Ntn Corporation

Junichi Hirata

Yingjie Zhang

Tomoya Sakaguchi

Yoshio Fujikawa

Yasuhiko Sakakibara

Teruyoshi Horiuchi

Nobuyuki Ninoyu

Provided is a drive source control device () for controlling two drive sources (L,R) of a vehicle. The vehicle including the two drive sources (L,R), left and right drive wheels (L,R), and a power transmission device () disposed among the two drive sources (L,R) and the drive wheels (L,R). The device () distributes powers from the two drive sources (L,R) to the wheels (L,R) to drive the wheels (L,R). The drive source control device () includes: an angular acceleration calculation () to calculate angular accelerations of the drive wheels (L,R) and/or angular accelerations of the drive sources (L,R); and a torque correction () to, using the angular accelerations calculated by the angular acceleration calculation (), correct command values for respective outputs of the drive sources (L,R).

Drive source control device

The control device () includes a rotational speed calculator (), a bearing torque estimator (), a torque difference calculator () and a drive source torque calculator (). The rotational speed calculator () calculates rotational speeds of first and second connection members. The bearing torque estimator () estimates a bearing torque, from the calculated, two rotational speeds. The torque difference calculator () calculates a target torque difference between torques to be generated by respective drive sources, from the estimated bearing torque, a torque difference amplification factor (&#x3b1;), and a difference between drive wheel torque command values for respective left and right drive wheels. The drive source torque calculation module () calculates drive source torque command values, which are torques to be generated by the respective, left and right drive sources, using the calculated, target torque difference and the drive wheel torque command values for the respective wheels.

Control device for left and right wheel drive device

The vehicle turning control device for a vehicle includes a first road surface frictional coefficient calculator (), a second road surface frictional coefficient calculator (), a control gain calculator (), a target yaw rate calculator (), a target yaw rate corrector (), a first braking/driving force calculator (), and a second braking/driving force calculator (). A second road surface frictional coefficient &#x3bc;is obtained without braking/driving forces for respective wheels () being taken into consideration, and thus has a magnitude smaller than or equal to the magnitude of a first road surface frictional coefficient &#x3bc;. A braking/driving force command value calculator () calculates a braking/driving force command value from a braking/driving force (FA) and a braking/driving force (FB) which are respectively calculated with use of the first and second road surface frictional coefficients &#x3bc;and &#x3bc;

Vehicle turning control device

Provided is a drive source control device that can suppress increase in the rotation speed of a drive source. This drive source control device () includes: an overspeed determination module () to determine whether the rotation speed of each of two drive sources (L,R) is overspeed; and a correction module () to, when the overspeed determination module () determines that the rotation speed of at least one of the drive sources is overspeed, correct command values for outputs of the two drive sources, supplied from a command module (). The correction module () corrects the command values of the outputs of the two drive sources (L,R) so that the torque of the drive wheel having greater rotation speed decreases from the torque before the correction, and the torque of the drive wheel having smaller rotation speed maintains or decreases from the torque before the correction.

Drive source control device, and vehicle equipped with said drive source control device

A slip control device for an electric automobile includes a maximum rotation frequency calculator to calculate a drive wheel maximum rotation frequency Nmax on the basis of a rotation frequency Nof a driven wheel and an ideal slip ratio &#x3bb;min according to the formula (Nmax&#x2212;N)/N=&#x3bb;min. It is determined whether a drive wheel rotation frequency Nexceeds the frequency Nmax. If it is determined that the frequency Nexceeds the frequency Nmax, a torque command value to a motor unit is made to be zero.

Slip control device for electric vehicle

A slip control device for an electric vehicle which determines without error slippage occurrence with only a rotation angle sensor for motor rotation control and perform rapid control to eliminate the slippage. A threshold calculator calculates a normal angular acceleration of a motor depending on a manipulation amount of an accelerator to obtain a threshold, and an angular acceleration calculator differentiates a detection value from a rotation angle sensor twice to calculate an angular acceleration. A slip determination determines whether a wheel driven by a motor has slipped, and a torque limitation limits a torque when determining a slippage. The determination compares the calculated acceleration to the threshold, counts a number of times it is consecutively determined that the calculated acceleration exceeds the threshold, and determines a slippage if the number of times has reached a set value.

