Patent Publication Number: US-2023135131-A1

Title: Wheel load assembly for a dynamometer test bench and dynamometer test bench

Description:
The present invention relates to a wheel load assembly for a dynamometer test bench and a dynamometer test bench for carrying out experimental tests characterizing the mechanical and acoustical behavior—the so-called NVH behavior (noise, vibration, harshness) of a brake, of a brake-wheel hub assembly or of a brake-wheel hub-suspension assembly of a vehicle, hereinafter referred to as a “part of wheel suspension” for simplicity. 
     Brake tests aiming to measure noise, vibrations and to subjectively assess the unpleasantness resulting from such noises or vibrations (NVH) using inertia dynamometer test benches are one of the most common laboratory tests in the automobile industry. 
     Dynamometer test benches are known, having a support structure (the so-called “fixture frame”) configured to support, according to the simulation detail:
         the brake disc and the related caliper or the drum and the related brake shoes, or   the brake disc and the related caliper or the drum and the related brake shoes, the wheel hub with the bearing thereof and the stub axle of the suspension, and possibly dust shields, or   the brake disc and the related caliper or the drum and the related brake shoes, the wheel hub with the bearing thereof and the stub axle of the suspension, the spring-damper assembly of the suspension, and possibly dust shields, or   the brake disc and the related caliper or the drum and the related brake shoes, the wheel hub with the bearing thereof and the stub axle of the suspension, the spring-damper assembly of the suspension, at least part of the steering mechanism, and possibly dust shields, and possibly further components of the “corner” of the vehicle, hereinafter referred to as a “part of wheel suspension” for simplicity.       

     The hub support structure further comprises a flywheel for simulating the inertia of the vehicle. 
     In addition to the support structure (“fixture frame”), the known dynamometer test benches comprise a wheel load assembly, the so-called “WLU” (wheel load unit) for forcing or simulating given loads which may act on the part of wheel suspension. 
     For this purpose, various approaches and systems are known which, according to the hardware detail of the vehicle available (and mounted to the support structure), apply loads resulting from braking forces (longitudinal direction—axis X); loads resulting from a high and/or low speed steering circumstance (lateral direction—axis Y); vertical forces due to the weight of the vehicle and to the dynamic transfer of the weight of the vehicle caused by the braking or curve or by both (vertical direction—axis Z). 
     The known wheel load assemblies are not generally configured to apply each of the loads which can be assumed in the intensity, position, and desired direction and most appropriate for the dynamometer experimental test to be carried out. 
     Moreover, the wheel load assemblies of the known art are not sufficiently versatile or configurable to carry out the experimental tests on parts of the wheel suspension with different geometries and with various levels of fidelity with respect to the actual vehicle. For example, it is desirable to carry out the tests with one or more of the following types of load: 
     constant load in one or more directions for the entire duration of the test; 
     change from a constant load to a further constant load to simulate specific braking events, e.g., parking maneuvers; 
     dynamic load during the braking events to simulate a specific maneuver; 
     dynamic load to stimulate the road load variations in real time (with a given level of model approximation) resulting from curves, roughness of the road surface, for example with the possibility of selecting the amplitude and the frequency of the specific load. 
     The known support structures, as well as the known wheel load assemblies have a metal frame structure which is adapted each time to the specific geometrical conditions for the support and load of the part of wheel suspension. This adaptation is at least partly done by hand and requires undesirably long times. 
     The known wheel load assemblies are also undesirably heavy, and the weight thereof affects and alters the boundary conditions, in particular the modal response of the part of wheel suspension subject to the experimental test and the NVH analysis. 
     Moreover, although they are suitable for the application of lateral forces, the known wheel load assemblies are not capable of applying longitudinal forces which are synchronized with the dynamic action applied by the brake. 
     A further disadvantage of the known wheel load assemblies is the lack of adjustment functions thereof for allowing an adaptation thereof to types and dimensions of different parts of wheel suspension. 
     Therefore, it is the object of the present invention to provide a wheel load assembly for a dynamometer test bench and a dynamometer test bench having such features as to obviate at least some of the drawbacks described with reference to the known art. 
     Within the scope of the general object, it is a specific object of the invention to provide a wheel load assembly having such features as to apply, on the part of wheel suspension, dynamic longitudinal loads in combination with the simulation of the inertia of the vehicle by means of the flywheel and, if required, contributed by an electric motor and/or pertaining synchronized or independent lateral loads to simulate lateral forces acting on the vehicle. 
     It is a further specific object of the invention to provide a wheel load assembly having a more lightweight structure and to facilitate the access to the brake components to allow a quick replacement of the brake components without modifying the entire set test configuration. 
     It is a further specific object of the invention to provide a wheel load assembly having such features as to apply longitudinal forces in the middle of the wheel hub, preferably in combination with the application of a braking torque in order to simulate the stresses of the vehicle during braking events as realistically as possible. 
     It is a further specific object of the invention to provide a wheel load assembly having such features as to apply dynamic longitudinal and/or lateral and/or vertical forces to the wheel hub according to force-time curves which can be set and synchronized with the dynamometric action of the brake. 
     It is a further specific object of the invention to provide a wheel load assembly having such features as to allow the adjustment of the application points of the forces with broad flexibility and the fastening thereof at the start of the test in order to simulate, more realistically, for example, the position of various offsets of the wheel rim (rim offset position or rim ET position) and/or various wheel radii with the intent to replicate the use of different tires. 
     It is a further specific object again of the invention to provide a wheel load assembly configured to allow a modular reconfiguration thereof and the repositioning, removal, and replacement of individual components in an easy and modular manner. 
     At least some of the objectives of the invention are achieved by a wheel load assembly according to claim  1 . The dependent claims relate to advantageous and preferred embodiments. 
    
