Exploring the Different Types of Grinding Machines

Not to be confused with a milling machine, a grinding machine is a heavy-duty machine that's used to remove material from the surface of a workpiece. While milling machines feature a rotating cutting tool that's placed against a stationary workpiece, a grinding machine features a rotating grinding wheel, which is also placed against a stationary workpiece. There are several different types of grinding machines, however, each of which works in a different way.

 

Bench Grinding Machine

Bench grinding machines are characterized by their bench-like shape. They usually feature two different grinding wheels: one for the removal of material and another for finishing processes. They are called "bench grinding machines" because their grinding wheels are secured to the top of a workbench. As a result, bench grinding machines are easy and convenient for manufacturing workers to use.

 

 

Belt Grinding Machine

Belt grinding machines are characterized by the use of a belt sander. Like other grinding machines, they are designed to remove material from workpieces, thereby making workpieces smaller and with a smoother and more desirable surface. With belt grinding, the belt is coated in an abrasive material, after which it's run against the surface of a workpiece until the desired results are achieved. Belt grinding is most commonly performed on metal workpieces, though it supports workpieces made of other materials as well.

 

Surface Grinding Machine

A third type of grinding machine is a surface grinding machine. Surface grinding machines are unique because they feature an adjustable head. The head on a surface grinding machine can be lowered down to the workpiece. Once lowered, the head can then rotate back and forth under the machine's grinding wheel.

While belt grinding machines are typically used for finishing processes, surface grinding machines are most commonly used for material removal. When compared to other grinding machines, surface grinding machines are able to remove significant amounts of material, making them desirable for such applications.

 

Gear Grinding Machine

 

 

Gear grinding machines are designed specifically for the removal of material from shafts. Using grinding wheels, they can grind the center of a shaft with extreme precision.

 

Die Grinding Machine

A smaller and more basic type of grinding machine is a die grinding machine. Unlike the other machines listed here, die grinding machines are handheld. They are connected to an air compressor, which works to power the machine's grinding wheel. If an air compressor isn't used, the die grinding machine will likely receive power from an electric motor.

 

We are a gear grinding machine supplier. If you are interested in our products, please contact us now!

Gear Hobbing Machine: Everything You need to Know about Gear Hobbing

Gear hobbing has been an integral part of gear making. Whereas milling would be used to produce the basic gear shape, gear hobbing performs the much more intricate task of shaping the gear. Various facets of gear teeth emerge once hobbing is complete, including its thickness, profile and addendum.

Gear hobbing is a specialised process of gear cutting, spline cutting and sprocket cutting. The central equipment in the gear hobbing process is the milling machine. This gear hobbing machine does the task of cutting the spline or teeth using a series of cuts using a hob. Gear hobbing is often used for spur gear and helical gear making, because of its ease of use and cost effectiveness.

 

 

Construction Of Gear Hobbing Machine

 

Hob– In this process, the gear blank is rolled with a rotating cutter called a hob. Gear hobbing is done by using a multipoint cutting tool called gear hob. It looks like a worm gear having a number of straight flutes all around its periphery parallel to its axis. These flutes are so shaped by giving proper angles to them so that these work as cutting edges.

In gear hobbing operation, the hob is rotated at a suitable rpm and simultaneously fed to the gear blank.

The gear blank is also kept as revolving. Rpm of both, gear blank and gear hob are so synchronized that for each revolution of gear bob the gear blank rotates by a distance equal to one pitch distance of the gear to be cut.

The motion of both gear blank and hob is maintained continuously and steady. A gear hob is shown in Figure and the process of gear hobbing is illustrated in Figure

The hob teeth behave like screw threads, having a definite helix angle. During operation the hob is tilted to helix angle so that its cutting edges remain square with the gear blank.

Gear hobbing is used for making a wide variety of gears like spur gear, helical, hearing-bone, splines and gear sprockets, etc.

 

Types Of Hobbing Process :

 

The process of gear hobbing is classified into different types according to the directions of feeding the hob for gear cutting. The classification is described as given below.

• Hobbing with Axial Feed

In this process the gear hob is fed against the gear blank along the face of the blank and parallel to its axis. This is used to make spur and helical gears.

