Abstract: The present invention realizes a calibration operation for detecting a motor speed, without employing digital correcting by an external CPU. The calibration operation calculates a comparison reference value corresponding to aback EMF detection signal of a back EMF detector circuit when a zero current flows through a motor and when an arm is fixed. Accordingly, the back EMF detection signal of the back EMF detector circuit is set as the first value and the second value responding to the non-zero current flowing through the motor, and the semiconductor integrated circuit calculates the comparison reference value from the first value and the second value. The difference between the comparison reference value and the comparison input value as the back EMF detection signal of the back EMF detector circuit is reduced by adjusting the gain of an internal amplifier of the back EMF detector circuit by an adjustment unit.

Abstract: The present invention realizes a calibration operation for detecting a motor speed, without employing digital correcting by an external CPU. The calibration operation calculates a comparison reference value corresponding to aback EMF detection signal of a back EMF detector circuit when a zero current flows through a motor and when an arm is fixed. Accordingly, the back EMF detection signal of the back EMF detector circuit is set as the first value and the second value responding to the non-zero current flowing through the motor, and the semiconductor integrated circuit calculates the comparison reference value from the first value and the second value. The difference between the comparison reference value and the comparison input value as the back EMF detection signal of the back EMF detector circuit is reduced by adjusting the gain of an internal amplifier of the back EMF detector circuit by an adjustment unit.

Abstract: A seal member includes a first seal portion inscribed on the outer circumferential surface of a small projection in an end cover, a second seal portion circumscribed around the inner surface of a cylinder tube, and a size expanded portion continuing from said second seal portion.

Abstract: When a guide block 20 is located on each of both ends of a guide rail 18, rollers 50 are situated at a position where they are supported by hard supporting members 28a and 28b of a rail member 36, so that the guide block 20 is positioned at a predetermined position precisely. On the other hand, when the guide block 20 is located at a position in the vicinity of a center of the guide rail 18, the rail member 36 is slightly bent by elasticity of an elastic supporting member 32 in spite of lowering of a position precision in the vicinity of the guide rail 18 due to a warp, a distortion, a bend and the like. Thus, an overload applied to the foregoing rail member 36 and the like is relieved.

Abstract: A rodless cylinder for feeding a workpiece has a cylinder having a cylinder tube with a bore defined therein and a piston reciprocally movably disposed in the bore. The cylinder tube has a slit defined therein and extending longitudinally therealong, the slit communicating between the bore and an exterior space. The slit is closed by a first seal member engaging the piston and a second seal member engaging a slide table. The piston has a separator separating the first and second seal members from each other. The cylinder tube has a pair of slanted first surfaces positioned one on each side of the slit. A pair of slide members is disposed on the slide table and have respective second surfaces engaging the first surfaces, respectively, for guiding the slide table when the piston reciprocally moves in the bore and bearing a load applied to the slide table.