How does the gear hobbing machine work, what is the working principle of the gear hob?

People are asking about gear hobbing machines, not engines, and the answer is not what they asked, hey, does anyone know? Speed.

The operating principle of the gear hobbing machine, even the internal mechanical structure is also clear!

According to the principle of helical gear pair meshing, the cutter of the gear is cut by the expansion method, the gear hob is equivalent to the pinion, and the cut gear is equivalent to a large gear. The gear hob is a helical gear with a large helix angle of 0 and a small number of threaded heads (1 3 teeth), a very long tooth, and many turns around the disc cutter indexing cylinder, so that it is like a worm with a small helix angle z.

In order to form the cutting edge, several chip grooves are milled along the axis on the end face of the worm to form the front and rake angles; After shovel teeth and shovel grinding, the flank face and trailing angle are formed.

Basic worm. 1. Involute worm.

The side of the threaded teeth of the involute worm is an involute helix, and the intersection of the arbitrary plane tangent to the base cylinder and the involute helix is a straight line, and its end profile is an involute. The intersection of the involute worm axial profile and the involute helix is a curve. Hobs made with this basic screw have no tooth shape design errors, and the gear precision of cutting is high.

However, it is difficult to manufacture hobs.

2. Archimedes worm.

The helical tooth flanks of the Archimedes worm are Archimedes spiral faces. The intersection of the worm axis profile and the Archimedes spiral plane is a straight line, and the other sections are curves, and its end profile is the Archimedes spiral. The hob made of this basic worm is easier and more convenient to manufacture and inspect than the involute worm.

However, there is a slight amount of tooth shape error. However, this error is within the permissible range, for which the basic worm of most finishing hobs in production is replaced by an Archimedes worm.

Commonly used tools for machining externally meshing cylindrical gears with spur and helical teeth. During machining, the hob is equivalent to a helical gear with a large helix angle, and the number of its teeth is the number of heads of the hob, and the workpiece is equivalent to another helical gear, which is spatially meshed with each other according to a pair of helical gears, rotates at a fixed speed ratio, and is enveloped into the tooth shape of the gear by the tooth tooth shape of each adjacent position of the cutting sequentially. Most of the commonly used hobs are single-head (see thread) in mass production, and multi-head hobs are often used to improve efficiency.

The number of teeth rotated by the gear is equal to the number of hob heads. When the spiral rise angle of the worm gear hob is less than 5 °, the disc cutter is often made into a straight flute, which is convenient for manufacturing and sharpening, and the disc cutter with a large spiral rise angle is often made into a spiral flute, so as to avoid the unfavorable situation that one side of the cutter tooth is cut with a large negative rake angle (see tool). Small and medium-sized module gear hobs made of high-speed steel generally adopt an integral structure.

In order to save high-speed steel, avoid forging difficulties and improve metallographic structure, disc structure is often used for disc cutters with a module of more than 10 mm. There are many structural forms of disc disc cutters, and the commonly used one is the rack structure, that is, the cutter tooth part is made of high-speed steel and fastened to the cutter body after heat treatment.

The manufacture of hobs from tungsten carbide can significantly increase cutting speed and cutting efficiency. Solid carbide hobbs have been widely used in the watch and instrument manufacturing industry to machine a variety of small module gears. Medium-module solid and insert carbide hobs have been used to machine cast iron and bakelite gears.

Tungsten carbide hobs with a module of less than 3 mm are also used to machine steel gears. The carbide hob cutter can also be used to machine hardened gears (HRC50 62). This kind of hob cutter often adopts a single-tooth welding structure, with a negative rake angle of 30°, and scrapes off a layer of tooth surface during cutting.

The state divides the accuracy grade of the disc cutter into AA level, A level and B level. Generally, the national standard hob adopts AA grade. The ministry standard and the enterprise standard adopt A-level.

The sprocket hob requires low precision, and generally uses grade B. In order to process particularly precise gears, some countries also have AAA grade hobs. In the process of tooth cutting, the manufacturing error of the hob mainly affects the tooth shape error and base joint deviation of the gear.

The hob used to process the tooth profile of the gear before shaving is called the pre-shaving hob. The tooth shape of the hob before shaving should be made into a special shape according to the requirements of the shaving surplus form (Fig. 2: The tooth profile of the hob before shaving). The tooth top with convex angle The hob tooth shape with chamfering at the tooth root is a more commonly used form of shaving retention, which makes the tooth root of the processed gear have some digging roots, some chamfers at the top of the tooth, and the middle part of the tooth shaving balance is uniform.

