Even in a freezer, the Linear Chain works efficiently

How the Linear Chain remains robust and precise despite extreme environmental conditions

Philipp Schmalzhaf - Sales Manager - GROB Antriebstechnik GmbH

by Philipp Schmalzhaf, Sales Manager

Linear Chain at freezing temperatures - GROB Drive Technology GmbH

Imagine you want to present something truly special to your guests at the next barbecue: perhaps kangaroo meat from Australia. To ensure it arrives fresh on your grill, it first needs to be frozen in Australia. And you'll be amazed: during the freezing process, the Linear Chain from GROB Antriebstechnik GmbH plays a crucial role.

Space-Saving Linear Chain

Whenever space is tight and loads need to be moved safely and precisely, the Linear Chain is indispensable. A typical example is the plate freezers at the New Zealand manufacturer of innovative cooling technology. In this specific application, meat and other food products are packaged and transported in a partially automated system.

At the end of the process, they're deep-frozen. This is where the Linear Chain comes into play, pushing the cardboard boxes (contents: meat) onto the plate rack. There, they're deep-frozen within 24 hours. You can see exactly how this works in this video.

From minute 1:04, you can see the Linear Chain moving the packaged meat onto the plate freezer.

Unusual Conditions

That's an understatement. When foods like meat, poultry, fish, or cheese are deep-frozen, the temperatures are very low – specifically below the freezing point, at about -42°C (-44°F). For the Linear Chain, this is no issue; it can perform satisfactorily even at lower temperatures.

Pusher with a Linear Chain - GROB Drive Technology GmbH

The Linear Chain pushes the load onto the storage plate

Which type of Linear Chain was used?

In this case, we utilized the SK18 with a maximum thrust force of 18,000 N. The distinct advantage of the Linear Chain is undoubtedly its capability to achieve very long strokes, especially in confined spaces. It can be installed both vertically and horizontally, enabling highly precise positioning.

FAQs about Linear Chains

A Linear Chain is a type of chain that can be both pulled and pushed. When the chain links are pushed together, they stay stable and rigid, allowing you to move things forward. It’s often used in machines to lift or push objects.

What a Linear Chain is and where it is used - GROB GmbH chevron_right

Depending on the size, the driving speed is usually below 50rpm.

Yes, lifting systems with multiple chains connected together are common.

The chain of the Linear Chain consists of links that rest on the shoulders and pins of the succeeding link. The chain of the Tower Chain is constructed with U-shaped chain links, providing greater stability and enabling unguided strokes of over 4m.

In standard applications, Linear Chains can be operated with a speed of 250mm/s. Special applications have already been implemented with speeds exceeding 800mm/s.

Yes, the use of stainless steel materials is a common practice for environments with aggressive media.

Yes, depending on the proximity to the product, the chain can also be completely made of stainless steel.

  1. When under pressure load: depending on the control, 100% repeatability can be achieved.
  2. Under changing loads: the control system must consider the backlash at the sprocket and manufacturing tolerances in the chain links.
  1. The load must always be guided
  2. Acceleration should be controlled via a ramp
  3. The chain cannot perform a swiveling movement
  4. The permissible buckling length must not be exceeded

No, within the buckling range, Linear Chains can also be used without guidance.

  1. Electronic bridge: If each lifting element of the system is driven by a motor, electronic synchronization can be achieved through encoders.
  2. Mechanical linkage: More cost-effective and fail-safe are cardan shafts and bevel gearboxes, which can connect all lifting elements of a system together.

The polygon effect occurs when a chain is positively driven by a sprocket. In this case, the chain cannot run perfectly circularly on and off the sprocket, causing deviations in the path of the traction medium. The speed of the chain then fluctuates periodically around a mean speed, which can manifest as vibrations in the chain.

Since the chain undergoes radial movement due to the polygon effect, the guide plates are extended, and minimal play is allowed. This helps mitigate this effect.

No, swiveling movements are not possible with the Linear Chain.

65% with chain magazine, 80% with free chain.

No, the load must always be guided.

There is no calculation basis for this. The buckling length has been determined through tests. You can find a corresponding diagram for horizontal applications here: General Catalog 2023 (grob-antriebstechnik.de). For vertical applications, please contact us.

No, a Linear Chain can never take over the guiding itself. The load must be guided.

  1. Lubrication system: attached lubrication brushes extend the lifespan.
  2. Chain magazine: the chain can be rolled up behind the housing.
  3. Reduction gear: especially useful in lifting systems to reduce torque through gears.
  4. Force sensor: for measuring axial load and protection against overload.

We always recommend using our standard link to connect your load. Utilize all the holes to ensure proper loading of the chain. Dimensions for the front link can be found here: General Catalog

As standard, GROB chains are galvanized. For environments with aggressive media, stainless steel chains can be used.

  1. Standard: 180°C (356°F)
  2. High-temperature continuous: 550°C (1022°F)
  3. High-temperature short-term (under 2 minutes): 1050°C (1922°F)
  1. The load must be guided
  2. The Linear Chain size must be chosen correctly
  3. It should be driven over a ramp

Yes, hardened chain links achieve a lifespan four times longer.

  1. A chain magazine winds the chain in multiple circular paths. Advantage: greater space saving.
  2. A chain cover protects the chain attached to the housing. Due to the attachment, the chain aligns itself and thus halves the stroke length. Advantage: more cost-effective.

Yes, the chain can be stored perpendicular to the lifting movement, such as 90°, or even 180° (parallel) to the lifting movement, as in the case of tool tables. The lift then operates on the table, while the storage runs parallel underneath it.

The T-guide was developed when space for the standard rail above the sliding surface was lacking. In one application example, the customer needed to maneuver with a forklift. The T-guide rail was then embedded in the floor, allowing the vehicles to continue maneuvering undisturbed.

No, you should provide a brake on the motor.

Check for dirt or worn-out parts. Thorough cleaning and, if necessary, replacement of damaged components may solve the problem. If the Linear Chain is noisy after acquisition, system tensions could be responsible.

The different installation positions do not affect the usability of Linear Chains (e.g., through oil sight glasses or similar). By simply changing the mounting side of the mounting brackets, the mounting sides can be adjusted as needed.

There's no calculation basis for this. Tests have shown that for standard chains, 250,000 cycles, and for hardened chains, 1,000,000 cycles represent realistic values.

Question not included?

You can find more application examples and drive solutions here

Linear Chain - GROB Antriebstechnik GmbH

What is a Linear Chain?

Discover the basics of Linear Chains and the impressive technology behind them in our article for beginners. We explain how Linear Chains work and the important role they play in various applications. Dive in and learn why Linear Chains are a key component for precise linear movements.

Learn more

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Thomas Moeschle

Thomas Möschle, Key Account Manager