Highland Hydraulics Hydrostatic Transmissions

Hydrostatic Transmissions

Hydrostatic transmissions consist of a hydraulic pump and motor, typically used as the main drive system on modern industrial equipment. Axial piston variable displacement pumps are of swashplate construction with variable flow capability, suitable for hydrostatic transmissions with a closed loop circuit. The flow is proportional to the pump's driven speed and displacement, which is in turn determined by the swashplate angle, the latter being infinitely adjustable between zero and maximum. Flow direction is reversed by tilting the swashplate in the opposite direction to the neutral or zero position. Axial piston fixed displacement motors are of swashplate construction with preset displacement, and are intended for closed circuit too. The output speed is proportional to the flow rate of the input fluid and the output torque is proportional to the differential between high and low pressures of the fluid circuit. The direction of motor shaft rotation depends upon which port fluid enters the motor.
POWER SYSTEM FOR HEAVY DUTY APPLICATIONS
Series 20 This heavy duty family offers: - 7 sizes of pump and motor - a wide range of mechanical, hydraulic and electrical control

Series 20 - Closed circuit
Sizes GR / MK	HYDRAULIC PISTON PUMPS					HYDRAULIC PISTON MOTORS
Sizes GR / MK	Displacement {ccm/rev}	Nominal pressure {MPa}	Max. speed {Rpm}	Power Pe {kW}	Weight {kg}	Displacement {ccm/rev}	Nominal pressure {MPa}	Max. speed {Rpm}	Power PE {kW}	Weight {kg}
033	33.3	35	3590	69.7	45	33.3	35	3590	69.7	30
052	51.6	35	3100	93.3	55	51.6	35	3100	93.3	35
070	69.8	35	2810	114.4	63	69.8	35	2810	114.4	40
089	89.0	35	2590	134.4	78	89.0	35	2590	134.4	47
119	118.7	35	2350	162.7	124	118.7	35	2350	162.7	70
166	165.8	35	2100	203.1	164	165.8	35	2100	203.1	124
334	334.4	35	1670	325.1	270	334.4	35	1670	325.1	197

Series 23
This heavy duty family consists of 4 piston pumps (short version) with these construction characteristics:
- swashplate with variable displacement
- generator charge pump incorporated in end cap (vol. 11ccm, 18ccc and 25ccm)
- auxiliary pads for tandem configuration

Series 23 - Closed circuit
Sizes GR / MK	HYDRAULIC PISTON PUMPS
Sizes GR / MK	Displacement {ccm/rev}	Nominal pressure {MPa}	Max. speed {Rpm}	Power PE {kW}	Weight {kg}
033	33.3	35	3590	69.7	45
052	51.6	35	3100	93.3	55
070	69.8	35	2810	114.4	63
089	89.0	35	2590	134.4	78
119	118.7	35	2350	162.7	124
166	165.8	35	2100	203.1	164
334	334.4	35	1670	325.1	270

Epicyclic gearboxes PM are used in central direct drives for truck mounted concrete mixers with drum capacity from 6 to 10m³. PM gearboxes are designed as 2 stages (PM45 and PM51) and 3 stages planetary reductors (PM 50 and PM60). The gearbox transmits the rotation to the direct mounted drum, supporting the front part. All models are available with water pump drive, and can be fitted with several hydraulic motor models.
Design of PM gearboxes has been supported by elasto-static calculation, intended to secure high working reliability and economy. Other benefits are:
high output torque low noise simple maintenance proven principles to give greater reliability

Basic Technical Data
Type	Max. output torque Nm	Gear ratio	Max. output revolutions rpm	Max. drum capacity m³	Weight		Oil filling	Ambient temp. °C	Efficiency
Type	Max. output torque Nm	Gear ratio	Max. output revolutions rpm	Max. drum capacity m³	.1	.2	Oil filling	Ambient temp. °C	Efficiency
PM45	45 000	100	20	6	237	232	13		0.96
PM51	51 000	100	20	8	296	288	11	-30	0.96
PM50	50 000	130	15	7	287	282	16	+40	0.94
PM60	60 000	130	15	10	346	338	14		0.94