STEAM INLET - University of Idaho
5
188 7.4 STEAM OUT 186 7.3 216 8.5 STEAM INLET MATERIAL ABBREVIATIONS: ALU = ALUMINIUM BRS = BRASS BRZ = BRONZE OR GUNMETAL (BRZ/GM) CI = CAST IRON CU = COPPER GRA = GRAPHITE MS = MILD STEEL/BRIGHT MILD STEEL S/S = SILVER STEEL OR STAINLESS STEEL SPS = SPRING STEEL SYN = SYNTHETIC MATERIAL SUCH AS VETON, NYLON, TEFLON OR RUBBER IN GENERAL SYNTHETIC MATERIALS SOULD BE ABLE TO WITHSTAND THE HEAT AND PRESSURE(S) APPLIED TO THEM. nnn/nnn MEANS THAT EITHER MATERIAL CAN BE USED OTHER ABBREVIATIONS DP = DEEP PF = PRESS FIT PCD = PITCH CIRCLE DIAMETER RM = REAM HEX = HEXACON, 6SIDED CP = COMPRESSED KNL = KNURLED SA-n-xxx = SUB ASSEMBL-n-xxx NOTES: 0. ALL DRAWINGS ARE IN METRIC MEASUREMENTS 1. ALL ENGINEERING PRACTICES SHALL BE APPLIED WITH REGARDS TO HOLE AND SHAFT TOLERANCES. 2. WHERE SCREWS OR BOLTS ARE USED THE CLEARANCE HOLES SHALL BE APPROXIMATELY 5% TO 8% LARGER THAN THE MATCHING TAPPED HOLE. 3. PREFERABLY ALL TAPPED HOLES AND MATCHING SCREWS AND/OR BOLTS TO BE METRIC FINE (MF) 4. MATERIALS SPECIFIED ON THE DRAWINGS ARE INDICATIVE ONLY. THE BUILDER CAN MAKE HIS/HER OWN MATERIAL CHOICE. 5. ALL CONNECTIONS/JOINTS WHICH HAVE STEAM PRESSURE APPLIED TO IT SHALL BE SOLDERED. 6. WHERE PREFERED, SCREW OR BOLTED CONNECTIONS CAN BE OMITTED AND PARTS CAN BE BONDED TOGETHER BY USING EITHER HIGH STRENGHT GLUE, POXY RESIN, OR SOLDER. 7. PARTS WHICH ARE DIRECTLY EXPOSED TO STEAM AND/OR WATER SHOULD BE CONSTRUCTED USING NON-FERROUS OR NON CORROSIVE MATERIAL SUCH AS BRASS, BRONZE, GUNMETAL, STAINLESS STEEL, COPPER OR MONEL. 10. THE ORDER IN WHICH THE PARTS/COMPONENTS ARE MANUFACTURED AND THE MODEL IS ASSEMBLED IS ENTIRELY LEFT TO THE BUILDER/MODELMAKER. 11. ERRORS AND/OR OMISSIONS MAY OCCUR IN THE DRAWINGS, DO NOT HESITATE TO CONTACT ME SO THAT THE ERRORS/OMISSSIONS CAN BE RECTIFIED. J.A.M. DE WAAL PAPAKURA NZ PROJECT No 09E-15-00 PROJECTION A3 Copyright © TITLE DWG SCALE: 1:2 @A3 OR AS SHOWN DRAWING CONTENTS MODEL SCALE: 1:1 J.A.M. DE WAAL. 12 BRIGHTWELL STREET PAPAKURA 2110. NEW ZEALAND. PHONE: OO64 09 2988815. MOB: 0211791000 E-MAIL: [email protected]. JDW DRAUGHTING SERVICES NOTES: LOOSLY BASED ON A GERMAN DESIGNED ENGINE BY GERY POSCH DATE No: VSDASE-01 SHEET: 01 OF 05 AUGUST-2015 GENERAL ARRANGEMENT AND ISOMETRIC VIEWS AND NOTES V-SHAPED DOUBLE ACTING STEAM ENGINE BORE 20mm x STROKE 24mm JDWDS
Transcript of STEAM INLET - University of Idaho
188 7.4
STEAM OUT186
7.3
216 8.5
STEAM INLET
MATERIAL ABBREVIATIONS:ALU = ALUMINIUMBRS = BRASSBRZ = BRONZE OR GUNMETAL (BRZ/GM)CI = CAST IRONCU = COPPERGRA = GRAPHITEMS = MILD STEEL/BRIGHT MILD STEELS/S = SILVER STEEL OR STAINLESS STEELSPS = SPRING STEELSYN = SYNTHETIC MATERIAL SUCH AS VETON, NYLON, TEFLON OR RUBBER
IN GENERAL SYNTHETIC MATERIALS SOULD BE ABLE TO WITHSTAND THE HEAT AND PRESSURE(S) APPLIED TO THEM.
