Comparison of energy consumption and power losses of a conventionally controlled CVT with a Servo-Hydraulic Controlled CVT and with a belt and chain as the Torque Transmitting Element

Siddharth Shastri, Andrew A FrankUC Davis HEV Center

04CVT55

Conventional CVT Control

Conventional CVT

Engine driven hydraulic controller Mechanically and electrically

complex High pressure bleed off – energy

intensive Control Vs Efficiency Idle stop systems?

Servo Hydraulic Control

Servo Hydraulic Control

Electro hydraulic system Pressure on demand Power consumption Idle Stop 42-300V Hybrid Applications

UC Davis SHC CVT Setup

INPUT

OUTPUT

M

CLAMPINGB40A8

M

RATIOB40A8

PRI

SEC

FORWARDCLUTCH

REVCLUTCH

M

TORQCONVERTERDC MOTOR

TORQUE CONVERTER

M

LUBE

P

P

P P

P

S

S

T

T

ClutchPressure

RatioPressure

ClampingPressure

TorqueConverterPressure

Sump

LubePressure

Servopump

Testing

Loaded and unloaded tests Characterize each system Energy and Efficiency mapping

Test Setup

DYNO PAD

CVTSYSTEM

DYNOABSORBER /

BRAKE

TORQUETRANSDUCER

ELECTRICMOTOR

TORQUE LOADCELL

Unloaded Tests

Ratio 2.3 1.5 1 0.7 0.4

Speed (RPM) 1000 2000 3000 4000  

Pressure (psi) 100 200 300 400  

Optimal operating region

Stock - Torque Vs Speed @ 300psi

0

5

10

15

20

25

30

0 500 1000 1500 2000 2500 3000 3500 4000 4500

Speed (RPM)

To

rqu

e (N

m)

Ratio 2.3 Ratio 1.5 Ratio 1.0 Ratio 0.7

Belt SHC - Torque Vs RPM @ 300psi

0

2

4

6

8

10

12

14

16

18

20

0 500 1000 1500 2000 2500 3000 3500 4000 4500

Speed (RPM)

To

rqu

e (N

m)

Ratio 2.3 Ratio 1.5 Ratio 1.0 Ratio 0.7

Stock & SHC Belt - Torque Vs Ratio @ 2000 RPM

0

5

10

15

20

25

30

35

40

45

00.511.522.5

Ratio

To

rqu

e (N

m)

Stock 200psi Stock 400psi SHC Belt 200psi SHC Belt 400psi

Belt Design

Clamping Pressure

Stock - Torque Vs Clamping Pressure @ 2000 RPM

0

5

10

15

20

25

30

35

40

45

0 50 100 150 200 250 300 350 400 450

Clamping Pressure (psi)

To

rqu

e (N

m)

Ratio 2.3 Ratio 1.5 Ratio 1.0 Ratio 0.7 Ratio 0.4

Belt SHC - Torque Vs Clamping Pressure @ 2000RPM

0

2

4

6

8

10

12

14

16

18

20

0 50 100 150 200 250 300 350 400 450

Clamping Pressure (psi)

To

rqu

e (N

m)

Ratio 2.3 Ratio 1.5 Ratio 1.0 Ratio 0.7

Power Consumption

Servo Hydraulic Control System Versus Stock CVT (Ratio 2.3)

0

2000

4000

6000

8000

10000

12000

1000 2000 3000 4000

Rpm

Po

wer

(W

atts

)

100psi SHC 400psi SHC 100psi Stock 400psi Stock

SHC 100 psi

SHC 400 psi

Stock 400 psi

Stock 100 psi

Test has been done on UC

Davis FacilitiesServo Hydraulic Control System Versus Stock CVT (Ratio 1)

0

2000

4000

6000

8000

10000

12000

1000 2000 3000 4000

Rpm

Po

wer

(W

atts

)

100 psi SHC 400 psi SHC 100 psi Stock 400 psi Stock

Testing has been done on UC

Davis Facilities

SHC 100 psi

SHC 400 psi

Stock 100 psi

Stock 400 psi

Power Flow and Losses

CVT

AC150

Losses

Electrical

Mechanical

42V

12V

Clamp RatioTorque

Converter

Controls

Sensors

Friction Belt

Power Input

Power Output

Data

Flow Diagram

Power Consumption of SHC Vs Stock

0

500

1000

1500

2000

2500

2.3 1.5 1 0.7

Ratio

Po

we

r (W

atts

)

Stock Pump Power 42V

Power consumption of SHC Vs Stock 3000RPM and 100psi

Loaded Tests

  Torque input (Nm)

