The mechanical characteristic estimating method is a method for estimating a value of a mechanical characteristic parameter of a test piece W provided with a first shaft S1, and a second shaft S2 and a third shaft S3 which are connected to the first shaft S1. The mechanical characteristic estimating method includes: a first measuring step of measuring a resonant frequency L of the test piece in a state in which a gear ratio of the transmission TM1 and the differential gear TM2 is set to a first gear ratio gL; a second measuring step of measuring the resonant frequency H of the test piece in a state in which the gear ratio is set to a second gear ratio gH; and an estimating step of calculating the resonant frequencies L and H, the gear ratios gL and gH, and an estimated value of a spring stiffness.

The mechanical characteristic estimating method is a method for estimating a value of a mechanical characteristic parameter of a test piece W provided with a first shaft S1, and a second shaft S2 and a third shaft S3 which are connected to the first shaft S1. The mechanical characteristic estimating method includes: a first measuring step of measuring a resonant frequency L of the test piece in a state in which a gear ratio of the transmission TM1 and the differential gear TM2 is set to a first gear ratio gL; a second measuring step of measuring the resonant frequency H of the test piece in a state in which the gear ratio is set to a second gear ratio gH; and an estimating step of calculating the resonant frequencies L and H, the gear ratios gL and gH, and an estimated value of a spring stiffness.

A deterioration diagnosis apparatus is for a mechanical apparatus including a power transmission mechanism that transmits power via a gear. The deterioration diagnosis apparatus includes: a storing unit that stores, in advance, a trend of change along with the operation of the mechanical apparatus, in consumption rate of an additive contained in lubricant used for the gear; and a determination unit that determines the period to be taken for the consumption rate of the additive to reach a predetermined value, based on the trend of change in the consumption rate of the additive.

The present invention is one that reproduces behavior close to an actual run of a vehicle in a test using a loading device, and is a specimen test apparatus that tests a specimen that is a vehicle or a part of a vehicle. The vehicle test apparatus includes; a loading device that is connected to a rotating shaft of the specimen and gives running resistance to the rotating shaft; a storage part that stores tire diameter data indicating the relationship between a running state of the specimen and a tire diameter; and a control part that, from the tire diameter data, calculates a tire diameter corresponding to a running state of the specimen, and controls the loading device with use of running resistance obtained from the calculated tire diameter.

A system and method for determining surface contact fatigue life may use a finite element method to determine when components, such as a power transmission component, may fail in operation. The method may generate a finite element model based on the material parameters related to a power transmission component, generate a surface pressure time history for a loading event based on one or more loading parameters, determine, based on the surface pressure time history for a loading event, a finite element solution that describes stress in the grain structure, calculate damage in the finite element solution using a damage model, and determine whether a damage threshold is exceeded.

A system and method for determining surface contact fatigue life may use a finite element method to determine when components, such as a power transmission component, may fail in operation. The method may generate a finite element model based on the material parameters related to a power transmission component, generate a surface pressure time history for a loading event based on one or more loading parameters, determine, based on the surface pressure time history for a loading event, a finite element solution that describes stress in the grain structure, calculate damage in the finite element solution using a damage model, and determine whether a damage threshold is exceeded.

An input-side control device includes: a feedback controller that generates a first control input signal for eliminating the difference between a model speed signal m and a speed detection signal by using the signal difference between a higher order torque command signal Tref and an axial torque detection signal Tsh to generate the model speed signal m which corresponds to the rotational speed of an inertial body having a set moment of inertia Jset moving under a torque corresponding to the signal difference; a feed-forward controller that generates a second control input signal by multiplying the signal difference by k.Math.Jdy/Jset; and a low-pass filter that generates a torque command signal Tr from a signal obtained by combining the outputs of the controllers and attenuating components at a higher frequency than a cut-off frequency fc set in the vicinity of the resonant frequency.

The input/output characteristic estimation method for testing system comprises; first excitation measurement steps (S3-S5) in which an input obtained by superimposing an excitation input d2 onto a second torque control input ib2 is input to a second dynamometer, and the frequency response i2d2 with respect to the excitation input d2 is measured; second excitation measurement steps (S7-S9) in which input obtained by superimposing excitation input d3 on third torque control input ib3 is input to a third dynamometer, and frequency response i2d3 with respect to the excitation input d3 and the like are measured; and mechanical characteristic estimation steps (S11 and S12) in which the response measured in the first and second excitation measurement steps are used to estimate the transfer function Gt2_i2 and the like from the second or third torque current command signals (i2, i3) to the first or second axial torque detection signals (t2 or t3).

A heat insulation plate (25) is interposed between a coupling (21) and an adapter flange (22) in a main shaft (6) of a dynamometer (3). A torque meter (24) is disposed between a coupling flange (23) that serves as a test-piece connection surface (56) and the adapter flange (22). To surround a periphery of these, a cover (7) is provided. An air conditioner utilizing a refrigeration cycle supplies a cold wind to an inside space of the cover (7). The heat insulation plate (25) suppresses heat transmission from an electric motor of the dynamometer (3) to the torque meter (24). Therefore, the torque meter (24) is effectively cooled by the cold wind.

The present disclosure relates to a fluid seal to prevent fluid and lubricant loss during automotive transmission testing. The fluid seal may be disposed on a surface of an axle shaft such that a variety of transmissions may be evaluated without replacement of the axle shaft, a laborious and ergonomically stressful task. Moreover, the fluid seal may be disposed on a standard collar of the axle shaft for interaction with an internal surface of a transmission coupler.