The document discusses camless engines, which eliminate mechanical linkages between the camshaft and valves. This allows for infinite variability of valve timing, lift, and duration compared to conventional engines with fixed cam profiles. Camless engines use electro-hydraulic actuators incorporating a hydraulic pendulum mechanism to independently control each valve with a hydraulic fluid-based liquid spring. The electronic control unit processes sensor inputs to command the actuators and optimize performance for factors like fuel efficiency and emissions. While more sophisticated than conventional engines, camless engines are expected to provide benefits like improved fuel economy and power.

1. CAMLESS ENGINES
BY
ARVIND KUMAR
RAJPUT

2. Introduction
 CAMS
 Control the breathing channels (valves) of an IC
engine
 Connected to camshaft which is operated by
crankshaft
 Cams push open valves at proper time & guide
their closure
 But they are inflexible except VTEC & VVT-I
 Engineers could not vary timing, lift & duration of
valve opening infinitely

3.  CAMLESS ENGINES
 Eliminated mechanical linkages
 Could provide infinite variation of valve
parameters
 It can make engines clean, efficient &
responsive

4. Working of conventional
engines
 The crankshaft turns camshaft which
operates valves by mechanism as in figure
 Spring brings back valve to initial position
 Timing of engine valves depends on shape
of cams

5. Conventional engine valves

6.  Engineers must design cams in the
development stages
 This design compromises b/n engine power
& fuel efficiency
 Considering this compromise automobile
companies brought variable valve timing
mechanisms
 But is effects were limited

7. Camless engines overview
 Main sensors -
Engine load sensor Exhaust gas sensor
Valve position sensor Engine speed sensor
ELECTRONIC
CONTROL
SENSORS ACTUATORS
UNIT

8.  Sensors sense parameters & send signals to
ECU
 ECU contains microprocessors with
associated software
 This ECU controls the actuators to work
according to requirements

9. Actuators
 It is a electro-hydraulic camless valve train
(ECV)
 Uses elastic property of compressed
hydraulic fluid which acts like a liquid
spring, accelerates & decelerates the valves

10. 
Hydraulic pendulum
 Involves conversion of PE to KE and back
to PE with minimum energy loss
 During acceleration of valves PE is
converted to KE
 During deceleration of valve energy of
moving valve is returned to fluid

11. Detailed view of Hydraulic
Pendulum

12. Operation of hydraulic
pendulum

15.  Lift, timing & duration of valve opening is
varied by controlling solenoid valves
 This is done by ECU when signals are sent
from the sensors

16. Modifier Rod
 Used to impart
 Unequal lift to the
paired valves
 Zero motion to any
valve

17. Modifier Rod Operation

19. Advantages
 Offers continuously variable & independent
control of all aspects of valve motion - lift,
operation duration, event of opening
 ECV system can control valve velocity,
valve acceleration and deceleration

20. Resultant Advantages
 Better fuel economy- 7 to 10 % increase
 Higher torque & power- 10 to 15 %
increase
 Lower exhaust emissions- EGR system is
eliminated since EGR effect occurs on its
own & thus reduces NOx emissions
 Reduction in size & weight

21. Disadvantages
 Opening & closing of valves requires some power-
Electromechanical- alternator
Electrohydraulic- accumulator

Sophisticated electronic control required for
gentle seating of valves

Current solenoids cannot run at high rpms;

Hidden cost of microprocessor & software
controls

22. Conclusion
Even though some disadvantages are
present, we can expect electrohydraulic &
electromechanical valves to replace the
conventional camshaft technology.

23. Thanks