Patent Description:
There is known a test device for simulating and examining an interaction between a rail and a wheel during when a railway vehicle is running. For example, <CIT> (Patent Document <NUM>) discloses a test device capable of performing a test simulating a running state of a railway vehicle by rotating both a rail wheel which is a disk-shaped member having a cross-sectional shape simulating a rail at an outer peripheral portion thereof and a wheel in a state where the wheel is pressed against the rail wheel. Other prior art documents relevant to the invention are patent documents <CIT>, <CIT> and <CIT>.

Since the test device disclosed in Patent Document <NUM> is driven by a single electric motor, when performing a test for applying a large torque to the wheel while rotating the wheel at a high speed, it is necessary to use a large-capacity electric motor, and thus there is a problem that power consumption during the test becomes enormous.

The present invention has been made in view of the foregoing circumstances, and it is an object of the present invention to reduce power consumption of a wheel test device.

According to an embodiment of the present invention, there is provided a wheel test device including a rail wheel support unit configured to rotatably support a rail wheel, a wheel support unit configured to rotatably support a test wheel in a state where the test wheel is in contact with the rail wheel, a first electric motor configured to rotate the rail wheel and the test wheel, and a torque generating device configured to generate torque to be applied to the test wheel, the torque generating device including a rotating frame rotationally driven by the first electric motor, and a second electric motor mounted on the rotating frame, and at least one of the rail wheel and the test wheel being connected to the first electric motor via the torque generating device.

The above-described wheel test device may include power distributing means configured to distribute power generated by the first electric motor to the rail wheel and the test wheel.

In the above-described wheel test device, the rail wheel and the test wheel may be configured to rotate in opposite directions at substantially the same peripheral speed when the operation of the second electric motor is stopped.

In the above-described wheel test device, the torque generating device may include an output shaft disposed coaxially with the rotating frame.

In the above-described wheel test device, the torque generating device may include a bearing unit configured to rotatably support the rotating frame, the rotating frame may have a cylindrical shaft part supported by the bearing unit, a bearing may be provided on an inner periphery of the shaft part; and the output shaft may pass through a hollow portion of the shaft part and may be rotatably supported by the bearing.

In the above-described wheel test device, the first electric motor may be disposed coaxially with the rotating frame.

In the above-described wheel test device, the second electric motor may be fixed to the rotating frame via a plurality of rod-shaped connecting members arranged radially about a rotation axis of the rotating frame.

In the above-described wheel test device, the rotating frame may include a cylindrical motor housing part configured to house the second electric motor.

The above-described wheel test device may include a control part configured to control the first electric motor and the second electric motor, a rotation speed measuring means configured to measure a rotation speed of the rail wheel, and a torque measuring means configured to measure the torque of the test wheel, and the control part may control driving of the first electric motor based on measurement result of the rotation speed measuring means, and may control driving of the second electric motor based on measurement result of the torque measuring means.

The above-described wheel test device may include a wheel load applying unit configured to apply a wheel load to the test wheel by moving one of the test wheel and the rail wheel forward and backward with respect to the other.

The above-described wheel test device may include an attack angle applying unit configured to apply an attack angle by rotating one of the test wheel and the rail wheel about a straight line perpendicular to a tread surface of the test wheel with respect to the other.

The above-described wheel test device may include a cant angle applying unit configured to apply a cant angle by rotating one of the test wheel and the rail wheel about a tangent line with respect to the other.

The above-described wheel test device may include a lateral pressure applying unit configured to apply lateral pressure to the test wheel by moving one of the test wheel and the rail wheel in an axial direction with respect to the other.

According to an embodiment of the present invention, it is possible to reduce power consumption of the wheel test device.

In the following description, the same or corresponding elements will be denoted by the same or corresponding numerals, and redundant description will be omitted. In each drawing, in a case where a plurality of item whose numerals are in common are shown, the numeral is not necessarily assigned to all of the plurality of items, and assignment of the numeral to some of the plurality of item is appropriately omitted.

<FIG> and <FIG> are perspective views of a wheel test device <NUM> according to a first embodiment of the present invention. <FIG> is a front side view and <FIG> is a rear side view. <FIG> is a plan view of the wheel test device <NUM>.

In <FIG>, as shown by the coordinate axes, a direction from lower right to upper left is defined as an X-axis direction, a direction from upper right to lower left is defined as a Y-axis direction, and a direction from bottom to top is defined as a Z-axis direction. The X-axis direction and the Y-axis direction are horizontal directions orthogonal to each other, and the Z-axis direction is a vertical direction. Arbitrary straight lines respectively extending in the X-axis direction, the Y-axis direction, and the Z-axis direction are referred to as an X-axis, a Y-axis, and a Z-axis, respectively. The X-axis positive direction is referred to as left, the X-axis negative direction is referred to as right, the Y-axis positive direction is referred to as front, the Y-axis negative direction is referred to as rear, the Z-axis positive direction is referred to as up, and the Z-axis negative direction is referred to as down.

The wheel test device <NUM> is a device capable of simulating an interaction between a rail and a wheel that occurs when a railway vehicle is running, and evaluating, for example, an adhesion property and the like between the rail and the wheel. In the present embodiment, a rail wheel R of which outer periphery having a cross-sectional shape that simulates a rail head is used, and both the rail wheel R and a wheel for tests (hereinafter referred to as a "test wheel W") are rotated in a state where the test wheel W is pressed against the rail wheel R, whereby the interaction between the rail and the wheel when a railway vehicle is running is simulated.

The wheel test device <NUM> includes a drive system DS that drives the rail wheel R and the test wheel W. <FIG> is a block diagram showing a schematic configuration of the drive system DS. The drive system DS includes an actuating section AS that generates mechanical power (hereinafter simply referred to as "power") and a transmitting section TS that transmits the power generated by the actuating section AS to the rail wheel R and the test wheel W which are targets to be driven, and constitutes a power circulation system together with the rail wheel R and the test wheel W, as will be described later.

The actuating section AS includes a rotary drive device <NUM> (a speed control drive device) capable of controlling rotation speed of a driven object, and a torque generating device <NUM> (a torque control drive device) capable of controlling torque to be applied to the driven object. In the drive system DS of the present embodiment, by adopting a configuration in which drive control is divided into speed control and torque control and dedicated drive units perform speed control and torque control, respectively, it is made possible to drive at high speed (or at high acceleration) and high torque while using a motor having a relatively small capacity. Furthermore, the drive system DS employs a power circulation system, thereby realizing a higher energy utilization efficiency than those of the conventional devices.

The transmitting section TS includes a first transmission section <NUM> and a second transmission section <NUM>. The torque generating device <NUM> also constitutes a part of the transmitting section TS. The first transmission section <NUM> transmits rotation output from the rotary drive device <NUM> to the rail wheel R and the torque generating device <NUM>. The torque generating device <NUM> adds power generated by the torque generating device <NUM> itself to the power transmitted from the rotary drive device <NUM> and outputs the added power. The second transmission section <NUM> transmits the output of the torque generating device <NUM> to the test wheel W.

