TEMB has been specialized in spring for 20 years. With 15 computer coiling machines, 13 heat-treatment furnaces, 16 spring grinding machines, 6 chamfering machines, 8 setting machines, 5 shot-blasting machines, 1 full automatic load sorting machine, 8 fatigue machines, 6 tension and compression testing machines, TEMB can produce all kinds of springs with diameter 0.2~12.0mm, annual capacity 80 million pcs.
We have established long and friendly cooperation relationship with high level steel manufacturers at home and abroad, ensuring the reliable raw material quality, such as SUMITOMO and Suzuki Garphyttan from Japan, KISWIRE from Korea, and SINOSTEEL from China.
The arc spring (also known as – bow spring, curved spring, circular spring or “banana” spring) is a special form of coil spring which was originally developed for use in the dual-mass flywheel of internal combustion engine drive trains. The term “arc spring” is used to describe pre-curved or arc-shaped helical compression springs. They have an arc-shaped coil axis.
Like other technical springs, arc springs are based on the fundamental principle of storing mechanical work in the form of potential energy and the ability to release this energy again. The force is applied through the ends of the spring. A torque can be transmitted around an axis via the force directed along this helical axis and the lever arm to the system center point. The wire of the arc spring is mainly subjected to torsional stress.
Arc spring with sliding shell.
Representation of the friction hysteresis of a single-stage arc spring supported by a sliding shell in a torque-angle characteristic curve.
An arc spring requires suitable support to transmit torque. The support is usually provided from the outside in the form of an arcuate channel (sliding shell) or radially shaped support plates. This prevents buckling of the arc spring. Another result of this support is a hysteresis between the loading and unloading curves in the characteristic curve. This results from the friction of the spring on the radial support and is an intended effect to achieve damping in the system.
Arc spring systems
As with compression springs, spring systems can also be used for arc springs. The main designs are series and parallel connection. With these, single-stage or multi-stage spring characteristics can be achieved. In order to make optimum use of the available space, systems consisting of inner and outer arc springs are often used.
Representation of the friction hysteresis of a two-stage arc spring supported by a sliding shell in a torque-angle characteristic curve.
In addition, the spring characteristic can be influenced by other parameters such as the cross-sectional geometry of the wire, the coil diameter or the number of coils.
Schematic representation of bow springs in a dual mass flywheel.
The arc spring is suitable for static and quasi-static as well as dynamic applications. Examples include:
Dual mass flywheel
Arc spring clutch
Belt tensioners, pulley decouplers
Types of Splines
There are 4 types of splines: Involute, Parallel key, helical, and ball. Learn about their characteristics. And, if you’re not sure what they are, you can always request a quotation. These splines are commonly used for building special machinery, repair jobs, and other applications. The CZPT Manufacturing Company manufactures these shafts. It is a specialty manufacturer and we welcome your business.
The involute spline provides a more rigid and durable structure, and is available in a variety of diameters and spline counts. Generally, steel, carbon steel, or titanium are used as raw materials. Other materials, such as carbon fiber, may be suitable. However, titanium can be difficult to produce, so some manufacturers make splines using other constituents.
When splines are used in shafts, they prevent parts from separating during operation. These features make them an ideal choice for securing mechanical assemblies. Splines with inward-curving grooves do not have sharp corners and are therefore less likely to break or separate while they are in operation. These properties help them to withstand high-speed operations, such as braking, accelerating, and reversing.
A male spline is fitted with an externally-oriented face, and a female spline is inserted through the center. The teeth of the male spline typically have chamfered tips to provide clearance with the transition area. The radii and width of the teeth of a male spline are typically larger than those of a female spline. These specifications are specified in ANSI or DIN design manuals.
The effective tooth thickness of a spline depends on the involute profile error and the lead error. Also, the spacing of the spline teeth and keyways can affect the effective tooth thickness. Involute splines in a splined shaft are designed so that at least 25 percent of the spline teeth engage during coupling, which results in a uniform distribution of load and wear on the spline.
Parallel key splines
A parallel splined shaft has a helix of equal-sized grooves around its circumference. These grooves are generally parallel or involute. Splines minimize stress concentrations in stationary joints and allow linear and rotary motion. Splines may be cut or cold-rolled. Cold-rolled splines have more strength than cut spines and are often used in applications that require high strength, accuracy, and a smooth surface.
A parallel key splined shaft features grooves and keys that are parallel to the axis of the shaft. This design is best suited for applications where load bearing is a primary concern and a smooth motion is needed. A parallel key splined shaft can be made from alloy steels, which are iron-based alloys that may also contain chromium, nickel, molybdenum, copper, or other alloying materials.
