HPR055-02

*) higher rotating speed by tank pressurization or swash angle reduction. See <<Suction speed>>

**) theoretical data of a single unit without efficiency effects

The maximum input and maximum PTO torque allows to form multiple units. One of the first two pumps in such an assembly can thereby operate at maximum power, while the other can operate at continuous power. The PTO at the second pump then offers 30% of a single pump's continuous power rating. Example for HPR 135-02: Maximum input torque = 907 Nm + 540 Nm + 540*0.3 Nm = 1609 Nm

Each Linde Hydraulics unit features a name plate showing the type and the serial number. For a single order via 'open variant' a customer-specific number or free text with up to 15 characters can be stamped on the name plate.

Life time recommendations

Linde high pressure units are designed for excellent reliability and long service life. The actual service life of a hydraulic unit is determined by numerous factors. It can be extended significantly through proper maintenance of the hydraulic system and by using high-quality hydraulic fluid.

Tank connection

The leakage and decompression oil generated during pump operation is drained from the rotating group into the pump housing. Excessive housing pressure must be avoided through suitably dimensioned piping between the housing and the tank.

Filtration

High purity oil can extend the service time of the hydraulic system significantly. In order to guarantee long-term proper function and high efficiency of the hydraulic pumps the purity of the pressure fluid must comply with the following criteria.

Mounting orientation

The preferred mounting orientation is generally horizontal. Pump configurations for vertical mounting with the shaft pointing upwards have an additional drain port "R" at the mounting flange. These units are available with certain combinations of features and have to be requested separately.
For further information concerning the installation of the unit please refer to the operating instructions manual.

In order to ensure the functional performance and high efficiency of the hydraulic pumps the viscosity and purity of the operating fluid should meet the different operational requirements. Linde recommends using only hydraulic fluids which are confirmed by the manufacturer as suitable for use in high pressure hydraulic installations or approved by the original equipment manufacturer.

Permitted pressure fluids

• Mineral oil HLP to DIN 51524-2
• Biodegradable fluids in accordance with ISO 15380 on request
• Other pressure fluids on request

Linde offers an oil testing service in accordance with VDMA 24 570 and the test apparatus required for in-house testing. Prices available on request.

Recommended viscosity ranges

In order to be able to select the right hydraulic fluid it is necessary to know the working temperature in the hydraulic circuit. The hydraulic fluid should be selected such that its optimum viscosity is within the working temperature range (see tables).

The temperature should not exceed 90 °C in any part of the system. Due to pressure and speed influences the leakage fluid temperature is always higher than the circuit temperature. Please contact Linde if the stated conditions cannot be met or in special circumstances.

Viscosity recommendations

In hydraulic systems pressure pulsations can lead to noise emission. These pressure pulsations are a result of the inherent non-uniformity of the volume flow in rotary piston pumps. In open loop hydraulic circuits pressure pulsations primarily originate from within the hydraulic pump during the compression stroke, i.e. when a piston coming from the low-pressure side (suction side) enters the high-pressure side, where it is suddenly subjected to high pressure. The higher the pump speed and the pressure difference between the low-pressure and high-pressure side, the more pulsation energy is added to the hydraulic system via the hydraulic fluid. Pressure pulsations can cause components of the hydraulic system or the machine to oscillate, thereby generating noise that is perceivable for the human ear.

In principle noise emissions from machinery with hydraulic systems can be reduced in the following ways:

• Reduction of operating pressure and speed. This reduces the pulsation energy introduced into the hydraulic system
• Primary measures for optimizing the compression stroke in rotary piston machines with the aim of reducing pulsation
• Secondary measures such as vibration-optimized design and installation of machine components and sound-proofing for noise suppression

Noise Generation

Noise reduction. SPU silencer

All Linde hydraulic pumps are optimized with respect to pulsation characteristics and therefore noise generation. In addition to common primary measures such as exclusive use of pulsation-optimized port plates, Linde Hydraulics offers the SPU silencer for HPR-02 open loop pumps. Without affecting the functionality and efficiency of the pump, this system reduces pressure pulsations by up to 70 %, irrespective of pressure, speed or temperature. The SPU system is adaptive over the entire operating range. No setting up or maintenance is required.

Pressure pulsations with and without SPU

SPU silencer function

• Reduction of pressure pulsations over the entire operating range
• Reduction of noise emission by approx. 50 % (equals approx. 3 dB(A))
• Reduction of volume flow fluctuations
• No impairment of efficiency
• Ready for use immediately, no maintenance required
• Simple and rugged design
• Minimum increase in weight and volume

HPR-02 with SPU

The following diagrams illustrate the immediate effect of pulsation level reduction via SPU on the sound pressure level and therefore the perceived noise emission.