The machining accuracy of ordinary gear hobbing machine is 7 6 grade (JB179-83), and the high-precision gear hobbing machine is 4 3 grade. The machining platform moves along the designated trajectory of the bed to adapt to different workpiece diameters and radial feed, and the turret of some gear hobbing machines can also move along the axis of the hob in order to process the worm gear by tangential feed method. [Click to get real-time from the manufacturer**].

Gear hobbing machine (gearhobbingmachine) is the most widely used machine tool in gear processing machine tools, on the gear hobbing machine can cut spur teeth, helical cylindrical gears, worm gears, sprockets, etc. A gear processing machine for processing spur, helical and herringbone cylindrical gears and worm gears by the hob method. This machine can also machine a wide range of workpieces with special tooth profiles, such as splines and sprockets, using special hobs.

Hebei Zhuohao Machinery Manufacturing ****'s unified social credit ** registration number is 91130526MA07N05D75, the enterprise legal person Li Xiaohua, the company is currently in a state of operation. The company adheres to the business philosophy of "co-creation and sharing, win-win future", adopts modern enterprise management mode, and advocates green ecological environment and sustainable development. The company has a R&D team with advanced level in the industry, with independent research and development of core technology and intellectual property rights, advanced product technology, and the yield rate is much higher than the same industry level.

The company has more than 20 years of professional manufacturing history, has a strong high-tech team, our company has excellent quality, reasonable, thoughtful service and other competitive advantages, the current products are exported to Southeast Asia, South Korea, Russia and other countries and regions. <>

Introduction to the parameters of the hobbing gear.

Type: Hobbing machine.

Model: Rock Tease Y3180

Machining accuracy class: 8

Maximum number of processing teeth: 250 Maximum rough selling processing module: M10 main Jensen motor power: 3 (kw).

Processing diameter range: 800 (mm).

Weight: 6800 (kg).

Power Type: Mechanical Transmission.

The operation steps of the gear hobbing machine are as follows:

1. Check the gear hobbing machine.

1.Check the fuselage, chuck, guide rail shaft and other components to ensure that they are in good working condition.

2.Check the bulbs, switches, wires, etc., to make sure the machine is not short-circuited, burned, etc.

3.Inspect the tip, holder, frame and other components to ensure that the blade and tank are not worn or stained.

4.Check the oil tank to make sure that the oil in the tank is sufficient and that there is a prescribed amount of lubricating oil.

2. Preparations.

1.Set the parameters of the gear hobbing machine according to the shape of the workpiece, the material, the size of the hobbing gear, the machining accuracy, etc.

2.Place the bearing seat and bearing clamp on the machine base, and install the bearing sleeve and bearing.

3.Install the tool holder and adjust the height of the tool holder to ensure that the position and angle of the workpiece are correct when doing rolling groove processing.

4.Install the blade to ensure that the blade sharpening edge, tip thickness, angle, etc. meet the processing requirements.

5.Carefully inspect to ensure that the workpiece can be processed safely and that the machine is running without abnormality.

3. Operate the gear hobbing machine.

1.Turn on the power and start the gear hobbing machine.

2.The workpiece is mounted on the machine base and the workpiece is fixed.

3.Control the gear hobbing machine to ensure that the gear hobbing machine is running normally, the tool holder movement is normal, and there is a specified lubricating oil addition.

4.Operate the gear hobbing machine and carry out gear hobbing according to the set parameters to ensure that the roller profile is correct, flat and high-precision.

5. Test results.

After the operation, use the gauge to measure the roller profile to ensure that the accuracy meets the requirements, and check whether the hobbing shape, depth, etc. meet the requirements.

Gear hobbing machines are divided into two categories: vertical and horizontal according to the layout. Most of the large and medium-sized gear hobbing machines are vertical, and the small gear hobbing machines and gear hobbing machines dedicated to processing long shaft gears are all horizontal. The vertical gear hobbing machine is divided into two types: table movement and column movement.

When the vertical gear hobbing machine is working, the hob cutter is installed on the hob spindle, driven by the main motor for rotary motion, and the turret can move vertically along the column guide rail, and can also adjust an angle around the horizontal axis. The workpiece is mounted on the workbench and rotated by the indexing worm gear pair, which together with the movement of the hob constitutes an expansion motion. When hobbing helical teeth, the differential mechanism makes the workpiece rotate accordingly.

