Hydraulic Rotary Unions — Rotary Joints for Machine Tools

Rotary Joints are required in almost all industries to transfer fluids from stationary to rotating machine parts. Some applications are simple to solve with standard rotary joint solutions. However, in more complex applications, such as machine tools, the performance of the machine depends to a large degree on the correct selection of the rotary joint. Maieroffers a complete range of rotary joints and sealing systems to suit individual customer specifications.

Cooling through the electro-spindle:

Traditionally, tool tips have been cooled by supplying coolant from an external source. However, in processes such as milling, this method of cooling does not provide optimum performance and decreases the service life of the tools, particularly in the case of high speeds of rotation. State-of-the-art machine tools use systems that supply cooling fluid through the electro-spindle.

Advantages:

Selection of the rotary joint for coolant:

TESS Technology:

The TESS technology (Thermal Expansion Sealing Systems) is an internationally patented Maier development. The system works like a classical closed seal when used with liquid coolant. In case of pressurized dry air, dry operation or minimal lubrication, the system detects an increase in temperature and reduces the specific closing pressure applied to the seal faces without separating the sealing surfaces.

K Series:

Series K consists of three basic versions: K 21, KT 21 and KT 41. Rotary joint type K 21 is only suitable for coolant. Rotary joint type KT 21 with TESS technology is resistant to pressure peaks. Suitable for coolant, dry operation without limitation, minimal quantity lubrication (MQL) and dry air under pressure and speed. Rotary joint type KT 41 with TESS is designed for high pressure and speed.

They share common characteristics such as:

K 21 C, KT 21 C and KT 41 C with axial inlet.
K 21 B, KT 21 B and KT 41 B with radial inlet.

KL Series:

Series KL rotary joints are designed for liquid coolants. Passage in one direction, closed seals. The housing is made of stainless steel and anodized aluminum. A labyrinth seal protects the bearings against fluid. Adapted rotating mechanical seals made of silicon carbide and carbon graphite. Ball bearings. Drain holes in the housing. KLT is the alternative with TESS technology with thermal relief of the seal. KLT is suitable for coolant, dry operation and MQL (minimal quantity lubrication). Outside dimensions identical to series KL.

KL 11 C and KLT 11 C with axial inlet.
KL 11 B and KLT 11 B with radial inlet.

Combijoint:

With Combijoint, different types of rotary joints such as MP, MPV, K, DP and electric slip rings can be combined. Hydraulic oil, compressed air, gas, water, grease, coolant, current and electric signals can be transferred. Combijont versions are the most versatile and flexible way of transferring fluids. Frequently, only a single type of seal is selected for multi-passage rotary joints, usually a radial seal, to seal the passage of different media under different working conditions. This considerably reduces the service life of the rotary joint. Combijoint allows you to combine different seal technologies that best suit a specific fluid. Mounting several rotary joints in series also lets you select different materials, depending on the specific requirements. This results in a costeffective and reliable solution. In case of leaks, it is sufficient to repair the failed rotary joint without having to open the other rotary joints since only one housing is affected. The connecting flange can be sized to customer requirements for this solution.

Maier is a supplier and rotary union manufacturer for various applications including construction, mechanical, marine, and industrial.

Hydraulic Rotary Unions — MP Series

The Maier MP Series is a multi-passage rotary joint for simultaneous supply of up to 10 different media. It is suitable for turntables, tools and forms. By means of many possible variations of sizes, materials and seals, MP Series covers a wide scope of applications. MP rotary joints can be combined with a slip ring or another rotary joint or with hollow shaft rotary joints. They can also be designed with multi-ports at the housing.

Hydraulic Rotary Union Product Features:

Combi-joint type MPE: MP rotary joint with two or four passages and slip ring with gold/gold contacts

Hollow shaft type MPH: Simplest version of series MP with one passage and hollow shaft. The radial connection at the housing corresponds to the customer’s shaft inlet. The technical characteristics are the same as series MP. Multi-passage versions are available on request.

Rotary joint type MPT: Two-way-design with two mechanical seals. Transfer of one fluid in and out, suitable for higher speed by means of mechanical seal. Custom-made design on request.

