Power Transmission IOE Ppt
Short Description
Transmission system as applied in construction equipment....
Description
POWER TRANSMISSION
The Beginning 2
Driver
Pedal
Driver pushes on Pedal to move vehicle He is more concern about smooth cruising g i.e.. Best output Er. Satya Narayan Shah
12 January 2010
Where Does the Force Come From? 3
Engine g produces p some torque, q , at a speed p
Power- the rate at which work is done: Power
is Force times Velocity (linear)
Power
is Torque q times Rotational Speed p (rotary) ( y)
Power = (Force)(Velocity ) = (F)(V )
Power = (Torque )(RotationalSpeed ) = (T )(ω) Er. Satya Narayan Shah
12 January 2010
Where Does the Force Come From? 4
Power owe iss conserved: co se ved:
Pengine = Ptrans = Paxle = Pvehicle
POWER IS ABSOLUTE
Torque is relative (depends on gear ratio) Ignoring Losses, of Course
Er. Satya Narayan Shah
12 January 2010
WHAT IS POWERTRAIN MATCHING ? 5
Selecting g the right g engine g and gearing g g for a given g application pp Not just performance, but giving the driver the expected response to pedal inputs Transmission shift schedules as fuel economy heavily impacted in automotive applications. Powertrain Matching makes best use of your engine potential Torque & Power shaping can give optimal performance for a given set of gearing Optimal gearing can make your car faster for no changes in engine performance Er. Satya Narayan Shah
12 January 2010
6
Er. Satya Narayan Shah
12 January 2010
DRIVE TRAIN 7
Er. Satya Narayan Shah
12 January 2010
POWER TRAIN SYSTEM
8
Er. Satya Narayan Shah
(1) Front driveshaft (2) Output transfer gearbox (3) Transmission (4) Upper driveshaft (5) Torque converter updrive transfer gears (6) Torque converter (7) Engine (8) Front differential (9) Front final drives (10) Centre bearing (11) Centre driveshaft (12) Rear driveshaft (13) Rear differential (14) Rear final drives
12 January 2010
Clutches Connects /disconnects Engine crankshaft to the transmission (gear box) Change of gears can not be smoothh when h the h engine i iis di directly l connected with the transmission. T Transmits it the th power to t the th road d wheels smoothly
9
Er. Satya Narayan Shah
12 January 2010
Clutches 10
Friction clutches are design to absorb energy during slippage. Virtually all vehicle clutches are springloaded friction disks. disks The torque transmission capacity of a clutch can be estimated as,
Tc = fFc rm ns
where, Tc is the torque capacity, f is the friction coefficient, coefficient Fc is clamping force of clutch, rm is the mean radius of the clutch, and ns is the number of friction surfaces.
Er. Satya Narayan Shah
12 January 2010
11
Er. Satya Narayan Shah
12 January 2010
Clutch should 12
Consume minimum physical effort Be free from slip Wearing surface should have long life Be provided a suitable mechanism for damping of vibration and elimination of noise Main parts of clutch Pressure p plate:- It p presses the driven plate p against g the flywheel Driven plate:- Is provided with annular facings and spring cushioned hub Er. Satya Narayan Shah
12 January 2010
Types of clutch The mostly used clutch is the friction type of following types Cone clutch: is only used in the synchromesh units of gear boxes and sometimes in epicyclical gear boxes p y g Single plate clutch:‐ Mostly used in cars and trucks Multi‐plate clutch:‐ Mostly used in motorcycles, tractors and mostly construction equipment. This type of clutch is mostly mostly construction equipment. This type of clutch is mostly used where high torque to be transmitted and limited space available Centrifugal clutch g Free wheel clutch or one way clutch Band type clutch Overrunning Clutch Overrunning Clutch Electrical clutch Jump Clutch 12 January 2010
Er. Satya Narayan Shah
13
14
Er. Satya Narayan Shah
12 January 2010
15
Er. Satya Narayan Shah
12 January 2010
16
Er. Satya Narayan Shah
12 January 2010
17
Er. Satya Narayan Shah
12 January 2010
18
Er. Satya Narayan Shah
12 January 2010
19
Er. Satya Narayan Shah
12 January 2010
20
Er. Satya Narayan Shah
12 January 2010
21
Er. Satya Narayan Shah
12 January 2010
Hydrodynamics drive system 22
Hydrodynamic drive system includes fluid coupling or Torque converter. This system possesses low pressure and high velocity of hydraulic flow. Fluid coupling: coupling:It is a hydraulic unit that replaces clutch in a semi or fully automatic system and transmits engine torque to transmission system t It consists of driving unit called impeller and driven unit called turbine. Power flows through liquid instead of mechanical device . Maximum efficiency is unity Fluid coupling always slips by about 2 to 4 % when transmitting u load oad full Er. Satya Narayan Shah
12 January 2010
23
Er. Satya Narayan Shah
12 January 2010
24
Er. Satya Narayan Shah
12 January 2010
Advantages of fluid coupling 25
Smoothen transmission of power from engine to transmission Eli i i off clutch Elimination l h plate l Damping of the torsional vibration of the crankshaft During braking or down hill, the transmission shocks are absorbed by the fluid Er. Satya Narayan Shah