The worktable (or column) can be moved along the bed to accommodate different workpiece diameters and radial feeds. The turret of some gear hobbing machines can also be moved along the axis of the hob in order to process the worm gear by tangential feed. The large gear hobbing machine is also equipped with a single-tooth indexing mechanism, a finger milling cutter tool holder and a differential reversing mechanism for processing herringbone gears.

Straight teeth. Helical teeth. Worm wheel. Drum teeth.

Summary. Hello, the main drive principle of the gear hobbing machine ** is as follows: the compound motion between the hob and the workpiece (B1+B2 in Figure 1) is called the expansion motion. The transmission chain from the power source (motor) to the tool spindle is called the external connection transmission chain, that is, the motor-1-2-iv-3-4-hob.

Since the rotation B1 of the hob cutter is the main motion, this transmission chain is called the main motion transmission chain. The transmission chain between the hob and the workpiece is called the transmission chain. It is used to maintain a strict transmission ratio relationship between B1 and B2, so it is called inline transmission chain, the number of heads of the hob is k, and the number of teeth of the workpiece is z, then the hob should be rotated 1 z per 1 k revolution, and the workpiece should be rotated 1 z.

In Fig. 1, this drive chain is: hob (B1)-4-5-ix-6-7-workpiece (B2).

Hello, the main drive principle of the gear hobbing machine ** is as follows, which requires the composite skin number between the hob and the workpiece to move (B1+B2 in Figure 1), which is called the development motion. The transmission chain from the power source (motor) to the spindle of Bitong tool is called the external transmission chain, that is, the motor-1-2-iv-3-4-hob. Since the rotation B1 of the disc cutter is the main motion, this combustion action chain is called the main motion transmission chain.

The transmission chain between the hob and the workpiece is called the transmission chain. It is used to maintain a strict transmission ratio relationship between B1 and B2, so it is called inline transmission chain, the number of heads of the hob is k, and the number of teeth of the workpiece is z, then the hob should be rotated 1 z per 1 k revolution, and the workpiece should be rotated 1 z. In Figure 1, this drive chain is:

Hob (B1) - 4-5-IX - 6-7 - Workpiece (B2).

Summary. 1.Principle of gear hobbing machining is to process gears according to the principle of the development method.

The use of hobs to process gears is equivalent to the meshing of helical gears with a pair of staggered shafts. In this pair of meshing gear pairs, a number of teeth is very small, only one or several, the helix angle is very large, it evolves into a worm-like gear, in order to form a cutting edge, the gear perpendicular to the direction of the helix groove is opened, grinding the rake and flank surfaces, forming the cutting edge and front and rear angles, so it becomes a hob. Hob cutter and tooth blank according to the meshing transmission relationship for relative motion, on the tooth blank cut out of the tooth groove, formed involute tooth surface, in the hobbing process, the disc cutter teeth distributed in the spiral successively cut out a thin layer of metal in the tooth groove, each tooth groove in the hob rotation by several cutter teeth in turn, involute tooth profile is enveloped by a series of instantaneous positions of the cutting edge.

Therefore, the forming method of the tooth surface when hobbing is the expansion method, and the forming motion is a composite motion (B1+B1Z) composed of the rotary motion of the hob and the rotary motion of the workpiece!

1.Principle of gear hobbing machining is to process gears according to the principle of the development method. Silian uses a hob cutter to process gears, which is equivalent to a pair of staggered shafts of helical gear mesh.

In this pair of meshing gear pairs, a number of teeth is very small, only one or several, the helix angle is very large, it evolves into a worm-like gear, in order to form a cutting edge, the gear perpendicular to the direction of the helix groove is opened, grinding the rake and flank surfaces, forming the cutting edge and front and rear angles, so it becomes a hob. Hob cutter and tooth blank according to the meshing transmission relationship for relative motion, cut out the tooth groove on the tooth blank, formed the involute tooth surface, in the hobbing process, the disc cutter distributed in the spiral each knife Qing song tooth successively cut out of a thin layer of metal in the tooth groove, each tooth groove in the disc cutter rotation by several cutter teeth in turn, involute tooth profile is enveloped by a series of instantaneous positions of the cutting edge. Therefore, the forming method of the tooth surface of the rolling gap grandchild tooth is the expansion method, and the forming motion is a composite motion (B1+B1Z) composed of the rotary motion of the hob and the rotary motion of the workpiece!