nnn/nnn MEANS THAT EITHER MATERIAL CAN BE USED
OTHER ABBREVIATIONSDP = DEEPPF = PRESS FITPCD = PITCH CIRCLE DIAMETERRM = REAMHEX = HEXACON, 6SIDEDCP = COMPRESSEDKNL = KNURLEDSA-n-xxx = SUB ASSEMBL-n-xxx
NOTES:0. ALL DRAWINGS ARE IN METRIC MEASUREMENTS1. ALL ENGINEERING PRACTICES SHALL BE APPLIED WITH REGARDS TO HOLE AND SHAFT TOLERANCES.2. WHERE SCREWS OR BOLTS ARE USED THE CLEARANCE HOLES SHALL BE APPROXIMATELY 5% TO 8% LARGER THAN THE MATCHING TAPPED HOLE.3. PREFERABLY ALL TAPPED HOLES AND MATCHING SCREWS AND/OR BOLTS TO BE METRIC FINE (MF)4. MATERIALS SPECIFIED ON THE DRAWINGS ARE INDICATIVE ONLY. THE BUILDER CAN MAKE HIS/HER OWN MATERIAL CHOICE.5. ALL CONNECTIONS/JOINTS WHICH HAVE STEAM PRESSURE APPLIED TO IT SHALL BE SOLDERED.6. WHERE PREFERED, SCREW OR BOLTED CONNECTIONS CAN BE OMITTED AND PARTS CAN BE BONDED TOGETHER BY USING EITHER HIGH STRENGHT GLUE, POXY RESIN, OR SOLDER.7. PARTS WHICH ARE DIRECTLY EXPOSED TO STEAM AND/OR WATER SHOULD BE CONSTRUCTED USING NON-FERROUS OR NON CORROSIVE MATERIAL SUCH AS BRASS, BRONZE, GUNMETAL, STAINLESS STEEL, COPPER OR MONEL.10. THE ORDER IN WHICH THE PARTS/COMPONENTS ARE MANUFACTURED AND THE MODEL IS ASSEMBLED IS ENTIRELY LEFT TO THE BUILDER/MODELMAKER.11. ERRORS AND/OR OMISSIONS MAY OCCUR IN THE DRAWINGS, DO NOT HESITATE TO CONTACT ME SO THAT THE ERRORS/OMISSSIONS CAN BE RECTIFIED.
J.A.M. DE WAAL PAPAKURA NZ
PROJECT No 09E-15-00 PROJECTION
A3Copyright ©
TITLE
DWG SCALE: 1:2 @A3 OR AS SHOWNDRAWING CONTENTS MODEL SCALE: 1:1
J.A.M. DE WAAL. 12 BRIGHTWELL STREET PAPAKURA 2110. NEW ZEALAND. PHONE: OO64 09 2988815. MOB: 0211791000 E-MAIL: [email protected].
