1. Introduction to Oilgear Pumps
PVWH/W/C, PVM, PVG, PVK, and PVV

2. PVWC

3. PVK
PVK
PVWC

4. PVK
PVM
PVWC

5. PVM
PVK
PVWC
PVV

6. PVM
PVK
PVWC
PVV
PVWH

7. PVM
PVK
PVWC
PVV
PVG

8. PVM
PVK
PVWC
PVG
PVV
PVWH

9. Common Features
There are many similarities in the basic construction of Oilgear’s, PVWH, PVWW, PVG, PVM, and PVWC lines of axial piston pumps.
The use of journal type swashblock bearings
Outboard bearing design
Ease of maintenance
Hardened running surfaces

10. Common Features
Some of the features just mentioned are also carried over into the PVK, and PVV pump lines.
Outboard bearing design
Journal type swashblock bearings
Ease of maintenance

12. Outboard Driveshaft Bearing

13. Outboard Bearing Large Sealed Outboard Shaft Bearing
Enables easy maintenance of shaft, bearing, and shaft seal.
Allows for quick conversions, ie; keyed to splined
Allows for operation on special fluids
The bearing is not subjected to the fluid in the pump.
Capable of being belt driven.

15. Hardened Running Surfaces
Valve Plates - PVWH, PVWC, PVG, and the PVK-140
PVM “A” Frame Port Plates,
Cylinder Barrels - All Pump Lines
Piston Shoes - All Pump Lines (except PVV- 440/540)
Swashblocks - All Pump Lines

16. Hardened PVM Port Plates

18. Pressure Lubricated Swashblock
Provides lubrication to the bearing under load.
Allowing high cycle, high pressure applications.
Provides long life.
Consistent Control Reaction

19. PVK
Pressure Lube Galleries

20. Swashblock Journal (Saddle) Bearing
Oilgear has been using using this style of bearings in pumps since the early 70’s, starting with heavy duty industrial PVL pump line.
Competitors such as Vickers, Sundstrand, Rexroth have only been using this technology for the last decade or so.

21. Swashblock Journal (Saddle) Bearing

23. Hydrodynamic Bearing
Cylinder Barrel is Supported by a Hydrodynamic Bearing
Allows operation special fluids
Provides for an Infinite Bearing Life
Provides a compact design
By reducing the internal driveshaft diameter.
By reducing the mean cylinder barrel diameter.
Eliminates the need for a roller or needle bearing in the valve plate.

25. Hydrodynamic Bearing
The hydrodynamic bearing supports the cylinder barrel.
In any axial piston pump, the cylinder barrel will try to run perpendicular to the face of the swashblock. To prevent this from happening most pump manufacturers support the cylinder barrel with a heavy driveshaft and a bearing in the valve plate.

26. The hydrodynamic bearing prevents the cylinder barrel from becoming perpendicular to the swashblock

27. Hydrodynamic Bearing
Oilgear on the other hand, prevents this from occurring by supporting the cylinder barrel with the hydrodynamic bearing, and a free floating spline arrangement. This allows the cylinder barrel face to run parallel to the valve plate.

28. PVM Cylinder Barrel is supported by the Hydrodynamic Bearing
Reduced mean diameters
Cylinder Barrel is supported by the Hydrodynamic Bearing

31. Full Thru-Shaft Torque
100% thru-shaft torque capability *
Enables multiple pump installations from one drive source.
* Thru-Shaft torque for the PVV series is limited to 150% of the horsepower rating of the prime mover driven pump.

33. Steel Piston Shoes Hardened Steel Piston Shoes
Specially Treated Shoe Faces
Provides More Fluid Retention on the Shoe Face
Hardened Technology
High Degree of Contamination Resistance
Allows Higher Pressure Operation (up to 5000 psi)
Provides Longer Life

34. Specially treated piston shoes faces

35. PVV Piston Shoes
The PVV- 200/250 pumps come standard with steel piston shoes.
The PVV- 440/540 come standard with bronze piston shoes.

37. Replaceable Quiet Port Plates
Allows for operation on low viscosity and special fluids.
Minimizes noise at electric and drive motor speeds.
Allows for easy maintenance
Allows easy conversion from RH to LH rotation or vice versa.

