2
PRM
®
INTRODUCTION
The purpose of this manual is to provide use-
ful information for servicing the Hydro-Gear
®
PRM
®
Motor. This manual includes a PRM
general description, technical specifications,
product identification, safety, troubleshooting,
maintenance, and repair procedures.
The PRM Motor normally will not require servic-
ing during the life of the vehicle in which it is in-
stalled. Should other servicing be required, the
PRM Motor will need to be thoroughly cleaned
before beginning most procedures.
Please refer to the instructions titled “How to
Use This Manual” in the Repair Section for an
explanation of the layout of the disassembly and
reassembly portions of this manual.
SECTION 1. DESCRIPTION AND OPERATION
GENERAL DESCRIPTION
The PRM is a fixed displacement axial piston
motor. The motor is designed to convert hy-
draulic power into rotational power at the axle
shaft. It operates at an infinitely variable speed
range between zero and maximum axle speed
determined by motor displacement and maxi-
mum pump flow in both forward and reverse
modes of operation.
The PRM motor is available in four different
displacements that range from 14 to 20 cu. in.
(229 to 327 cc) per revolution.The cylinder
block pistons in the PRM Motor are set at a
fixed displacement by a fixed swash angle that
is integral to the motor housing. Therefore, the
motor is always at maximum displacement. As
pressurized fluid from the pump pushes against
the cylinder block pistons, they are forced to
rotate with the thrust bearing. As the pistons
rotate with the thrust bearing, they create torque
and rotory motion that is transmitted to the axle
shaft. Torque continues to develop as long as
the piston is being pushed out of the cylinder
block. When the piston reaches the end of its
movement out of the cylinder block, it gets
pushed back into the cylinder and fluid inside
the piston is discharged through the low pres-
sure port of the motor. Pistons develop torque
only through half of the cylinder block rotation
cycle. Therefore, multiple pistons are used to
provide a constant and continuous torque to
the motor shaft. Reversing the direction of the
incoming pressurized fluid into the motor re
-
verses the direction of the motor output rotation.
The PRM motor utilizes a friction type brake
controlled by a cam attached to an actuating
arm.
Summary of Contents for HGM-H Series
Page 1: ...BLN 0043 January 2018 HGM H Series Motor Service and Repair Manual ...
Page 25: ...24 HGM H HGM H MOTOR EXPLODED VIEW ...
Page 29: ...HEMTM Series Motor Service and Repair Manual BLN 0083 January 2018 ...
Page 52: ...PRM MOTOR Service and Repair Manual ...
Page 56: ...PRM 3 EXTERNAL FEATURES PRM MOTOR Figure 1 PRM External Features ...
Page 77: ...24 PRM SECTION 8 PARTS LIST Figure 48 MA04K030 ...
Page 81: ...BLN 50231 January 2018 BDP 10L PL Hydrostatic Pump Service and Repair Manual ...
Page 82: ......
Page 83: ......
Page 84: ......
Page 85: ......
Page 86: ......
Page 87: ......
Page 88: ......
Page 89: ......
Page 90: ......
Page 91: ......
Page 92: ......
Page 95: ......
Page 96: ......
Page 97: ......
Page 98: ......
Page 99: ......
Page 100: ...HGM 12P LSHT Wheel Motor Service and Repair Manual BLN 52197 January 2018 ...
Page 102: ...2 Exploded view HGM P ...
Page 117: ...HGM E LSHT Wheel Motor Service and Repair Manual BLN 52198 January 2018 ...
Page 144: ...2 P Series EXTERNAL FEATURES PC SERIES Figure 1 PC Pump with Standard Charge Pump ...
Page 146: ...4 P Series EXTERNAL FEATURES PJ SERIES Figure 3 PJ Pump with Standard Charge Pump ...
Page 147: ...5 P Series Figure 4 PK Pump With Standard Charge Pump EXTERNAL FEATURES PK SERIES ...
Page 176: ...34 PC Series Figure 16 PC Pump BOXES INDICATE ITEMS INCLUDED IN Kit Number ...
Page 192: ...52 PG PE Series Figure 17 PG PE Pump BOXES INDICATE ITEMS INCLUDED IN KITS Kit Number ...
Page 208: ...70 PJ Series Figure 17 PJ Pump BOXES INDICATE ITEMS INCLUDED IN Kit Number ...
Page 224: ...88 PK Series Figure 17 PK Pump BOXES INDICATE ITEMS INCLUDED IN Kit Number ...
Page 240: ...106 PR Series Figure 17 PR Pump BOXES INDICATE ITEMS INCLUDED IN KITS Kit Number ...
Page 261: ...HGM C LSHT Wheel Motor Service and Repair Manual BLN 52690 January 2018 ...