12 January 2010
Torque Convertor 26
Er. Satya Narayan Shah
12 January 2010
Torque q Convertor 27
Er. Satya Narayan Shah
12 January 2010
28
Er. Satya Narayan Shah
12 January 2010
29
Er. Satya Narayan Shah
12 January 2010
30
Er. Satya Narayan Shah
12 January 2010
31
Er. Satya Narayan Shah
12 January 2010
Torque converter basic operation 32
Coupling stage:- Turbine is rotating at 90 % of the impeller speed d Fluid from the turbine strikes the convex side of the stator blade causing it to overrun Coupling stage will be high when acceleration is not required and the equipment is cruising At this p point the torque q converter is acting g like a fluid clutch The impeller is rotating at engine speed, the turbine is stationary and the stator is locked against rotation As engine speed increases impeller speed accelerates increasing vertex flow The vertex flow strikes the turbine blades and diverted around the curvature and strikes to the concave side of the stator Er. Satya Narayan Shah
12 January 2010
Advantages of torque converter 33
Torque converter is the fluid clutch used in the automatic transmission of the construction equipment It multiplies the torque Smoothes out the transfer of engine torque to the transmission Acts as cushion between the engine and transmission D Dampens vibrations ib ti Virtually wear free Er. Satya Narayan Shah
12 January 2010
34
Er. Satya Narayan Shah
12 January 2010
Types yp of Transmissions 35
Sliding Gear
Constant-Mesh Co s a Mes
Synchromesh
Powershift
Hydrokinetic H d ki i
Er. Satya Narayan Shah
12 January 2010
Mechanical transmission 36
The engine Th i power is i ttransmitted itt d tto th the wheels h l off equipment through mechanical arrangements. It is achieved by gear mechanisms in manual gearbox Mostly this system is found in vehicles, trucks and light construction equipment
Depending on the no. of gear for forward speeds and reverse gear, power flows takes place in manual transmission system T Types off gear boxe b 1. Sliding mesh type 2. Constant mesh type 3. Synchromesh type Er. Satya Narayan Shah
12 January 2010
Mechanical transmission 37
Sliding mesh type:- is oldest and simplest, meshing of gears takes place by sliding of gears on each other. Consists of main shaft, countershaft and idler gear shaft for reverse speed Constant mesh type yp :- In this g gearbox all the gears g mesh with each other all the time. Gear changing is made easier by helical gear. The primary shaft which carries the clutch is splined p and carries a gear g that mesh with gears g on the layshaft gear Synchromesh gearbox:- Use synchromesh gear devices on the principle of engagement of two matting gears in motion and equalizes their speed with readily and smoothly and the devices used is synchronizer ring. Er. Satya Narayan Shah
12 January 2010
Gear Design g 38
Spur or helical gears are meshed between parallel shafts. Spur gears have teeth that are parallel to the shafts, while helical g gear teeth are angled g with respect p to the shafts. Helical gears continually transfer the load from one gear to the other. Gear teeth typically have a tooth profile that is “involute” (generated by unwrapping a string from a cylinder). Constant involute profiles generate constant angular velocities. Er. Satya Narayan Shah
12 January 2010
39
Er. Satya Narayan Shah
12 January 2010
40
Er. Satya Narayan Shah
12 January 2010
41
Er. Satya Narayan Shah
12 January 2010
42
Er. Satya Narayan Shah
12 January 2010
43
Er. Satya Narayan Shah
12 January 2010
44
Er. Satya Narayan Shah
12 January 2010
45
Er. Satya Narayan Shah
12 January 2010
46
Er. Satya Narayan Shah
12 January 2010
47
Er. Satya Narayan Shah
12 January 2010
48
Er. Satya Narayan Shah
12 January 2010
49
Er. Satya Narayan Shah
12 January 2010
50
Er. Satya Narayan Shah
12 January 2010
51
Er. Satya Narayan Shah
12 January 2010
52
Er. Satya Narayan Shah
12 January 2010
53
Er. Satya Narayan Shah
12 January 2010
54
Er. Satya Narayan Shah
12 January 2010
55
Er. Satya Narayan Shah
12 January 2010
56
Er. Satya Narayan Shah
12 January 2010
57
Er. Satya Narayan Shah
12 January 2010
58
Er. Satya Narayan Shah
12 January 2010
The Planetary Gear combinations provide 5 basic b i operations i 59
Gear Reduction
Overdrive
Position-I Carrier is held; Ring gear-input Position-II Carrier is held; Sun gear-input
Direct Drive
Position-I P i i I Ri Ring gear is i held; h ld Carrier-input C i i Position-II Sun gear is held; Carrier-input
Reverse
Position-I P iti I SSun gear iis held; h ld Ring Ri gear -input i t Position-II Ring gear is held; Sun gear -input
Entire planetary unit works as single unit At a time Two units –input; one out put
Neutral
When no unit is held Er. Satya Narayan Shah
12 January 2010
Powershift Transmissions 60
Can be shifted with virtually no interruption in power. Types of powershift transmissions: a) countershaft, and b) planetary. Hydraulic pressure is utilized to actuate the clutches.