38. PVM
PVV
Port Plates
Port Plates

39. PVM
PVV
Compression slot
Decompression orifice

41. PVK-140
De-compression exhaust
Compression slot
Decompression orifice

45. Pump Selection
Given the number of different pump models to choose from, how do you select what pump to use?

46. Pump Selection Things to look at when selecting a pump are:
Pressure requirements
Flow requirements
RPM requirements
Duty cycle (how often will the pump be required to go on and off stroke)
Response time
Fluid Requirements

47. Pump Selection PVWH - Medium duty applications PVWW - Medium duty
Where fast response times are not required
Medium cycle rates (6 times per minute)
PVWW - Medium duty
Low viscosity and water based fluid applications

48. Pump Selection PVM - Heavy duty applications
High cycle applications
Fast response to small system load changes
PVG - Heavy duty applications
Applications that require very fast response times

49. Pump Selection PVWC - Heavy duty hydrostatic applications
Small displacement
High pressure
High degree of contamination resistance

50. Pump Selection PVK-140 - Heavy duty applications High cycle
Fast response
Industrial or Mobile applications

51. Pump Selection PVK-270/370 Heavy duty industrial applications
High cycle
Fast response
High volume

52. Pump Selection
PVV-200/250 - Heavy duty Mobile or Industrial applications
High Pressure
High Cycle
High volume
Speeds up to 2200 rpm

53. Pump Selection PVV-440/540 Heavy duty Industrial applications
High pressure
High cycle
High volume

54. PVG
PVK
PVM
PVV
PVV

55. PVWC
PVWH/W
PVWH

56. PVWH/W Pump Specifications

59. PVWH Pump Construction
1. Outboard Bearing
2 Saddle
3.Pressure Lube Swashblock
4. Saddle Bearings
5. Hydrodynamic Cylinder Bearing
6. Rotating Group
7. Hardened Quiet Valve Plate 7 6 5 4 3 1 2
PVWH

60. PVWW Pump Construction
1. Outboard Bearing
2 Saddle
3. Swashblock
4. Saddle Bearings
5. Hydrodynamic Cylinder Bearing
6. Rotating Group
7. Hardened Valve Plate 7 6 5 4 3 1 2
PVWW

61. Differences PVWH vs PVWW

62. Saddle Bearings PVWH vs PVWW
The PVWH pump uses a Garfil® Multi-fill 427bearing (shown on the left), the PVWW on the other hand uses a Turcite® bearing (shown on the right)
PVWW
PVWH

63. PVWW Cylinder Barrel
Due to the lack of lubricity of most water based fluids, Kingsbury pads are used to help balance the cylinder barrel to the valve plate. Thus helping to minimize wear.
PVWW Cylinder Barrel
Kingsbury Pads
Kingsbury Pads

64. PVWH Cylinder Barrel
The lack of Kingsbury pads allows PVWH pumps to operate at higher rpm’s. At speeds above 1800 rpm the Kingsbury pads actually cause the cylinder barrel to hydroplane. This causes the cylinder to ride farther off the valve plate increasing case leakage, and reduced output volume.
The arrow indicates the balance area of the cylinder barrel.

65. PVWH
PVWH

66. PVWH Construction Hard-on-Hard Running Surfaces Hardened parts are:
Quiet Valve Plate
Cylinder Barrel
Piston Shoes and Shoe Retainer
Swashblock and Saddle
Control Housing
ISO Contamination Rating of

67. PVWH Construction
Close proximity of the saddle bearings in relation to one another, minimizes swashblock deflection while under high pressure loading.
The saddle bearing design also eliminates trunion bearings and leaky trunion bearing covers.

68. Closeness of the bearings helps minimize swashblock deflection.
Load
Closeness of the bearings helps minimize swashblock deflection.
The forces created by the pistons under load is directly over the saddle bearing.

69. Closeness of the bearings helps minimize swashblock deflection.
The forces created by the pistons under load is directly over the saddle bearing.

70. Closeness of the bearings helps minimize swashblock deflection.
Load
Closeness of the bearings helps minimize swashblock deflection.
The forces created by the pistons under load is directly over the saddle bearing.

71. Closeness of the bearings helps minimize swashblock deflection.
The forces created by the pistons under load is directly over the saddle bearing.