Comparison of sound pressure levels for a HPR 75-02 pump with and without SPU

Comparison of resulting noise emission

Shown in 2 dB(A) steps over a typical diesel engine operating speed range.

Depending on the selected components, different torques may be transferred. Please ensure that the load transfer components such as mounting flange, PTO-through shaft and additional pumps are designed adequately. Our sales engineers will be pleased to provide design advice.

Torque transmission of HPR-02

This shows the input side (A) and PTO- / output side (B) of a HPR-02 pump.
The information on the following pages refers to

• mounting flange and drive shaft (A)
• PTO flange and through shaft (B)

A) Flange profile

Bolt hole diameter / Bolt hole length

*) Option for standard design, necessary for tandem units

2-hole flange / 4-hole flange

2-hole flange with 4 additional threaded holes / 2-hole flange with 4 additional bolt holes

A) Dimensions drive shafts

*) Recommended for tandem configurations

A) Linde Hydraulics shaft types

Type 1. Without undercut / Type 2. With undercut

The previously given information and dimensions refer to pumps according to ISO 3019-1 (SAE J 744). In addition to that, certain configurations are available according to ISO 3019-2. These units offer an additional drain port “R” at the mounting flange for upright installation and a keyed drive shaft.

• Further dimensions and position of the other ports, see (Dimensions. Single pumps HPR-02 for TL2, LEP, ETP)

Detailed shaft view / View on R / Mounting flange

Linde HPR pumps can be delivered matching a flange according to SAE J617a. The pumps are therefore equipped with an adaptor. Depending on the rated size, the base unit is a standard HPR-02 or a plug-in type HPR-02. The plug-in-flange is shown in section (Dimensions. Double pumps and plug-in pumps).

Linde pumps can be combined into tandem and multiple pumps. The combination options are determined by the permitted transfer torque. The following data refers to the PTO (pump output side, without further attachments).

B) Dimensions PTO

B) Dimensions PTO

Beside the combination of the HPR with other HPRs or HPVs to create multiple and tandem units (see section Dimensions. Multiple pumps), single HPRs can be prepared ex works for the combination with other pumps. Depending on the rated size, we offer different centrings for the rear pump. A matching coupling muff for the drive shaft can also be selected. Currently, the following combinations are available. For more information about the output torque, see annotations to table at chapter (General technical data).

B) PTO mounting possibilities

B) Output shaft transfer torque

The gear pumps are available in two designs. Internal gear pumps (IGP) and external gear pumps (EGP). Both types can be used for the control circuits as well as the cooling circuit. The suction is always external for both types, when used in combination with a HPR-02. The internal connection of the IGP is closed.
Internal gear pumps offer a cold start valve and a PTO interface for mounting further pumps. The possible combinations of IGPs and EGPs are determined by PTO option and the permitted shaft torque.

Overview gear pumps

• Port names clockwise rotation: A pressure port, B suction port (as shown)
• Port names counter-clockwise rotation: A suction port, B pressure port (not shown)
• Ports according to ISO 6149-1
• Alternatively DIN 3852-1
• Suction port of the IGP according to ISO 8434-1 L28

External gear pump EGP

Internal gear pump IGP with external suction

PTO flange with IGP

PTO SAE A with IGP / PTO SAE B, B-B, and C with IGP

Linde pumps with load sensing control enable the movement speed required of the selected actuator, e.g. of a boom, to be specified via the valve opening. The measured pump and load pressures are continuously balanced by the load sensing controller of the hydraulic pump.

Load Sensing

Flow on demand control / Self-regulating pump with LS-controller and measure orifice (in valve)

A pressure gradient is set at the controller, which is defined by the actuator requirements. The volume flow results from the orifice A of the control valve and the actual pressure gradient. Due to the LS-controller, the Δp corresponds to the setting value. If the required volume flow differs, the pump displacement is changed accordingly. This happens automatically and reduces the effort required by the operator. Since varying loads and varying numbers of actuators are compensated automatically. The Δp LS basic setting is possible from 16 to 27 bar with 20 bar as standard (the LS differential pressure influences the response times of the pump system).