The rail wheel R and the test wheel W are attached to the wheel test device <NUM> so that they are arranged in the radial direction with their rotation axes parallel to each other. When performing test, the test wheel W is pressed against the rail wheel R, and the test wheel W and the rail wheel R are driven to rotate in directions opposite to each other at substantially the same peripheral speed (i.e., a linear speed of an outer peripheral surface) in a state where an outer peripheral surface (tread surface) of the test wheel W is in contact with an outer peripheral surface (top surface) of the rail wheel R. At this time, the transmitting section TS together with the test wheel W and the rail wheel R constitutes a power circulation system (i.e., a loop of power transmission shafts). The torque generating device <NUM> applies torque to the power circulation system by giving a phase difference between an input shaft (first transmission section <NUM>) and an output shaft (second transmission section <NUM>). By the adoption of the power circulation system, the wheel test device <NUM> can apply torque (or tangential force) to the test wheel W without substantially absorbing the generated power, and thus the wheel test device <NUM> can be operated with relatively little energy consumption.

The first transmission section <NUM> of the present embodiment is configured so that the rail wheel R and the test wheel W are rotationally driven at the same peripheral speed in opposite directions with respect to each other in a state where the operation of the torque generating device <NUM> (specifically, the second electric motor <NUM> described later) is stopped. It should be noted that a configuration may be adopted in which a difference in peripheral speed occurs between the rail wheel R and the test wheel W in a state where the operation of the torque generating device <NUM> is stopped. However, in this case, since the amount of operation of the torque generating device <NUM> increases in order to compensate for the difference in peripheral speed, the energy consumption increases. Also, although the first transmission section <NUM> of the present embodiment is configured so that the rail wheel R and the torque generating device <NUM> are rotationally driven at the same rotation speed, a configuration may be adopted in which the rail wheel R and the torque generating device <NUM> are rotated at different rotation speeds as long as the rail wheel R and the test wheel W are rotationally driven at substantially the same peripheral speed.

As shown in <FIG>, the rotary drive device <NUM> includes a tension adjustment table <NUM> and a first electric motor <NUM> (a speed control motor) installed on the tension adjustment table <NUM>. The first electric motor <NUM> of the present embodiment is a so-called inverter motor whose drive is controlled by an inverter, but another type of motor, such as a servo motor or a stepping motor, in which rotation speed can be controlled, may be used for the first electric motor <NUM>. The rotary drive device <NUM> may include a reducer for reducing the rotation output from the first electric motor <NUM>. The tension adjustment table <NUM> will be described later.

The first transmission section <NUM> includes a first belt mechanism <NUM>, a rail wheel support unit <NUM>, a shaft <NUM>, and a gear box <NUM> (gear device).

As shown in <FIG>, the first belt mechanism <NUM> includes a drive pulley <NUM> driven by the rotary drive device <NUM>, a driven pulley <NUM> attached to an input shaft (one of shafts <NUM> described later) of the rail wheel support unit <NUM>, and a belt <NUM> wound around the drive pulley <NUM> and the driven pulley <NUM>.

The rotation output from the rotary drive device <NUM> is transmitted to the rail wheel support unit <NUM> by the first belt mechanism <NUM> of the first transmission section <NUM>.

The belt <NUM> of the present embodiment is a V-ribbed belt having a plurality of V-shaped ribs arranged in a width direction, but may be another type of belt such as a V-belt having a trapezoidal cross-sectional shape, a toothed belt, a flat belt, or a round belt.

The first belt mechanism <NUM> of the present embodiment includes a single belt transmission unit including a drive pulley <NUM>, a driven pulley <NUM>, and a belt <NUM>, but may include two or more belt transmission units connected in parallel or in series.

The transmission from the rotary drive device <NUM> to the rail wheel support unit <NUM> is not limited to belt transmission, but other types of winding transmission such as chain transmission or wire transmission, or other transmission systems such as gear transmission may be used. The rotary drive device <NUM> and the rail wheel support unit <NUM> may be disposed coaxially (i.e., so that the rotation axes or the center lines are coincident with each other) and an output shaft of the rotary drive device <NUM> and an input shaft of the rail wheel support unit <NUM> may be directly connected to each other.

The tension adjustment table <NUM> of the rotary drive device <NUM> will now be described. As shown in <FIG>, the tension adjustment table <NUM> includes a fixed frame <NUM> fixed to a base B and a movable frame <NUM> to which the rotary drive device <NUM> is attached. The movable frame <NUM> is pivotally connected to the fixed frame <NUM> via a rod 114R extending in the Y-axis direction at a right end portion of the movable frame <NUM>, so that an inclination around the Y-axis can be adjusted. A distance between the drive pulley <NUM> (<FIG>) and the driven pulley <NUM> can be changed by changing the inclination of the movable frame <NUM>, whereby it is made possible to adjust the tension of the belt <NUM> wound around the drive pulley <NUM> and the driven pulley <NUM>.

As shown in <FIG> and <FIG>, the rail wheel support unit <NUM> includes a pair of bearings <NUM> and a pair of shafts <NUM>. The pair of bearings <NUM> are arranged across the rail wheel R, in front of and behind the rail wheel R (i.e., arranged in the Y-axis direction), with the rotation axes thereof oriented the Y-axis direction, and are coaxially arranged.

One shaft <NUM> is rotatably supported by the front bearing <NUM>, and the other shaft <NUM> is rotatably supported by the rear bearing <NUM>. The shafts <NUM> are flanged shafts each provided with a flange for mounting the rail wheel R at one end thereof, and are removably and coaxially mounted on respective side surfaces of the rail wheel R by bolts.

The driven pulley <NUM> of the first belt mechanism <NUM> is attached to the other end of the front shaft <NUM>. One end of the shaft <NUM> is connected to the other end of the rear shaft <NUM>. The other end of the shaft <NUM> is connected to an input shaft 342a of the gear box <NUM>.

Part of the power transmitted by the first belt mechanism <NUM> to the rail wheel support unit <NUM> is given to the rail wheel R, and the rest is given to the shaft <NUM> (and to the test wheel W via the shaft <NUM>, the torque generating device <NUM>, and the second transmission section <NUM>). That is, the rail wheel support unit <NUM> (specifically, the shafts <NUM>) functions as power distributing means for distributing the power generated by the first electric motor <NUM> and transmitted by the first belt mechanism <NUM> to the rail wheel R and the shaft <NUM> (and finally to the test wheel W).

The coupling structure between the shafts <NUM> and the rail wheel R is not limited to the coupling by the flange, but may be another coupling structure such as, for example, a structure in which the shaft <NUM> is fitted into a through hole provided at the center of the rail wheel R.

As shown in <FIG>, the rail wheel support unit <NUM> includes a rotary encoder <NUM> (rotation speed detecting means) for detecting a rotation speed of the rail wheel R.

<FIG> is a schematic cross-sectional view of the gear box <NUM> and its periphery cut along a horizontal plane. The gear box <NUM> includes a case <NUM>, a pair of first bearings <NUM> and a pair of second bearings <NUM> attached to the case <NUM>, a first gear <NUM> (an input gear) rotatably supported by the pair of first bearings <NUM>, and a second gear <NUM> (an output gear) rotatably supported by the pair of second bearings <NUM>.

