Why Power Transmission Shafts Have Both Keys and Keyways
These two-axis and three-axis mills cut keyways, slots, pockets, or flats on shaft diameters of 1.5 to 24 inches (38 to 610 mm). They can be operated in any position, thanks to their sealed gear box lubrication. CONTACT A CLIMAX EXPERT KM3000 KEY MILL. Keyway Calculator.tweaked. just enter diameter of shaft (or bore)! DMFTomB, I took your calculator you posted, added some more graphical info and tweaked a bit, so it automatically looks up the standard keyway for any given diameter shaft or bore and adds everything (again, automatically) to the graphic. Anyone tried cutting a slot for a key on a motor shaft with a dremel or angle grinder, or other 'poor man's tool'? I have a few motors laying about without keyways on the shafts, I'm not sure how to put them to use. One part of the key fits into a precut slot in the shaft known as a key seat. The remainder slides into a groove in the hub called a keyway. Woodruff keys are flat, semicircular keys that rock into place and adjust to an angular spine without coming unseated. Machine keys are elongated, with either rounded ends, square ends, or tapered gib heads.
Short answer: Keys and keyways prevent the shaft from rotating on the bore and can assist in torque transmission between the two connected shafts.
Sometimes understanding the small details, help us understand the big picture. On this blog we will dive into some basic concepts of power transmission.
Have you tried to start an engine, or put a drive train into gear, and nothing happened?
You may have even heard the starter motor engage and start, but then there was no forward motion when the transmission finally became engaged. Most of the time, when this occurs, there are a few things that you can check, such as the transmission fluid, transmission shift cable, or the transmission shaft key. But, let me explain this a bit further.
Breaking down the components
Power transmission
As the term easily implies, power transmission is the transfer of energy from a place of generation to a place where it is applied to perform useful work. In Figure 1 below, you can see how a steam turbine transfers the power generated by steam into a generator, which in turn creates electricity. Note the shaft connecting the steam turbine with the generator. Power generation is one of the many industries covered by Lovejoy products.
(Figure 1)
Shaft
A shaft is an element used to transmit both the power and torque. Shafts are made in a variety of different shapes and forms, but most tend to have circular cross sections that are either solid or tubular shaped. Shafts transmit power directly from a driving device or power source into a load (figure 1). Shafts can carry gears, pulleys, and sprockets in order to transmit rotary motion and power via mating gears, belts, and chains. Alternatively, a shaft may simply connect to another shaft via a coupling mechanism. Couplings are connected to a shaft by means of a key, keyway, or keyseat.
Shaft Keyway Slot Bearing
Key, Keyway, and Keyseat
A key is a piece of metal used to connect a rotating machine element to the shaft. A key prevents a relative rotation between the two parts, and may enable torque transmission to occur. For a key to function properly, both the shaft and rotating elements (gear, pulley and coupling) must have a keyway and a keyseat. Usually the term keyseat is referred as a groove or pocket on a shaft, and a keyway is a slot in a hub in which the key fits into. The complete system is called a keyed joint (Figure 2).
(Figure 2)
Shaft Keyway Slot Bearings
Keys are made of varied types of materials, and also come in different shapes and sizes. The most common key shapes are rectangular or tapered, and are typically made of steel.
Shaft Keyway Tolerance Chart
Mechanics
In order to lock a hub or bushing and shaft together, and also to prevent a shaft from rotating in the bore (Figure 2), a key is commonly inserted into a keyway that is machined in both the bore and the shaft. The key is responsible for preventing any rotation between the shaft and the bore, and also carries a portion of the torque load to the keys. Torque transmission by keys is the most common and widely used power transmitting method. Unfortunately, misaligned keys and keyways can result in mechanical failures. Therefore, in order to ensure an appropriate fit, the width and height dimensions of a standard key and keyway must adhere to recommended tolerances. Industry standards for key sizes in various bores exist for both the English and Metric systems.
In addition, when there is a distance that exists between the driving and driven components, drive shafts frequently connect with one another using one or more universal joints, jaw couplings, or in some cases, a splinted joint or prismatic joint.
Short answer: Keys and keyways prevent the shaft from rotating on the bore and can assist in torque transmission between the two connected shafts.
Sometimes understanding the small details, help us understand the big picture. On this blog we will dive into some basic concepts of power transmission.
Have you tried to start an engine, or put a drive train into gear, and nothing happened?
You may have even heard the starter motor engage and start, but then there was no forward motion when the transmission finally became engaged. Most of the time, when this occurs, there are a few things that you can check, such as the transmission fluid, transmission shift cable, or the transmission shaft key. But, let me explain this a bit further.