• Hobbing with Radial Feed

In this method the hob and gear blanks are set with their axis normal to each other. The rotating hob is fed against the gear blank in radial direction or perpendicular to the axis of gear blank. This method is used to make the worm wheels.

• Hobbing with Tangential Feed

This is also used for cutting teeth on the worm wheel. In this case, the hob is held with its axis horizontal but at the right angle to the axis of the blank. The hob is set at full depth of the tooth and then fed forward axially. The hob is fed tangentially to the face of the gear blank.

 

 

The process of gear hobbing is as follows:

 

• The gear hobbing machine is checked for any mechanical issues. This includes the synchronisation of the rotating gears for the workpiece and the hob.

• The gear hobbing machine has two skew spindles, one of which has the gear blank while the other one has the hob.

• The spindles are set at an angle from each other, depending on the type of teeth to be set on the gear blank.

• The two spindle shafts are then rotated proportionally with the hob cuts on the gear blank. Having them properly rotating is the key to making the right gear teeth on the gear blank.

• The hob would then be applied to the gear blank until the correct tooth depth has been reached.

• The hob is then run through the gear blank’s axis of rotation as a final step.

• The process is repeated for each gear blank, which is often stacked one atop another. The rotation ensures identical gear spindle depth and a consistent number of teeth on each gear blank.

• The completed gears are removed from the milling machine.

• The central tool to gear hobbing is the hob, a worm-shaped cutter. The hob makes successive cuts on the gear blank to create the gear teeth. In order for the cutting to be precise, the gear blank and the hob must be synchronised in the rotation.

 

The 5 Advantages of Gear Hobbing

 

Gear manufacturing gives us lots of options. There are a handful of different processes we can use to make dozens of different gear types from dozens of different materials. Accordingly, when we choose a gear manufacturing method, it’s because it’s the best one for the job.

Gear hobbing is just one way we can manufacture gears. It relies on a special form milling machine with a tool known as a hob, which generates the teeth in both gears and splines. So what are the advantages of this process?

• Speed. Some gear manufacturing processes take a long time, but gear hobbing is relatively fast. The machine is simple, so it doesn’t require as much operational attention, and for some gears, we can stack multiple units to hob them all at the same time.

• Precision. That said, not just anyone can operate a hobbing machine. With the right expertise, hobbing can be highly precise, resulting in high quality gears.

• Flexibility. There’s more than one type of hob—and more than one type of hobbing machine. There are countless variations that cater to specialized applications, so you always have options available.

• Applications. While hobbing is often used for spur gears, the process can be used for a variety of other gears, such as cycloid gears, helical gears, worm gears, ratchets, splines, and sprockets (as long as you have the right tools for the job).

• Related processes. One of hobbing’s only weaknesses is that it does not work for internal gears (with inward-facing teeth). However, there’s a related process called shaping that can be used instead—with all the same advantages of hobbing.

 

Geepro Machinery

 

WUXI GEEPRO GEAR HOBBING MACHINE has been one of the professional gear hobbing machine manufacturer and supplier in China since 2007.

Benefits From Our Advantages:

• Professtional Sales Engineers

• Stable Performance of Machines

• Reasonable Price For Users

• Long Life After-Sales Service

We provide high speed high accuracy gear machinery and other workpieces solutions with premium quality service to global users. Contact us now!

Difference Between Gear Milling and Gear Hobbing

Gear is a vital component for rotating machines, with teeth mesh with another toothed part to transmit torque. How gears are made? Other than casting, forging, CNC machining can be applied to achieve the final shapes, dimensions, and surface finish of a gear. Here we introduce and compare two gear manufacturing methods – gear milling vs gear hobbing, what are the differences between them?

 

CNC Gear Hobbing Machine

 

What is Gear Milling?

 

Gear milling is a common CNC milling operation and gear-cutting process of creating a gear. It can be operated either after or instead of forming processes including casting, forging, and extruding. Gears are usually made from metal, plastic, and wood. Many metal and plastic gears made by die-casting, injection molding, or additive manufacturing may not require cutting. For coarse-pitch gears, the generative gear milling technology can improve efficiency, expand the pitch capacity of the machine, reduce cutter cost, and may decrease the machining times.

 

What Cutter Used in Gear Milling?