Rotary joint type MPV: One-to-four-way-designs with gap seal bushes – “hydrostatic relief”. Gap seals create controlled leakage recirculated to the hydraulic unit. With this technology it is possible to transfer the medium at high speed and high pressure simultaneously.

Maier is a supplier and rotary union manufacturer for various applications including construction, mechanical, marine, and industrial.

Hydraulic Rotary Unions — M and DA Series

The Maier M Series is a sturdy rotary joint for polluted media at low speeds, suitable for water and steam.

Hydraulic Rotary Union Product Features:

The Maier DA Series is a shaft-supported rotary joint with maintenance-free, metal-impregnated sealing rings. These rotary joints are suitable for thermal oil, steam and water at low RPM.

Hydraulic Rotary Union Product Features:

Maier is a supplier and rotary union manufacturer for various applications including construction, mechanical, marine, and industrial.

Hydraulic Rotary Unions — H Series

The Maier H Series is a universal rotary joint to accommodate transfer of water, steam and thermal oil under temperature, rotation and pressure. These rotary joints are equipped with maintenance-free carbon sealing rings and carbon bushing. Metal-impregnated sealing rings for thermal oil and higher pressure loads are provided for hot water and steam applications.

The H3 type features an integrated vacuum valve for the steam cylinder. Maier offers the H Series in many different versions to meet the customers requirements. The new improved and fortified generation of the standard H series is faster and more robust and offers more flexibility, due to a modular system. It contains a low friction moment as well and a large variety of different designs, from 1/2″ up to 12″.

Hydraulic Rotary Union Product Features:

Maier is a supplier and rotary union manufacturer for various applications including construction, mechanical, marine, and industrial.

Hydraulic Rotary Unions — DX and DXS Series

The Maier DX and DXS Series is a water rotary joint with mechanical seal and ball bearings, suitable for cooling water (DX and DXS) and hot water (DXS). The DXS is equipped with highly resistant ceramics-coated sealing surface for higher temperatures and speeds as well as prolonged service life.

Hydraulic Rotary Union Standard Product Features:

Maier is a supplier and rotary union manufacturer for various applications including construction, mechanical, marine, and industrial.

Hydraulic Rotary Unions — DP Series

The Maier DP series is an universal rotary joint for hot and cold water and thermal oil, with balanced mechanical seal and ball bearings. Thanks to a low frictional torque high speeds are possible. Various application-specific seal combinations can be selected according to the application. The small series is also suitable for hydraulic oil and compressed air.

The Maier DP Series meets the special requirements of the printing and plastics industries. It is available in four variants, including different sizes from small to large and a stainless steel series.

Hydraulic Rotary Union Standard Product Features:

The Small Series DP 1/4:

The Large Series DP 2 1/2 to 4:

The Stainless Steel Series DPN:

Maier is a supplier and rotary union manufacturer for various applications including construction, mechanical, marine, and industrial.

Hydraulic Rotary Unions — DQ Series

The Maier DQ series is a rotary joint for thermal oil and high temperature and speed ranges with balanced mechanical seal. The DQ, DQT and DQTX types up to 752 °F work as “leak-free” solutions with additional cooling units for cooling and lubrication of bearings and seals by using the same heat transfer medium as in the main circuit. The DQL type and the 5th generation of DQ don’t require additional cooling units.

The DQ series offers a patented system to avoid seal damage and meets the requirements of specialized industries and processes including polymer, coating and lamination applications, paper and textile manufacturing processes including non-woven and textile calendars, industrial dryers and in rotary reaction vessels.

Hydraulic Rotary Union Product Features:

Maier is a supplier and rotary union manufacturer for various applications including construction, mechanical, marine, and industrial.

Hydraulic Rotary Unions — DC Series

The Maier DC Series is a rotary joint for steam and hot water at high pressures and speeds. The patented system includes balanced mechanical seal with external water cooling. It meets the special requirements of applications as coating and laminating systems, paper, non-woven and textile calendars as well as driers.

Hydraulic Rotary Union Product Features:

Maier is a supplier and rotary union manufacturer for various applications including construction, mechanical, marine, and industrial.