    
     
       In order to better understand the invention and appreciate the advantages thereof, a description of exemplary and non-limiting embodiments is provided below, with reference to the drawings, in which: 
         FIG.  1    is a perspective view of a dynamometer test bench according to an embodiment. 
         FIG.  2    diagrammatically shows the interaction of a control system of the dynamometer test bench with some of the operating units thereof. 
         FIG.  3    is a perspective view of a wheel load assembly of the dynamometer test bench according to an embodiment, showing a part of wheel support on which the dynamometer test is to be performed. 
         FIG.  4    is a perspective view of a wheel load assembly in  FIG.  3   , in which the part of wheel support has been removed. 
         FIG.  5    is a perspective view of the individual load devices of the wheel load assembly, according to an embodiment. 
         FIG.  6    is a further perspective view of the individual load devices of the wheel load assembly in  FIG.  5   . 
         FIG.  7    is a perspective view of a detail of a vertical load device of the wheel load assembly according to an embodiment. 
         FIGS.  8  and  9    are perspective views of details of a longitudinal load device of the wheel load assembly according to an embodiment. 
         FIGS.  10 ,  11  and  12    are perspective views of details of a lateral load device of the wheel load assembly according to an embodiment. 
         FIG.  13    is a perspective view of the wheel load assembly with actuators for an application of dynamic forces, according to an embodiment. 
     
    
    
     DESCRIPTION OF THE DYNAMOMETER TEST BENCH  1   
     A dynamometer test bench  1  comprises:
         a support structure  2  for supporting, in a stationary manner, at least a wheel suspension part  3  of a suspension-wheel hub-brake unit (“corner”) of a vehicle (not shown), and/or   a wheel load assembly  5  (WLU) for applying simulation forces  6 ,  7 ,  8  on the wheel suspension part  3 , in addition to a possible braking torque  9  which can be generated by operating brake  10 , for example by means of a disc brake or a drum brake of the wheel suspension part  3 . The operation of brake  10 , a flywheel and/or a motor of the dynamometer bench, which are described later.       

