Direct drive torque motors are replacing gears. But is this statistically significant?
Direct drive torque motors have a greater presence in the marketplace, but overall their impact and potential threat to gearboxes is limited.
IMS Research has been measuring the market for direct drive torque motors for over a decade now, and during this period, the replacement of mechanical gears is frequently identified as the leading contributor to the growth of the torque motor market. Yet discuss this with any gearbox supplier and they will tell you that there is little threat to the gear market from direct drive technology. So how significant is the replacement of gears with direct drive torque motors from a market sizing perspective?
Let’s first consider the global landscape of the torque motor market. According to IMS Research’s latest report, the market for direct drive torque motors (sold as components, modules or systems) was estimated to be worth approximately $450 million in 2010, and is likely to have grown by around 10% in 2011. Replacement of traditional gear-based systems was reported to account for up to 60% of these market revenues, representing between 120,000 and 130,000 torque motors sold; or put another way, 120,000 to 130,000 newly redundant gearbox systems.
However, this was not impacting the entire gearbox market. There remain very few instances of gear replacement in applications requiring torque above 6000Nm. Above this, power transmission using gear reduction is still preferred over use of torque motors operating at or near capacity. This means that over one third of the industry grade gear market (representing 70% of market revenues) is currently out of range for this replacement trend. That is not to say that the available replacement base is not significant; it represented over 7.4 million units in 2010. But then this highlights the limited penetration of direct drive torque motors into industry grade gearing markets where relatively basic power transmission is often the primary requirement.
What about replacement within the low backlash gearing sector? This market uses more dynamic, higher performance geared components and was estimated to be worth around $715 million globally in 2010, representing roughly 1 million units. Almost all backlash rated gearboxes are mounted to servo motors, and well within the typical 6000Nm replacement torque range. Current estimates for 2010 suggest that approximately 1 in every 6 AC brushless servo motors sold that year required a backlash rated gearbox, which provides some context for the market for these products. So is the servo motor/gearbox combination at a greater threat from direct drive torque motors? Well, there are replacement feasibility limitations here too. Issues of inertia mismatching currently reduce the replacement market to applications involving less than 10:1 reduction. This once again limits the available replacement market for torque motor products to a smaller fraction of the overall gear market. Now let’s consider the stability of the AC brushless servo motor market, as these products represent the motor element of the potentially “at risk” geared solution package. IMS Research’s latest study on the market for these products showed that the AC brushless servo motor market grew 21% from 2010 to 2011 to reach $3.9 billion and 7.2 billion units. This is not low growth by any means, and shows that the market base for backlash rated gearboxes is actually increasing at a greater rate than the reported growth of direct drive torque motors reaching the market.
So is the replacement of gearing by torque motors significant on market statistics? If you are a torque motor supplier, yes. It represents 60% of all market growth. If you are a gearbox supplier, no. In 2010, torque motors were successfully targeting only 0.7% of global gear unit shipments.