 

The gear can be cut on a milling machine or jig grinder utilizing a gear cutter and indexing head or rotary table, the quantity of gear cutter is determined by tooth count of the gear required. Various types of cutters can be used for producing gears, for example, the rack shaper, with six to twelve teeth, straight and move in a direction tangent to the gear. The cutter has to move back to the beginning position for the new round cut.

 

What is Gear Hobbing?

 

Gear hobbing is also a gear manufacturing method to cut teeth into the blank with a hob like an index hob and master hob on CNC gear hobbing machines. The hob and gear blank rotate at the same time in a mesh and cut the teeth by continuous cut, the rotating hob is fed inward until achieving proper depth, then work for the entire gear. Gear hobbing is a great choice for medium to high volume production runs. The hobbing features for gears including straight, helical, straight bevel, face, crowned, worm, and chamfering.

 

How to differentiate gear hobbing and gear milling?

 

1. The way gear teeth are produced

 

In gear milling, a single tooth spacing or gap between gear teeth will be created by a rotating multi-edge cutter at a time, the cross-section of generated teeth is similar to that of the cutter. In gear hobbing, the gear teeth are progressively produced by a series of cuts with a hob. So the hob cuts several gaps simultaneously.

 

Hobbing Machine

 

2. Cutter

 

Gear milling uses a rotating form cutter, when each tooth space is cut, the cutter will return to the starting point and gear blanks are indexed for next cutting process; gear hobbing uses a helical hob cutter, the hob and the workpiece are both rotating constantly when the hob is fed across the face width of the blank.

 

3. The number of teeth cut in one time

 

Each cutter in gear milling is designed to cut a range of tooth numbers, while in gear hobbing, both the hob and gear blank rotate continuously as in two gears meshing until all teeth are cut.

 

4. Price of tool

 

Generally, the gear milling cutting tool is cheaper than that of hobbing, but the productivity of gear hobbing may be higher.

 

5. Application

 

Gear hobbing is more often used for high production runs, and gear milling is a low production process.

 

6. Others

 

– Gear milling requires deburring

– Gear milling is often used when other generating processes are unavailable.

 

If you’re eager to learn more about the gear hobbing machine, or if you have an order you’re ready to place, contact GEEPRO today! We’ll have a quote back to you in less than 24 hours.

How Gear Hobbing Works

A gear hobbing machine contains two skew spindles. One of these spindles houses the hob, while the other houses the gear blank. The angle at which these spindles are placed relative to each other depends largely on the type of gear being manufactured.

 

Once the spindles are placed at the proper angle, the machine is set up to begin rotating the shafts at a speed ratio that suits the gear type. As the shafts rotate, the hob gradually cuts the teeth into the gear with the proper depth. To facilitate faster production, manufacturers can stack multiple blanks on the spindle together, allowing the hob to cut teeth into multiple gears at once.

 

 

Just like there are multiple different angles, speeds, and techniques manufacturers can use to customize the process, there is also a wide variety of hobbing machines available for use. Most hobbing machines specialize in distinct applications. Hobbing machines are built to handle gears of a particular size and come in two different varieties: single-threaded and multi-threaded hobs. Multi-threaded machines allow for increased production, but they aren’t as precise as single-threaded machines.

 

Hobbing is one of the most fundamental processes in gear manufacturing. Its productivity and versatility make hobbing the gear manufacturing method of choice for a majority of spur and helical gears.

 

One of the most important concepts  to understand about gear hobbing is that it is a generating process. The term generating refers to the fact that the shape of the gear tooth that results is not the conjugate form of the cutting tool. Rather, the shape of the tooth is generated by the combined motions of workpiece and cutting tool. During hobbing, both the hob and the workpiece rotate in a continual, timed relationship.

 

For a spur gear being cut with a singlestart hob, the workpiece will advance one tooth for each revolution of the cutter. When hobbing a 20-tooth gear, the hob will rotate 20 times, while the workpiece will rotate once. The profile is formed by the equally spaced cutting edges around the hob, each taking successive cuts on the workpiece, with the workpiece in a slightly different position for each cut. Several cutting edges of the tool will be cutting at the same time.

 

During this rotation, the hob is typically fed axially with all the teeth being gradually formed as the tool traverses the work face.