Breaking down the components
Power transmission
As the term easily implies, power transmission is the transfer of energy from a place of generation to a place where it is applied to perform useful work. In Figure 1 below, you can see how a steam turbine transfers the power generated by steam into a generator, which in turn creates electricity. Note the shaft connecting the steam turbine with the generator. Power generation is one of the many industries covered by Lovejoy products.
(Figure 1)
Shaft
A shaft is an element used to transmit both the power and torque. Shafts are made in a variety of different shapes and forms, but most tend to have circular cross sections that are either solid or tubular shaped. Shafts transmit power directly from a driving device or power source into a load (figure 1). Shafts can carry gears, pulleys, and sprockets in order to transmit rotary motion and power via mating gears, belts, and chains. Alternatively, a shaft may simply connect to another shaft via a coupling mechanism. Couplings are connected to a shaft by means of a key, keyway, or keyseat.
Shaft Keyway Slot Bearing
Key, Keyway, and Keyseat
A key is a piece of metal used to connect a rotating machine element to the shaft. A key prevents a relative rotation between the two parts, and may enable torque transmission to occur. For a key to function properly, both the shaft and rotating elements (gear, pulley and coupling) must have a keyway and a keyseat. Usually the term keyseat is referred as a groove or pocket on a shaft, and a keyway is a slot in a hub in which the key fits into. The complete system is called a keyed joint (Figure 2).
(Figure 2)
Shaft Keyway Slot Bearings
Keys are made of varied types of materials, and also come in different shapes and sizes. The most common key shapes are rectangular or tapered, and are typically made of steel.
Shaft Keyway Tolerance Chart
Mechanics
In order to lock a hub or bushing and shaft together, and also to prevent a shaft from rotating in the bore (Figure 2), a key is commonly inserted into a keyway that is machined in both the bore and the shaft. The key is responsible for preventing any rotation between the shaft and the bore, and also carries a portion of the torque load to the keys. Torque transmission by keys is the most common and widely used power transmitting method. Unfortunately, misaligned keys and keyways can result in mechanical failures. Therefore, in order to ensure an appropriate fit, the width and height dimensions of a standard key and keyway must adhere to recommended tolerances. Industry standards for key sizes in various bores exist for both the English and Metric systems.
In addition, when there is a distance that exists between the driving and driven components, drive shafts frequently connect with one another using one or more universal joints, jaw couplings, or in some cases, a splinted joint or prismatic joint.
So, to conclude, the two most important functions of keys and keyways on a power transmission shaft are to:
- Prevent the shaft from rotating in the bore
- Enable power transmission through the torque
Simply put, a keyway is a slot in a lock for receiving and guiding the key. Of course, with each specially designed keyway made to make a lock even more secure, the definition gets more complicated with plenty of options. When making a duplicate key for your lock, it is important to understand what type of keyway you have in order to determine whether or not your duplicate key is able to be cut and to ensure you have the right type.
Shape of Key
The shapes vary, but you can generally figure out what type of key you need just by looking at the top of the key, called the head or base. This is the part of the mechanically cut key that you hold in your fingers when trying to lock or unlock a door. Kwikset keys are typically more rounded and have between one to three-hole openings on the head. Schlage keys are usually a bit rougher at the top with a block or edgy look to them.
Engraving
Sometimes, the key will have an engraving on the head. Inside the engravings is a code containing letters and/or number combinations, such as KW1, KW10, 5, 6, 66, 65, and so on. Schlage key types usually have a code such as SC1, 68, or C.
Grooves
Place the key down flat with the head on top and the tip on the left. Flip the key over, and look at the correct side of the key. A Kwikset key will have two grooves or indentations. A Schlage key will have only one groove or indentation. Some keys have grooves that look similar, but the grooves alone don't mean that the keys are compatible with the keyway.
Interchangeable
Some keys may appear to be interchangeable with another, but over time will wear down the lock if you keep using them on the wrong keyway. For instance, Weiser keys usually contain engravings such as WR5 or WR3 and can be duplicated using the Kwikset key type. However, Kwikset keys cannot be used in a Weiser lock.
There are different ways to determine which type of keyway is the one that you need most. When in doubt, seek the advice of a professional. A skilled and trained locksmith will be able to take one look at your key and tell you what type of keyway you have and be able to recommend which are the best keyways for your needs. Let Phoenix Locksmith 24 help you with your keyways and keyways types.
