2, the turning tool holder 3 is used for turning the bearing outer ring 2, and the conductive rod 1 is used for injecting the pulse current output by the pulse power supply 8 into the bearing outer ring 2.

[0012] Preferably, the first end of the conductive rod 1 is in a cylindrical shape, and the side surface is in an arc shape, the arc side surface of the conductive rod 1 is in contact with the inner circular surface of the bearing outer ring 2, and the conductive rod 1 rotates along with the bearing outer ring in the turning process.

[0013] Preferably, the device further comprises a bearing 9, a spring 10, a conductive rod fixing frame 11 and a graphite brush 12; the conductive rod fixing frame 11 is in a split type and is locked by two bolts, and the conductive rod fixing frame 11 is fixed on the lathe workbench 6 by the bolts.

[0014] The two bearings 9 are fixedly arranged in the inner cavity of the conductive rod fixing frame 11, the end of the conductive rod 1 extends into the inner cavity of the conductive rod fixing frame 11 and is fixed on the bearing 9 by a nut, at least two springs 10 are fixedly arranged in the inner cavity of the conductive rod fixing frame 11 between the two bearings 9, the plurality of springs 10 are circumferentially distributed in the inner cavity of the conductive rod fixing frame 11, and each spring 10 presses one graphite brush 12 against the conductive rod 1.

[0015] Preferably, the device further comprises a sleeve insulation pad 5, and the bearing outer ring 2 is fixed on the lathe chuck 4 by the sleeve insulation pad 5.

[0016] Preferably, the turning tool holder 3 is fixed on the lathe workbench 6 by a bolt, and the bolt pad has an insulation pad, and the holder body of the turning tool holder 3 is provided with an insulation pad at the lower side.

[0017] Preferably, the device further comprises a brush insulation pad 13, and the brush insulation pad 13 is arranged between the graphite brush 12 and the spring 10.

[0018] Preferably, the device further comprises a bearing insulation pad 14, and the bearing insulation pad 14 is arranged between the bearing 9 and the conductive rod 1.

[0019] The beneficial effects of the present application: after the pulse current is passed in the turning process of the present application, the directional moving electrons will generate electronic wind force to promote the movement of metal dislocation, open the entanglement, and help the dislocation to overcome the obstacles on the slip surface, so that the metal fluidity is improved, the deformation resistance is reduced, the turning is easy, thereby reducing the material heat generation during turning, controlling the temperature in the groove of the ring within the quenching critical temperature, avoiding the secondary quenching phenomenon. Thus, the quality of the bearing outer ring groove is improved, and the problems such as burning and micro-cracks in the bearing outer ring groove are reduced. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 is a structural schematic diagram of the bearing outer ring groove turning method based on pure electroplastic effect according to the present application.

[0021] Figure 2 is Figure 1 A-A sectional view of. DETAILED DESCRIPTION

[0022] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0023] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0024] The present application will be further described below with reference to the drawings and specific embodiments, but not as a limitation of the present application.

[0025] Specific embodiment one: the present embodiment will be described below with reference to Figure 1 and Figure 2 The present embodiment describes a bearing outer ring groove turning method based on pure electroplastic effect. The method is: injecting pulse current into the bearing outer ring during the turning process of the bearing outer ring groove, and the pulse current is used to generate pure electroplastic effect in the bearing outer ring.

[0026] The conductive rod injecting the pulse current rotates with the bearing outer ring during the turning process, and the conductive rod is in contact with the bearing outer ring at all times during the rotation process.

[0027] The pulse current flows out from the positive pole of the pulse power supply 8, flows into the conductive rod 1 through the wire 7, and the conductive rod 1 keeps close contact during rotation. The conductive rod 1 rotates with the bearing outer ring 2 during turning, and the conductive rod 1 keeps contact with the bearing outer ring 2 during rotation. The pulse current flows along the bearing outer ring to the tool holder 3, and then flows back to the pulse power supply 8 through the wire. The current flow direction 15 in the bearing outer ring is shown in Figure 2 .

[0028] The pulse current parameters are: effective current 1-2A, duty cycle 1%, pulse width 100μs, pulse interval 9900μs, peak current density at cutting position 1000-2000A / mm2. The turning speed is 150m / min, and the cutting depth is 0.1mm.