 

 

The hob itself is basically a worm with gashes cut across it to produce the cutting edges. Each cutting tooth is also relieved radially to provide chip clearance behind the cutting edge. This also allows the hob face to be sharpened and still maintain the original tooth shape. In its simplest form, the hob tooth takes on the shape of a straightsided rack tooth. The final profile of the tooth is created by a number of flats blending together. The number of flats corresponds to the number of cutting gashes which pass the workpiece tooth during a single rotation. Thus, the greater the number of gashes in the hob, the greater the number of flats along the profile, which improves the “smoothness” of the tooth profile.

 

Geepro Machinery

WUXI GEEPRO GEAR HOBBING MACHINE has been one of the professional gear hobbing machine manufacturer and supplier in China since 2007.

Benefits From Our Advantages:

• Professtional Sales Engineers

• Stable Performance of Machines

• Reasonable Price For Users

• Long Life After-Sales Service

We provide high speed high accuracy gear machinery and other workpieces solutions with premium quality service to global users. Contact us now!

Know The Difference Between Gear Shaping And Gear Hobbing

 Just like any sheet metal is fabricated to form the right mold, shape, size, and so on, gear manufacturing has certain machining processes such as shaping, hobbing, and so on. Gears are required to be set in motion, rotate, and raise the speed of any machine, industrial equipment, automobiles, and so on. So, how are these gears made? CNC machining methods are widely applied in the last stages of gear manufacturing, and milling, casting, forging, and so on are some of the methods used. Gear shaping and hobbing are also two important processes of gear manufacturing. The process to be used depends on gear specifications such as the shape and size required, among other parameters. This post discusses and compares the two methods- gear shaping and gear hobbing.

 

 

What is Gear Shaping?

Shaping is almost a subset of the milling process. This process helps form the gear teeth with the help of a rotating cutter tool, wherein its axis is parallel to that of the gear. The rotating speed and velocity of the cutter must match with the gear blank for teeth formation. A train of gears helps achieve the relative motion between the cutter shaft and the gear blank. Here the cutting may happen either at a downward or upward stroke. This is suitable for shaping of gears closely located toward the flanges or other obtrusive surfaces. This is widely used process for making internal and external gears. High dimensional accuracy is one of the major benefits of the shaping process apart from its cost-effective tools. After this process, surface finishing may be required depending upon the application.

 

What is Gear Hobbing?

Hobbing is a method also used for teeth formation in gear manufacturing. This teeth formation is done on the gear blank with the help of a hob on CNC gear hobbing machines. This machine is a type of special milling equipment. It could be an index hob or a master hob. There are various other types of hobs such as spline, spur, helical, chamfer, roller chain sprocket, straight side, and so on. The gear blank and the hob rotate simultaneously and produce continuous cuts on the blank gear which gives the required depth to the teeth. As mentioned above, the machining processes chosen are largely based on the shape and size of the gear. Likewise, hobbing is applicable for gear shapes such as helical, straight bevel, crowned, worm, face, and chamfering. Also, it is suitable for medium to high production volume. This cost-effective yet efficient process is useful to make several parts irrespective of the quantity.

 

 

Accuracy

There are benefits that come with each gear production. For example, the movement accuracy of gear hobbing is high. While that is not the case for gear shaping, gear shaping is more accurate in the surface finish. This is because the mechanic gear shaper is more complex. When comparing the two even further, the manufacturing process is simpler and easier to manufacture more accurately.

 

Productivity

In most scenarios, gear hobbing is more productive than gear shaping. This is because, in gear hobbing, there is not a large number of redundant metals. There is an instance, however, where gear shaping can compete with gear hobbing in terms of productivity. That scenario occurs when the gear is smaller in size and the teeth have a large and small-tooth width.

 

The conclusion

Looking at the accuracy and productivity allows you to better see the difference between gear shaping and gear hobbing. These two gear producing systems are alike, yet have their differences. Hopefully, this explanation gives you a better foundation to understand that.

If you notice, the difference between these two methods is really in the way the gear teeth are formed.

If you happen to be searching for a company that can create custom made gears, look no further. Not only do we have skilled professionals who can create exactly what you need, but we will provide you with insight on all things gears as well.

Exploring the Different Types of Grinding Machines

Not to be confused with a milling machine, a grinding machine is a heavy-duty machine that's used to remove material from the surface of a workpiece. While milling machines feature a rotating cutting tool that's placed against a stationary workpiece, a grinding machine features a rotating grinding wheel, which is also placed against a stationary workpiece. There are several different types of grinding machines, however, each of which works in a different way.