Er. Satya Narayan Shah
12 January 2010
61
Er. Satya Narayan Shah
12 January 2010
62
Er. Satya Narayan Shah
12 January 2010
63
Er. Satya Narayan Shah
12 January 2010
64
Er. Satya Narayan Shah
12 January 2010
65
Er. Satya Narayan Shah
12 January 2010
66
Er. Satya Narayan Shah
12 January 2010
67
Er. Satya Narayan Shah
12 January 2010
Fig. 12.10a Countershaft Powershift Transmission (Hi/Lo / Shift) f 68
Er. Satya Narayan Shah
12 January 2010
Hi/Lo / Powershift 69
When neither clutch is engaged, transmission is in neutral. When left clutch is engaged, output shaft turns slower than input. When right clutch is engaged, output shaft turns the same speed as the input. When both clutches are engaged, transmission is in ‘Park.” Er. Satya Narayan Shah
12 January 2010
Fig. 12.10b Countershaft Powershift Transmission (Reverser) 70
Er. Satya Narayan Shah
12 January 2010
Reverser Powershift 71
When neither Wh i h clutch l h iis engaged, d transmission i i iis in neutral. When left clutch is engaged, engaged output shaft turns opposite direction of the input. When right clutch is engaged, output shaft turns the same direction as the input. When both clutches are engaged, g g transmission is in ‘Park.”
Er. Satya Narayan Shah
12 January 2010
Compound Planetary Transmissions 72
Contains two set of different size planets, one meshing with the sun and the second meshing with the ring g gear. g May also include two sun and/or two ring gears.
Er. Satya Narayan Shah
12 January 2010
Hydrostatic transmission system 73
Basic p power train of hydrostatic y system y Actuator Engine
Hydraulic pump
Control valve
Basic p power flow in hydrostatic y drive system y Like in hydraulic excavator
Er. Satya Narayan Shah
Travel motor
Swing motor
12 January 2010
74
Er. Satya Narayan Shah
12 January 2010
75
Er. Satya Narayan Shah
12 January 2010
76
Er. Satya Narayan Shah
12 January 2010
77
Er. Satya Narayan Shah
12 January 2010
78
Er. Satya Narayan Shah
12 January 2010
79
Er. Satya Narayan Shah
12 January 2010
80
Er. Satya Narayan Shah
12 January 2010
81
Er. Satya Narayan Shah
12 January 2010
82
Er. Satya Narayan Shah
12 January 2010
83
Er. Satya Narayan Shah
12 January 2010
84
Er. Satya Narayan Shah
12 January 2010
85
Er. Satya Narayan Shah
12 January 2010
86
Er. Satya Narayan Shah
12 January 2010
87
Er. Satya Narayan Shah
12 January 2010
88
Er. Satya Narayan Shah
12 January 2010
89
Er. Satya Narayan Shah
12 January 2010
90
Er. Satya Narayan Shah
12 January 2010
91
Er. Satya Narayan Shah
12 January 2010
92
Er. Satya Narayan Shah
12 January 2010
93
Er. Satya Narayan Shah
12 January 2010
94
Er. Satya Narayan Shah
12 January 2010
View more...
Comments