The first gear <NUM> and the second gear <NUM> are arranged side by side in the X-axis direction with the rotation axes oriented in the Y-axis direction so that their teeth mesh with each other, and are housed in the case <NUM>. One end of the first gear <NUM> is the input shaft 342a of the gear box <NUM> and is connected to the other end of the shaft <NUM>. A flange formed at one end of the second gear <NUM> is an output shaft 344a of the gear box <NUM> and is connected to a flange (an input shaft 211b) formed at one end of a later-described casing <NUM> of the torque generating device <NUM>.

The second gear <NUM> is formed with a cylindrical through hole 344b centered on the rotation axis. An output shaft <NUM> of the torque generating device <NUM>, which will be described later, is inserted into the through hole 344b from one end of the second gear <NUM> (the left end in <FIG>, i.e., the front end of the output shaft 344a), penetrates the second gear <NUM>, and a front end thereof protrudes from the other end of the second gear <NUM>.

In the present embodiment, the first gear <NUM> and the second gear <NUM> have the same number of teeth, and thus a gear ratio of the gear box <NUM> is <NUM>. The gear ratio of the gear box <NUM> may be set to a value other than <NUM> as long as the test wheel W and the rail wheel R can be rotated in the opposite direction at substantially the same peripheral speed.

The transmission from the shaft <NUM> to the torque generating device <NUM> is not limited to the gear transmission, but other transmission systems such as, for example, a winding transmission such as a belt transmission or a chain transmission may be used.

<FIG> is a schematic cross-sectional view of the torque generating device <NUM>, the gear box <NUM>, and the periphery thereof taken along a plane perpendicular to the X-axis direction.

The torque generating device <NUM> includes a main body 20A (rotating part) rotationally driven by the rotary drive device <NUM>, and a pair of bearing units <NUM> and <NUM> for rotatably supporting the main body 20A.

The main body 20A includes a substantially cylindrical casing <NUM> (rotating frame) supported by bearing units <NUM> and <NUM>, a second electric motor <NUM> and a reducer <NUM> attached to the casing <NUM>, and an output shaft <NUM>. The output shaft <NUM> is disposed coaxially with the casing <NUM>. A shaft <NUM> and a rotor <NUM> of the second electric motor <NUM> which will be described later may be disposed coaxially with the casing <NUM>. By arranging the second electric motor <NUM> coaxially with the casing <NUM>, unbalance of the main body 20A is reduced, and it becomes possible to rotate the main body 20A smoothly (i.e., with less unnecessary fluctuation of the rotation speed and torque). Although the second electric motor <NUM> in this embodiment is an AC servo motor, other types of electric motor capable of controlling driving amount (rotation angle), such as a DC servo motor or a stepping motor, may be used as the second electric motor <NUM>. In the present embodiment, as the second electric motor <NUM>, an ultra-low inertia high power type AC servo motor of which moment of inertia of a rotating part is <NUM>·m<NUM> or less (more preferably <NUM>·m<NUM> or less) and a rated output is <NUM> kW to <NUM> kW (more practically <NUM> kW to <NUM> kW) is used. As a result, it is possible to generate rapid torque change (e.g., a vibration torque of a high frequency exceeding <NUM> or <NUM>).

The casing <NUM> has a substantially cylindrical first cylindrical part <NUM> and a substantially cylindrical second cylindrical part <NUM> (a motor housing part), a connecting part <NUM> that connects the first cylindrical part <NUM> and the second cylindrical part <NUM>, a first shaft part <NUM> connected to the first cylindrical part <NUM>, and a second shaft part <NUM> connected to the second cylindrical part <NUM>. The first shaft part <NUM>, the first cylindrical part <NUM>, the connecting part <NUM>, the second cylindrical part <NUM>, and the second shaft part <NUM> are all cylindrical members having a hollow portion passing through in the axial direction, and are coaxially connected in this order to form the cylindrical casing <NUM>. The casing <NUM> is supported at the first shaft part <NUM> by the bearing unit <NUM> and at the second shaft part <NUM> by the bearing unit <NUM>. A flange formed at the tip end of the first shaft part <NUM> is the input shaft 211b (<FIG>) of the torque generating device <NUM>, and is connected to the output shaft 344a of the gear box <NUM>.

<FIG> is a vertical cross-sectional view showing a schematic configuration of the second electric motor <NUM>. The second electric motor <NUM> includes a shaft <NUM>, a rotor <NUM> composed of a permanent magnet or the like and integrally coupled with the shaft <NUM>, a tubular stator <NUM> provided with a coil 223a on its inner periphery, a pair of flanges <NUM> and <NUM> attached to both ends of the stator <NUM> so as to close openings, a pair of bearings <NUM> and <NUM> attached to the respective flanges <NUM> and <NUM>, and a rotary encoder RE for detecting an angular position (phase) of the shaft <NUM>.

The shaft <NUM> is rotatably supported by the pair of bearings <NUM> and <NUM>. One end (the right end in <FIG>) of the shaft <NUM> protrudes to the outside through the flange <NUM> and the bearing <NUM> and serves as an output shaft of the second electric motor <NUM>. The other end (the left end in <FIG>) of the shaft <NUM> is connected to the rotary encoder RE.

As shown in <FIG>, the second electric motor <NUM> is housed in a hollow portion (compartment C1) of the second cylindrical part <NUM> of the casing <NUM>. One end (left end in <FIG>) of the connecting part <NUM> of the casing <NUM> is formed with an inner flange part 213a projecting to the inner periphery. The stator <NUM> (<FIG>) of the second electric motor <NUM> is fixed to the second cylindrical part <NUM> via a plurality of rod-shaped coupling members <NUM> radially arranged around the rotation axis of the torque generating device <NUM>. As the coupling members <NUM>, for example, stud bolts or full-threaded bolts having male screws formed at both ends are used. The flange <NUM> (<FIG>) of the second electric motor <NUM> is supported by the inner flange part 213a of the connecting part <NUM>.

The reducer <NUM> is housed in a compartment C2 surrounded by the connecting part <NUM> and the first cylindrical part <NUM> of the casing <NUM>. The shaft <NUM> of the second electric motor <NUM> is connected to an input shaft <NUM> of the reducer <NUM>, and the output shaft <NUM> of the torque generating device <NUM> is connected to an output shaft <NUM> of the reducer <NUM>. The output shaft <NUM> may be directly connected to the shaft <NUM> of the second electric motor <NUM> without providing the reducer <NUM> in the torque generating device <NUM>.

A case <NUM> of the reducer <NUM> is fixed to the other end of the connecting part <NUM>. That is, the flange <NUM> of the second electric motor <NUM> (<FIG>) and the case <NUM> of the reducer <NUM> are integrally coupled to each other by a single cylindrical connecting part <NUM>. Therefore, the second electric motor <NUM> and the reducer <NUM> are integrally coupled with high rigidity, and it is made difficult to apply bending moment to the shaft <NUM>. As a result, friction that the shaft <NUM> receives from the bearings <NUM> and <NUM> (<FIG>) can be reduced, and thus accuracy of torque control by the torque generating device <NUM> improves.

