Overview

This document details the specifications, configurations, technical features, and application guidelines for Transfluid's RBD elastic couplings, SRBD single pump drives, and PF power take-off (PTO) units. These products are designed for industrial and mobile applications involving engines, pumps, compressors, and other machinery requiring torque transmission with elastic coupling solutions.

1. RBD Elastic Couplings

Description

RBD couplings are designed for stationary and mobile industrial engines, offering advantages such as ease of assembly, compact size, low weight, and competitive pricing. They come with standard SAE flanges for easy installation.

Configuration Options

• With or without hub
• Spline or keyway options (minimum quantity required)
• Conical locking coupling (standard)
• Housing available for hydrostatic drives

Technical Features

The coupling uses internal and external teeth, where external teeth are rubber blocks molded from special compounds. By varying the rubber compound, different torque capacities can be achieved. The external aluminum ring matches the rubber profile and mounts directly on the prime mover flange, allowing absorption of small angular and radial misalignments.

Selection Criteria

• Nominal torque (TKN) must exceed load torque (TLN) multiplied by service factor (St = 1.3)
• Maximum torque (TKmax) must exceed peak load torque (TLS)
• For ATEX applications, TKN must exceed TLN × St × StAtex (StAtex = 1.56)

Custom rubber blocks with different hardness and elasticity are available on request.

Performance Data

Couplings are available in various sizes (6S to 18D) with torque ratings from 310 Nm to 5300 Nm nominal torque and maximum torque up to 16720 Nm. Maximum operating speeds range from 2400 to 4500 rpm depending on size. Ambient temperature range is -40°C to +120°C.

Static stiffness ranges from 20,000 Nm/rad to over 1,000,000 Nm/rad depending on size. Weight varies from 1.4 kg to 50 kg.

Misalignment

Maximum permissible parallel and angular misalignment is 0.7 mm total indicated runout (T.I.R.).

2. RBD Couplings with QD (Quick Disconnect) and SRBD Single Pump Drives

Features

• QD hubs provide easy assembly, high torque transmission, and quick disassembly without special tools.
• Positive contact between locking hub and shaft prevents fretting.
• Available with single or double rubber blocks.

Single Pump Drive Kit

The SRBD single pump drive kit includes the RBD coupling, machined QD bushing, SAE housing with inch threaded holes, and spacer. The housing internal flanging fits SAE pumps with 2 or 4 bolt holes.

Dimensions and Bolt Specifications

Detailed dimensional data and bolt sizes are provided for each size variant, including locking torque values.

Compatibility

Compatible with various SAE flywheel sizes (6½" to 18") and pump mounting standards (SAE J744, DIN 5480 spline shafts).

3. RBD Power Take Off (PTO) Units

Description

PF series PTOs are designed for both inline and radial load applications. They feature a heavy-duty bearing to absorb high shock loads.

Technical Data

• Nominal torque ranges from 560 Nm (PF10SS) to 5300 Nm (PF18D).
• Maximum speeds range from 2400 to 4000 rpm.
• Weights vary from 41 kg to 217 kg depending on size.

Installation Notes

Support plates are required for some models and not for others, with references to specific Transfluid technical documents for details. Special keys are used for certain models.

Applications

PF PTOs can be fitted with pulleys, cardan shafts, or fluid couplings (KRG/D/U or KSD).

4. ATEX Certification and Safety

Transfluid offers ATEX-certified versions of RBD, SRBD, and PF products for use in hazardous zones compliant with directive 94/9/EC. Selection must include an additional safety factor (Af = 1.2) on top of the service factor.

Certification categories include:

• ε x II 3 G/D c T4 (Surface non-mining)
• ε x II 2 G/D c T4 (Surface non-mining)
• ε x I M2 c T4 (Mining applications)

Application forms must be completed for ATEX product inquiries.

5. Application Data Sheet

The document includes a detailed application data sheet template to capture customer and project information, prime mover specifications, application conditions, ambient environment, and safety requirements.

6. Additional Products

• HF Series Oil Operated PTOs (up to 800 kW)
• KFBD Fluid Coupling PTOs (up to 500 kW)
• SL Hydraulic Brakes (up to 9000 Nm)
• Power Shift Transmissions (electric selector up to 95 kW)
• KPTO Fluid Couplings (up to 1700 kW)
• SH-SHC Hydraulic Clutches (up to 2500 Nm)

7. Contact Information

Transfluid provides contact details for offices in Italy, China, France, USA, UK, and Northern Europe for sales and technical support.

Summary of Critical Information

• Torque ratings and speed limits must be respected for safe operation.
• Misalignment tolerance is limited to 0.7 mm T.I.R.
• Use of QD hubs facilitates assembly and maintenance.
• ATEX certification requires additional safety factors and documentation.
• Compatibility with SAE and DIN standards ensures broad application.
• Custom rubber compounds are available for specialized torque and elasticity requirements.