In a gear spindle, outer cylinder gear sections (11) are each integrally formed on an inner peripheral surface of a spindle outer cylinder and inner cylinder gear sections (14) are each integrally formed on an outer peripheral surface of a spindle inner cylinder (13). An oil seal (27) that seals in the lubricating oil (20) for each of the aforementioned gear sections includes, a seal body (29) having a channel-shaped cross section and interposed in the peripheral gap between the inner peripheral surface of the spindle outer cylinder and the outer peripheral surface of the spindle inner cylinder (13), and a seal mounting member (30) that includes a band, a spring, or the like that tightens and fixes the seal body to the outer peripheral surface of the spindle inner cylinder (13) to allow expansion of the seal body in the axial direction in the aforementioned peripheral gap.

A splined coupling comprises a radially inner shaft and a radially outer shaft having a cavity for receiving the inner shaft. First splines are provided on a radially outwardly facing surface of the inner shaft. Second splines are provided on a radially inwardly facing surface of the cavity of the outer shaft. The first splines are slidably engaged with the second splines. At least one biasing element, for example a diaphragm is arranged to act between the radially inner and radially outer shafts for locating the first splines in a desired axial position relative to the second splines and to provide a biasing force resisting the axial movement of the first splines relative to the second splines upon relative axial movement of the inner and outer shafts.

A torque transmitting coupling for an electric submersible pump equipment string. A torque transmitting coupling system includes a first adapter including a first inner diameter mated to a first shaft rotatable about a first axis of rotation, and a first splined outer diameter mated to a splined coupling inner surface, a second adapter including a second inner diameter mated to a second shaft rotatable about a second axis of rotation, and a second splined outer diameter mated to the splined coupling inner surface, the first and second splined outer diameter at least partially spherical such that when the first axis of rotation moves with respect to the second axis of rotation, at least one of the splined outer diameters rock along the coupling inner surface.

In a gear spindle, outer cylinder gear sections (11) are each integrally formed on an inner peripheral surface of a spindle outer cylinder and inner cylinder gear sections (14) are each integrally formed on an outer peripheral surface of a spindle inner cylinder (13). An oil seal (27) that seals in the lubricating oil (20) for each of the aforementioned gear sections includes, a seal body (29) having a channel-shaped cross section and interposed in the peripheral gap between the inner peripheral surface of the spindle outer cylinder and the outer peripheral surface of the spindle inner cylinder (13), and a seal mounting member (30) that includes a band, a spring, or the like that tightens and fixes the seal body to the outer peripheral surface of the spindle inner cylinder (13) to allow expansion of the seal body in the axial direction in the aforementioned peripheral gap.

A flexible diaphragm coupling that includes a primary torque path and a secondary torque path. The secondary torque path includes a crowned or spherical spline assembly and provides additional capability during transient overtorque of the primary torque path or acts as the primary torque path in the unlikely event of diaphragm failure.

A driving force transmission mechanism is capable of preventing breakage of an oil chamber when the internal pressure in the oil chamber rises by impact when replacing work rolls and the like. The driving force transmission mechanism transmits power of a driving source to a work roll through a spindle and includes a first gear portion disposed on one end portion of the spindle, a second gear part disposed on the driving source or the work roll and fitted to the first gear part and an oil chamber for supplying a lubricating oil to the first gear part and the second gear part, where the oil chamber is provided with a first valve for discharging inner air in the oil chamber to an outside of the oil chamber and a second valve for introducing outer air into the oil chamber.

A constant-velocity joint can have three pieces: a yoke, a first adaptor, and a second adaptor. Grooves on opposite sides of the yoke can receive forks of the adaptors and be perpendicular to one another. The yoke can have a guide surface within each groove so that a matching following surface on the fork of the adaptor can engage the guide surface to guide the movement of the fork within the groove. The adaptors may pivot within the grooves such that surfaces of flanks of the forks remain engaged or provide a consistent amount of surface contact with flanks of the groove throughout the pivot of the forks. Torque can be transferred through the engaged flanks as the joint is used to convert eccentric rotation to concentric rotation.

A constant-velocity joint can have three pieces: a yoke, a first adaptor, and a second adaptor. Grooves on opposite sides of the yoke can receive forks of the adaptors and be perpendicular to one another. The yoke can have a guide surface within each groove so that a matching following surface on the fork of the adaptor can engage the guide surface to guide the movement of the fork within the groove. The adaptors may pivot within the grooves such that surfaces of flanks of the forks remain engaged or provide a consistent amount of surface contact with flanks of the groove throughout the pivot of the forks. Torque can be transferred through the engaged flanks as the joint is used to convert eccentric rotation to concentric rotation.

A drive-side concavo-convex part (26, 26a) is made to engage the half of a cup-side concavo-convex part (35) which is on the other side in the axial direction, while the central axes of a drive shaft (12a) and a driven shaft (8a) are aligned with each other, and drive-side gaps (36, 36a), the width of which in the circumferential direction increases toward the other side in the axial direction, are interposed between the circumferential side surface of each drive-side convex part (25, 25a) and the circumferential side surface of each cup-side convex part (34). In addition, a driven-side concavo-convex part (32, 32a) is made to engage the half of the cup-side concavo-convex part (35) which is on the one side in the axial direction, while the central axes of the drive shaft (12a) and the driven shaft (8a) are aligned with each other, and driven-side gaps (37, 37a), the width of which in the circumferential direction increases toward the one side in the axial direction, are interposed between the circumferential side surface of each driven-side convex part (31, 31a) and the circumferential side surface of each cup-side convex part (34).

A steering mechanism configured to rotate first and second axles relative to bogie-frame to perform steering; electric motors supported by bogie-frame, arranged at the front and rear sides in the car longitudinal direction, respectively, including output shafts, respectively, and output shafts being parallel to first and second axles at the time of non-steering; reducers connected to axles, respectively; and first constant velocity ball joint by which the first output shaft is coupled to the first reducer and which follows rotations of the first axle at the time of steering to allow relative displacement between the first output shaft and the first reducer, and a second constant velocity ball joint by which the second output shaft is coupled to the second reducer and which follows rotations of the second axle at the time of the steering to allow relative displacement between the second output shaft and the second reducer.