The output shaft <NUM> of the torque generating device <NUM> passes through the hollow portions of the first shaft part <NUM> of the casing <NUM> and the gear box <NUM> (specifically, the second gear <NUM>) and protrudes to the rear of the gear box <NUM>. A bearing 211a and a bearing 344c for rotatably supporting the output shaft <NUM> are provided on the inner peripheries of the first shaft part <NUM> of the casing <NUM> and the second gear <NUM> of the gear box <NUM>, respectively.

Two drive pulleys <NUM> of a second belt mechanism <NUM>, which will be described later, are attached to a distal end portion of the output shaft <NUM> protruding rearward from the gear box <NUM>. The distal end portion of the output shaft <NUM> is rotatably supported by a bearing unit <NUM> of the second belt mechanism <NUM>.

A slip ring part <NUM> is provided adjacent to the front side (left side in <FIG>) of the bearing unit <NUM>. The slip ring part <NUM> includes a movable part 27A that rotates together with the main body 20A of the torque generating device <NUM> and a fixed part 27B that is fixed to the base B.

The movable part 27A includes a ring support tube <NUM> coaxially connected to the second shaft part <NUM> of the torque generating device <NUM>, and a plurality of slip rings <NUM> coaxially attached to an outer periphery of the ring support tube <NUM> at intervals in the axial direction.

A cable <NUM> of the second electric motor <NUM> of the torque generating device <NUM> passes through the second shaft part <NUM> of the casing <NUM>. A plurality of electric wires constituting the cable <NUM> pass through a hollow portion of the ring support tube <NUM> and are connected to the corresponding slip rings <NUM>.

The fixed part 27B includes a brush support part <NUM>, a plurality of brushes <NUM> supported by the brush support part <NUM>, and a bearing part <NUM> that rotatably supports a tip portion of the ring support tube <NUM>. The brushes <NUM> are arranged at intervals in the Y-axis direction so as to be in contact with outer peripheral surfaces of the corresponding slip rings <NUM>. The brushes <NUM> are wired and connected to a servo amplifier 22a and the like which will be described later.

A rotary encoder <NUM> for detecting the rotation speed of the ring support tube <NUM> (i.e., the rotation speed of the casing <NUM> being the input shaft of the torque generating device <NUM>) is attached to the bearing part <NUM>.

As shown in <FIG>, the second transmission section <NUM> includes a second belt mechanism <NUM>, a slide type constant velocity joint <NUM>, and a wheel support unit <NUM>.

The second belt mechanism <NUM> includes two sets of belt transmission units each including a drive pulley <NUM>, a driven pulley <NUM>, and a belt <NUM>, a bearing unit <NUM>, a shaft <NUM>, and a pair of bearing units <NUM>.

As described above, the two drive pulleys <NUM> are attached to the distal end portion of the output shaft <NUM> of the torque generating device <NUM> passing through the gear box <NUM>. The bearing unit <NUM> rotatably supports the distal end portion of the output shaft <NUM>.

An additional bearing unit <NUM> may be provided between the gear box <NUM> and the drive pulley <NUM> so that the distal end of the output shaft <NUM> is supported by a pair of bearing units <NUM>. In the present embodiment, the drive pulley <NUM> is directly attached to the output shaft <NUM> of the torque generating device <NUM>, but a shaft for supporting the drive pulley <NUM> may be provided separately from the output shaft <NUM> so that the shaft connected to the output shaft <NUM> is supported by the bearing unit <NUM>.

The two driven pulleys <NUM> are attached to the shaft <NUM> rotatably supported by the pair of bearing units <NUM>.

Each belt <NUM> is wound around corresponding drive pulley <NUM> and driven pulley <NUM>.

The belt <NUM> of the present embodiment is a toothed belt having a core wire of a steel wire. The belt <NUM> may be a belt having a core wire formed of a so-called super fiber such as carbon fiber, aramid fiber, or ultra-high molecular weight polyethylene fiber. By using a lightweight and high-strength core wire such as a carbon core wire formed of carbon fiber, it becomes possible to drive at a high acceleration (or to apply a high driving/braking force to the test wheel W) using a motor having a relatively low output, and thus it becomes possible to reduce the size of the wheel test device <NUM>. When a motor having the same output is used, it is possible to increase the performance of the wheel test device <NUM> by using a lightweight (i.e., low inertia) belt <NUM> having a core wire formed of the so-called super fiber. A general automotive or industrial timing belt may be used as the belt <NUM>. A flat belt or a V-belt may be used as the belt <NUM> in place of the toothed belt. These belts that can be used as the belt <NUM> can also be used as the belt <NUM> of the first belt mechanism <NUM>.

The second belt mechanism <NUM> of the present embodiment includes a pair of belt transmission units connected in parallel, but may include a single belt transmission unit or three or more belt transmission units connected in parallel.

The transmission from the torque generating device <NUM> to the to the slide type constant velocity joint <NUM> is not limited to belt transmission, and other types of winding transmission such as chain transmission or wire transmission, or other transmission systems such as gear transmission may be used. The torque generating device <NUM> and the slide type constant velocity joint <NUM> may be arranged in a substantially straight line (or in a V-shape), and the output shaft <NUM> of the torque generating device <NUM> and the input shaft of the slide type constant velocity joint <NUM> may be directly connected.

The wheel support unit <NUM> is connected to the torque generating device <NUM> via the slide type constant velocity joint <NUM>. Specifically, one end portion (i.e., an input shaft) of the slide type constant velocity joint <NUM> is connected to the shaft <NUM> of the second belt mechanism <NUM>, and the other end portion (i.e., an output shaft) of the slide type constant velocity joint <NUM> is connected to a later-described spindle <NUM> of the wheel support unit <NUM>.

The slide type constant velocity joint <NUM> is configured to be able to smoothly transmit rotation without rotation fluctuation regardless of an operating angle (i.e., an angle formed by the input shaft and the output shaft). The slide type constant velocity joint <NUM> also has a variable length (transmission distance) in the axial direction.

As will be described later, the spindle <NUM> is supported so that its position can change. By connecting the spindle <NUM> to the shaft <NUM> of the second belt mechanism <NUM> (or to the output shaft <NUM> of the torque generating device <NUM>) via the slide type constant velocity joint <NUM>, even if the position of the spindle <NUM> changes, the slide type constant velocity joint <NUM> flexibly follows this change, so that large strain is prevented from being applied to the spindle <NUM> and the shaft <NUM> (or to the output shaft <NUM> of the torque generating device <NUM>), and rotation can be smoothly transmitted to the spindle <NUM>. By using the slide type constant velocity joint <NUM>, the rotation speed transmitted to the spindle <NUM> is prevented from changing depending on the position of the spindle <NUM> (or the operating angle of the slide type constant velocity joint <NUM>).

As shown in <FIG>, the wheel support unit <NUM> includes a fixed base <NUM>, and a main body <NUM> and a wheel load applying unit <NUM> disposed on the fixed base <NUM>.