LS-function at Δp = constant / LS-function at area A = constant

Benefits of LS-control

• Any volume flow below the pump`s maximum can be set
• Response speed of the machine can be defined
• OEM-specific machine response is possible
• Optimum precision control capability

Demand-oriented pump control offers the following benefits

• Load-independent machine control
• Minimum heat generation
• Increased pump service life
• Low noise generation in the whole system
• Fewer components for the control mechanism
• Lower energy consumption, particularly with partial volume flow

The modular controller unit enables a wide range of functional system requirements to be met. In all controller unit versions, the regulating functions are integrated in a housing in order to ensure direct signal transfer without delays and with maximum compactness. All controllers equipped with load sensing function are fully compatible with the Linde Synchron Control System (see section, Linde LSC-System).

Technical data

Controllers without swashplate position feedback

Mounting on the port plate housing

Controllers with swashplate position feedback

Mounting on the pump housing

In addition to the load sensing function the LP-controller offers maximum pressure limitation. Once the system pressure reaches the set pressure of the pressure cut-off valve, the LS-controller is overridden and the pump swashes back, whilst maintaining the system’s regulating pressure. The hydraulic pump remains in this state until the system pressure falls below the set pressure. The hydraulic pump then returns to normal LS operation.

LP. LS with hydraulic pressure cut-off

The maximum pressure cut-off valve prevents prolonged operation of pressure relief valves installed in the hydraulic system for protection. This has the following benefits for the hydraulic system:

• Operating pressure is maintained
• No operation in the overload range
• Any operating point under the power curve remains accessible
• Demand-oriented volume flow generation
• Minimum power loss
• Reduced heat and noise generation
• Longer service life of the pump and the entire hydraulic system
• Improved energy consumption of the overall system

LP-characteristic curve

LP-controller

Possible maximum pressure control setting ranges

• 125 - 230 bar
• 231 - 350 bar
• 351 - 420 bar

In addition to the load sensing function, HPR-02 pumps with H1L or E1L controllers offer the possibility of overriding the Δp LS-signal hydraulically or electrically. This enables a so called mode control for selecting different operating points or enables a power limit regulation (underspeed control). The integration of all functions in the pump controller enables direct signal transfer without delay. The controller-specific data are independent of the nominal pump size.

Possible applications of the LS signal override

Mode-control

A mode control (mode selection) modulates electrically the Δp LS-signal at an orifice (e.g. directional control valve). The current Δp LS value is reduced proportionally or in steps and the pump output adjusted via the pressure reducing valve (see the diagrams on following pages.) In this way the volume flow of the pump can be reduced using the same orifice. In applications with proportional valves this leads to enhanced control resolution, enabling particularly precise and sensitive actuator movement.

Power limit regulation

Any reduction in the prime mover speed is detected in conjunction with an electronic control unit, and the pump's volume flow is limited through modulation of the Δp LS value to ensure that the maximum power capacity is not exceeded. The maximum prime mover power is thus available at all times, irrespective of ambient influences and the number of actuators.

In principle, the Δp LS value acting at the LS-pilot can be modulated down to zero, whereas modified response times of the pump system should be expected in the operating range near zero.

E1L/H1L-characteristic curve

Pump volume flow at fixed orifice

In addition to the load sensing function, the HPR-02 E1L offers an electric override for mode selection and power limit regulation (underspeed control). The integration of all functions in the pump controller enables direct signal transfer without delays. The controller-specific data are independent of the nominal pump size.

In the event of an electric override of the LS-signal, a pressure reducing valve is activated via the proportional solenoid. The control pressure generated in this way acts proportionally against the LS-spring, and the effect of the Δp LS signal is modulated accordingly. This causes the pump to swash back, thereby reducing its output. The function between control current (l) at the control solenoid and the associated Δp LS value is shown in the diagram. At the port "A", the control pressure can be picked up and forwarded to an H1L controller at another HPR pump, which follows the first pump with the E1L controller (master-slave-operation).

Δp LS-reduction / E1L-controller

1. 16 bar Δp setting
2. 20 bar Δp setting
3. 25 bar Δp setting
4. 28 bar Δp setting

In addition to the load sensing function, HPR-02 pumps with H1L-controller offer the possibility of overriding the Δp LS-signal hydraulically. This enables either a so called mode control for selecting different operation points or establish a power limit regulation (underspeed control). The integration of all functions in the pump controller enables direct signal transfer without delay. The controller-specific data are independent of the nominal pump size. The H1L-controller is particularly useful for tandem configurations of two HPR-02 pumps, in which the first is equipped with an E1L-controller. The second pump with H1L-controller uses the resulting hydraulic signal of the first controller and follows the first pump’s actions (master-slave-configuration).

