CN113462878A

CN113462878A - Single-tooth induction quenching process and equipment for large gear

Info

Publication number: CN113462878A
Application number: CN202110847342.7A
Authority: CN
Inventors: 闫满刚; 赵秀华; 王佩璋
Original assignee: Beijing Magnetic Electric Heating Technology Co ltd
Current assignee: Beijing Magnetic Electric Heating Technology Co ltd
Priority date: 2021-07-23
Filing date: 2021-07-23
Publication date: 2021-10-01

Abstract

A single-tooth induction quenching process and equipment for large gears are characterized in that a numerical control manipulator is adopted to drive inductors on 3 quenching units to perform single-tooth induction scanning quenching on one large gear along a tooth groove, so that the time of the whole gear quenching process is saved by nearly 2/3, the quenched gear can be tempered in time, and the occurrence of quenching cracking is greatly avoided. The specific method is that three T-shaped numerical control manipulators are arranged on the circumference of the gear to be quenched to drive respective quenching units to simultaneously perform single-tooth scanning quenching on the gear along the tooth grooves, and each quenching unit is respectively powered by a respective intermediate frequency power supply. The quenching unit is connected with the manipulator through a 3-degree-of-freedom displacement compensation mechanism, so that when the tooth number cannot be completely removed by 3, the quenching unit can translate and rotate through the compensation mechanism, and the sensor is guaranteed to be aligned with the gullet. The kit also comprises a quench liquid system and a cooling system. After an operator aligns the inductors and the tooth grooves of the three quenching units for the first time, the whole quenching operation is completely driven by a numerical control program.

Description

Single-tooth induction quenching process and equipment for large gear

Technical Field

The invention belongs to the field of manufacturing of large gears (gear rings), in particular to a surface quenching processing method and equipment for a large gear ring of a wind power main gearbox, and relates to novel process and novel equipment for performing single-tooth scanning quenching by adopting induction heating.

Background

The large gear ring is one of the key components in the main gearbox of the wind power generation. With the great increase of the demand of clean energy in China and international society, the demand of single machine power and the demand of quantity of wind power generation are increasing. Particularly, the single machine capacity of the wind driven generator installed on the ocean is 10 megawatts or even more, so that the corresponding specification of the main gear box is also very large, the diameter specification of a large gear ring therein is 3 meters or more, and the tooth width is more than half a meter. Common case quenching methods include carburizing and quenching, nitriding, and single tooth induction quenching. The single-tooth induction quenching process is the tooth surface quenching processing process with the shortest time, low process cost and high efficiency and has the highest cost performance.

The conventional single-tooth induction quenching adopts a quenching mode of scanning along a tooth groove, namely, a quenching unit on a quenching machine tool moves to an initial position at the beginning, a certain gap is kept between the tooth grooves by an inductor on the quenching unit, the whole tooth groove is scanned from one end along the tooth width by adopting a medium-frequency induction heating mode, the quenching unit which is arranged next to the inductor sprays liquid to quench until the other end of the tooth width, then the inductor leaves the tooth groove, a quenched gear rotates and indexes to the next tooth groove, the quenching unit drives the inductor to enter the tooth groove to repeat the previous process, and the process is repeated in a circulating way until all the tooth grooves are quenched by induction.

The conventional single-tooth quenching machine tool is provided with a single upright post and a quenching unit, wherein each quenching unit is provided with an inductor, and only one tooth groove can be quenched each time. If the number of teeth is small or the tooth width is narrow, the time required for quenching one gear ring in this mode is less than 3 hours, and then the gear ring is sent to a tempering furnace for tempering in time, so that the quenching processing method and the quenching processing device have no problems.

When the gear specification becomes bigger, and the number of teeth becomes more, and the time of finishing a complete gear under the original processing mode exceeds 2 hours a lot, then the risk of cracking is extremely high because the tempering is not in time. In order to avoid cracking, it is inevitable that all teeth cannot be quenched at once. Conventionally, after some teeth are quenched, the quenching operation is interrupted, and the gear is unloaded from the machine tool, tempered and returned to be secondarily clamped to continue quenching and processing the rest teeth.