JDW DRAUGHTING SERVICES
NOTES: LOOSLY BASED ON A GERMAN DESIGNED ENGINE BY GERY POSCH
DATE
No: VSDASE-01SHEET: 01 OF 05 AUGUST-2015GENERAL ARRANGEMENT AND
ISOMETRIC VIEWS AND NOTESV-SHAPED DOUBLE ACTING STEAM ENGINEBORE 20mm x STROKE 24mm
JDWDS
ALU/MS
14
14
32
32
26
26
40
40
10 10 45 59
67 53 R8
38 21 43.5 26.5 31
20 10 10
11
7 4PL
4
6PL
8 16
8
M6
C'BORE 6 HOLES 9x8DEEP SCALE 1:1.5
ALU or MSBRZ
10RM 12PF
10 10 16 16
R6
R4
R6 R4
22 22 14 14
22
6 2
15
5 5 2
M4
R0.5
BRS
45°
46.8
3
24
8
10 10
R40
16 16
10 10
8
6 46.8
4 4PL
8
FOLD LINE
FLAT PATTERNSCALE 1:2
BRS
45° 45°
99.8
3
24 24
R40 R40
10 10
16
16 9
14
45°
45°
4 8PL 3 3 49.9 49.9
62.7 62.7
54.7 54.7
21 21 40 40
FLAT PATTERNSCALE 1:2
BRZALU/BRS
10 10
22
6
28
9
9
M4x7.5DP 4PL
3x4DP
3x11DP R2
4
16 16
16
16
M3x6DP
20
RM
21.5PF
26PC
D
1.5mm DP
3 TAPPED HOLES EQUALLY SPACED ON PCD
OPPOSITE FACE EQUAL
10 10
8
24
40 M4x8.5DP
OPPOSITE FACE EQUAL
ALU/BRS
32
30°
3
4 30°
26
PCD AA
1.5mm DP TAKE OVER FROM 1-05
9 20 1
.5
3 3
16 45°
5 1
SECTION A-A
BRZSYNALU/BRS
30° 30°
32
3
4
26
PCD BB
1.5mm DP TAKE OVER FROM 1-05
6RM 8PF 1
.5
3
10
2.5
SECTION B-B
SEAL
BRS
32
16
22
45 3
8 22.5 9.5
7 R3.5
43
6R
M
8PF
C
C
3
30°
6
6
6
26PCD
SECTION C-C
TAKE OVER FROM 1-06
20
15
15
16
3 3
3x10DP
3x12DP
SLOT3mm DP
M4
4
M4
12
9
9
20
8mmDEEP
HIDDEN LINES REMOVED FOR CLARITY
9
9
20
M4
M4
4
12
8mmDEEP
8mmDEEP
16mmDEEP
45°
4
4 45°
6
28
6
9
12
9
5
4 4PL
2
2
DRILL THRU
3x10DP SLOT
3mm DP
10RM 12PF
16 16
12
12
20
ALU/BRSBRZ
ALU/BRS
20 6 6
6
28
6
4 4PL
1mm CHAMFER4mm THICKSCALE 1:1.5
BRS
10
1.5
4
R5 6
6 8
8
8
R4 10
9 9
12
4 4
M5
8
30
6
M8 10
SCALE 1:1.5
S/S
BRS
16
8
8
20 32
12 3
3
3mm THICK SCALE 1:1.5
BRS
M5
2
45°
12
10
14 19
BRS
M6
12 1
5
.5 5.5
4
M4
8
8
20
28
4
6
6
8
8
M6
6
R3
50
MS
1-01
1-02
1-03
1-04
1-05
1-06
1-07
1-08
1-10
1-11
1-131-15
1-16
1-17
1-18
QTY. PART NUMBER1 VSDASE-1-01-BASE PLATE3 VSDASE-1-02-MAIN BEARING2 VSDASE-1-03-CYLIDER HOLDER1 VSDASE-1-04-CYLINDER TOP HOLDER2 VSDASE-1-05-CYLINDER2 VSDASE-1-06-CYLINDER TOP COVER2 VSDASE-1-07-CYLINDER BOTTOM COVER2 VSDASE-1-08-CROSS HEAD GUIDE2 VSDASE-1-09-PORT BLOCK2 VSDASE-1-10-PORT BLOCK COVER4 VSDASE-1-11-PORT BLOCK INLET PIPE CONNECTOR1 VSDASE-1-12-REVERSING