In the event of hydraulically overriding the LS-signal, a control pressure is applied to the port “A” of the controller. This pressure acts proportionally against the LS-spring, and the LS signal is modulated accordingly. This causes the pump to swash back, thereby reducing its output. The function between control pressure at the port A and the associated Δp LS value is shown in the following diagram.

Δp LS-reduction / 1L-controller

1. 16 bar Δp setting
2. 20 bar Δp setting
3. 25 bar Δp setting
4. 28 bar Δp setting

E1L-controller

Rectangular solenoid and AMP-connector

ETP-controller

Tubular solenoid and AMP-connector

TL2-, LEP- and ETP-controllers offer a feedback of the swashplate position. Therefore they are – unlike LP-, E1L- and H1L-controllers – not mounted on the valve plate housing, but on the pump housing. Besides their individual characteristics, these controllers have some similar features.

P-axis (LEP/ETP): Pressure cut-off characteristic

LEP- and ETP-controllers offer a pressure cut-off (PCO), just like the LP-controller. This prevents the pump pressure exceeding a previously set maximum. The PCO is set to a customer-specific value between 125 bar and 420 bar ex works. Using a control signal at the XD port, the actual response pressure of the PCO valve of LEP- and ETP-controllers can be increased steplessly. The response pressure of the valve is increased by 4.3 bar by every bar increase at the XD port. The maximum pressure of 420 bar must not be exceeded.

E-Axis (LEP/ETP): Electric flow setting

The swash angle and thus the flow of the pump is set by means of an electric signal with the LEP and ETP controller. The actual current depends on the voltage-level of the application and the nominal size of the pump. Without an electric signal, the pump swashes to minimal displacement.

T-Axis (TL2/ETP): hydraulic movement of the regulation begin

Controllers of the TL2 and ETP type offer a power limitation with a hyperbolical characteristic. The controller is set ex works to a customer specific power limit value. The volume flow is restricted, when this limit is exceeded. By means of control ports at the controller, the point at which the power limiter sets in can be raised, as well as lowered during operation.

Dependent on the rated size of the unit, there is a minimum value for the power limitation which must not be underrun, neither by the ex work setting, nor by shifting. The maximum mechanically set value at which the power limitation sets in, is 250 bar, independent of the pump's rated size and speed. The pump must never be operated with more than its maximum power.

Power limiter characteristic curve

Shifting of the regulation begin

Power limiter performance

The control principle with power limitation is used to optimize power utilization of the prime mover in applications where less than the full power capacity is available for the hydraulic system. In addition to the load sensing function the HPR-02 TL2 offers hyperbolic power limitation. The volume flow is limited when the set value is reached.

TL2. LS with hyperbolic power limitation

The TL2 controller offers a so called hydraulic power mode function. This means, that the regulation begin of the power limitation / torque control can be shifted from its mechanical basic setting by means of a remote control port Z1/Z2 at the controller. If the regulation begin is intended to be below the basic setting, which means that the pump performance is reduced, then the port Z2 is used while S4 is closed. If the mode function is not used at all, or only with the Z1 port, S4 is equipped with an orifice. Z2 is then sealed pressure tight. For details, see Pump controllers with position feedback. T-axis

TL2-characteristic curve

TL2-controller

The HPR with LEP-controller offers an on-demand load sensing flow control. The actual volume flow, delivered by the pump can be restricted by an electrical signal in certain points of operation. A pressure cut-off function protects the hydraulic system from overload.

Without any signal at the solenoid or the LS-port, the pump is swashed back to stand-by position. Both signals at the same time are required for the pump to leave stand-by position. The actual swash angle of the pump is determined by the signal with the lower target value.

The responding behaviour of the pressure cut-off can be remote-controlled by a hydraulic signal at the XD port as an option. S1 is then equipped with an orifice and S2 is sealed. If only the mechanical preset of the PCO is used, S1 is sealed and S2 is not equipped. Details, see (Pump controllers with position feedback. P-axis)

Characteristic LEP controller

LEP controller

The HPR with ETP-controller delivers a volume flow which is exactly proportional to the electric control signal. Superposed, the controller offers a hyperbolic power limitation, which optimally exploits the power of the prime mover and also protects it from overload. In addition to this, a pressure cut-off protects the hydraulic system. The controller is supplied via a feed port "E" at the port plate housing.