With the increasing specification of the wind power main gearbox, quenching may need to be interrupted for tempering for 2-3 times according to a conventional quenching processing method, so that the efficiency is greatly reduced, energy is wasted, and the labor intensity is increased.

The invention aims to solve the technical problem, and provides a process and equipment for quenching the whole gear within about 2 hours by only installing and clamping the gear once, which is an efficient process without intermediate tempering for multiple times.

Disclosure of Invention

The invention aims to solve the technical problems, provides a process method which can finish quenching processing of all teeth within 2-3 hours by one-time clamping, and provides an equipment structure for implementing the process.

The technical scheme of the invention is as follows:

an induction quenching process for a large gear comprises the following implementation steps:

the bull gear is horizontally and concentrically clamped on a rotary table. The rotary table is driven by a servo motor and can be arbitrarily indexed according to the number of teeth;

three T-shaped numerical control manipulators are uniformly distributed on the circumference outside the rotary table in a trisection manner, the tail end of each manipulator is connected with one set of quenching unit, and quenching inductors on the three quenching units can simultaneously perform induction quenching processing on three corresponding teeth. The processing process is controlled by a numerical control system.

In the same time, after the three quenching units respectively finish the quenching processing of one tooth according to the scanning quenching along the tooth groove, the large gear automatically rotates and indexes along with the rotary table to carry out the next quenching cycle. The three quenching units respectively perform quenching machining on the other three corresponding teeth. After the total teeth number/3 cycles, the quenching of all teeth is finished (the remainder is 0) or the

rest

2 or 1 teeth are quenched and processed by two or one quenching unit in the process sequence control.

Thus, the quenching time of the whole tooth is saved by more than 2/3 compared with the conventional scanning quenching process of one tooth by using one quenching unit.

Therefore, the time for finishing the quenching processing of the whole gear is less than 3 hours, and then one-time tempering is sufficient and timely.

The inductors of the three quenching units are respectively powered by three sets of medium frequency power supplies. Other auxiliary equipment such as a cooling unit and a quenching liquid circulating cooling unit can be shared and are uniformly controlled by a numerical control system program.

Drawings

FIG. 1 is a drawing of the present invention: a schematic diagram of the principle of a large gear induction quenching process;

FIG. 2 is a drawing of the present invention: a schematic diagram of the induction hardening machine tool for large gears;

FIG. 3 is a drawing of the present invention: the structural schematic diagram of one set of mechanical arm and a quenching unit of the large gear induction quenching machine tool;

FIG. 4 is a drawing of the present invention: a schematic diagram of a displacement compensation mechanism of a set of quenching units;

FIG. 5 shows the present invention: a plane layout schematic diagram of a large gear induction quenching complete equipment (comprising an auxiliary unit);

wherein: 1-a large gear (gear ring), 2-a quenching unit a, 3-a quenching unit b, 4-a quenching unit c, 5-a rotary table, 6-T type mechanical arm e, 7-T type mechanical arm f, 8-T type mechanical arm g, 9-a cross arm linear module, 10-a vertical arm linear module, 11-a displacement compensation mechanism, 12-a quenching unit deflection mechanism, 13-a radial displacement compensation linear mechanism, 14-a tangential displacement compensation mechanism, 15-a machine tool numerical control cabinet, 16-a quenching variable frequency power supply (3), 17-a quenching auxiliary machine 1 (a quenching liquid circulating cooling system) and 18-a quenching auxiliary machine 2 (a cooling water circulating system).

Detailed Description

The invention is described in detail below with reference to the accompanying drawings and examples.

