Portable hydraulics trainer

Apparatus for training an operator in use of hydraulic and electrohydraulic fluid power systems that includes a vertical panel upstanding from a wheeled base. A first plurality of electrohydraulic devices are mounted on one side of the panel, and second plurality of hydromechanical devices are mounted on the opposing side of the panel. Both of the device pluralities include fluid flow control valves that are distinct from each other between the respective pluralities, and fluid load devices such as rotary hydraulic motors and linear hydraulic cylinders that are shared by the respective pluralities. A fluid power source is carried by the base, as are a multiplicity of hoses for connecting the fluid power source to the devices among either or both of the first and second pluralities. Thus, a hydromechanical trainer and an electrohydraulic trainer are provided in a single device with shared components for loading the valves of the respective training sections, which may be used simultaneously.

The present invention is directed to hydraulic fluid power systems, and 
more particularly to apparatus for training an operator in theory and 
operation of hydraulic equipment and electrohydraulic equipment with 
associated control electronics. 
BACKGROUND AND OBJECTS OF THE INVENTION 
Apparatus has heretofore been marketed by applicants' assignee for use as a 
training aid in theory and operation of hydromechanical fluid power 
systems. In such apparatus, a plurality of hydromechanical devices, such 
as fluid-powered hydraulic motors, valves and cylinders, are mounted on a 
vertical panel carried by a wheeled frame. A hydraulic pump is carried by 
the frame, and is selectively connectable by quick-disconnect hoses to one 
or more of the hydromechanical devices. All components are standard 
industrial devices with which the laboratory or classroom trainee thus 
becomes familiar through a series of exercises or problems set by an 
instructor or instruction manual. For training in electrohydraulics, which 
represents the current trend in the fluid power industry, an 
electrohydraulic servo trainer module has been provided as a separate unit 
or as an accessory to the standard hydromechanical trainer. 
U.S. Pat. No. 5,009,067 assigned to the assignee hereof discloses apparatus 
for training an operator in theory and practice of electrohydraulic 
control systems. The apparatus includes a plurality of electrohydraulic 
devices for performing hydraulic operations as differing functions of 
associated electronic control signals. A plurality of differing electronic 
controllers are adapted to generate electronic control signals to operate 
the electrohydraulic devices. The electronic controllers bear graphic 
indicia identifying the controller and associating each controller with 
corresponding electrohydraulic devices on the training unit. Each 
controller has a plurality of available input, output and control 
connections, which may be selectively interconnected with each other and 
with the electrohydraulic devices by suitable cables for configuring the 
controller and associated device in a multiplicity of differing operating 
modes. The electrohydraulic devices are connectable by quick-disconnect 
hoses to a fluid power source carried by the trainer, and are associated 
with indicia for generating a visually observable indication of operation 
of the devices, so that an operator can observe effects of differing 
electronic control configurations on the devices. 
Although the apparatus described above and disclosed in the noted patent 
have met with substantial acceptance and success in both the academic and 
the industrial training environments, further improvements remain 
desirable. In particular, in order to obtain complete training in both 
hydromechanical and electrohydraulic fluid power systems, the training 
centers must have at least one training apparatus of each type. The 
hydraulic load devices in the prior art, such as the rotary hydraulic 
motors and linear motors or actuators, are not dynamically loaded, so that 
operation during training is not as realistic as desired. It is therefore 
a general object of the present invention to provide a fluid power 
training apparatus of the described character that is more versatile in 
terms of capability for training a student or technician in a wide variety 
of fluid power control techniques, that forms an integral unit with which 
the trainee can readily become familiar, and in which the electronic 
control modules are constructed and arranged realistically to simulate 
situations that the trainee may encounter in the field while at the same 
time providing enhanced trainee understanding of electronic control theory 
and practice. 
SUMMARY OF THE INVENTION 
Apparatus for training an operator in use of hydraulic and electrohydraulic 
fluid power systems in accordance with a presently preferred embodiment of 
the invention includes a vertical panel upstanding from a wheeled base. A 
first plurality of electrohydraulic devices are mounted on one side of the 
panel, and second plurality of hydromechanical devices are mounted on the 
opposing side of the panel. Both of the device pluralities include fluid 
flow control valves that are distinct from each other between the 
respective pluralities, and fluid load devices such as rotary hydraulic 
motors and linear hydraulic motors (cylinders) that are shared by the 
respective pluralities. A fluid power source is carried by the base, as 
are a multiplicity of hoses for connecting the fluid power source to the 
devices among either or both of the first and second pluralities. Thus, a 
hydromechanical trainer and an electrohydraulic trainer are provided in a 
single apparatus with shared components for loading the valves of the 
respective training sections, which may be used simultaneously. 