     According to the embodiment, the support structure  2  and the wheel load assembly  5  may be assembled on a single dynamometer test bench  1  or they may belong to two separate test benches which are positioned and used together to carry out the tests of brake  10  or of the wheel suspension part  3  in general. 
     The dynamometer test bench  1  defines an axial direction  55  which is parallel to the wheel rotation axis  40  of the wheel hub  43  of the wheel suspension part  3  mounted on the test bench  1 , a longitudinal direction  56 , which is horizontal and perpendicular to the axial direction  55 , and which substantially corresponds to a guiding direction of the vehicle, as well as a vertical direction  57  which is perpendicular to the axial direction  55  and to the longitudinal direction  56 . 
     Similarly, also the support structure  2  and the wheel load assembly  5  define the same axial, longitudinal, and vertical geometrical axes or directions. 
     In the continuation of the description, indications of direction of force, adjustment, orientation, or movement indicated with the terms “longitudinal”, “axial”, “vertical” refer to the aforesaid longitudinal  56 , axial  55 , vertical  57  directions or to directions parallel thereto, unless otherwise specified. 
     Description of the Support Structure  2   
     According to an embodiment, the support structure  2  may comprise a wall or a base frame  11  mounted on a base  12  of the test bench  1 , and one or more portions or connecting brackets  13 , which are possibly adjustable in height and/or in horizontal direction, for fastening (for example by means of screws) the wheel suspension part  3 . 
     Advantageously, also the position of the base frame  11  on base  12  is adjustable, for example by means of the releasable and lockable engagement of a plurality of connecting members  14  which engage both the base frame  11  and a guide and adjustment channel  15  formed in the base  12 . 
     Base  12  may comprise two horizontal, and preferably parallel, rails or elongated base profiles, extending in axial direction  55 . Each of the two longitudinal base profiles may form its own guide and adjustment channel  15 , advantageously a channel  15  formed in an upper surface of the elongated base profile and having an upside-down “T”-shaped cross section. 
     To the support structure  2  may be associated a flywheel  4  operatively connected to, and rotationally operable by means of, a flywheel motor  16  for simulating the inertia of the vehicle. The flywheel may be connected to a bearing body  96  which in turn is connected to the suspension assembly  3 , or directly to the suspension assembly  3 . 
     Description of the Wheel Load Assembly  5   
     According to one embodiment, the wheel load assembly  5  comprises:
         a support structure  17  assembled, or which can be assembled, on a base, for example on base  12 ,   a vertical load device  18  having a first application bracket  19  which is connectable (rigidly to a bearing body  96  belonging to the wheel load assembly  5  and in turn connectable) to the wheel suspension part  3 , a first reaction support  20  connected to the support structure  17 , a first force transmission connector  21  connected between the first reaction support  20  and the first application bracket  19 , as well as a first load apparatus  22  operatively connected to the first force transmission connector  21  to load (in traction and/or compression) the first force transmission connector  21  in a first vertical load direction  23 ,   a longitudinal load device  24  having a second application bracket  25  which is connectable (rigidly to the bearing body  96 , in turn connectable) to the wheel suspension part  3 , a second reaction support  26  connected to the support structure  17 , a second force transmission connector  27  connected between the second reaction support  26  and the second application bracket  25 , as well as a second load apparatus  28  operatively connected to the second force transmission connector  27  to load (in traction and/or compression) the second force transmission connector  27  in a second (preferably horizontal) longitudinal load direction  29  transverse (preferably orthogonal) to the first vertical load direction  23  and to a wheel rotation axis  40  of the (wheel hub  43  of the) wheel suspension part  3 ,   a lateral load device  30  having a third application bracket  31  which is connectable (rigidly to the bearing body  96 , which in turn is connectable) to the wheel suspension part  3 , a third reaction support  32  connected to the support structure  17 , a third force transmission connector  33  connected between the third reaction support  32  and the third application bracket  31 , as well as a third load apparatus  34  to load (in traction and/or compression) the third force transmission connector  33  in a third (horizontal) lateral load direction  35  parallel to the rotation axis  40  and therefore, transverse (preferably orthogonal), to the first vertical load direction  23  and to the second longitudinal load direction  29 .       