As shown in fig. 1a and 1b, a large gear 1 (which may be an external gear 1a or an internal gear 1b, the same applies hereinafter) is subjected to single-tooth scanning quenching simultaneously by 3 quenching sensors of quenching units a, b, and c, by a single-tooth-edge-tooth-groove quenching method. For the gear with the tooth number being multiple of 3, 1/3 of the gear quenching process is respectively completed by 3 quenching units, so that compared with the traditional quenching method, the process time is saved by 2/3; and for the gear with the tooth number not being divided by 3, scanning and quenching the rest teeth along the tooth grooves by adjacent two or one quenching units until all the teeth are quenched.

As shown in fig. 1a and 1b, the intermediate frequency output end of the quenching unit has two symmetrical combined end surfaces, so that the quenching inductor can select different installation directions according to the type (external teeth or internal teeth) of the gear 1.

As shown in fig. 1 and 2, in order to quench three teeth of the gear 1 at the same time, the gear 1 is concentrically mounted on a support arm of a rotary table 5; the quenching units a, b and c are correspondingly arranged on three T-shaped manipulators e, f and g which are arranged along concentric circles of the gears at equal angles (120 degrees);

as shown in fig. 3, the three T-shaped manipulators are one, and the other two T-shaped manipulators are the same. Taking the T-robot 2 as an example, the quenching unit 2 is attached to a vertical arm 10 of an inverted T-robot 7. An upright post with horse hoof feet lifts the inverted T-shaped manipulator to a certain height. The T-shaped manipulator 7 is provided with a cross arm 9 and a vertical arm 10, and the linear extension of the cross arm 9 on the upright post can meet the requirements of quenching units and radial positions of gears with different diameters during quenching; the vertical arm 10 moves up and down to drive the quenching unit to meet the requirement of scanning quenching movement; all movements are realized by driving a linear movement unit by a servo motor;

between the connecting surfaces of the manipulator and the quenching unit there is a displacement compensation mechanism 11, see fig. 4.

As shown in fig. 4, the displacement compensation mechanism 11 includes a yaw motion pair 12, a tangential compensation motion pair 13, and a radial compensation motion pair 14. The deflection kinematic pair 12 drives the compensation mechanism to rotate by beta degrees (maximum +/-45 degrees) through a synchronous belt wheel by a servo driving device; the tangential compensation kinematic pair 13 drives the linear unit through the servo motor to drive the displacement compensation mechanism 11 to translate along the tangential direction of the gear (the maximum is +/-20 mm); when the gear tooth number cannot be divided by 3 (fig. 1b), the sensor is ensured to be symmetrical to the tooth space gap by the deflection and translation quenching unit; the radial compensation kinematic pair is formed by maintaining the radial position (maximum +/-15 mm) of the quenching unit relative to the gear in the quenching process through an elastic device and a linear guide rail, so that the quenching quality is ensured.

Since the alignment of the first tooth of the gear wheel and the quenching unit can always be performed by the rotation of the gear wheel, a connection between the quenching unit and the robot can be made by direct connection, i.e. the displacement compensation means 11 is omitted, and careful installation is required to make the center line of symmetry of the sensor pass through the center of the rotary table.

The whole set of equipment is controlled by a machine tool numerical control cabinet 15 through a unified program, and special operation software allows a user to input necessary parameters such as gear modulus, tooth number, tooth width, scanning speed, input power and the like, and after the alignment of an initial test position, the whole quenching process is automatically carried out.

As shown in fig. 5, each quenching unit has a separate set of if power supplies 16 to supply if current to it. Therefore, the whole set of equipment comprises 3 intermediate frequency power supplies;

as shown in fig. 5, all pipelines of the 17 quenching

auxiliary machines

1 and 18 quenching auxiliary machines 2 are connected with a quenching machine tool and a medium-frequency power supply as required, so that the normal operation of the system is guaranteed.

An example of a large gear quenching process comprises five steps:

as shown in fig. 5, the gear 1 is hoisted to the supporting arm of the turntable in a concentric position with the turntable. And opening a numerical control system of the machine tool and filling corresponding parameters.