72. Closeness of the bearings helps minimize swashblock deflection.
Load
Closeness of the bearings helps minimize swashblock deflection.
The forces created by the pistons under load is directly over the saddle bearing.

73. PVWC Pump Specifications

75. PVWC Hydrostatic Construction
The same technology that went into the PVM, and PVWH went into building the PVWC hydrostatic. The use of a hydrodynamic cylinder barrel bearing, journal type swashblock bearings, and hardened running surfaces all contribute to make the PVWC a rugged heavy duty hydrostatic. Some of these features are typically found in the larger more expensive transmissions.

77. PVWC Relief Function

78. PVWC Hydrostatic Pump 1. Supercharge Relief Valve
2. Optional Supercharge Pump
.42 in³/rev
3. Optional Implement Relief Valve
4. A & B Port Combination High Pressure Relief Valves and Supercharge Check Valves
5. Optional Tow Valve 5
“A” 3 2
“B” 4 1

79. PVG Pump Specifications

81. PVG Pump Construction
The basic concept of the PVG pump design is very similar to that of the PVWH series, however, internal differences and more modern materials makes the PVG series pump a more robust, and heavy duty pump.

82. PVG Pump Construction 1. Outboard Bearing 2. Guide Plate
3. Pressure Lube Swashblock
4. Hydrodynamic Bearing
5. Rotating Group
6. Hardened Valve Plate 6 5 4 3 2 1

83. PVG PVG The radius for the Saddle Bearing
Note the elimination of the saddle. The bearing journals are machined into the pump housing.
Saddle Bearing
Eliminating the saddle allows room for larger bearings and increased swashblock bearing area.

84. PVM Pump Specifications

86. PVM Pump Construction
It was the dawning of the new millennium, and Oilgear was being driven by the market to develop a more cost effective pump line. Literally starting with many blank pieces of paper, we (representatives from our sales and marketing departments) developed a plan of what we wanted in a new pump design, This plan was in-turn submitted to engineering. Surprisingly very little changes were made to the concept.

87. PVM Pump Construction
We used the tried and true designs of the PVWH, PVWC, and PVG pump, using the strong points of each design as a starting point. Then we added innovations such as, a one piece swashblock journal bearing, constant port location (regardless of rotation), and a simplified meter-out style compensator. The meter-out style compensator makes the pump more responsive to small load changes in the system. The end result is the PVM, “Millennium” pump.

88. PVM Pump Construction 1. Integral Control Piston Housing
2. One Piece Saddle Bearing
3. Replaceable Port Plate
4. Case Purge Port
5. Constant Port Location (regardless of rotation) 4 3 1 2 5

89. PVK Pump Specifications

91. PVK Pump Construction
In the mid 1980’s Oilgear took a radical departure from our typical axial piston pump designs. Instead of orientating the control piston perpendicular to the driveshaft, we opted to develop a pump with the control piston in-line with the driveshaft. By doing so, the valve plate truly became side ported vs top and bottom. This also allowed us to make the controls a modular design by using our standard Hydrostack pilot control modules for various control functions, i.e. load sense, multiple pressure, proportional pressure and soft start.

92. PVK Pump Construction 1. Pressure Lube Swashblock 2. Saddle
3. Maximum Volume Stop
4. Optional Minimum Volume Stop
5. Rotating Group
6. Hardened Valve Plate 3 4 5 6 2 1

93. PVV Pump Specifications

95. PVV Pump Construction
Around the same time we were developing the PVG pump line for the small pump market, be were being pushed for larger and more cost effective pumps in the large displacement, high pressure pump market. That being the case we started development of the PVV series pump. Once again we looked what works in our other pump lines, and incorporated these ideas into the PVV pump, i.e. hydrodynamic cylinder barrel bearings, journal type swashblock bearings, and modular style controls.

96. PVV Pump Construction PVV 1. Control Pistons
2. Pressure Lube Swashblock
3. Swashblock Wear Plate
4. Shoe Hold Down Plate
5. Cylinder Wear Plate
6. Port Plate
7. Rotating Group
8. Hydrodynamic Bearing
PVV 8 7 1 6 3 4 5 2

97. PVV

98. End of Pump Presentation
For more information, please continue to the Controls Presentation