 

Bench Grinding Machine

Bench grinding machines are characterized by their bench-like shape. They usually feature two different grinding wheels: one for the removal of material and another for finishing processes. They are called "bench grinding machines" because their grinding wheels are secured to the top of a workbench. As a result, bench grinding machines are easy and convenient for manufacturing workers to use.

 

 

Belt Grinding Machine

Belt grinding machines are characterized by the use of a belt sander. Like other grinding machines, they are designed to remove material from workpieces, thereby making workpieces smaller and with a smoother and more desirable surface. With belt grinding, the belt is coated in an abrasive material, after which it's run against the surface of a workpiece until the desired results are achieved. Belt grinding is most commonly performed on metal workpieces, though it supports workpieces made of other materials as well.

 

Surface Grinding Machine

A third type of grinding machine is a surface grinding machine. Surface grinding machines are unique because they feature an adjustable head. The head on a surface grinding machine can be lowered down to the workpiece. Once lowered, the head can then rotate back and forth under the machine's grinding wheel.

While belt grinding machines are typically used for finishing processes, surface grinding machines are most commonly used for material removal. When compared to other grinding machines, surface grinding machines are able to remove significant amounts of material, making them desirable for such applications.

 

Gear Grinding Machine

 

 

Gear grinding machines are designed specifically for the removal of material from shafts. Using grinding wheels, they can grind the center of a shaft with extreme precision.

 

Die Grinding Machine

A smaller and more basic type of grinding machine is a die grinding machine. Unlike the other machines listed here, die grinding machines are handheld. They are connected to an air compressor, which works to power the machine's grinding wheel. If an air compressor isn't used, the die grinding machine will likely receive power from an electric motor.

 

We are a gear grinding machine supplier. If you are interested in our products, please contact us now!

Why Spiral Bevel Gears Are So Widely Used in High Load Applications?

Bevel gears play a key part in power transmission roles, being used in helicopters, power generation machines and more; essentially, instances when power musty be transferred across two non-parallel axes. A spiral bevel gear is one which has helical teeth. Like the helical gear, using a spiral bevel gear brings the benefit of less vibration and noise. Spiral bevel gears are used often in vehicle transmissions as drive from the driveshaft must be turned 90 degrees to drive the wheels.

 

Despite the more complicated manufacturing processes that are required to make spiral bevel gears and that two interfacing spiral gears are usually replaced as a set, spiral bevel gears are the gear of choice in high load situations.

 

Another type of spiral bevel gear is the hypoid gear. It is distinct from the spiral bevel gear in that the axis of the gear does not intersect with the axis of the meshing gear. Hypoid gears amplify the benefits of the spiral bevel gear. Since multiple teeth mesh together at the same time, they are able to handle larger loads, while retaining the other useful characteristics of spiral bevel gears.

 

 

Some benefits of using spiral bevel gears:

 

ㆍReduced heat - Spiral bevel gears produce less heat than bevel gears in similar conditions. It makes their use desirable in situations where heat build-up can adversely affect operation of nearby components or safety.

 

ㆍHigh torque - Spiral bevel gears have a relatively larger tooth area, and one which is in mesh. As such they are perfect for high torque and high speed application. It is also one of the reasons why they are used in large trucks.

 

ㆍOffset - With no offset, the teeth of spiral bevel gears slide little between each other. This increases the effectiveness and efficiency of the gear and reduces heat generation.

 

ㆍSmoothness - Abrupt power delivery has the potential to both damage machinery as well as compromise safety; which is why spiral bevel gears with their smooth engagement are preferred when gear engagement should not upset drive.

 

 

Focusing on improving efficiency in the gear processing industry

 

Do you want to purchase a CNC Gear Cutting Machine for your gear manufacturing plant to solve the problem that the processing speed and efficiency of the old Gear Cutting Machine cannot meet the current production requirements? Our CNC Gear Cutting Machine can help customers replace 3-5 old Gear Cutting Machines to greatly improve productivity and save labor costs. Geepro Machinery's CNC Gear Cutting Machine is currently one of the most cost effective and professional hobbing machines you can find in China.