Adjustable-axle distance roller device

The invention discloses an adjustable-axle distance roller device, which comprises a machine frame, a primary roller, a secondary roller, a tire diameter detection device, a roller axle-distance detection and regulation device, a transmission device and a tensioning mechanism. When the device is used, vehicle detection equipment, such as braking detection platforms, chassis dynamometers and speedometer calibration consoles, can realize the automatic adjustment of the axle distance of rollers, the requirements for the longitudinal positioning of tires of different diameters and the adjustment of an adhesive force in a detection process are met, the detection accuracy and efficiency are improved, and the range of vehicles detected is enlarged; a wheel lifting mechanism is not required to be arranged between the primary and secondary rollers; and the adhesive force can be regulated by changing the sum of the supporting forces applied by the rollers onto the wheels in a normal direction so as to realize the simulation of different adhesion coefficients.