As shown in <FIG>, the main body <NUM> includes a movable base <NUM>, a pair of linear guides <NUM> that support the movable base <NUM> so as to be movable in the X-axis direction with respect to the fixed base <NUM>, a support frame <NUM> installed on the movable base <NUM>, a bearing unit <NUM> attached to the support frame <NUM>, a spindle <NUM> rotatably supported by the bearing unit <NUM>, a torque sensor <NUM> and a detection gear <NUM> coaxially attached to the spindle <NUM>, and a rotation detector <NUM> for detecting rotation of the detection gear <NUM>. The linear guide <NUM> is a guide-way type circulating rolling bearing provided with a linear rail (guideway) and a carriage capable of running on the rail via rolling elements. However, other types of linear guide mechanism may be used as the linear guide <NUM>. The linear guide <NUM> constitutes a part of the wheel load applying unit <NUM>. The detection gear <NUM> and the rotation detector <NUM> constitute rotation speed detecting means for detecting the rotation speed of the spindle <NUM>.

The support frame <NUM> has a support column 523a fixed to the movable base <NUM> and an arm 523b fixed to the support column 523a. Although the support column 523a of the present embodiment is an L-shaped bracket, other types of support column 523a may be used. The support column 523a and the arm 523b may be integrally formed. The arm 523b is a substantially L-shaped structure as seen from above, having a base part 523b1 extending rearward from an upper portion of the support column 523a and a trunk part 523b2 extending leftward from a rear end portion of the base part 523b1. A hollow portion penetrating in the Y-axis direction is formed at a distal end portion of the trunk part 523b2. A drive shaft (specifically, an assembly of the slide type constant velocity joint <NUM>, the torque sensor <NUM>, the detection gear <NUM>, and the spindle <NUM> connected to each other) passes through the hollow portion.

The bearing unit <NUM> is attached to the arm 523b. More specifically, the bearing unit <NUM> is attached to a front surface of the front end portion of the trunk part 523b2 with the rotation axis thereof oriented in the Y-axis direction. The bearing unit <NUM> is provided with a plurality of three component force sensors <NUM> (tangential force detecting means and first lateral pressure detecting means) for detecting force received from the spindle <NUM>. The three component force sensors <NUM> are piezoelectric force sensors, but other types of force sensors may be used as the three component force sensors <NUM>.

The spindle <NUM> is connected to the output shaft of the slide type constant velocity joint <NUM> via the detection gear <NUM> and the torque sensor <NUM>. The detection gear <NUM> and the torque sensor <NUM> are housed in a hollow portion formed at a distal end portion of the trunk part 523b2. The test wheel W is attached to a mounting portion provided at a distal end portion of the spindle <NUM>. The torque sensor <NUM> detects a torque acting on the spindle <NUM> (i.e., acting on the test wheel W).

The rotation detector <NUM> is disposed to face an outer peripheral surface of the detection gear <NUM> and is fixed to the trunk part 523b2 of the support frame <NUM>. The rotation detector <NUM> is, for example, a non-contact type rotation detector such as an optical type, an electromagnetic type, or a magnetoelectric type, and detects a change in an angular position of the detection gear <NUM>.

The wheel load applying unit <NUM> is a mechanism that applies a wheel load of a predetermined size to the test wheel W by moving the main body <NUM> of the wheel support unit <NUM> in the X-axis direction and pressing the test wheel W attached to the spindle <NUM> against the rail wheel R.

The wheel load applying unit <NUM> includes a motor <NUM>, a motion converter <NUM> that converts a rotational motion of the motor <NUM> into a linear motion in the X-axis direction, and a wheel load detector <NUM> (<FIG>) for detecting a wheel load acting on the test wheel W.

Although the motor <NUM> is an AC servo motor, other types of electric motor capable of controlling drive amount (rotation angle), such as a DC servo motor or a stepping motor, may be used as the motor <NUM>.

The motion converter <NUM> of the present embodiment is, for example, a screw jack in which a reducer such as a worm gear device is combined with a feed screw mechanism such as a ball screw, but other types of motion converter may be used. A linearly moving part 532a of the motion converter <NUM> is fixed to the support frame <NUM> via the wheel load detector <NUM>.

When the motor <NUM> drives the motion converter <NUM>, the support frame <NUM> and the spindle <NUM> supported by the support frame <NUM> move in the X-axis direction together with the linearly moving part 532a. As a result, the test wheel W attached to the spindle <NUM> moves back and forth with respect to the rail wheel R. When the motor <NUM> drives the motion converter <NUM> further in a direction in which the test wheel W moves toward the rail wheel R (i.e., in the X-axis positive direction) in a state where the test wheel W and the rail wheel R are in contact with each other, the test wheel W is pressed against the rail wheel R, and the wheel load is applied to the test wheel W.

The wheel load detector <NUM> is a force sensor that detects a force in the X-axis direction (i.e., wheel load) acting on the test wheel W via the support frame <NUM> and the spindle <NUM> by the wheel load applying unit <NUM>. The wheel load detector <NUM> of the present embodiment is a load cell of a strain gauge type, but other types of force sensor such as a piezoelectric force sensor may be used as the wheel load detector <NUM>. A control part <NUM> which will be described later controls the drive of the motor <NUM> so that the wheel load of a predetermined magnitude is applied to the test wheel W based on the detection result by the wheel load detector <NUM>.

<FIG> is a block diagram showing a schematic configuration of a control system CS of the wheel test device <NUM>. The control system CS includes a control part <NUM> that controls operation of the entire wheel test device <NUM>, a measuring part <NUM> that performs various measurements based on signals from various detectors provided to the wheel test device <NUM>, and an interface part <NUM> for performing input from and output to the outside.

The second electric motor <NUM> and the motor <NUM> are connected to the control part <NUM> via servo amplifiers 22a and 531a, respectively, and the first electric motor <NUM> is connected to the control part <NUM> via a driver 12a (inverter circuit).

The rotary encoders <NUM> and <NUM>, the torque sensor <NUM>, the three component force sensors <NUM>, and the wheel load detector <NUM> are connected to the measuring part <NUM> via amplifiers 28a, 323a, 524a, 529a, and 533a, respectively. In <FIG>, only one representative set is shown among a plurality of sets of three component force sensors <NUM> and amplifiers 529a provided to the wheel test device <NUM>. The rotation detector <NUM> embedded with an amplifier circuit and an analog-to-digital conversion circuit is directly connected to the measuring part <NUM>.

The measuring part <NUM> measures the rotation speed of the rail wheel R on the basis of a signal from a rotary encoder <NUM>, measures the rotation speed of the input shaft (casing <NUM>) of the torque generating device <NUM> on the basis of a signal from the rotary encoder <NUM>, measures the rotation speed of the spindle <NUM> (i.e., the rotation speed the test wheel W) on the basis of a signal from the rotation detector <NUM>. The measuring part <NUM> further measures the torque acting on the test wheel W on the basis of a signal from the torque sensor <NUM>, measures a tangential force (longitudinal creep force) and a lateral pressure (thrust load) acting on the test wheel W on the basis of signals from a plurality of three component force sensors <NUM>, and measures the wheel load on the basis of a signal from a wheel load detector <NUM>. That is, the measuring part <NUM> functions as a first rotation speed measuring means for measuring the rotation speed of the rail wheel R, a second rotation speed measuring means for measuring the rotation speed of the torque generating device <NUM>, a third rotation speed measuring means for measuring the rotation speed of the test wheel W, a torque measuring means for measuring the torque acting on the test wheel W, a tangential force measuring means for measuring the tangential force acting on the test wheel W, a lateral pressure measuring means for measuring the lateral pressure acting on the test wheel W, and a wheel load measuring means for measuring the wheel load acting on the test wheel W. The measuring part <NUM> transmits these measured values to the control part <NUM>.