An effective value operation unit calculates an effective value of a vibration waveform of a bearing, the vibration waveform being measured by using a vibration sensor. An envelope processing unit performs envelope processing on the vibration waveform measured by using the vibration sensor, thereby generating an envelope waveform of the vibration waveform. An effective value operation unit calculates an effective value of an AC component of the envelope waveform generated by the envelope processing unit. A diagnostic unit diagnoses an abnormality of the bearing based on the effective value of the vibration waveform calculated by the effective value operation unit and the effective value of the AC component of the envelope waveform calculated by the effective value operation unit.

Abnormality diagnostic device for rolling bearing, wind turbine generation apparatus and abnormality diagnostic system

A hydrostatic bearing pad in which separation between a housing and a pad member and entry of an adhesive into an air supply groove are prevented to obtain stable bearing performance is provided. The hydrostatic bearing pad includes the pad member having a bearing surface forming a hydrostatic bearing and having air supply holes formed therein, and the housing bonded to the pad member with the adhesive. The air supply groove for supplying compressed gas to the pad member is formed in a surface of the housing bonded to the pad member in a manner corresponding to arrangement of the air supply holes. An adhesive inflow groove, is formed between a bonded portion, where the housing and the pad member are bonded to each other with the adhesive interposed therebetween and the air supply groove. The adhesive inflow groove, is formed along the air supply groove in the surface of the housing bonded to the pad member.

Hydrostatic bearing pad

A gas bearing spindle includes a rotation shaft, a sleeve, and a housing. The sleeve includes a bearing portion formed of a nonmetallic sintered body; and a retaining ring formed of a metal. Further, the retaining ring and the bearing portion are in contact with each other at a first fit surface that is a boundary surface between the outer circumferential surface of the bearing portion and the inner circumferential surface of the retaining ring, as well as at a second fit surface that is a boundary surface between the outer circumferential surface of the bearing portion and the inner circumferential surface of the retaining ring, is distant further away from the sleeve through hole relative to the first fit surface, and is formed adjacent to a center of the sleeve through hole in a direction in which the sleeve through hole extends, when viewed from the first fit surface.

Gas bearing spindle

A hydrostatic gas bearing capable of easily adjusting a clearance between a rotor and a radial bearing pad is provided. This hydrostatic gas bearing comprises a radial bearing pad radially supporting a rotor, a linear motion guide moving the radial bearing pad and a ball stud swingably coupling the radial bearing pad to the linear motion guide. The linear motion guide moves the radial bearing pad in a direction intersecting with a direction connecting the center of rotation of the rotor and the ball stud with each other. The quantity of adjustment in movement of the radial bearing pad caused by the linear motion guide is larger than the quantity of change in the clearance between the outer peripheral surface of the rotor and the radial bearing pad, whereby a small quantity of the bearing clearance can be precisely adjusted.

Hydrostatic gas bearing, rotator and CT scanner

There is provided a spindle device utilizing an externally pressurized gas bearing assembly, in which the center of a pulse disc of a rotary encoder can be adjusted to minimize an unbalance of the weight of the pulse disc and such unbalance can be adjusted easily to minimize fluctuation of the pulse disc during rotation and to achieve a highly precise detection of the rotational position consistent with the resolution of the rotary encoder. The spindle device includes an externally pressurized gas bearing assembly () for rotatably supporting a shaft (), a motor () for driving the shaft (), and a rotary encoder () for detecting a rotational position. A pulse disc () of the rotary encoder () is fixed on a mounting surface (S), arranged in the vicinity of one end of the shaft () and lying perpendicular to a central axis of the shaft (), by a fastening member () such as a bolt removably inserted through a fastening member inserting portion () provided in the pulse disc (). The mounting surface (S) is an end face of a mounting base () fixed to that end of the shaft (). This mounting base () is fixed to the shaft () by means of a plurality of radially extending set screws ().

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Iwata, Japan

Junichi Hirata