[0029] Specific implementation method two: the following Figure 1 and Figure 2 will be described. The bearing outer ring groove turning device based on pure electroplastic effect described in this embodiment is used to realize the method described in embodiment one. The device includes a conductive rod 1, a bearing outer ring 2, a tool holder 3, a lathe chuck 4, a lathe workbench 6, a pulse power supply 8, a bearing 9, a spring 10, a conductive rod fixing frame 11, and a graphite brush 12.

[0030] The bearing outer ring 2 is fixed on the lathe chuck 4 through the ring insulation pad 5, the tool holder 3 is fixed on the lathe workbench 6 by bolts, and the tool holder 3 is padded with an insulation pad. The bolt is padded with an insulation pad to prevent the pulse current from flowing into the lathe body through the bolt, which is dangerous to the operator. The conductive rod 1 is fixed on the bearing 9 through a nut, the bearing 9, the spring 10, the brush insulation pad 13, and the graphite brush 12 are fixed on the conductive rod fixing frame 11, two bearings 9 are fixed in the inner cavity of the conductive rod fixing frame 11, the end of the conductive rod 1 extends into the inner cavity of the conductive rod fixing frame 11 and is fixed on the bearing 9 through a nut, at least two springs 10 are fixed in the inner cavity of the conductive rod fixing frame 11 between the two bearings 9, and multiple springs 10 are evenly distributed in the inner cavity of the conductive rod fixing frame 11. Each spring 10 presses one graphite brush 12 against the conductive rod 1. The graphite brush 12 and the spring 10 are provided with a brush insulation pad 13. The bearing insulation pad 14 is arranged between the bearing 9 and the conductive rod 1.

[0031] In order to facilitate assembly, the conductive rod fixing frame 11 is split and locked by two bolts, and the conductive rod fixing frame 11 is fixed on the lathe workbench 6 by bolts.

[0032] The conductive rod 1, the tool holder 3, and the pulse power supply 8 are fixed on the lathe workbench 6; the positive and negative poles of the pulse power supply 8 are respectively connected to the ends of the conductive rod 1 and the tool holder 3.

[0033] The bearing outer ring 2 is fixed on the lathe chuck 4; the head ends of the conductive rod 1 and the turning tool holder 3 are in contact with the inner circular surface of the bearing outer ring 2 respectively, the turning tool holder 3 is used to turn the bearing outer ring 2, and the conductive rod 1 is used to inject the pulse current output by the pulse power supply 8 into the bearing outer ring 2.

[0034] The head end of the conductive rod 1 is cylindrical and the side surface is arc-shaped. The arc-shaped side surface of the conductive rod 1 contacts the inner surface of the bearing outer ring 2, and the conductive rod 1 rotates with the bearing outer ring during the turning process.

[0035] according to Figure 1 Assembled as shown, pulse current flows from the positive terminal of pulse power supply 8, through wire 7, to two graphite brushes 12. Spring 10 compresses brush insulation pads 13, ensuring close contact between brushes 12 and conductive rod 1 during rotation. Conductive rod 1 rotates with bearing outer ring 2 during turning via bearing 9. During rotation, conductive rod 1 remains in contact with bearing outer ring 2. The pulse current flows along the bearing outer ring to tool holder 3, then back to pulse power supply 8 through wire 7.

[0036] The Joule heating effect of electric current is only related to the effective current. Therefore, the present invention uses a low effective current to reduce Joule heating, while simultaneously using a low duty cycle to achieve a high peak current density. Because the electroplastic effect is only affected by the peak current density, the present invention primarily utilizes the pure electroplastic effect of electric current during the bearing outer ring groove turning process.

[0037] During traditional bearing outer ring groove turning, the material's resistance to deformation gradually increases as turning progresses, leading to greater turning resistance and localized overheating. Furthermore, the rapid cooling of the cutting fluid during turning causes secondary quenching of the bearing ring, resulting in quality issues such as burns and microcracks in the outer ring groove. In the present invention, when pulsed current is applied during turning, the directed electrons generate an electron wind that promotes the movement of metal dislocations, untangling them and helping them overcome obstacles on the slip surface. This improves metal fluidity, reduces deformation resistance, and makes turning easier, thereby reducing material heat generation during turning and keeping the inner ring groove temperature below the critical quenching temperature, thus avoiding secondary quenching. This improves the quality of the bearing outer ring groove and reduces issues such as burns and microcracks in the bearing outer ring groove.