Each of the flow control valves in both of the electrohydraulic and 
hydromechanical pluralities is mounted on a manifold that is carried on an 
associated side of the panel. Quick-disconnect couplings are mounted on 
each such manifold for fluid communication with the associated valve 
through passages in the manifold, and for connection to each other and to 
the motors through quick-disconnect hoses. The fluid power source feeds a 
manifold carried by the wheeled base beneath each side of the panel, with 
quick-disconnect couplings on each such power source manifold for feeding 
fluid under pressure to the flow control valves on each side of the panel. 
The fluid power source includes an electric motor coupled to a hydraulic 
pump for supplying fluid under pressure to the source manifolds, and the 
manifolds are also coupled to return fluid to the sump. A filter cleans 
fluid circulated by the pump. 
The hydraulic load devices shared by the hydromechanical and 
electrohydraulic valve pluralities include both rotary and linear 
hydraulic motors--i.e., rotary hydraulic motors and linear hydraulic 
motors (cylinders). The rotary hydraulic motor employed as a load device 
is coupled to a second rotary hydraulic motor for dynamic loading during 
operation. One linear actuator employed as a load device is coupled to a 
second opposing actuator for dynamic loading during operation, and a 
second linear actuator is coupled to a suspended weight for dynamic 
loading during operation. Plates are mounted on the vertical panel 
adjacent to each of the valves and motors, and bear a schematic diagram of 
the associated adjacent device. The apparatus seeks to train the student 
in use of components from a predetermined system product line, and the 
plates additionally bear indicia for identifying the adjacent associated 
device within such product line. 
The electrohydraulic valves are responsive to electronic control signals 
for controlling fluid flow, and an electronic controller is carried by the 
base adjacent to the vertical panel beneath the electrohydraulic valves 
and is responsive to an operator for generating such control signals. At 
least some of the valves and/or motors among the electrohydraulic devices 
include sensors for generating feedback signals as a function of operation 
thereof, and the electronic controller includes facility for generating 
the control signals as a function of such feedback signals. The electronic 
controller includes facility for removably receiving a plurality of 
preassembled electronic control assemblies that each include a 
circuitboard bearing control electronics, a panel at one edge bearing 
graphic indicia identifying the operating characteristics of the assembly, 
and a connector at the opposing edge for connection to the control 
electronics on the circuitboard. A special board within the controller 
makes connection with the connector of the circuitboard, and brings the 
connections to terminals on the controller operator panel. Electronic 
cables are employed for connecting such terminals to the electrohydraulic 
devices for applying control signals to such devices and returning 
feedback sensor signals from the devices to the control electronics.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT 
The drawings illustrate a fluid power trainer 10 in accordance with a 
presently preferred embodiment of the invention as comprising a hollow 
vertical panel 12 upstanding from a generally rectangular base 14 that is 
supported by four casters 16. Within base 14 is an electric motor 18 that 
is coupled to a pair of vane pumps 20,22. Pumps 20,22 draw fluid from a 
sump 24 within base 14, and feed fluid under pressure to quick-disconnect 
male couplings on a pair of manifolds 26, which are supported on base 14 
beneath the respective sides of panel 12 as best seen in FIGS. 1 and 2. 
Manifolds 26 also include quick-disconnect couplings for returning fluid 
to sump 24, as best seen in FIG. 4A. A filter 28 (FIGS. 2 and 4A) is 
connected between the outlet of pump 22 and manifold 26, and a second 
filter 30 (FIGS. i and 4A) connected in the return line between manifold 
26 and sump 24. 