Although the wheel test device <NUM> of the present embodiment includes many measuring means and corresponding detecting means because it is a relatively versatile device, the wheel test device <NUM> need not be provided with all of these measuring means and detecting means, but may be provided with one or more sets of measuring means and detecting means which are appropriately selected according to the matters to be examined by the test.

The phase information of the shaft detected by the rotary encoder RE embedded in each servo motor (the second electric motor <NUM> and the motor <NUM>) is input to the control part <NUM> via the corresponding servo amplifiers 22a, 531a.

The interface part <NUM> includes, for example, one or more of a user interface for performing input/output with a user, a network interface for connecting with various networks such as the LAN (Local Area Network), and various communication interfaces such as the USB (Universal Serial Bus) and the GPIB (General Purpose Interface Bus) for connecting with external devices. The user interface includes, for example, one or more of various operation switches, various display devices such as indicators and LCD (Liquid Crystal Display), various pointing devices such as a mouse and a touch pad, and various input/output devices such as a touch screen, a video camera, a printer, a scanner, a buzzer, a speaker, a microphone, and a memory card reader/writer.

The control part <NUM> controls the driving of the first electric motor <NUM> based on setting data of the rotation speed (or peripheral speed) of the rail wheel R inputted through the interface part <NUM> and the measurement result of the rotation speed of the rail wheel R by the measuring part <NUM> so that the rail wheel R rotates at a set rotation speed.

The control part <NUM> controls the driving of the motor <NUM> of the wheel load applying unit <NUM> based on wheel load setting data input through the interface part <NUM> and the wheel load measurement result by the measuring part <NUM> so that a set wheel load is applied to the test wheel W.

The control part <NUM> controls the driving of the second electric motor <NUM> of the torque generating device <NUM> based on setting data of the torque of the test wheel W inputted through the interface part <NUM> and the measurement result of the torque of the test wheel W by the measuring part <NUM> so that a set torque is applied to the test wheel W.

Next, an example of a method of performing a test using the wheel test device <NUM> will be described. First, the control part <NUM> drives the motor <NUM> of the wheel load applying unit <NUM> in a state where the rail wheel R and the test wheel W are attached to the wheel test device <NUM> to bring the test wheel W close to and into contact with the rail wheel R, and applies the set wheel load to the test wheel W. As the set value of the wheel load, a constant value or a variable value that varies with time can be set.

Then, the control part <NUM> drives the first electric motor <NUM> of the rotary drive device <NUM> so that the rail wheel R rotates at the set rotation speed. As the set value of the rotation speed of the rail wheel R, a constant value or a variable value that varies with time can be set. The control part <NUM> also controls the second electric motor <NUM> so that the torque of the test wheel W is <NUM> (no load) until the rotation speed of the rail wheel R reaches the set value.

As the rotation speed of the rail wheel R reaches the set value, the control part <NUM> controls the driving of the second electric motor <NUM> of the torque generating device <NUM> so that the set torque is applied to the test wheel W. As the set value of the torque of the test wheel W, a constant value or a variable value that varies with time can be set. The driving of the second electric motor <NUM> may be controlled so that the set torque is applied to the test wheel W from the start of the rotational drive of the rail wheel R.

In this state, the control part <NUM> rotates the rail wheel R and the test wheel W while continuously measuring the rotation speed of the rail wheel R, the torque of the test wheel W, the tangential force, the lateral pressure, and the wheel load for a predetermined time (test time). At this time, the control part <NUM> stores each measurement value in a storage device <NUM> of the control part <NUM> (or, for example, a storage means accessible by the control part <NUM> such as a server connected to the control part <NUM> via a LAN) in association with the measured time.

When a predetermined time elapses, the control part <NUM> controls the driving of the second electric motor <NUM> of the torque generating device <NUM> so that the torque of the test wheel W becomes <NUM>. Then, the control part <NUM> controls the first electric motor <NUM> of the rotary drive device <NUM> to gradually reduce the rotation speed of the rail wheel R to stop the rotation, and then drives the motor <NUM> of the wheel load applying unit <NUM> to move the test wheel W away from the rail wheel R by a predetermined distance to end the test.

The test procedure described above is only an example of test procedures that can be performed using the wheel test device <NUM>, and various other test procedures can be performed.

In the following description of the second embodiment, emphasis is placed on matters different from those of the first embodiment described above, and configurations that are the same as or correspond to those of the first embodiment are assigned the same or corresponding reference numerals, and redundant description is omitted.

<FIG> is a plan view showing a schematic configuration of a wheel test device <NUM> according to a second embodiment of the present invention. <FIG> is a front view showing a schematic configuration of the wheel test device <NUM>.

The wheel test device <NUM> includes a wheel support unit <NUM> in which a lateral pressure applying function, an attack angle applying function and a cant angle applying function are added to the wheel support unit <NUM> of the first embodiment.

As shown in <FIG>, the wheel support unit <NUM> of the wheel test device <NUM> includes a lateral pressure applying unit <NUM>, a cant angle applying unit <NUM>, and an attack angle applying unit <NUM> in addition to the wheel load applying unit <NUM>. As shown in <FIG>, the wheel support unit <NUM> also includes three movable bases (a first movable base 522A, a second movable base 522B, and a third movable base 522C).

The lateral pressure applying unit <NUM> is a mechanism that applies lateral pressure (thrust load) to the test wheel W. The lateral pressure includes lateral creep force (a component of adhesive force in the axial direction of the test wheel W) and flange reaction force (force caused by a contact between a flange of the test wheel W and a gauge corner of the rail wheel R), and the latter flange reaction force is applied (or adjusted to a predetermined value) by the lateral pressure applying unit <NUM>.

The lateral pressure applying unit <NUM> includes a plurality of (for example, three) linear guides <NUM> that support the first movable base 522A with respect to the base <NUM> so as to be movable in the Y-axis direction, a motor <NUM> (<FIG>) attached to the base B together with the fixed base <NUM>, a motion converter <NUM> (<FIG>) that converts rotational motion of the motor <NUM> into a linear motion in the Y-axis direction, and a lateral pressure detector <NUM> (<FIG>) that detects the lateral pressure acting on the test wheel W. The linear guide <NUM> is a guide-way type circulating rolling bearing having the same configuration as the linear guide <NUM>, but other types of linear guide mechanism may be used as the linear guide <NUM>.