     According to an aspect of the invention:
         the first application bracket  19  comprises a first adjusting device  36  for adjusting the connection position of the first application bracket  19  with the first transmission connector  21  along a first (horizontal) axial adjustment direction  37  parallel to the wheel rotation axis  40 , with the first application bracket  19  in the position of use,   the second application bracket  25  comprises a second adjusting device  38  for adjusting the connection position of the second application bracket  25  with the second transmission connector  27  along a second (horizontal) axial adjustment direction  39  parallel to the wheel rotation axis  40 , with the second application bracket  25  in the position of use,   the third application bracket  31  comprises a third adjusting device  41  for adjusting the connection position of the third application bracket  31  with the third transmission connector  33  along a third vertical adjustment direction  42 , with the third application bracket  31  in the position of use.       

     This configuration of the wheel load assembly  5  allows dynamic longitudinal loads to be applied on the wheel suspension part  3 , in combination with the simulation of the inertia of the vehicle by means of the flywheel and/or in combination with pertaining synchronized or independent lateral loads to simulate lateral forces acting on the vehicle. 
     By virtue of the second adjustment device  38 , longitudinal forces may be precisely applied in the middle of the wheel hub  43  in combination with the application of a braking torque in order to simulate the stresses of the vehicle during braking events as realistically as possible. 
     Moreover, the first  36 , second  38 , third  41  adjustment devices allow the independent adjustment of the force application points  6 ,  7 ,  8  to simulate for example, the axial offset position of the rim of the wheel (rim offset position or rim ET position) and/or the variation of the radial dimension of the wheel as realistically as possible by simulating different wheel sizes and/or different radial compression intensities of the wheel, and therefore, the (variation of the) position of the application of the lateral force during braking in a curve. 
     Detailed Description of the Support Structure  17   
     According to an embodiment, the support structure  17  comprises a main frame  48  in the shape of bridge or frame, at least partially extending about a middle opening  44  passing in axial direction  55 , and therefore open and freely accessible both from an inner side  45  of the wheel load assembly  5  facing, during use, the support structure  2  and corresponding to an inner side of the vehicle, and from an outer side  46  of the wheel load assembly  5  facing, in use, away from the support structure  2  and corresponding to an outer side of the vehicle. 
     The main frame  48  may comprise two, preferably vertical, uprights  47 , an upper, preferably horizontal, cross beam  51  which connects upper ends  52  of the two uprights  47 , and one or more connection portions  50  formed at lower ends  49  of the uprights  47  for connecting the main frame  48  to base  12 . 
     The connection of the main frame  48  on base  12  preferably is adjustable, for example by means of the releasable and lockable engagement of a plurality of connecting members  53  which engage both the connection portions  50  and the guide and adjustment channels  15  formed in the base  12 . 
     The position adjustment of the main frame  48  on the base  12  takes place in the axial direction  55 . The adjustment of the position of the support structure  17  with respect to the base  12 , and therefore with respect to the support structure  2 , together with the adjustment of the first adjustment device  36  and of the second adjustment device  38 , all in axial direction  55 , allow the application of the vertical force  8  and of the longitudinal force  6  at axial distances from the wheel hub  43  precisely corresponding to the axial offset position of the rim of the wheel (rim offset position or rim ET), and therefore a true simulation of the real load conditions. 
     The main frame  48  may further comprise a lower, preferably horizontal, cross beam  54  which connects the lower ends  49  of the uprights  47 , thus completing the aforesaid frame-shaped configuration and giving the main frame  48  increased rigidity. The entire main frame  48  preferably defines a frame plane which is vertical and orthogonal to the axial direction  55 . 
     The vertical load device  18 , in particular the first reaction support  20 , is connected to the upper cross beam  51 . The longitudinal load device  24 , in particular the second reaction support  26 , is connected to one of the uprights  47 . The selection of upright  47  on which to mount the longitudinal load device  24  depends on the volume of the components of the wheel suspension part  3 , thus increasing the flexibility in use. 
     The support structure  17  may further comprise an auxiliary frame  58  spaced apart from the main frame  48  in axial direction  55 , preferably on an inner side  45  of the support structure  17 , i.e., between the main frame  48  and the support structure  2  of the test bench  1 , and which supports the lateral load device  30 , in particular the third reaction support  32 . 
     The auxiliary frame  58  has a height which is less than half the height of the main frame  48 , as well as a weight which preferably is less than half the weight of the main frame  48 . 
     The auxiliary frame  58  may comprise a connection beam  59  for the connection of the auxiliary frame  58  to base  12 , as well as a central upright  92  which extends from the connection beam  59  upwards, and which supports or forms the third reaction support  32 . 
     The connection of the auxiliary frame  58  on base  12  is removable and preferably adjustable, preferably in axial direction  55 , for example by means of the releasable and lockable engagement of a plurality of connecting members  60  which engage both the connection beam  59  and the guide and adjustment channels  15  formed in base  12 . The axial sliding of the auxiliary frame  58  further allows the application points of the load to be adjusted according to the set rim axial offset value (ET). 
     The division of the support structure  17  into a main frame  48  in the shape of frame and a much smaller and lighter auxiliary frame  58  allows access to the space between the support structure  2  and the main frame  48  to be freed quickly and easily, i.e., the space where the wheel suspension part  3  is, by unmounting and removing the auxiliary frame  58  alone. 
     The support structure  17  thus configured is lighter than a construction as a single frame and such as to facilitate access to the components of brake  10  to allow a quick replacement of the components of brake  10  without modifying the entire set dynamometer test configuration. 
     Detailed Description of the Vertical Load Device  18   
     According to one embodiment, the first application bracket  19  has an angular shape with:
         a first adjusting plate  61  which forms a first guide profile  62  extending in axial direction  55  during use, to which a first slide  63  is coupled which is slidingly positionable and lockable (for example by means of lock screws) along the first guide profile  62 ,   a first application arm  64  protruding at an angle from the first adjusting plate  61  and the free end of which forms a first fastening seat  65  (for example a perforated profile, possibly having “L”- or “U”-shaped section) which is connectable to the bearing body  96 .       