   (psi) 10 50 100 150 200

Ratio

2.326 22 110 220 330 440

1.5 15 75 150 224 299

1 11 54 107 161 214

0.7 9 46 92 137 183

0.434 8 39 78 117 156

Efficiency

Stock 100Nm Efficiency Vs Speed at different Ratios

77

78

79

80

81

82

83

84

85

86

87

0 500 1000 1500 2000 2500 3000 3500 4000 4500

RPM

Eff

icie

ncy

Stock 100Nm - 2.3 Stock 100Nm - 1.5 Stock 100Nm - 1.0 Stock 100Nm - 0.7 Stock 100Nm - 0.4

Belt SHC - 100Nm Efficiency Vs Speed at different Ratios

74

76

78

80

82

84

86

88

90

0 500 1000 1500 2000 2500 3000 3500 4000 4500

RPM

Eff

icie

ncy

Belt 100Nm - 2.3 Belt 100Nm - 1.5 Belt 100Nm - 1.0 Belt 100Nm - 0.7 Belt 100Nm - 0.4

Chain Vs Belt - Unloaded

SHC - Chain & Belt - Torque Vs Speed

0

2

4

6

8

10

12

14

16

18

20

0 500 1000 1500 2000 2500 3000 3500 4000 4500

Speed (RPM)

To

rqu

e (N

m)

Chain 1.5 Chain 1.0 Chain 0.7 Belt 1.5 Belt 1.0 Belt 0.7 Stock 1.5 Stock 1.0 Stock 0.7

Chain SHC - Torque Vs RPM @ 200psi

0

2

4

6

8

10

12

14

0 500 1000 1500 2000 2500 3000 3500 4000 4500

RPM

To

rqu

e (N

m)

Ratio 2.3 Ratio 1.5 Ratio 1.0 Ratio 0.7 Ratio 0.4

Chain, Belt & Stock - Torque Vs Ratio @ 2000RPM

0

5

10

15

20

25

00.511.522.5

Ratio

To

rqu

e (N

m)

Chain 200psi Belt 200psi Stock 200psi

Chain Design

Loaded Tests

SHC Chain - Efficiency Vs Speed

75

76

77

78

79

80

81

82

83

84

85

86

0 500 1000 1500 2000 2500 3000 3500 4000 4500

RPM

Eff

icie

ncy

50Nm - 2.3 50Nm - 1.5 50Nm - 1.0 50Nm - 0.7 50Nm - 0.4

Chain SHC - 100Nm - Efficiency Vs Speed

76

78

80

82

84

86

88

90

92

0 500 1000 1500 2000 2500 3000 3500 4000 4500

RPM

Eff

icie

ncy

100Nm - 2.3 100Nm - 1.5 100Nm - 1.0 100Nm - 0.7 100Nm - 0.4

Chain SHC - 200Nm - Efficiency Vs Speed

86

87

88

89

90

91

92

93

94

95

96

0 500 1000 1500 2000 2500 3000 3500 4000 4500

RPM

Eff

icie

ncy

200Nm - 2.3 200Nm - 1.5 200Nm - 1.0 200Nm - 0.7 200Nm - 0.4

Chain Vs Belt Vs Stock at 100Nm - Efficiency Vs Speed

76

78

80

82

84

86

88

90

92

0 500 1000 1500 2000 2500 3000 3500 4000 4500

RPM

Eff

icie

ncy

Chain 100Nm - 1.5 Chain 100Nm - 1.0 Chain 100Nm - 0.7 Belt 100Nm - 1.5 Belt 100Nm - 1.0

Belt 100Nm - 0.7 Stock 100Nm - 1.5 Stock 100Nm - 1.0 Stock 100Nm - 0.7

SHC - Chain Vs Belt - Efficiency Vs Load @ Ratio 1.0

78

80

82

84

86

88

90

92

94

96

0 50 100 150 200 250

Load (Nm)

Eff

icie

ncy

1.0 - 1000 1.0 - 2000 1.0 - 3000 1.0 - 4000 1.0 - 1000 - Belt

1.0 - 2000 Belt 1.0 - 1000 Stock 1.0 - 2000 Stock

Conclusions Stock CVT 89.5% efficient SHC system is 50% more efficient The VDT Belt

Optimum at Ratio 1.0 2000 – 3000 RPM Energy intensive below Ratio 1.0

GCI Chain Ratio 1.5 3000 RPM Linear with respect ratio change Exhibits about ½ the internal losses of the belt at 1:1 -

lesser at overdrive

SHC CVT with GCI Chain 94.97% 3% more than SHC CVT with Belt 5.56% more than Stock CVT