As shown in fig. 1a and 1b, three

quenching units

1, 2 and 3 are aligned with each first quenching tooth groove by operating a numerical control button or an electronic hand wheel. If the number of teeth is integral multiple of 3, the initial 3 quenching tooth grooves are evenly distributed on the circumference of the gear in trisection; if the number of teeth is not a multiple of 3, the turntable is rotated to enable the inductor of one quenching unit to be over against the tooth space, and the other two quenching units are tangentially adjusted and deflected through the displacement compensation mechanism 11 and finally located at the center of the tooth space.

Starting a program, and driving inductors, quenching tools and the like on the three quenching units to scan and quench from the lower edge of the gear tooth groove to the upper edge of the gear along the tooth groove by the numerical control system; when the inductor and the quenching tool leave the tooth groove, the rotary table automatically indexes to the next tooth groove according to a program, and the three quenching units descend to the lower edge of the gear according to the program and enter the tooth groove to perform the next quenching cycle.

After the circulation of the number of teeth/3 times, all teeth (the number of teeth can be completely divided by 3) or most teeth (the number of teeth can not be completely divided by 3) of the gear ring are quenched, if one or two of the rest teeth are quenched by one or two quenching units which are adjacent to each other;

in the process, except that the initial tooth space positions of the three quenching units and the gear are required to be aligned, other quenching operations are carried out in a program mode, and the quenching operation can be completed completely without manual intervention.

Furthermore, after the position detection sensors are installed on the three quenching units, the initial position alignment of the three quenching units can also be automatically completed by a numerical control program.

The foregoing illustrates and describes the principles of the present invention and the construction of the apparatus. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are described in the specification and illustrated only to illustrate the principle of the present invention, but that various changes and modifications may be made therein without departing from the spirit and scope of the present invention, which fall within the scope of the invention as claimed. The scope of the invention is defined by the appended claims and equivalents thereof.

Claims

1. An induction quenching process and equipment for large gears are characterized in that: three quenching units are adopted to simultaneously carry out induction scanning quenching on a large gear along a tooth groove, so that the whole quenching process time is saved by nearly 2/3, the quenched gear can be tempered in time, the occurrence of quenching cracking is greatly avoided, and the economic benefit is remarkable.

2. The bull gear induction quenching process and apparatus of claim 1, wherein: the quenched big gear is concentrically arranged on a revolving platform driven by a numerical control servo, three T-shaped manipulators driving three quenching units are positioned on a circle concentric with the working platform, and the included angle of the circle center is 120 degrees.

3. Large gear induction quenching process and equipment according to claims 1 and 2, characterized in that: the cross arm of each T-shaped manipulator can perform servo drive horizontal linear motion on the stand column of the manipulator; the vertical arm is in servo drive vertical linear motion at the end of the cross arm; the lower end of the vertical arm is connected with a displacement compensation mechanism, and the lower end of the compensation mechanism is connected with a quenching unit.

4. The displacement compensation mechanism of claim 3, wherein: it is a connector of 3 horizontal degrees of freedom; comprises a rotary connecting body driven by a servo motor through a synchronous belt; a linear link driven by a servo and a linear link compensated by an elastic element. The quenching unit connected with the lower end of the manipulator through the mechanism can have a rotation of +/-45 degrees, a horizontal tangential deviation of +/-20 mm and a horizontal radial deviation of +/-15 mm.

5. Large gear induction quenching process and equipment according to claims 1, 2 and 3, characterized in that: each quenching unit is respectively provided with induction electric energy by a respective variable frequency power supply.

6. Large gear induction quenching process and equipment according to claims 1 and 2, characterized in that: other quenching auxiliary machines including a quenching liquid circulating system and a cooling water circulating system can be shared and uniformly controlled by a numerical control system program. When the program interface is filled with the main parameters of the gear, the operator aligns the sensors and the tooth grooves of the three quenching units for the first time, and the whole quenching operation is completely finished by the driving program of the numerical control system.