A Guide to Gear Hobbing

A Guide to Gear Hobbing

What Is Gear Hobbing?

Gear hobbing is a quick and versatile process that is fundamental for gear manufacturing. Gear hobbing machines utilize a rotating cutting tool, or hob, to generate a tooth profile on gears as they are fed through the machine. The precision and accuracy of gear hobbing makes it the ideal method for gear manufacturing.

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.

Differences Between Gear Hobbing and Gear Milling

Gear hobbing and gear milling are both processes that can be used for gear manufacturing; however, they utilize different cutting techniques.

Gear Hobbing

Gear hobbing is the process of generating gear teeth with a helical cutting tool, or hob. The gear blank and hob rotate continuously until all gear teeth are cut into the blank. The speed of this process makes it ideal for large production runs.

Gear Milling

The gear milling process uses a cutter, known as a form cutter, that moves axially to produce a gear tooth at the proper length and depth. After one tooth is cut, the cutter is withdrawn to allow the gear blank to rotate to the next position. Once the blank is rotated, the form cutter cuts the next tooth, and this process continues until all teeth are cut into the blank. This process is slower, making it a low production process.

Contact Avon Machining for Gear Hobbing Services

Gear hobbing is a quick and accurate manufacturing method for producing gears. Avon Machining provides high quality, complex manufacturing solutions for a variety of industries with competitive prices, on-time delivery, and an emphasis on customer satisfaction. For more information, or to get started on your gear manufacturing solution, contact us today.

What is an Axle Shaft?

Axle shafts are heavy-duty, load-bearing components used in motorized vehicles. Also called CV axles or half-shafts, these components transfer rotational force from the vehicle’s transmission system to the wheels attached to the axles. Axle shafts must support heavy loads by design, including cargo, riders, and the vehicle’s own mass. While they are built to handle heavy weights, it is possible to overload the component and force it to warp or break from the strain. Similarly, physical impact from collisions, potholes, and rough roads may cause damage.

What Does an Axle Shaft Do?

Drive axles are crucial drivetrain components that connect a vehicle’s transmission to the vehicle’s wheels. Axle shafts are primarily responsible for transferring the transmission’s rotational force and power to make the vehicle move. When the force from the transmission causes the axle shaft to rotate, the wheels connected to it also turn. Every axle shaft has a differential between two half axles and two universal (UV) joints.

Ultimately, axle shafts allow vehicles to roll and facilitate controlled movement of their wheels. Without reliable drive shafts, the wheels of the vehicle wouldn’t move properly or at all.

Types of Axle Shafts

The type of axle shaft varies depending on the requirements of the vehicle type, and each axle shaft handles different types of stress. This factor depends on the length of the axle shaft relative to the position of the vehicle’s hubs and bearings, as well as how the vehicles are designed to attach to the axle shafts. These are three most common axle shaft types:

1. Semi-Floating Axle Shafts

This design has flange faces on both outer ends of the axle shaft. These faces attach directly onto the associated wheels.

2. Fully Floating Axle Shafts

Instead of having flange faces that directly connect the axle shaft to the wheels, this style of axle shaft has hubs between the two components. Each wheel connects to a hub, and that hub rotates on roller bearings attached to a spindle at both ends of the axle shaft. The roller bearings are tapered and face opposing directions, and the hubs and bearings handle the vehicle weight to take strain off the axle bearing. Without the need to support the weight of the vehicle and its cargo, the axle bearing “floats,” instead only having to withstand the transmission system’s torque.

3. Three-Quarter Floating Axle Shafts

These axle shafts feature elements from both semi-floating and fully floating axle shaft designs. Three-quarter floating axle shafts have bearings positioned between the axle casing and hub axle shaft. However, the bearings remain protected from shearing or bending forces.

How to Measure Axle Length

It’s important to accurately measure the axle length to find the right replacement parts or supporting hardware for your vehicle. Nonstandard axle shafts can be difficult to find, and almost every vehicle has unique requirements regarding the size, durability, and weight handling capabilities for its axle shafts.

Determining the axle shaft length for your vehicles allows you to compile a database of their lengths, which is especially useful for fleet managers. This makes it easier to find suppliers for rare axles, axles with custom-width housings, or even standard axles that need regular replacement due to frequent commercial or industrial use.

For a full accounting of your vehicle’s axle shaft measurements, you need to know both the dimensions and the spline count. Also, follow these four steps to measure the hub face:

1. Make the hubs of the vehicle’s trailer axle accessible by removing the tires and wheels.
2. Set one end of your tape measure on the outside edge of the first trailer hub.
3. Extend the tape measure until the other end is against the outside edge of the other trailer hub’s face. Measure outside edge to outside edge, not from the inside edges.
4. Record the length and label the measurement as the hub face measurement.

Drive Shaft vs. Axle Shaft

Drive shafts and axle shafts are both types of vehicle components that transfer power to make a vehicle move. However, a drive shaft is a hollow metal tube with universal end joints that handles the power transfer from the transmission to the rear differential gearbox. The axle shaft then transfers that power onward to the wheels.

Axle shafts are solid rods with teeth cut into both ends. Whereas drive shafts visibly run down the center of the vehicle, the axle shaft is concealed in the perpendicular housing that runs from the rear differential gearbox to each wheel.

Axle Shafts from Avon Machining

At Avon Machining, we specialize in creating high-quality shafts for standard and oversized vehicles. We can produce steel axles up to 80 inches long and with diameters up to 18 inches wide. We offer in-house inspection services from our lab using multiple different quality testing methods to assess the integrity and quality of our products. We have the equipment, knowledge, and expertise to produce high-quality axles you and your staff can rely on.

If you need standard, oversize, or custom axle shafts, Avon Machining is here to help. Contact us today to learn more about our capabilities or to place your order.