     Advantageously, the first adjusting plate  61  comprises a first graduated scale  69  and the first slide  63  comprises a marking or a reference edge adjacent to the first graduated scale  69  to facilitate a precise adjustment of position, for example a continuous adjustment of the axial offset of the vertical force  8 , for example in the range between +60 mm and −100 mm. 
     The first adjusting plate  61  and the first application arm  64  together form a concave groove  66  facing in axial direction  55  towards the inner side  45  of the wheel load assembly  5  to avoid violations of space between the wheel load assembly  5  and the wheel suspension part  3  undergoing the test. 
     The first force transmission connector  21  may comprise a tie rod provided with a first load cell  67  and connected to the first slide  63 , preferably in an articulated manner. 
     The first load apparatus  22  may comprise a first actuator  68 , for example a fluid-dynamic, in particular hydraulic, cylinder-piston unit or an electric actuator, connected between the first reaction support  20  and the first transmission connector  21 . 
     Alternatively, the first load apparatus  22  may comprise a screw and nut screw tensioner  68 ′ integrated in the first force transmission connector  21 , or a damper  68 ″ for generating a preload, possibly cushioned, force in vertical direction. 
     The first load apparatus  22  may be configured to generate a vertical load, for example almost static or dynamic. 
     The constant static vertical load  8  during the dynamometer test may be for example, in the range between 500 Newtons and 7000 Newtons. A dynamic variation of the vertical force  8  during a braking simulation and consistent with the actuation of brake  10  (e.g., 1000 bar/s) may be in the range between +1000 Newtons and −1000 Newtons. 
     Detailed Description of the Longitudinal Load Device  24   
     According to one embodiment, the second application bracket  25  has an angular shape with:
         a second adjusting plate  70  which forms a second guide profile  71  extending in axial direction  55  during use, to which a second slide  72  is coupled which is slidingly positionable and lockable (for example by means of lock screws) along the second guide profile  71 ,   a second application arm  73  protruding at an angle from the second adjusting plate  70  and the free end of which forms a second fastening seat  74  (for example a perforated profile, possibly having “L”- or “U”-shaped section) which is connectable to the bearing body  96 .       