The ETP-controller offers a so called hydraulic power mode function. This means, that the regulation begin of the power limitation can be shifted from its mechanical basic setting by means of a remote control port Z1/Z2 at the controller. If the regulation begin is intended to be below the basic setting, which means that the pump performance is reduced, then the port Z2 is used, S4 is closed. If the mode function is not used at all, or only with the Z1 port, S4 is equipped with an orifice. Z2 is then sealed pressure tight. For details, see (Pump controllers with position feedback. T-axis)
The responding behaviour of the pressure cut-off can be remote-controlled by an hydraulic signal at the XD port as an option. S1 is then equipped with an orifice and S2 is sealed. If only the mechanical preset of the PCO is used, S1 is sealed and S2 is not equipped. Details, see (Pump controllers with position feedback. P-axis)

Characteristic ETP-controller

ETP Regler

Dimensions:

• approx. 151 x 105.6 x 37 mm

• X Test port actuating pressure M14x1.5
• LS1, 2 Load sensing signal / test port M14x1.5
• P1 Test port pump pressure M14x1.5

Dimensions:

• approx. 196.6 x 62.3 x 54.8 mm

Connections:

• A Test port control pressure M14x1.5
• X Test port actuating pressure M14x1.5
• LS/LS2 Load sensing signal / test port M14x1.5
• P1 Test port pump pressure 12 S (ISO 8434-1)

Dimensions:

• approx. 187 x 105.3 x 43.4 mm

Connections:

• A Test port control pressure M14x1.5
• X Test port actuating pressure M14x1.5
• LS1,2 Load sensing signal / test port M14x1.5
• P1 Test port pump pressure M18x1.5
• M Solenoid with AMP-JPT connector (example)
• Further information, see

Dimensions:

• approx. 178.4 x 228.5 x 78 mm

Connections:

• X Test port actuating pressure M14x1.5
• LS Load sensing signal M14x1.5
• Z1/Z2 Remote control for power limitation M14x1.5

Dimensions:

• approx. 269.2 x 187.9 x 103.5 mm

Connections:

• X Test port actuating pressure M14x1.5
• Y Test port pressure-reducing valve M14x1.5
• XD Port for external pressure cut-off M14x1.5
• LS Load sensing signal M14x1.5
• P Test port pump pressure M14x1.5
• M Solenoid with AMP-JPT connector (example) Further information, see

Dimensions:

• approx. 269.2 x 229.1 x 103.5 mm

Connections:

• X Test port set pressure M14x1.5
• Y Test port actuating pressure M14x1.5
• XD Connection for external pressure cut-off M14x1.5
• Z1/Z2 Remote control for power limitation M14x1.5
• M Solenoid with AMP-JPT connector (example) Further information, see

The dimensioning is shown by one exemplary pump configuration. The external dimensions are determined by the individual configuration, including the choice of a controller, direction of rotation, optional SPU and the settings of the pump. Further information can be found in the specific sections of this datasheet, in particular the sections Torque transmission. Mounting flange and Torque transmission. Drive shaft

Dimensions of the pump without controller

Ports

Double pumps consist of two HPR rotating groups, arranged back-to-back to a common port plate housing, sharing one common suction port. They are thus more compact than two standard pumps in a tandem configuration. Compared to a pump of equal rated size with a single rotating group, double pumps offer higher speed and more narrow radial dimensions. They also provide a PTO option. The position of the ports, controllers and SPU differs from the previously shown pumps.
Further details on request.

Double pump with SAE J744 flange / Double pump with SAE J617a flange

Plug-in flange / SAE bell housing

Multiple pumps are created by connecting individual pump units in series, with the pumps arranged by capacity. Positioning the gear pump(s) at the end of the tandem ensures optimum space utilisation, output allocation and load distribution. The following table is based on the attached gear pump acting as a pilot pressure pump for the control circuit.

Multiple pump HPR-HPR-02

Overall length of multiple pump HPR-HPR-02

Multiple pumps are created by combining individual pump units in series, with the pumps arranged by capacity. Positioning the gear pump(s) at the end of the unit ensures optimum space utilization, output allocation and load distribution. The following table is based on the gear pump acting as boost pump for the HPV-02 variable pump.

Multiple pump HPR-HPV-02

Overall length of multiple pump HPR-HPV-02

The HPR-02 is based on a modular system with the following characteristics. This enables our distribution partners to
configure the product according to your requirements. The latest characteristics and available options can be taken from the model code, which is available on our homepage.

• Rated size
• Vmax
• Direction of rotation
• Pump controller
• Solenoid connector type
• Solenoid operating voltage
• Noise reduction SPU
• Port threads
• Mounting flange
• Drive Shaft
• PTO through-drive
• PTO attachment
• Gear pumps
• Gear pump PTO
• Pump settings like speed, LS-setting, pressure cut-off, power-limitation
• Pressure cut-off remote control
• Power limitation remote control
• Surface treatment
• Name plate