HOUSING BLOCK1 VSDASE-1-13-REVRSING HOUSING BLOCK STEM1 VSDASE-1-14-REVERSER VALVE1 VSDASE-1-15-REVERSER BLOCK BOTTOM COVER1 VSDASE-1-16-REVERSER HOLDING DOWN DOME1 VSDASE-1-17-REVERSER OPERATOR COLLAR1 VSDASE-1-18-REVERSER OPERATOR COLLAR HANDLE4 VSDASE-1-19-REVERSER PIPE CONNECTOR TYPE-12 VSDASE-1-20-REVERSER PIPE CONNECTOR TYPE-21 VSDASE-1-21-OILER CONTAINER1 VSDASE-1-22-OILER BOTTOM VALVE SPINDLE BODY1 VSDASE-1-23-OILER BOTTOM VALVE SPINDLE1 VSDASE-1-24-OILER BOTTOM VALVE SPINDLE NUT1 VSDASE-1-25-OILER TOP BODY1 VSDASE-1-26-OILER FILLER SCREW1 VSDASE-1-27-TOP VALVE BODY1 VSDASE-1-28-OILER TOP VALVE SPINDLE NUT1 VSDASE-1-29-OILER TOP VALVE SPINDLE2 VSDASE-1-30-OILER SPINDLES HAND WHEEL1 VSDASE-1-31-OILER CONNECTOR NIPPLE1 VSDASE-1-32-OILER CONNECTOR BUSH1 VSDASE-1-33-OILER CONNECTOR NUT1 VSDASE-1-34-OILER INLET CONNECTOR NIPPLE2 VSDASE-1-35-OILER INLET PIPE1 VSDASE-1-36-OILER INLET CONNECTOR NUT1 VSDASE-1-37-PORT BLOCK STEAM INLET PIPE1 VSDASE-1-37-PORT BLOCK STEAM INLET PIPE1 VSDASE-1-38-PORT BLOCK STEAM OUTLET PIPE1 VSDASE-1-38-PORT BLOCK STEAM OUTLET PIPE1 VSDASE-1-39-WOODEN BASE BLOCK1 VSDASE-2-01-CRANK SHAFT PART-11 VSDASE-2-02-CRANK SHAFT PART-2 VSDASE-2-03-CRANK CHEEK1 VSDASE-2-04-CRANK PIN1 VSDASE-2-05-FLYWHEEL1 VSDASE-2-06-ECCENTRIC SHEAVE1 VSDASE-2-07-ECCENTRIC SHEAVE COVER2 VSDASE-2-08-PISTON2 VSDASE-2-09-PISTON ROD2 VSDASE-2-10-CROSSHEAD2 VSDASE-2-11-CROSSHEAD WRIST PIN2 VSDASE-2-12-CON ROD BIG END2 VSDASE-2-13-CON ROD2 VSDASE-2-14-SLIDE VALVE2 VSDASE-2-15-VALVE SCREW PIN2 VSDASE-2-16-ECCENTRIC STRAP2 VSDASE-2-17-ECCENTRIC STRAP CON ROD2 VSDASE-2-18-ECCENTRIC STRAP SCREW NUT7 VSDASE-M3x818 VSDASE-M3x102 VSDASE-M3x10 C-SINK SCREW4 VSDASE-M3x128 VSDASE-M4 DOME NUT2 VSDASE-M4 NUT1 VSDASE-M4x7 GRUB SREW28 VSDASE-M4x101 VSDASE-M4x126 VSDASE-M4x208 VSDASE-M4x35 STUD1 VSDASE-M5 DOME NUT1 VSDASE-M5x20 GRUB SREW2 VSDASE-M6x154 VSDASE-M7x30WOOD SCREW
J.A.M. DE WAAL PAPAKURA NZ
PROJECT No 09E-15-00 PROJECTION
A3Copyright ©
TITLE
DWG SCALE: 1:1 @A3 OR AS SHOWNDRAWING CONTENTS MODEL SCALE: 1:1
J.A.M. DE WAAL. 12 BRIGHTWELL STREET PAPAKURA 2110. NEW ZEALAND. PHONE: OO64 09 2988815. MOB: 0211791000 E-MAIL: [email protected].