In the present embodiment, the lateral pressure detector <NUM> (second lateral pressure detecting means) is used to detect the lateral pressure when the flange reaction force is applied, and the three component force sensors <NUM> (first lateral pressure detecting means) are used to detect the lateral pressure when the flange reaction force is not applied. The wheel test device <NUM> may be configured to detect the lateral pressure by using the three component force sensors <NUM> even when the flange reaction force is applied without providing the lateral pressure detector <NUM>. Alternatively, the wheel test device <NUM> may also be configured to detect the lateral pressure by using the lateral pressure detector <NUM> even when the flange reaction force is not applied. Alternatively, the wheel test device <NUM> may be configured to detect static lateral pressure (mainly the flange reaction force) by using the lateral pressure detector <NUM> and detect dynamic lateral pressure (mainly the lateral creep force) by using the three component force sensors <NUM>.

Although the motor <NUM> in the present embodiment is an AC servo motor, other types of motor capable of controlling driving amount (rotation angle), such as a DC servo motor or a stepping motor, may be used as the motor <NUM>.

Although the motion converter <NUM> in the present embodiment is a feed screw mechanism such as a ball screw, other types of motion converter may be used. The screw shaft of the motion converter <NUM> is rotatably supported by a pair of bearings attached to the fixed base <NUM>, and one end of the screw shaft is connected to a shaft of the motor <NUM>. A nut (linearly moving part) of the motion converter <NUM> is fixed to the first movable base 522A via the lateral pressure detector <NUM>. When the screw shaft of the motion converter <NUM> is rotated by the motor <NUM>, the first movable base 522A moves in the Y-axis direction together with the nut of the motion converter <NUM>. As a result, the test wheel W supported by the first movable base 522A also moves in the Y-axis direction, changing a position of the test wheel W in the axial direction with respect to the rail wheel R. When the test wheel W is displaced in the Y-axis direction and the flange of the test wheel W is brought into contact with the rail wheel R, a flange reaction force is applied to the test wheel W. A magnitude of the flange reaction force varies depending on the position of the test wheel W in the Y-axis direction.

As shown in <FIG>, the motor <NUM> is connected to the control part <NUM> via a servo amplifier 542a. The lateral pressure detector <NUM> is connected to the measuring part <NUM> via an amplifier 544a. Phase information of the shaft detected by the rotary encoder RE embedded in the motor <NUM> is input to the control part <NUM> through the servo amplifier 542a.

The measuring part <NUM> measures the lateral pressure acting on the test wheel W on the basis of a signal from the lateral pressure detector <NUM>. The control part <NUM> controls the driving of the motor <NUM> on the basis of lateral pressure setting data input through the interface part <NUM> and the lateral pressure measurement result by the measuring part <NUM> so that a set lateral pressure is applied to the test wheel W.

The cant angle applying unit <NUM> is a mechanism having a function of applying a cant angle to the test wheel W. As shown in <FIG>, the cant angle applying unit <NUM> includes a vertically extending swing support shaft <NUM> attached to one of the first movable base 522A and the second movable base 522B, and a bearing <NUM> attached to the other of the first movable base 522A and the second movable base 522B and that rotatably supports the swing support shaft <NUM>. The second movable base 522B is supported by the swing support shaft <NUM> and the bearing <NUM> so as to be rotatable about a rotation axis A1 of the bearing <NUM>, which is a vertical line.

The bearing <NUM> is disposed substantially immediately below a contact position P at which the test wheel W contacts the rail wheel R (in the present embodiment, a right end of the rail wheel R) so that the rotation axis A1 passes through the contact position P. The rotation axis A1 is a tangent line between the rail wheel R and the test wheel W at the contact position P. Therefore, when the second movable base 522B rotates about the rotation axis A1, the test wheel W swings about the contact position P around the Z axis (in other words, the test wheel W rotates about the common tangent line between the test wheel W and the rail wheel R), and an inclination (i.e., a cant angle) about the tangent line with respect to the rail wheel R changes.

The cant angle applying unit <NUM> includes a curved guide <NUM> that supports the second movable base 522B at an outer peripheral portion apart from the rotation axis A1 so that the second movable base 522B can swing about the rotation axis A1 with respect to the first movable base 522A. The curved guide <NUM> is a guideway type circulating rolling bearing including a curved rail (guideway) and a carriage capable of running on the rail via rolling elements, but other types of curved guide mechanism may be used as the curved guide <NUM>.

Further, the cant angle applying unit <NUM> includes a motor <NUM> (<FIG>) and a motion converter <NUM> that converts rotational motion of the motor <NUM> into a linear motion in the Y-axis direction. Although the motor <NUM> in the present embodiment is an AC servo motor, other types of motor capable of controlling driving amount (rotation angle), such as a DC servo motor or a stepping motor, may be used as the motor <NUM>. Although the motion converter <NUM> in the present embodiment is a feed screw mechanism such as a ball screw, other types of motion converter may be used.

A screw shaft 555a of the motion converter <NUM> is rotatably supported by a pair of bearings, and one end of the screw shaft 555a a is connected to a shaft of the motor <NUM>. In <FIG>, the bearings supporting the screw shaft 555a are not shown. The motor <NUM> and the pair of bearings of the motion converter <NUM> are attached to a not-shown rotary table which is rotatable about a vertical shaft provided on the first movable base 522A. The motor <NUM> is disposed so that the shaft thereof intersects perpendicularly with a rotation axis of the rotary table.

As shown in <FIG>, a nut 555b (linearly moving part) of the motion converter <NUM> is coupled to the second movable base 522B via a hinge <NUM> so as to be rotatable about a vertical axis. When the screw shaft 555a is rotated by the motor <NUM>, the hinge <NUM> attached to the second movable base 522B moves substantially in the Y-axis direction together with the nut 555b. Accordingly, the second movable base 522B rotates about the rotation axis A1, and the test wheel W supported by the second movable base 522B rotates about the contact position P, whereby the cant angle is changed.

As shown in <FIG>, the motor <NUM> is connected to the control part <NUM> via a servo amplifier 554a. Phase information of the shaft detected by a rotary encoder RE embedded in the motor <NUM> is input to the control part <NUM> through the servo amplifier 554a.

The control part <NUM> calculates a current value of the cant angle based on a signal from the rotary encoder RE embedded in the motor <NUM>. The control part <NUM> controls the driving of the motor <NUM> based on setting data of the cant angle inputted through the interface part <NUM> and the current value of the cant angle so that a set cant angle is given to the test wheel W.

The attack angle applying unit <NUM> is a mechanism having a function of applying an attack angle to the test wheel W. The attack angle is an angle formed between the rail and the wheel, and more specifically, an angle about a vertical axis (i.e., an angle in the yawing direction) formed between a width direction of the rail (railroad tie direction) and the axial direction of the wheel. In the wheel test device <NUM>, the attack angle is defined as an angle between the rotation axis of the rail wheel R and the rotation axis of the test wheel W about the X axis.

As shown in <FIG>, a support frame <NUM> of the wheel support unit <NUM> of the present embodiment includes a box-shaped support column 1523a fixed to the third movable base 522C, and an arm 1523b connected to the support column 1523a so as to be rotatable about a rotation axis A2 extending in the X-axis direction. Similarly to the arm 523b of the first embodiment, the arm 1523b is a substantially L-shaped member as seen from above, and includes a base part 1523b1 extending in the Y-axis direction and connected to an upper portion of the support column 1523a, and a trunk part 1523b2 extending to the left from a rear end portion of the base part 1523b1.