A splined shaft can be used to transmit torque and provide anti-rotation when operating as a linear guide. These shafts have square profiles that match up with grooves in a mating piece and transmit torque and rotation. They can also be easily changed in length, and are commonly used in aerospace. Its reliability and fatigue life make it an excellent choice for many applications.
The main difference between a parallel key splined shaft and a keyed shaft is that the former offers more flexibility. They lack slots, which reduce torque-transmitting capacity. Splines offer equal load distribution along the gear teeth, which translates into a longer fatigue life for the shaft. In agricultural applications, shaft life is essential. Agricultural equipment, for example, requires the ability to function at high speeds for extended periods of time.
Involute helical splines
Involute splines are a common design for splined shafts. They are the most commonly used type of splined shaft and feature equal spacing among their teeth. The teeth of this design are also shorter than those of the parallel spline shaft, reducing stress concentration. These splines can be used to transmit power to floating or permanently fixed gears, and reduce stress concentrations in the stationary joint. Involute splines are the most common type of splined shaft, and are widely used for a variety of applications in automotive, machine tools, and more.
Involute helical spline shafts are ideal for applications involving axial motion and rotation. They allow for face coupling engagement and disengagement. This design also allows for a larger diameter than a parallel spline shaft. The result is a highly efficient gearbox. Besides being durable, splines can also be used for other applications involving torque and energy transfer.
A new statistical model can be used to determine the number of teeth that engage for a given load. These splines are characterized by a tight fit at the major diameters, thereby transferring concentricity from the shaft to the female spline. A male spline has chamfered tips for clearance with the transition area. ANSI and DIN design manuals specify the different classes of fit.
The design of involute helical splines is similar to that of gears, and their ridges or teeth are matched with the corresponding grooves in a mating piece. It enables torque and rotation to be transferred to a mate piece while maintaining alignment of the 2 components. Different types of splines are used in different applications. Different splines can have different levels of tooth height.
Involute ball splines
When splines are used, they allow the shaft and hub to engage evenly over the shaft’s entire circumference. Because the teeth are evenly spaced, the load that they can transfer is uniform and their position is always the same regardless of shaft length. Whether the shaft is used to transmit torque or to transmit power, splines are a great choice. They provide maximum strength and allow for linear or rotary motion.
There are 3 basic types of splines: helical, crown, and ball. Crown splines feature equally spaced grooves. Crown splines feature involute sides and parallel sides. Helical splines use involute teeth and are often used in small diameter shafts. Ball splines contain a ball bearing inside the splined shaft to facilitate rotary motion and minimize stress concentration in stationary joints.
The 2 types of splines are classified under the ANSI classes of fit. Fillet root splines have teeth that mesh along the longitudinal axis of rotation. Flat root splines have similar teeth, but are intended to optimize strength for short-term use. Both types of splines are important for ensuring the shaft aligns properly and is not misaligned.
The friction coefficient of the hub is a complex process. When the hub is off-center, the center moves in predictable but irregular motion. Moreover, when the shaft is centered, the center may oscillate between being centered and being off-center. To compensate for this, the torque must be adequate to keep the shaft in its axis during all rotation angles. While straight-sided splines provide similar centering, they have lower misalignment load factors.
Essentially, splined shafts have teeth or ridges that fit together to transfer torque. Because splines are not as tall as involute gears, they offer uniform torque transfer. Additionally, they provide the opportunity for torque and rotational changes and improve wear resistance. In addition to their durability, splined shafts are popular in the aerospace industry and provide increased reliability and fatigue life.
Keyed shafts are available in different materials, lengths, and diameters. When used in high-power drive applications, they offer higher torque and rotational speeds. The higher torque they produce helps them deliver power to the gearbox. However, they are not as durable as splined shafts, which is why the latter is usually preferred in these applications. And while they’re more expensive, they’re equally effective when it comes to torque delivery.
Parallel keyed shafts have separate profiles and ridges and are used in applications requiring accuracy and precision. Keyed shafts with rolled splines are 35% stronger than cut splines and are used where precision is essential. These splines also have a smooth finish, which can make them a good choice for precision applications. They also work well with gears and other mechanical systems that require accurate torque transfer.
Carbon steel is another material used for splined shafts. Carbon steel is known for its malleability, and its shallow carbon content helps create reliable motion. However, if you’re looking for something more durable, consider ferrous steel. This type contains metals such as nickel, chromium, and molybdenum. And it’s important to remember that carbon steel is not the only material to consider.