Shock Absorbers For Pneumatic Cylinders

Pneumatic shock absorbers are mechanical devices used with pneumatic cylinders to absorb and dissipate energy during the piston rod's extension and retraction. Pneumatic cylinders can generate significant kinetic energy during rapid movements. If not properly managed, this energy can cause excessive wear, vibration, noise, and even damage to machinery. These shock absorbers reduce unwanted shock and vibration caused by impacts during movements, significantly enhancing production quality, process speed, production stability, and extending the service life of production equipment. Additionally, they help reduce operating noise in industries.

Pneumatic cylinder shock absorber working

Hydraulic shock absorbers

Hydraulic shock absorbers function based on fluid dynamics. When a moving load impacts the shock absorber, a piston inside the absorber is forced to move through a hydraulic fluid. This movement creates a controlled resistance, converting kinetic energy into heat, which is then dissipated through the body of the shock absorber.

In pneumatic cylinders, hydraulic shock absorbers are often used at the end of the stroke to decelerate the load smoothly. This prevents the cylinder from slamming into its end caps, reducing noise and wear. Advanced models may feature adjustable damping, allowing for fine-tuning based on specific application requirements.

Mechanical shock absorbers

Mechanical shock absorbers, also called elastomer shock absorbers, utilize the compressive and restorative properties of elastomeric materials (such as rubber or polyurethane) to absorb and dissipate kinetic energy. When a load impacts the shock absorber, the elastomer deforms, absorbing energy, and then gradually returns to its original shape, dissipating the energy as heat.

Elastomer shock absorbers are often used in applications where space is limited or where a simpler, maintenance-free solution is desired. They are particularly effective in low to moderate impact applications, providing a cost-effective means of reducing noise and wear at the end of the cylinder stroke.

Festo self-adjusting hydraulic shock absorbers

The range of hydraulic shock absorbers is designed to meet a wide variety of requirements with no maintenance requirements. These self-adjusting products feature a path-controlled throttle function and come in two main versions: rapid and gentle cushioning.

Rapid cushioning

Variants YSR-C, DYSC, and DYSS have a rapidly increasing cushioning force curve and a short cushioning stroke.

• The YSR-C and DYSC types are both suitable for rotary drives, with YSR-C featuring a continuous mounting thread and being compatible with linear drives like DGPL, DGC, and SLE, commonly used in automation systems.
• DYSC, on the other hand, has a metal end position on the housing and an internal hex thread, making it suitable for swivel modules like DSM-B and semi-rotary drives like DRRD.
• DYSS is designed for low-vibration operation, not suitable for rotary drives, and also features a metal end position with an internal hex thread.

Gentle cushioning

Variants YSRW and DYSW come with a gently increasing cushioning force curve and a long cushioning stroke. They are suitable for low-vibration operation with short cycle times and are maintenance free.

Festo adjustable hydraulic shock absorbers (DYSR)

Adjustable hydraulic shock absorbers can be fine-tuned to meet the specific needs of various applications, providing optimal performance and protection. The main features of adjustable hydraulic shock absorbers DYSR are:

• Hydraulic shock absorber with spring return, ensuring quick reset after each use.
• Adjustable cushioning hardness allowing for precise control over the cushioning characteristics

Festo mechanical shock absorbers

Mechanical shock absorbers typically use flexible rubber or elastomer materials to cushion and reduce the force transmitted through them. There are two versions: one without a fixed stop and a non-adjustable cushioning stroke (DYEF-Y1), and another with an adjustable cushioning stroke and a fixed stop (DYEF-Y1F). The DYEF mechanical shock absorber is ideal for cushioning movements with lower energy.

Festo stop elements

Stop elements provide a definitive end point for the cushioning stroke, preventing over-compression and potential damage to the shock absorber or the equipment it is protecting. Stop elements are crucial for maintaining the integrity and longevity of the shock absorber, as well as ensuring precise and repeatable positioning in various applications. The various features of Festo stop element YSRWJ are:

• Cushioning with self-adjusting, progressive hydraulic shock absorber (YSRW)
• Slowly increasing cushioning force curve with adjustable cushioning stroke
• Suitable for various applications in handling and assembly technology

Hydraulic cushioning cylinders

Hydraulic cushioning cylinders operate continuously and allow for the adjustment of the speed at which it provides braking or cushioning. They are typically used in applications where precise and consistent braking is required to protect machinery and components from damage due to sudden stops or impacts. The main features of hydraulic cushioning cylinders DYHR are:

• Designed for consistent, slow braking speeds throughout the entire stroke
• Adjustable braking speed
• Features a built-in compression spring that returns the piston rod to its initial position
• Suitable for slow feed speeds up to 0.1 m/s

Festo shock absorber comparison

Table 1: Festo shock absorber comparison

Feature	Type	Cushioning cylinder adjustable	Fixed stop	Suitable for rotary drives	Mounting thread	Suitable applications
DYEF-Y1	Elastomer	No	No	No	Internal hex	Mini slide DGSL
DYEF-Y1F	Elastomer	Yes	Yes	No	Internal hex	Mini slide DGSL, swivel module DSM-B
DYSR	Adjustable hydraulic	Yes	No	No	Lock nut	Various linear drives DGPL, DGC, SLE
YSR-C	Self-adjusting hydraulic	No	No	Yes	Lock nut	Swivel module DSM-B, swivel/linear drive DSL-B, semi-rotary drive DRRD
DYSC	Self-adjusting hydraulic	No	No	Yes	Lock nut	Linear drive DGC, Handling modules HSP, HSW
YSRW	Self-adjusting hydraulic	No	No	No	Lock nut	Linear drive DLGF, mini slide DGST
DYSS	Self-adjusting hydraulic	No	No	No	Lock nut	Mini slide DGSL, handling module HSW
DYSW	Self-adjusting hydraulic	No	No	No	Lock nut	Handling and assembly technology
YSRWJ	Self-adjusting hydraulic	No	Yes	No	Lock nut	Slow feed Speeds
DYHR	Stop element hydraulic	Yes	No	No	Lock nut	Slow braking speeds with precise adjustment capabilities across the stroke

Note: There are calculation tools designed to help the user find the perfect shock absorber for specific application requirements, including vertical, horizontal, inclined, and rotary movements. By entering relevant parameters, these tools provide tailored recommendations to ensure optimal performance.