From a right end of the base part 1523b1, a swing support shaft <NUM> protrudes in the X-axis direction. A bearing <NUM> that rotatably support the swing support shaft <NUM> is attached to an upper portion of the support column 1523a. The arm 1523b is supported by the bearing <NUM> via the swing support shaft <NUM> so as to be rotatable about the rotation axis A2 extending in the X-axis direction. The bearing <NUM> is disposed such that the rotation axis A2 passes through the contact position P. That is, the rotation axis A2 is a straight line perpendicularly passing through the tread surface of the test wheel W. The swing support shaft <NUM> and the bearing <NUM> form a part of the attack angle applying unit <NUM>.

As shown in <FIG>, the attack angle applying unit <NUM> includes a motor <NUM>, and a motion converter <NUM> that converts rotational motion of the motor <NUM> into a linear motion in the Z-axis direction. Although the motor <NUM> in the present embodiment is an AC servo motor, other types of motor capable of controlling driving amount (rotation angle), such as a DC servo motor or a stepping motor, may be used as the motor <NUM>. Although the motion converter <NUM> in the present embodiment is a feed screw mechanism such as a ball screw, other types of motion converter may be used.

The screw shaft of the motion converter <NUM> is rotatably supported by a pair of bearings, and one end of the screw shaft is connected to a shaft of the motor <NUM> via a bevel gear. The screw shaft of the motion converter <NUM> may be directly connected to the shaft of the motor <NUM>. The motor <NUM> and the motion converter <NUM> are attached to a swing frame coupled to the third movable base 522C via a hinge having a rotation shaft extending in the X-axis direction so as to be rotatable (i.e., swingable) within a predetermined angular range about the rotation shaft of the hinge.

A nut (linearly moving part) of the motion converter <NUM> is coupled to the arm 1523b of the support frame <NUM> via a hinge having a rotation shaft extending in the X-axis direction so as to be swingable about the rotation shaft of the hinge. When the screw shaft of the motion converter <NUM> is rotated by the motor <NUM>, the hinge attached to the arm 1523b moves together with the nut substantially in the Z-axis direction. Accordingly, the test wheel W supported by the arm 1523b together with the arm 1523b rotates about the rotation axis A2 passing through the contact position P (in other words, a straight line perpendicular to the tread surface of the test wheel), whereby an attack angle is given.

As shown in <FIG>, the motor <NUM> is connected to the control part <NUM> via a servo amplifier 564a. Phase information of the shaft detected by a rotary encoder RE embedded in the motor <NUM> is input to the control part <NUM> through the servo amplifier 564a.

The control part <NUM> calculates the current value of the attack angle based on the signal of the rotary encoder RE embedded in the motor <NUM>. The control part <NUM> controls the driving of the motor <NUM> based on setting data of the attack angle input through the interface part <NUM> and the current value of the attack angle so that a set attack angle is given to the test wheel W.

As shown in <FIG>, the linearly moving part 532a of the motion converter <NUM> of the wheel load applying unit <NUM> is fixed to the support column 1523a of the support frame <NUM> via the wheel load detector <NUM>. The linearly moving part 532a of the motion converter <NUM> is disposed so that the center line thereof coincides with the rotation axis A2. This prevents a large moment of force from being applied to the support frame <NUM> when the wheel load is applied.

The foregoing is the description of the embodiments of the present invention. The embodiments of the present invention are not limited to those described above, and various modifications are possible. For example, appropriate combinations of configurations of embodiments and the like explicitly illustrated in this specification, configurations of embodiments that are obvious to a person with ordinary skills in the art from the description of this specification, and/or well-known art are also included in the embodiments of this application.

In the above-described embodiment, the wheel load applying unit <NUM> is provided on the wheel support unit <NUM> and is configured to adjust the wheel load by moving the test wheel W back and forth with respect to the rail wheel R. However, the present invention is not limited to this configuration. For example, the wheel load applying unit may be provided to the rail wheel support unit and the wheel load may be adjusted by moving the rail wheel R back and forth with respect to the test wheel W.

In the above-described embodiment, the rail wheel R is connected to the rotary drive device <NUM> without the torque generating device <NUM> therebetween, and the test wheel W is connected to the rotary drive device <NUM> via the torque generating device <NUM>. However, the present invention is not limited to this configuration. For example, the rail wheel R may be connected to the rotary drive device <NUM> via the torque generating device <NUM>, and the test wheel W may be connected to the rotary drive device <NUM> without the torque generating device <NUM> therebetween. Alternatively, two torque generating devices <NUM> may be provided, and the rail wheel R may be connected to the rotary drive device <NUM> via one torque generating device <NUM>, and the test wheel W may be connected to the rotary drive device <NUM> through another torque generating device <NUM>.

In the above-described embodiment, a plurality of three component force sensors are provided to the wheel support unit <NUM>, and the measuring part <NUM> measures the torque and wheel load acting on the test wheel W based on the detection results of the plurality of three component force sensors. However, the present invention is not limited to this configuration. For example, the torque and wheel load may be measured based on detection results of a plurality of two component force sensors or one component force sensors.

In the above-described embodiment, the function of the power distributing means is incorporated in the rail wheel support unit <NUM>, but the power distributing means may be separated from the rail wheel support unit <NUM>. For example, the first transmission section <NUM> may not be connected to the rail wheel support unit <NUM>, and the rotary drive device <NUM> and the first transmission section <NUM> may be connected via additional power transmission means (e.g., winding transmission or gear transmission). In this case, the drive pulley <NUM> of the first belt mechanism <NUM> and the shaft of the rotary drive device <NUM> to which a pulley or gear of the additional power transmission means is to be mounted function as the power distributing means.

Claim 1:
A wheel test device (<NUM>, <NUM>) comprising:
a rail wheel support unit (<NUM>) configured to rotatably support a rail wheel (R);
a wheel support unit (<NUM>) configured to rotatably support a test wheel (W) in a state where the test wheel is in contact with the rail wheel (R);
a first electric motor (<NUM>) configured to rotate the rail wheel (R) and the test wheel (W);
power distributing means (<NUM>, <NUM>) configured to distribute power generated by the first electric motor (<NUM>) to the rail wheel (R) and the test wheel (W);
the wheel test device characterised in that it further comprises:
a torque generating device (<NUM>) configured to generate torque to be applied to the test wheel (W),
wherein the torque generating device (<NUM>) includes:
a rotating frame (<NUM>) rotationally driven by the first electric motor (<NUM>); and
a second electric motor (<NUM>) mounted on the rotating frame (<NUM>),
wherein at least one of the rail wheel (R) and the test wheel (W) is connected to the first electric motor (<NUM>) via the torque generating device (<NUM>),
wherein the rail wheel (R) and the test wheel (W) are configured to rotate in opposite directions at substantially the same peripheral speed when the operation of the second electric motor (<NUM>) is stopped, and
wherein a rated output of the second electric motor (<NUM>) is equal to or more than <NUM> kW, and moment of inertia of a rotating part of the second electric motor (<NUM>) is equal to or less than <NUM>· m<NUM>.