The present disclosure relates to an ultrasonic imaging apparatus that has a tolerance for easy assembly and reduces shaking and noise by reducing the tolerance after assembly. The ultrasonic imaging apparatus includes a main body, a probe connected to the main body to irradiate and receive ultrasonic waves and to transmit the ultrasonic signals to the main body, a control panel configured to control the main body or the probe, and a moving device configured to connect the control panel and the main body and to move the control panel with respect to the main body in the upward and downward directions, wherein the moving device includes a housing fixed to the main body, a moving member configured to be movable with respect to the housing in the upward and downward directions, and a regulating bearing installed in the housing and configured to assist the upward and downward movement of the moving member by coming into rolling contact with the moving member and to regulate a gap with the moving member.

A ball screw includes a screw, a nut, a plurality of balls and a ball return path. A spiral screw groove is formed on an outer peripheral surface of the screw shaft. The nut is disposed around the screw shaft. A spiral screw groove is formed on an inner peripheral surface of the nut. The balls are housed in rolling paths formed by the two screw grooves facing each other. The ball return path circulates the balls in no more than one turn of the rolling paths. A length of the ball return path between scoop-up points where the balls are scooped up from the screw groove of the screw shaft is set to a value which is from −0.1 to +0.3 times of a diameter of the balls with respect to an integer value of a number of the balls filled between the scoop-up points.

A transport system has a mobile carriage for transport of products along a guide path that has a first guide profile and a second guide profile. A first pair of rollers is mounted rotatably on a first rotation shaft borne by the carriage, so as to engage the first guide profile. A second pair of rollers rotatably mounted on the second rotation shaft engages the second guide profile. For each roller of the first pair of rollers and for each roller of the second pair of rollers, a reinforcing element is provided which is friction-coupled to at least a part of the main portions of external lateral walls of the rollers.

A carrier plate with rollable balls therein comprises a plate body including an upper plate and a lower plate; the lower plate being fixed to a lower side of the upper plate; the upper plate and lower plate having a plurality of through holes which are positioned corresponding to the through holes of the upper plate; a plurality of balls loosely embedded into the through holes of the upper plate and the lower plate. A diameter of the ball is larger than the summation of widths of the upper plate and lower plate, and the balls protrude from an upper side of the upper plate and a lower side of the lower plate.

A carrier plate with rollable balls therein comprises a plate body including an upper plate and a lower plate; the lower plate being fixed to a lower side of the upper plate; the upper plate and lower plate having a plurality of through holes which are positioned corresponding to the through holes of the upper plate; a plurality of balls loosely embedded into the through holes of the upper plate and the lower plate. A diameter of the ball is larger than the summation of widths of the upper plate and lower plate, and the balls protrude from an upper side of the upper plate and a lower side of the lower plate.

A transport system has a mobile carriage for transport of products along a guide path that has a first guide profile and a second guide profile. A first pair of rollers is mounted rotatably on a first rotation shaft borne by the carriage, so as to engage the first guide profile. A second pair of rollers rotatably mounted on the second rotation shaft engages the second guide profile. For each roller of the first pair of rollers and for each roller of the second pair of rollers, a reinforcing element is provided which is friction-coupled to at least a part of the main portions of external lateral walls of the rollers.

The invention relates to universal machine parts, and more particularly to a curved groove ball bearing without a retainer, which can solve the problems in the prior at such as high pendulating frequency and small amplitude. For the bearing, an inner ring and an outer ring are respectively provided with a first curved groove and a second curved groove, where peaks and valleys of the first curved groove are respectively the same as those of the second curved groove in number. The second curved groove is filled with steel balls, and a retainer for fixing the relative positions of the steel balls is removed, increasing the amplitude and reducing the pendulating frequency.

The invention relates to universal machine parts, and more particularly to a curved groove ball bearing without a retainer, which can solve the problems in the prior at such as high pendulating frequency and small amplitude. For the bearing, an inner ring and an outer ring are respectively provided with a first curved groove and a second curved groove, where peaks and valleys of the first curved groove are respectively the same as those of the second curved groove in number. The second curved groove is filled with steel balls, and a retainer for fixing the relative positions of the steel balls is removed, increasing the amplitude and reducing the pendulating frequency.

The invention relates to universal machine parts, and more particularly to a curved groove ball bearing without a retainer, which can solve the problems in the prior at such as high pendulating frequency and small amplitude. For the bearing, an inner ring and an outer ring are respectively provided with a first curved groove and a second curved groove, where peaks and valleys of the first curved groove are respectively the same as those of the second curved groove in number. The second curved groove is filled with steel balls, and a retainer for fixing the relative positions of the steel balls is removed, increasing the amplitude and reducing the pendulating frequency.

A ball screw includes a screw, a nut, a plurality of balls and a ball return path. A spiral screw groove is formed on an outer peripheral surface of the screw shaft. The nut is disposed around the screw shaft. A spiral screw groove is formed on an inner peripheral surface of the nut. The balls are housed in rolling paths formed by the two screw grooves facing each other. The ball return path circulates the balls in no more than one turn of the rolling paths. A length of the ball return path between scoop-up points where the balls are scooped up from the screw groove of the screw shaft is set to a value which is from 0.1 to +0.3 times of a diameter of the balls with respect to an integer value of a number of the balls filled between the scoop-up points.