On one side of panel 12, there are mounted a plurality of electrohydraulic 
flow control valves illustrated in FIGS. 1 and 4G-4L. These valves include 
an electrohydraulic proportional relief valve 32, a solenoid-operated 
proportional valve 34, two proportional directional valves 36,38 and a 
servo valve 40. Each valve 32-40 is separately mounted an associated 
manifold plate 42-50 carried by panel 12. The manifold plates 42-50 have 
internal passages that connect the fluid inlet and outlet ports of the 
associated valves to male quick-disconnect fittings or couplings 52 
disposed along the edges of the respective manifolds. Manifold plate 42 
also connects valve 32 to a pilot valve 54. Each of the valves 32-40 is 
solenoid-operated, and has female electrical terminals 32a,34a,36a,38a and 
38b, and 40a for electrical connection to the control electronics to be 
described to supply valve control signals to the valve-operating 
solenoids. Valves 34 and 36 also include internal LVDT sensors coupled to 
associated female terminals 34b and 36b to provide sensor feedback signals 
to the control electronics. A plate 32c,34c,36c,38 c and 40c is mounted on 
panel 12 adjacent to each associated valve 32-40 bearing a graphic 
schematic illustration of the associated valve, as well as alphanumeric 
indicia identifying the valve by model number (see Table I) in the product 
line of the training apparatus. 
On the opposing side of panel 12 there are mounted a plurality of 
hydromechanical valves illustrated in FIGS. 2 and FIGS. 4A-4F. These 
valves include a directional valve 54 coupled to a switch 53 for 
controlling direction of flow through valve 54, a sequencing valve 56, a 
counterbalancing valve 58, a pressure reducing valve 60, a flow control 
valve 62 and a deceleration valve 64. Each of the valves 54-64 is mounted 
on an associated manifold plate 66-76 affixed to panel 12 and containing 
internal passages connecting the ports of the associated valve to male 
quick-disconnect fittings 52 disposed along the edges of the manifolds. A 
plate 54a-64a is disposed on panel 12 immediately adjacent to each 
associated valve 54-64, bearing a schematic illustration of the associated 
valve and an alphanumeric identification of the valve by model number (see 
Table I). 
Fluid power load components or devices are also mounted on panel 12, and 
are shared between the electrohydraulic (FIG. 1) and hydromechanical (FIG. 
2) sides of the trainer through apertures in the panel. These components 
include a balanced vane motor 80 and an inline piston servo motor 82, each 
having a rotary output shaft that is connected to the other by a coupling 
84. Motors 80,82 are mounted on base 14 within an aperture 86 in panel 12, 
with an associated plate 80a being positioned on the panel adjacent to the 
aperture with schematic illustration of the motors and alphanumeric 
identification of model number. A tachometer 88 is also coupled to motor 
82 for providing an electrical signal as a function of speed of motor 
shaft rotation. Male quick-disconnect couplings 52 are mounted on a 
manifold 82a that projects from motor 82 with internal passages for 
feeding fluid to the motor. Motor 80 is connected (FIG. 4A) to a load 
block 90 on panel 12 having adjustable relief valves for adjusting load on 
motor 80. Motor 82 thus acts as a drive motor for use by the trainer 
operator, and motor 80 functions as a dynamic load on motor 82, with the 
load being adjustable by means of load block 90. 
A pair of cylinders 92,94 are mounted in opposition to each other within 
panel 12, and are accessible from both sides of panel 12 through openings 
96. Each cylinder 92,94 has a male quick-disconnect couplings 52 at both 
ends accessible from both sides of panel 12 for connection to fluid 
manifold 26 and/or flow control valves. Thus, the actuators may be 
employed for either electrohydraulic or hydromechanical training purposes. 
A variable resistance position sensor 96 is carried by cylinder 92, and is 
coupled by a bracket 98 to the interconnected actuator shafts. A female 
electrical connector 96a on sensor 96 provides an electrical signal as a 
function of position of the interconnected actuator shafts. The shafts of 
opposed cylinders 92,94 are coupled to each other, and either actuator may 
be coupled to load block 90 to function as an adjustable load on the 
other. An upper cylinder or actuator 100 is mounted on panel 12, again 
having male quick-disconnect couplings 52 at each end of the cylinder 
accessible from both sides of panel 12. The actuator rod 102 that projects 
from cylinder 100 is coupled by a bracket 104 to the shaft of a position 
sensor 106. Bracket 104 also connects the actuator rod to a weight 108 
suspended by a cable 108 within panel 12 to provide dynamic loading on 
cylinder 100. Plates 92a and 100a are mounted on both sides of panel 12 
adjacent to cylinders 92,100 bearing schematic illustrations and model 
identification (Table I) thereof. Hoses 121 with female quick-disconnect 
couplings are provided for selective operator interconnection of the 
various valves, actuators or cylinders and source manifolds 26. 
