These companies work to balance effective manufacturing and customer needs.
by Peter Goretzki
October 24, 2017

Increased cost, competitive prices, the demand for rapid project completion and highest quality, and safety requirements are affecting the development strategies for new products from suppliers in the oil and gas industry, as well as the petrochemical and power industries. In order to derive concrete action strategies for product development, the differing visions of customers and the various disciplines of the company’s own organization in the field of special machine and plant engineering must be understood.

Customers—both original equipment manufacturers (OEMs) and end users—usually demand maximum flexibility with regard to equipment, short delivery times and low prices at maximum quality. Their suppliers strive for simplicity, cost reduction and optimized processes to achieve maximum profit with as few resources as possible.

The supplier’s sales team represents the interface between the organization and customer and requires appropriate sales tools in order to make the products palatable to the customer.

Project vs. Process Machines

In principle, these products can be categorized as either project machines or process machines. Project machines fulfill the customer’s maximum requirements, leading to the highest level of customer satisfaction. In contrast, process machines can be processed in the supplier’s organization optimally within existing capacities and existing know-how, reducing costs and thereby increasing profits.

customer vs supplierFigure 1. Customer’s and supplier’s point of view (Graphics courtesy of Voith Turbo)

A suitable standardization and modularization strategy in product development is essential to meet the requirements of the market mentioned above. It is important to select the appropriate standardization level for each component. This helps create the optimal balance between cost-saving equality and customer-oriented flexibility while taking into account the company’s internal resources and developing it in a suitable way.

This article describes the approach, both advantages and disadvantages, and the implementation of modularization ideas in product development using the example of a hydrodynamic geared variable-speed drive.

Gearbox Example

This gearbox is often used in the oil and gas industry as a variable speed drive for pumps and compressors and connects a constantly rotating electric motor to a working machine. An actuator is used for the variation of the rotational speed—in this case, adjustable pump vanes of a torque converter.

The hydrodynamic geared variable speed drive combines a counter-rotational torque converter (a), with a mechanical planetary gear (b) and a parallel shaft gear (c). The geared variable speed drive connects a driving machine, such as an electric motor, and a working machine, such as a pump or a compressor.

geared vsdFigure 2. Geared variable speed drive

The input shaft (1) is connected to the planet carrier (2) of the planetary gear. This means that a large proportion of the input power is transmitted to the planetary gear directly, mechanically and at a very
high efficiency.

Additionally, the pump wheel (3) of a hydrodynamic torque converter is coupled to the input shaft and diverts just a small proportion of the input power. A liquid flow transmits this power from the pump wheel to the turbine wheel (4) of the torque converter. The diverted power is transmitted to the sun gear (5) of the planetary gear. The power from the planet carrier and from the sun gear is combined in the planetary gear, where ring gear (6) transmits the accumulated power to the output gear stage.

The required specified output speed is achieved by the gear ratio of the parallel shaft gear (7). Adjustable guide vanes (8) at the pump wheel control the liquid flow in the torque converter and determine the speed of the turbine wheel. This allows the speed of the driven machine to be infinitely adjusted.

In previous machine concepts, the design and adaptation of the core machine, in particular the gearbox parts, and thus the gear ratios, were executed on an order- and project-specific basis according to required speed and power. Thus, only a small standardization depth was possible and the engineering effort was high, adversely affecting both delivery time and product costs.

The new gear concept makes it possible to separate the core machine from project-specific parts, which is the basis of any modularization and standardization: defined interfaces between customer-specific (customized) and modular units. In the case of the hydrodynamic transmission, this interface represents the connection between the ring gear of the planetary gear unit and the input shaft of the parallel shaft gear stage.

Furthermore, the general and boundary conditions must be defined in a detailed market and product requirement document. In this case the power range (1,000-13,000 horsepower), limits for gear ratio, machine monitoring, oil quantities and pressures must be clearly described considering customer needs.