JDW DRAUGHTING SERVICES
NOTES: LOOSLY BASED ON A GERMAN DESIGNED ENGINE BY GERY POSCH
DATE
No: VSDASE-02SHEET: 02 OF 05 AUGUST-2015BILL OF MATERIALS, PARTS
AND ASSEMBLIESV-SHAPED DOUBLE ACTING STEAM ENGINEBORE 20mm x STROKE 24mm
JDWDS
BRS
BRS
3
10 10
4x13DP
13 13
10
10
AA
DRILL 13 DEEPTAP 10 DEEP
DRILL 26 DEEPTAP 10 DEEP
FACE-A
SECTION A-AFACE-A
FACE
-B
FACE-C
FACE
-D 13
13
26
26
13 13 26 26
4x6.5DP 4PL
44x6mm DEEP
M8x6.5DP
9 9 4 4 9 9
10
26
4x18DP 4x18DP M3x8DP
FACE-D
12
13
26
7
M3x10DP M3x10DP
5
8 8 21 21
4x9DP 4PL
SLOT 3.5mm DEEP
20 10
12
8
44
2
2
45°
4
45°
R11 R
15
10
26
PCD 4
BRS
6 10
10 1.5
3 5 1
4
R13 3 3
9 9
7
7
60°
5 12
1.5
3 8
.5
M12
2.6
13 13
R22
8
8
4 4
BRS
24
28
8.5
BB
32
4
12
9
3 8
4 6
14
46
45° 8
16
3
3.5
SECTION B-B
SYNBRS
8 10
M10
12H
EX
1.5
3
M10
M6
8
12
SEAL
S/S
3
2 1
1
8
1
9 30
0.7 M6 4 6 M
4
4
M10
8 3
12H
EX
BRS
14 30
M10
M10
9
9
24 R4
16
16
EE
M3
10
6
10 8
M12 14 M12
14 10
4
12
6
2
6
6
6
SECTION E-E
SYNBRS
4
2
3
8
M12
10 2
16
2
SEAL
BRS
SYN
M10 12HEX
3
19
8
4 M6
6
M12
10
2
SEAL
BRS
REFER TO 1-24
S/S
M4
6 30
M6
7.2 10
45°
4
BRS
6
M4
8
24 KNL
SYNBRS
18 4 8
6
10
12H
EX
1.5 O-RING SEAL
BRS
5
6
10
8
10 2 4
60°
10
BRSSYN
M12
16H
EX
8
1
8
11
SEAL
SYN
BRS
5
M10
12H
EX
8 4 8
6
M10
11 O-RING SEAL
CU
30
4.5
6
BRSSYN
6
8 11
M10
14H
EX
1 SEAL
CU
41
TUBE 6x4.5SCALE 1:1.5
45°
R5
14.9 16
.3
1-37B
MIRROR OF 1-37A
CU
67
TUBE 6x4.5
SCALE 1:1.5
1-38A
CU
R5 42.7
33
45°
1-38B
MIRROR OF 1-38A
CU
TIMBER
140
100
18 104
18
64
25mm THICK SCALE 1:2
5mm CHAMFER
2mm PILOT HOLES
S/S
70 10PF
SCALE 1:1.5
S/S
45
10
SCALE 1:1.5
MS
50
10PF
12
24
8 SCALE 1:1.5
12
1
S/S
42
8P
F
MS
45°
M5
14
33PCD
45°
F
F
SCALE 1:2
1
16
10
50
58
5 5
=20=
9 9
SECTION F-FSCALE 1 : 2
2.5 6 6 1.5
10
SCALE 1:1.5
MS
11.5 11.5
M4
10 18
34
30
M3 2
.5
18 34
11.5 11.5 2
.5
3
C'SINK
1.5 mm THICKSCALE 1:1.5
GRA/BRZ/CISYN
20
M
4
4 4 10
17
20.2
S/S
M4
M4
13 37.1 5
6
SCALE 1:1.5 2-09
M4
6 6
16
SCALE 1:1.5
BRZ
M3
4 1
0 5
6
S/S
4 8
M3
4 1
0.8 M4
4 3 10
S/S
BRS
5
6
M4
4
7HE
X
6
NOTE: FACE-A AND FACE-C ARE EQUAL FACE-B AND FACE-D ARE EQUAL
1-12
1-14
1-19
1-21
1-22
1-23
1-24
1-25
1-26
1-27
1-28
1-29
1-30
1-31
1-32
1-33
1-34
1-35
1-36
1-37A
1-39
2-01
2-02
2-032-04
2-05
2-06
2-07
2-09
2-10
2-10 2-11
2-18
J.A.M. DE WAAL PAPAKURA NZ
PROJECT No 09E-15-00 PROJECTION
A3Copyright ©
TITLE
DWG SCALE: 1:1 @A3 OR AS SHOWNDRAWING CONTENTS MODEL SCALE: 1:1
J.A.M. DE WAAL. 12 BRIGHTWELL STREET PAPAKURA 2110. NEW ZEALAND. PHONE: OO64 09 2988815. MOB: 0211791000 E-MAIL: [email protected].
