Abstract: Provided is a liquid pump configured to suppress discharge of air from an air pool formed in a discharge-side tank. A discharge-side tank part formed in a housing has a first inner wall surface and a second inner wall surface facing each other in a horizontal direction in an installed position of the liquid pump. The first inner wall surface is formed with a discharge port, and the second inner wall surface is formed with an opening of a discharge-side communicating passage. An air pool is formed in a space in the discharge-side tank part above the opening of the discharge-side communicating passage and the discharge port. A circular cylindrical partition is provided in the discharge-side tank part. The circular cylindrical partition projects from the second inner wall surface toward the first inner wall surface with at least a portion of the cylindrical partition positioned above the opening of the discharge-side communicating passage so as to cover the opening as seen from the air pool side.

Abstract: Provided is a liquid pump configured to suppress discharge of air from an air pool formed in a discharge-side tank. A discharge-side tank part formed in a housing has a first inner wall surface and a second inner wall surface facing each other in a horizontal direction in an installed position of the liquid pump. The first inner wall surface is formed with a discharge port, and the second inner wall surface is formed with an opening of a discharge-side communicating passage. An air pool is formed in a space in the discharge-side tank part above the opening of the discharge-side communicating passage and the discharge port. A circular cylindrical partition is provided in the discharge-side tank part. The circular cylindrical partition projects from the second inner wall surface toward the first inner wall surface with at least a portion of the cylindrical partition positioned above the opening of the discharge-side communicating passage so as to cover the opening as seen from the air pool side.

Abstract: A boring device has a spindle moving mechanism which retards a tool spindle when the spindle rotates through a predetermined angle. The mechanism has coaxial first and second thrust rings. Thrust balls are disposed between the thrust rings in rolling contact therewith. A retaining element holds the thrust balls such that they keep constant circumferential spaces therebetween. The first thrust ring is fixed to the tool spindle and has recesses in the surface facing the second thrust ring. The second thrust ring is fixed to the casing of the boring device. As the first thrust ring is rotated by the tool spindle, the thrust balls are fitted in the respective recesses, whereby the tool retards by the amount equal to the depth of the recesses. Then, cutting edges of a cutter is separated from the face of a workpiece which is being cut, and a continuous chip is broken into pieces having a predetermined length and is removed from a hole being formed.

Abstract: A boring device includes a casing and an upwardly biased tool spindle supported in the casing so as to move in a feed direction and a return direction opposite thereto. A first thrust ring with a track surface is disposed coaxial with the tool spindle and is fixed thereto. A second thrust ring with a track surface is also disposed coaxial with the tool spindle and fixed to the casing such that the track surfaces of the first and second thrust rings face each other. A rolling element retaining ring is provided coaxially with the tool spindle between the first and second thrust rings and has bores circumferentially arranged at predetermined angular intervals. Rolling elements are fitted in the bores of the rolling element retaining ring such that the rolling elements roll on the track surfaces of the first and second thrust rings. Receptacles complementary to the bores are formed in the track surface of the first thrust member.

Abstract: A boring device includes a casing and an upwardly biased tool spindle supported in the casing so as to move in a feed direction and a return direction opposite thereto. A first thrust ring with a track surface is disposed coaxial with the tool spindle and is fixed thereto. A second thrust ring with a track surface is also disposed coaxial with the tool spindle and fixed to the casing such that the track surfaces of the first and second thrust rings face each other. A rolling element retaining ring is provided coaxially with the tool spindle between the first and second thrust rings and has bores circumferentially arranged at predetermined angular intervals. Rolling elements are fitted in the bores of the rolling element retaining ring such that the rolling elements roll on the track surfaces of the first and second thrust rings. Receptacles complementary to the bores are formed in the track surface of the first thrust member.

Abstract: A boring device has a spindle moving mechanism which retards a tool spindle when the spindle rotates through a predetermined angle. The mechanism has coaxial first and second thrust rings. Thrust balls are disposed between the thrust rings in rolling contact therewith. A retaining element holds the thrust balls such that they keep constant circumferential spaces therebetween. The first thrust ring is fixed to the tool spindle and has recesses in the surface facing the second thrust ring. The second thrust ring is fixed to the casing of the boring device. As the first thrust ring is rotated by the tool spindle, the thrust balls are fitted in the respective recesses, whereby the tool retards by the amount equal to the depth of the recesses. Then, cutting edges of a cutter is separated from the face of a workpiece which is being cut, and a continuous chip is broken into pieces having a predetermined length and is removed from a hole being formed.