The cooperation between the
international automotive suppliers Schaeffler and Continental, which has
already proved its worth in the highly efficient Gasoline Technology Car hybrid
vehicle, is also the source of another innovation: The compact module
comprising a 48 V belt starter generator (BSG) and an integrated belt drive is
a prototype solution for integrating a BSG between the internal combustion
engine and transmission. Adding a second coupling in front of the BSG means
that it can be driven by the belt in recuperation phases without the internal
combustion engine having to be dragged along too. Because no drag losses occur,
more power is available for fuel-saving driving strategies.
“The major benefit of BSG
integration between the internal combustion engine and transmission is that
recuperation becomes more efficient as a crucial source of energy for the 48 V
side. Consequently, we estimate that a mild hybrid with a 48 V Eco Drive using
the side-mounted architecture will be capable of saving an additional 5 percent
of CO2," explained José Avila, Head of the Powertrain Division and Member
of Continental's Executive Board.
“To assist customers in
applying the BSG module for side-mounting, we have integrated the belt drive
and the second coupling in a highly compact configuration. For series
production, every millimeter counts," said Prof. Dr. Peter Gutzmer, Chief
Technology Officer and Member of the Executive Board at Schaeffler.
Continental will be launching series
production of the 48 V Eco Drive for several customers in 2016. The initial
applications will involve integrating the BSG in the belt drive on the front
side of the engine. This integration requires extremely minor modification of
the vehicle architecture. In order to be prepared for the next level of 48 V
integration, Continental and Schaeffler have now developed a generic concept,
in the form of the P2-BSG module for side-mounting, which is intended to be
ready for use from around 2020 onward.
and mechanical systems closely interlinked in the module
The 48 V belt starter
generator is the centerpiece of the closely integrated P2-BSG module for
side-mounting, and will enter series production at Continental as early as
2016. In terms of design, the BSG in the new prototype module for side-mounting
is practically identical to the version for integration in the engine belt
drive. In view of the limited space available for belt integration between the
internal combustion engine and the transmission, Schaeffler has integrated the
belt drive, including the tensioner, in the module in a very compact arrangement.
The second coupling between the internal combustion engine and the BSG also
comes from Herzogenaurach. Depending on the application, the accompanying LuK
coupling actuator system can be either electrohydraulic or electromechanical.
In this arrangement, the internal combustion
engine can be disengaged at any time when the coupling between the transmission
and BSG is engaged. During recuperation phases, the work done by friction and
the compressor output of the engine, which would otherwise absorb part of the
kinetic energy from the vehicle's inertia mass, therefore have no effect.
However, if the engine is idle, the full extent of the inertia mass of the
coasting vehicle exerts its forces on the belt drive of the BSG. Braking energy
recuperation is more efficient as a result.
Because a hybrid achieves its
economy partly through the recuperation of kinetic energy during deceleration
and partly due to the fact that the internal combustion engine is switched off
as often as possible, more effective recuperation means that more electrical
energy is also available. More extensive use can be made of intelligent driving
strategies, such as electric torque assistance, supply to electrical consumers
when the engine is idle, and a particularly fast, comfortable engine start.
Source: Continental /