[0038] While the application has been described with reference to particular embodiments thereof, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present application. It will be apparent to those skilled in the art that numerous modifications can be made within the scope of the present application as defined by the appended claims. It is intended that all such modification fall within the spirit and scope of the present application. It will be understood that the features described in connection with one embodiment can be used in connection with another embodiment.

Claims

1. Bearing outer ring groove turning device based on pure electroplastic effect, characterized in that: The device comprises a conductive rod (1), a bearing outer ring (2), a lathe tool holder (3), a lathe chuck (4), a lathe workbench (6) and a pulse power supply (8); The conductive rod (1), the lathe tool holder (3) and the pulse power supply (8) are fixedly arranged on the lathe workbench (6); the positive and negative electrodes of the pulse power supply (8) are respectively connected to the ends of the conductive rod (1) and the lathe tool holder (3); The bearing outer ring (2) is fixed on a lathe chuck (4); the head ends of the conductive rod (1) and the turning tool holder (3) are in contact with the inner surface of the bearing outer ring (2), respectively; the turning tool holder (3) is used to turn the bearing outer ring (2); and the conductive rod (1) is used to inject the pulse current output by the pulse power supply (8) into the bearing outer ring (2); The head end of the conductive rod (1) is cylindrical and the side surface is arc-shaped. The arc-shaped side surface of the conductive rod (1) contacts the inner surface of the bearing outer ring (2), and the conductive rod (1) rotates along with the bearing outer ring during the turning process. The pulse current parameters output by the pulse power supply (8) are: effective current 1~2A, duty cycle 1%, pulse width 100μs, pulse interval 9900μs, and peak current density at the cutting point 1000~2000A / mm 2 .

2. The bearing outer ring groove turning device based on pure electroplastic effect according to claim 1 is characterized in that: It also includes a bearing (9), a spring (10), a conductive rod fixing frame (11) and a graphite brush (12); the conductive rod fixing frame (11) is split and locked by two bolts, and the conductive rod fixing frame (11) is fixed to the lathe workbench (6) by bolts; Two bearings (9) are fixedly arranged in the inner cavity of the conductive rod fixing frame (11), the end of the conductive rod (1) extends into the inner cavity of the conductive rod fixing frame (11) and is fixed to the bearing (9) through a nut, and at least two springs (10) are fixedly arranged in the inner cavity of the conductive rod fixing frame (11) between the two bearings (9), and the plurality of springs (10) are uniformly distributed in the inner cavity of the conductive rod fixing frame (11) in a circumferential direction, and each spring (10) presses a graphite brush (12) onto the conductive rod (1).

3. The bearing outer ring groove turning device based on pure electroplastic effect according to claim 1 is characterized in that: It also includes a ferrule insulating pad (5), and the bearing outer ring (2) is fixed on the lathe chuck (4) through the ferrule insulating pad (5).

4. The bearing outer ring groove turning device based on pure electroplastic effect according to claim 1 is characterized in that: The turning tool holder (3) is fixed on the lathe workbench (6) by using bolts, and the bolts are padded with insulating pads, and the frame of the turning tool holder (3) is padded with insulating pads.

5. The bearing outer ring groove turning device based on pure electroplastic effect according to claim 2, characterized in that: It also includes a brush insulation pad (13), which is arranged between the graphite brush (12) and the spring (10).

6. The bearing outer ring groove turning device based on pure electroplastic effect according to claim 2, characterized in that: It also includes a bearing insulating washer (14), which is arranged between the bearing (9) and the conductive rod (1).

7. The bearing outer ring groove turning device based on pure electroplastic effect according to claim 1, characterized in that: The conductive rod (1) rotates along with the bearing outer ring during the turning process.

8. The bearing outer ring groove turning device based on pure electroplastic effect according to claim 1 is characterized in that: The pulse current causes the outer ring of the bearing to produce a pure electroplastic effect.

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