Development and Implementation of a New Gear System for High Speed Reduction Ratios

Project Information

NUGEAR

Grant agreement ID: BRST975188

Project closed

Start date 1 January 1998

End date 31 December 1999

Funded under

• Specific research and technological development programme in the field of industrial and materials technologies, 1994-1998

Total cost No data

EU contribution No data

Coordinated by

Costamasnaga SpA
Italy

Deliverables

Prototype of a gearbox for medium size applications (NUGEAR MSA)

This result consists of the prototype of a gearbox for medium size applications (NUGEAR MSA). In the design development the critical aspects before listed for NUGEAR SSA have been overcome, and the configuration defined for NUGEAR SSA has been taken into account. The following characteristics of the NUGEAR MSA have to be pointed out: -Input shaft: the input shaft is divided in three parts. Two of them are assembled as shrink ring and cannot be disassembled, while the third part is removable to allow wheels bearing integration. -Bearings: three bearing for the input shaft as well for the output shaft were selected, because the solution with two bearings (one of them supporting axial load too) does not seem to be convenient in term of cost for a large mass production. Maximum size requirements allow NUGEAR MSA to be competitive with epicycloidal reducers available on the market, even at relative low reduction ratios (30:1), in terms of overall dimension. Another characteristic of such a gearbox is that, in order to have not very severe loads on bearings, it is necessary to increase the centre distance of the bearings of the input shaft, and this fact gives a lengthened shape to the gearbox. This characteristic can be employed to produce a gearbox with the electrical motor integrated inside. This solution is particularly suitable to be applied in the sector of small components of the automotive industry powered by electrical motors, or in other application sectors where the size of the gearbox is a critical requirement, such as conveyors or cranes powered by electrical motors. The satisfactory outcome, of the research work associated to this major result, indicates that this gearbox is likely to be exploited in other sectors, where the gearbox simple configuration can yield to major saving in manufacturing cost in respect to reducers available on the market. Examples of such sectors are the same as the NUGEAR SSA: -Servo-mechanisms and gearboxes for radar antennas. -Actuators of arms in robotics. Progress towards these applications is being investigated.

Detailed design of a gearbox for large size applications (NUGEAR LSA)

This result consists of the detailed design of a gearbox for large size applications (NUGEAR LSA). The critical aspects listed in the design development for NUGEAR SSA and MSA have been overcome, and the configurations defined for NUGEAR SSA and MSA have been taken into account. The following characteristics and differences in respect of NUGEAR MSA have to be pointed out: -Input shaft: the input shaft is divided in two parts assembled as shrink ring that cannot be disassembled, while the third part is removable to allow wheels bearing integration. The solution with the shaft divided in three parts like in NUGEAR MSA is possible and can be selected to reduce total length (if it is required). -Bearings: the solution with three bearing for each shaft is possible and can be selected if convenient from an economical point of view. The detailed design of a gearbox for large size applications has demonstrated the capability of the system to provide high transmission ratios with relatively small size and a low number of parts. This characteristic is particularly suitable in other application sectors where the size of the gearbox is a critical requirement, such as mixers or drivers for satellite antennas.

Prototype of a gearbox for small size applications (NUGEAR SSA)

This result consists of the prototype of a gearbox for small size applications (NUGEAR SSA). In the design development the following critical aspects have been overcome: -Input shaft: manufacturing in one piece is very complex and expensive. -Bearing: dimensions of bearings are quite large, when compared with the gearbox overall dimension. -Bearing of the input shaft: this bearing has to support a similar level of the bearing of the output shaft, but at a higher speed, resulting in a more severe condition. In the finally adopted solution, the quantity of bearings was reduced due to the low input torque value, and each shaft was supported by only one bearing. The input shaft is assembled in two parts as shrink ring that cannot be disassembled. It has been shown that its simple configuration (reduction ratios up to 3000:1 with only four bevel gears) can yield to major saving in manufacturing cost in respect to reducers available on the market. The characteristics of such a gearbox are particularly suitable to be applied in the sectors of portable electrical devices (e.g. drilling tools) or of small components of the automotive industry powered by electrical motors (e.g. wind-screen wipers). The satisfactory outcome, of the research work associated to this major result, indicates that this gearbox is likely to be exploited towards other sectors, where the gearbox simple configuration can yield to major saving in manufacturing cost in respect to reducers available on the market. Examples of such sectors are: -Servo-mechanisms and gearboxes for radar antennas. -Actuators of arms in robotics. Progress towards these applications is being investigated.