     Advantageously, the second adjusting plate  70  comprises a second graduated scale  75  and the second slide  72  comprises a marking or a reference edge adjacent to the second graduated scale  75  to facilitate a precise adjustment of position, for example a continuous adjustment of the axial offset of the longitudinal load  6 , for example in the range between +60 mm and −100 mm. 
     The second adjusting plate  70  and the second application arm  73  together form a concave groove  76  facing in axial direction  55  towards the inner side  45  of the wheel load assembly  5  to avoid violations of space between the wheel load assembly  5  and the wheel suspension part  3  undergoing the dynamometer test. 
     The second force transmission connector  27  may comprise a push-pull bar, having one or more segments, provided with a second load cell  77  and connected to the second slide  72 , preferably in an articulated manner. 
     The second load apparatus  28  may comprise a screw and nut screw tensioner  78  integrated in the second force transmission connector  27 . 
     Alternatively, the second load apparatus  28  may comprise a second actuator  79 , for example a fluid-dynamic, in particular hydraulic, cylinder-piston unit or an electric actuator, connected between the second reaction support  26  and the second force transmission connector  27 . 
     The second load apparatus  28  may be configured to generate an almost static longitudinal stress or a dynamic longitudinal stress. The constant static longitudinal load  6  during the dynamometer test may be for example, zero or in the range between −6000 Newtons and +6000 Newtons. A dynamic variation of the longitudinal force  6  during a braking simulation and consistent with the actuation of brake  10  (e.g., 1000 bar/s) may be in the range between +6000 Newtons and −6000 Newtons, preferably in the range between +4000 Newtons and −4000 Newtons, with absolute maximum values up to 6000 Newtons or also higher. 
     A maximum stroke of the second actuator  79  in longitudinal direction  56  advantageously is limited to maximum 5 mm or 10 mm in order to obviate the risk of misalignment between the wheel rotation axis  40  (wheel shaft) and the test bench  1 . 
     According to a further embodiment, the position of the second reaction support  26  with respect to the support structure  17  is adjustable in height. 
     Detailed Description of the Lateral Load Device  30   
     According to one embodiment, the third application bracket  31  has an elongated shape with:
         a third adjusting plate  80  which forms a third guide profile  81  extending in vertical direction  57  during use, to which a third slide  82  is coupled which is slidingly positionable and lockable (for example by means of lock screws) along the third guide profile  81 ,   a third application arm  84  connected and extending parallel to the third adjusting plate  80 , and the free end of which forms a third fastening seat  83  (for example a perforated profile, possibly having “L”- or “U”-shaped section) which is connectable to the bearing body  96 .       

