Spare Woodward Governor Parts 

  Woodward XX Herringbone Gear Pump
XX Herringbone Gear PumpXX Herringbone Gear Pump The XX Herringbone Gear Pump is a positive displacement gear pump. Also known as the “Double-X” pump, these pumps consist of two matched herringbone gears in a pump assembly that includes unloader, check, and relief valves. The drive gear is turned by a drive shaft, which is also the shaft of the electric drive motor. The clearances between the gear teeth as they mesh and between the teeth and the pump housing are very small.

The inlet port is connected to the suction line from the sump, and the outlet port is connected to the pressure line which feeds the accumulator and governor distributing valve.

As the teeth pass the inlet port, liquid is trapped between the teeth and the housing. This liquid is carried around the housing to the outlet port. As the teeth mesh again, the liquid between the teeth is pushed into the outlet port. This action produces a positive flow of liquid into the system.

The Herringbone Gear Pump is better than a standard spur gear pump because each set of teeth begins its fluid discharge phase before the previous set of teeth has completed its discharge phase. This overlap (and the relatively larger space at the center of the gears) tend to minimize pulsations and give a steadier flow than the spur gear pump.

XX Herringbone CutawayXX Herringbone Gear Pump Cutaway
The unloader valve (or bypass valve) acts to route the oil back to the sump with minimal backpressure. This allows the motor to start and stop with minimal load. After the motor has started, the bypass closes and forces the oil into the main pressure header. When the pumping cycle is complete, the bypass opens and allows the motor to be stopped without load.
Recommended Maintenance

Severe damage can occur if regular maintenance is not performed. Woodward recommends that the bearings be changed every 5 to 7 years.

XX Herringbone Disassembly for RefurbishingXX Herringbone Disassembly for Refurbishing There are 5 bearings (four gear bearings and a motor bearing) and a number of seals that should be replaced. The bearings must be maximum capacity type. Maximum capacity bearings have more ball bearings to take the high loads and vibrations associated with pumping. If the correct bearings are not used, catastrophic failure can occur within 3 to 4 years.Customers have resisted the 5 to 7 year recommended time frame because the pumps have been running for 15 plus years without problems. These pumps are running on borrowed time.
Minor problems with the gears or case can be repaired with minimal (if any) loss of pumping ability. Major failures will require extensive rework or total replacement. Because of the special nature of these pumps, new, drop-in replacements are not available. Engineered replacements can cost in excess of $75,000 which makes routine maintenance a bargain.
Gear Face DamageGear Face Damage Gear Hot SpotGear Hot Spot Broken Retainer Bolts
Broken Retainer Bolts
Factory Repair Service

Our Training and Repair Facility offers Factory Repair Services for XX Herringbone Gear Pumps.

Factory repairs save you money compared to a service call and allow us to perform additional services that are difficult or impossible to do in the field.

XX Herringbone Gear Pumps are very robust and will last many more years with routine maintenance. In addition to basic pump overhaul services, we offer advanced repair services and have been able to repair some severely damaged pumps that customers thought were beyond saving.

Basic pump overhaul includes:

  • Disassembly, cleaning and inspection of pump and unloader
  • Replacement of pump (4) and motor (1) bearings
  • Inspection and dressing of herringbone gears
  • Installation of new gaskets, seals and O-rings
  • Reassembly and adjustment of end clearance to OEM specs

Advanced repair services include:

  • Side grinding the drive and idler gears to maintain proper centering of the gears when meshed
  • Magnaflux inspection of drive and idler gear journals for cracks
  • Resurfacing of inboard and outboard bearing plates to remove any score marks
Two overhauled 40HP XX Pumps ready to ship

Two overhauled 40HP XX Pumps ready to ship

See our Factory Repair Bulletin below for more information.
Factory Repair Factory Repair Services for Governor Pumps and PMGs

Bulletin FRS – Factory Repair Services.pdf

Our Training and Repair Facility offers repair services for major governor auxiliary systems like XX Herringbone Gear Pumps and Permanent Magnet Generators. Factory repairs save you money compared to a service call and allow us to perform additional services that are difficult or impossible to do in the field.

XX Pump Parts

Woodward produced various sizes of XX Pumps. While the reference numbers are the same, the parts required for XX Pump maintenance are specific for each pump size and motor frame.