JDW DRAUGHTING SERVICES
NOTES: LOOSLY BASED ON A GERMAN DESIGNED ENGINE BY GERY POSCH
DATE
No: VSDASE-03SHEET: 03 OF 05 AUGUST-2015PARTS AND ASSEMBLIESV-SHAPED DOUBLE ACTING STEAM ENGINE
BORE 20mm x STROKE 24mmJDWDS
MS
MS
BRZ
5 5
R4 R4
17
7
12
7 7 9.5 9.5
7
8 13
3 3
M3M3
3.5 3.5
0.5
11.5
45°
3
8
M4 7.25
2
2
30° 30°
8RM 10PF
REAM AFTER ASSEMBLY
M4 8
7
34
5
4RM 5.5PF
4 4
4.6
4
R1
BRZ
MS 4
S/S
M4
4
4
10
9
4.5
21.7
3
11 9
.5
11.5 3
7
8
4 4 3
3
3
45°
30RM 33PF 40
41
SCALE 1:1.5
2-16
2-16
BRZ
MS
6
2 4 8.5
R2 12
M4
DRILL THIS HOLE AFTER ASSEMBLY
BRZ
MS
4RM
6.5
R9
38.5
18
M4
5
1
3
8
6.5
5PF
9
1-39
1-01
1-02
1-02
1-02
1-03
1-03
1-04SA-1-102
SA-1-103
SA-1-101
1-10
1-091-05
1-06
1-07
1-08
1-11
1-11
SA-1-102
1-10
1-091-05
1-06
1-07
1-08
1-11
1-11
SA-1-103
1-18
1-17
1-16
1-14
1-20
1-20
1-19 1-19
1-191-19
1-15
1-131-12
SA-1-104
1-30
1-29
1-28
1-271-26
1-251-34
1-35
1-36
1-301-24
1-231-22 1-35
1-21
SA-1-105
1-311-33
1-32
SA-1-106
SA-1-104SA-1-105
SA-1-107
SA-1-101
SA-1-106
1-38
1-381-371-37
SA-2-201
2-07
2-06
2-02
2-03
2-032-04
2-01
2-05
2-08 2-09
2-10 2-11SA-2-202
2-13
2-12
SA-2-203
2-17
2-18
2-16
SA-2-204
SA-2-205
SA-1-107
SA-2-203SA-2-203
SA-2-201
2-152-15
2-142-14
SA-2-205
SA-1-107
SA-2-204SA-2-204
16 11 89
APPROX 20°
THIS ANGLE TO BE DETERMINED BY BUILDER
2-12
2-13
2-14
2-17
J.A.M. DE WAAL PAPAKURA NZ
PROJECT No 09E-15-00 PROJECTION
A3Copyright ©
TITLE
DWG SCALE: 1:1 @A3 OR AS SHOWNDRAWING CONTENTS MODEL SCALE: 1:1
J.A.M. DE WAAL. 12 BRIGHTWELL STREET PAPAKURA 2110. NEW ZEALAND. PHONE: OO64 09 2988815. MOB: 0211791000 E-MAIL: [email protected].
JDW DRAUGHTING SERVICES
NOTES: LOOSLY BASED ON A GERMAN DESIGNED ENGINE BY GERY POSCH
DATE
No: VSDASE-04SHEET: 04 OF 05 AUGUST-2015PARTS AND ASSEMBLIESV-SHAPED DOUBLE ACTING STEAM ENGINE
BORE 20mm x STROKE 24mmJDWDS
J.A.M. DE WAAL PAPAKURA NZ
PROJECT No 09E-15-00 PROJECTION
A3Copyright ©
TITLE
DWG SCALE: 1:1 @A3 OR AS SHOWNDRAWING CONTENTS MODEL SCALE: 1:1
J.A.M. DE WAAL. 12 BRIGHTWELL STREET PAPAKURA 2110. NEW ZEALAND. PHONE: OO64 09 2988815. MOB: 0211791000 E-MAIL: [email protected].
JDW DRAUGHTING SERVICES
NOTES: LOOSLY BASED ON A GERMAN DESIGNED ENGINE BY GERY POSCH
DATE
No: VSDASE-05SHEET: 04 OF 05 AUGUST-2015RENDERED PICTUREV-SHAPED DOUBLE ACTING STEAM ENGINE
BORE 20mm x STROKE 24mmJDWDS