An electronic controller enclosure 120 (FIGS. 1 and 5) is mounted on base 
14 beneath and in front of the electrohydraulic side of panel 12 as 
illustrated in FIG. 1. Enclosure 120 has a sloping operator panel 122 with 
an aperture in which there are mounted several preassembled amplifier 
cards 124,126 and 128. An operator joystick 130 is internally connected to 
female terminals 132 on panel 122, as are a pair of potentiometers 134,136 
connected to sets of female terminals 138,140. A power on/off switch 142 
on panel 122 selectively applies power to the amplifier cards. One or more 
of cards 124-128 are connected within enclosure 120 to connector panels 
144,146 on panel 122 to facilitate connection to the card electronics. 
Preferably, each card 124,126,128 is of the type having a front panel, 
exposed at panel 122, identifying the card to an operator, and a connector 
at the remote edge for connection to the electronics. This connection is 
removably plugged into a mating fixed connector within enclosure 120 that 
is connected to panel 144 or 146 so as to bring the card connector 
terminals out to the front panel. Typical card/connector panel 
arrangements are illustrated in FIGS. 6A and 6B. Cards 124-128 may thus be 
selectively replaced, and enclosure 120 used for training in multiple 
electrohydraulic setups. The female connector terminals on connector 
panels 144,146 are selectively connectable to the various sensors and 
valve coils (FIGS. 4A-4L) by cables with male connectors provided with the 
unit to configure the unit in training arrangements set by an instructor 
or manual. 
In accordance with an important feature of the present invention, all of 
the hydromechanical and electrohydraulic equipment and the controllers of 
training apparatus 10 comprise standard industrial components, in this 
case components of the fluid power equipment product line of applicants' 
assignee selected as being representative for training purposes. The 
following Table correlates the hydromechanical devices, the 
electrohydraulic devices the load devices and the controllers hereinabove 
identified with specific equipment marketed by applicants' assignee: 
TABLE I 
______________________________________ 
Device/Controller Vickers Model No. 
______________________________________ 
Proportional valve 32 
EHST3BVE11 
Pilot valve 54 CG-03-B-10 
Proportional valve 34 
KSDG4V-3 
Directional valve 36 
KFDGV3 
Directional valve 38 
KDGV32 
Servo valve 40 SM4207 
Directional valve 54 
DG4V3S6 
Sequencing valve 56 RCG03D23 
Counterbalancing valve 58 
RCG-03-A1-30 
Reducing valve 60 XCG-03-1B-30 
(?) valve 62 FCG-02-300-50 
Deceleration valve 64 
DG1652 
Motor 80 M2230251A13 
Motor 82 MFB5-FU-20-S61 
Load block 90 BKM0D617 
Actuator 92 TF02EAWB3 
Actuator 94 TF02DAGB3 
Cylinder 100 TF02CKB3 
Power amplifier 126 EEA-PAM-118 
Amplifier Module 124 
EM-D-30 
Amplifier Module 128 
EM-D-20 
______________________________________ 
As previously noted, the devices and controllers listed in Table I are 
standard components heretofore marketed by applicants' assignee. These 
components are illustrated, for example in Vickers Catalog 400A 
"Hydraulics & Electronics Systems and Components" (1992). Position sensor 
36 is marketed by Temposonics, Inc. of Plainview, New York and disclosed 
in U.S. Pat. No. 3,898,555. The disclosures of the noted catalog relative 
to the devices enumerated in Table I, and of the noted U.S. patent, are 
incorporated herein by way of background. The other components hereinabove 
described are standard items. 
There has thus been provided in accordance with the present invention a 
combined hydromechanical and electrohydraulic training apparatus that 
fully satisfies all of the objects and aims previously set forth. 
Different types of electronically controlled hydraulic apparatus and 
hydromechanical apparatus are mounted on respective sides of a vertical 
panel readily accessible to the trainee, and load apparatus are also 
mounted on or at the vertical panel and shared by both the 
electrohydraulic and hydromechanical flow control devices. All of the 
devices are selectively interconnectable with quick-disconnect lines and 
the like.