     Advantageously, the third adjusting plate  80  comprises a third graduated scale  85  and the third slide  82  comprises a marking or a reference edge adjacent to the third graduated scale  85  to facilitate a precise adjustment of position, for example a continuous adjustment of the vertical downwards offset (which simulates the wheel diameter) of application of the lateral load  7 . 
     The third transmission connector  33  may comprise a push-pull bar, having one or more segments, provided with a third load cell  86  and connected to the third slide  82 , preferably in an articulated manner. 
     The third load apparatus  34  may comprise a screw and nut screw tensioner  87  integrated in the third force transmission connector  33 . 
     Alternatively, the third load apparatus  34  may comprise a third actuator  88 , for example a fluid-dynamic, in particular hydraulic, cylinder-piston unit or an electric actuator, connected between the third reaction support  32  and the third force transmission connector  33 . 
     The third load apparatus  34  may be configured to generate an almost static lateral stress or a dynamic lateral stress. The constant static lateral load  7  during the dynamometer test may be for example, zero or in the range between +6000 Newtons and −6000 Newtons, preferably between −4000 Newtons and +4000 Newtons. A dynamic variation of the lateral force  7  during a braking in a curve simulation may be in the range between +6000 Newtons and −6000 Newtons, preferably between +4000 Newtons and −4000 Newtons, with absolute maximum values up to 6000 Newtons or also higher. An actuation frequency of the third actuator  88  may be for example, maximum 5 Hz. 
     A maximum stroke of the third actuator  88  in longitudinal direction  56  advantageously is limited to maximum 5 mm in order to obviate the risk of misalignment between the wheel rotation axis  40  of the wheel suspension part  3  (wheel shaft) and the test bench  1 . 
     According to a further embodiment, the position of the third reaction support  32  with respect to the support structure  17  is adjustable in longitudinal direction  56  and preferably in height. 
     The lateral load device  30  may comprise a fourth device  41 ′ for adjusting the connection position of the third transmission connector  33  to the third reaction support  32  or more generically, to the support structure  17 , in a fourth adjustment direction  42 ′ which is parallel to the aforesaid third vertical adjustment direction  42 . 
     For this purpose, the third reaction support  32  with the support structure  17  forms a fourth guide profile  81 ′ extending in vertical direction  57 , to which a fourth slide  82 ′ is coupled which is slidingly positionable and lockable along the fourth guide profile  81 ′. The third reaction support  32  or the fourth guide profile  81 ′ comprises a fourth graduated scale  85 ′ and the fourth slide  82 ′ comprises a marking or a reference edge adjacent to the fourth graduated scale  85 ′ to facilitate a precise adjustment of position, in particular the continuous adjustment of the vertical downwards offset (which simulates the wheel diameter) of application of the lateral load  7 , and at the same time maintain the lateral force  7  parallel to the wheel rotation axis  40 . 
     According to one embodiment, for example in the presence of the third actuator  88  which may cause a given volume between the auxiliary frame  58  and the main frame  48 , the auxiliary frame  58  may be arranged on the outer side  46  of the support structure  17 . In this case, to avoid violations of space between the wheel load assembly  5  and the wheel suspension part  3  undergoing the test, also the third application bracket  31  may form a concave groove  89  facing in the axial direction  55  towards the inner side  45  of the load assembly  5 . 
     By virtue of the configuration of the vertical, longitudinal, and lateral load devices, the wheel load assembly  5  allows a versatile, modular reconfiguration thereof and the repositioning, removal, and replacement of individual components in an easy and modular manner. 
     Description of the Bearing Body  96   
     According to one embodiment, the first application bracket  19 , the second application bracket  25  and the third application bracket  31 , or more correctly, the first fastening seat  65 , the second fastening seat  74  and the third fastening seat  83 , are assembled, or can be assembled, for example by means of screws, to corresponding first  97 , second  98  and third  99  connection sides of a bearing body  96  belonging to the load assembly  5  but which is connectable to the wheel suspension part  3  so as to allow the rotation of the wheel hub  43  and/or of a disc brake of brake  10  about the wheel rotation axis  40  with respect to the first application bracket  19 , the second application bracket  25  and the third application bracket  31  to thus allow the transmission of the rotation speed and of the torque from the engine to the brake disc. 
     The bearing body  96  and the first application bracket  19 , the second application bracket  25  and the third application bracket  31  may be preassembled to form a bearing unit which is connectable to the wheel suspension part  3 . 
     Description of the Electronic Control System  90   
     According to one embodiment, the dynamometer test bench  1  or the wheel load assembly  5  comprises an electronic control system  90  connected to one or more or all of the first  68 , second  79 , third  88  actuators, and possibly with brake  10  of the wheel suspension part  3 , as well as possibly with one, several or all of the first, second and third load cells, and configured for an independent and selective, or coordinated and synchronized, control of the one or more or all of the first  68 , second  79 , third  88  actuators, and possibly of brake  10 , depending on a dynamometer test program which can be uploaded or programmed by a user or stored in a memory  91  of the electronic control system  90 . 
     The electronic control system  90  may comprise for example, a computer with a processor  93 , memory  91 , a user interface  94  (monitor, keyboard) and possibly, wireless and cabled signal communication interfaces  95 . The first  68 , second  79 , third  88  actuators and the electronic control system  90  allow dynamic longitudinal  6  and/or lateral  7  and/or vertical  8  forces to be applied to the wheel suspension part  3  according to force-time curves which can be set and synchronized with the dynamometric action of brake  10 . 
     Obviously, those skilled in the art, in order to meet contingent and specific needs, may make further changes and variations to the dynamometer test bench  1  and to the wheel load assembly  5  according to the present invention, all without departing from the scope of protection of the invention, as defined by the following claims.