Please call or email us for assistance in determining which part numbers are appropriate for your unit.You will need the name plate data from the motor and the number of bolts on the top flanges (4,6, or 8).

XX Motor Data Tag
XX Herringbone Motor Data Tag
XX Herringbone Pump Parts
Reference Number Part Number Description
10001-3 188543
188547
Piston Ring – Small Unloader Assembly
10001-5 191930 Unloader Piston Spring
10001-17 100209 Safety Valve Disc
10001-18 191086 Large Safety Spring
10001-19 191477 Small Safety Spring
10001-24 191554
192022
192023
XX Pump Relief Valve Spring – 200 PSI
Safety Spring
Safety Relief Valve Spring – 300 PSI
10001-25 102029 Safety Disc
10001-29 188498 Piston Ring – Large Unloader Assembly
10001-30 010037 Unloader Piston
10001-31 191107 Unloader Piston Spring
10001-33 100967 Unloader Case/Cartridge
10001-34 100840
100880
100912
Unloader Sleeve
Unloader Sleeve
Unloader Sleeve
10001-36 184572 1/8″ x 1-1/2″ Pin
10001-37 100500
100966
101267
3550-031
Unloader Disc
Unloader Disc
Unloader Disc
Relief Valve Disc
10001-44 206496
206497
Bonnet Gasket (30-100 GPM)
Bonnet Gasket (150-265 GPM)
10001-54 206499
206500
Valve Case Gasket (100 GPM and below)
Valve Case Gasket
10001-64 182011 Oil Seal – Echelon Control
10001-95 182026
182050
182075
182077
182080
206499
Pump Case Seal (30 & 40 GM)
Shaft Seal
Pump Case Seal (150-200 & 250 GPM)
Pump Case Seal (300-400 & 500 GPM)
Pump Shaft Seal (30, 50-75 & 100 GPM)
Valve Case Gasket (100 GPM and below)
10001-98 206485
206486
206488
206489
Case to Plate Gasket (50-100 GPM)
Case to Plate Gasket (150-265 GPM)
Plate to Case Gasket (300-400 GPM)
Case to Plate Gasket (500-600 GPM)
10001-103 180070
180071
180075
180076
180159SPL
180161
180299
Pump Bearing
Pump Bearing – Max. Capacity
Pump Bearing – Max. Capacity
Pump Bearing
Motor Bearing
Bearing
Pump Bearing
10001-104 182250
182251
182252
182253
182670
206222
206224
206226
206228
Case O-Ring
O-Ring Seal
O-Ring Seal
O-Ring Seal
O-Ring Seal
O-Ring Seal
O-Ring Seal
O-Ring Seal
O-Ring Seal
10001-126 182007 Oil Seal – Unloader Switch
10001-147 140354 Strainer Wire Cloth
10001-156 180012
180154
180154SPL
180155
180156
180156SPL
180157
180157SPL
180158
180159
180160
180164
180166
180167
180167SPL
Motor Bearing
Motor Bearing (Frame Size: 326)
Motor Bearing
Motor Bearing (Frame Size: 284Y)
Motor Bearing
Radial Ball Bearing with 2 shields
Motor Bearing
Bearing, Ball – Sealed
Bearing – XX Pump Motor
Motor Bearing
Motor Bearing
Motor Bearing
Motor Bearing (200-250 GPM, 200-300 PSI)
Motor Bearing (75-100 GPM, 200-300 PSI)
Motor Bearing
10001-162 206491 Adapter Plate Gasket
10001-171 206502
206503
206504
Pump Case to Base Gasket (50-100 GPM)
Pump Case to Base Gasket (150-265 GPM)
Pump Case to Base Gasket (300-600 GPM)
10001-172 076020 O-Ring – Drive Shaft
10001-174 1327-204 Filter Element – Disposable
10001-177 182597 O-Ring – Strainer Bottom Cap
10001-178 182381 O-Ring – Acorn Nut
10001-180 Screw 3/8-16 X 1 LG
10001-182 206493

206494

206495

Pilot Valve Case-Pump Case Gasket (50-100 GPM)
Pilot Valve Case-Pump Case Gasket (150-250 GPM)
Pilot Valve Case-Pump Case Gasket (300-600 GPM)
10001-185 1327-146 Filter Element – Disposable
10001-186 1327-805 O-Ring – Marvel Filter