The invention relates to a drive system (1) for an engine arrangement (2), the drive system comprising an epicyclical gear reduction mechanism (20) having a main axis (15) and comprising: a first main gear (123), a second main gear (121) arranged to rotate about main axis (15) in the same direction as the first main gear (123), a first set of planet gears with planet gears (23) meshing with the first main gear (123), a second set of planet gears with planet gears (21) meshing with the second main gear (121), a planet carrier (25), supporting planet gears (23, 21) of the first and second planet gears (23, 21), the planet carrier (25) being located, along the main axis (15), between the first main gear (123) and the second main gear (22, 121). Each planet gear (23) of the first set of planet gears (23) is coupled to a planet gear (21) of the second set of planet gears (21) such that no relative rotation is possible between them. In the mounted position: the first main gear (123) is connected to an engine crankshaft (5), the planet carrier (25) is connected to an accessory pulley (9) which is drivingly connected to an electric machine (6) and at least one accessory (7). The drive system further comprises a free wheel (30) which is connected to a non-rotating part (16) of the engine arrangement in the mounted position. The second main gear (121) is configured to be coupled, preferably via an intermediate junction element (22) of the drive system, to the free wheel (30) in a first operating phase of the drive system (1). In the first operating phase, the free wheel (30) is configured such that when the second main gear (22, 121) exerts torque on the free wheel in one direction, the free wheel is in an engaged state and stops the rotation of the second main gear (22, 121), and when the second main gear (22, 121) exerts torque on the free wheel in the opposite direction, the free wheel is in a free state and allows rotation of the second main gear (22, 121).

An epicyclic gearbox with an integral arrangement of meshing gear elements, including an annulus gear, planet gears, and sun gears, to transfer power from a motive power source to a driven element with a range of applications is provided. The annulus gear, in contact with the power source, forms an exterior gearbox input and is in meshing contact with a number of stepped planet gears supported on floating planet carriers. Each stepped planet gear is positioned internally of the annulus gear and includes two planet stages in meshing contact with corresponding sun gear stages. One of the sun gear stages is an interior gearbox output and transfers power to a machine or device to be driven. Meshing surfaces of the gear elements support helical teeth or spur teeth, with numbers of teeth on meshing gear elements selected for optimal torque transfer from the exterior input to the interior output.

A planetary gear device configured by combining a plurality of planetary gear mechanisms includes first and second planetary gear mechanisms sharing a carrier, wherein each planetary gear mechanism is composed of an internal gear I.sub.k (k is an integer equal to or larger than 2) and a planetary gear P.sub.k which is engaged with the internal gear I.sub.k and revolves in a circumferential direction of the internal gear, the planetary gear P.sub.k of each planetary gear mechanism is composed of a spur gear in the form of an external gear, the planetary gears P.sub.k of the planetary gear mechanisms share a central axis or have central axes integrally connected to integrally rotate on a common rotation central axis line or are integrated with each other to integrally rotate on the common rotation central axis line in order to configure the entire planetary gear device as a two-stage gear mechanism, the planetary gear device is configured such that the number of teeth z.sub.p1 of a first planetary gear constituting the first planetary gear mechanism and the number of teeth z.sub.p2 of a second planetary gear constituting the second planetary gear mechanism are different from each other, the number of teeth on the internal gear I.sub.1 is z.sub.i1, and the number of teeth on the internal gear I.sub.2 is z.sub.i2, an addendum modification coefficient of the first planetary gear is x.sub.p1, an addendum modification coefficient of an internal gear which is engaged with the first planetary gear and constitutes the first planetary gear mechanism is x.sub.i1, an addendum modification coefficient of the second planetary gear is x.sub.p2, an addendum modification coefficient of an internal gear which is engaged with the second planetary gear and constitutes the second planetary gear mechanism is x.sub.i2, a power transmission efficiency of the planetary gear device having the addendum modification coefficients x.sub.p1, x.sub.i1, x.sub.p2, and x.sub.i2 is , an addendum modification coefficient of the internal gear I.sub.1 is x.sub.i1, and an addendum modification coefficient of the internal gear I.sub.2 is x.sub.i2, and the addendum modification coefficients have relationships in which values selected from combinations of the addendum modification coefficients which maximize or submaximize the power transmission efficiency within an allowable range of design specifications given in advance are combined.

An electrically operated valve having excellent wear resistance while suppressing cost is provided.

The electrically operated valve comprises a valve main body having a valve seat; a motor including a stator fixed to the valve main body and a rotor driven to rotate with respect to the stator,

a planetary gear type deceleration mechanism configured to decelerate rotation of the rotor to transmit to an output gear, a valve member configured to be movable toward and away from the valve seat in an axial direction, and a feed screw mechanism configured to convert rotational movement of the output gear into movement of the valve member in the axial direction. The planetary gear type deceleration mechanism includes a sun gear coupled to the rotor, a planetary gear engaged with the sun gear, a carrier for rotatably supporting the planetary gear, an annular ring gear engaged with the planetary gear, and a sliding member abutting against an axial end of the sun gear. The output gear has a different number of teeth than the ring gear, and engages with the planetary gear, and the sliding member is made of a different material from the material of the sun gear.

A precision planetary gear comprising: a pinion; a movable annular gear; a fixed annular gear; one or more planet gears; wherein each planet gear simultaneously meshes with the pinion, the fixed annular gear and the movable annular gear; the pinion comprising a gear with a beveloid toothing; each planet gear comprising a gear with a beveloid toothing; wherein a beveloid toothing has a correction, which linearly varies along the longitudinal direction of the tooth; wherein each tooth of the beveloid toothing has a thickness and a height which increase moving from the apex of said beveloid gear along the longitudinal direction of the tooth.

Actuators with one or more gears disposed at least partially within a central bore passing axially through a stator and/or a rotor of an actuator are described.

A planetary gear support shaft is provided in a shaft hole of a planetary gear to support the planetary gear. The planetary gear is disposed between an internal gear and an external gear supported coaxially so as to be rotatable relative to each other. The planetary gear support shaft includes a body made of a tubular steel pipe with two open ends, and a pair of lid bodies that block opening portions at the two ends of the body. The body has an in-flow hole that allows lubricating oil to flow into a hollow portion between the pair of lid bodies and an out-flow hole through which the lubricating oil is supplied from the hollow portion into the shaft hole.

An actuation mechanism including one or more motors having an output shaft with a sun gear. A sun gear of a non-back drivable planetary gear assembly is drivingly connected to at least a portion of one or more planetary gears. The one or more planetary gears are drivingly connected to at least a portion of the sun gear, a carrier, a fixed non-rotating ring gear and a selectively rotatable output ring gear. The disclosure further relates to a method of operating an actuation mechanism that is drivingly connected to at least a portion of a vehicle parking mechanism. The method includes providing an actuation mechanism, providing a parking mechanism and one or more sensors that are operably configured to collect an amount of data to be analyzed. Based on the data analyzed, one or more failures within the parking mechanism may be determined and an alert may be sent.

A gas turbine engine includes a fan section that includes a fan rotatable about an engine axis. A compressor section includes a low pressure compressor rotatable about the engine axis. A turbine section includes a fan drive turbine for driving the fan and the low pressure compressor. A speed reduction device connects the fan drive turbine to the fan and the low pressure compressor. The speed reduction device includes a sun gear driven by an inner shaft. A plurality of intermediate gears surround the sun gear. A carrier supports the plurality of intermediate gears for driving the low pressure compressor. A ring gear is located radially outward from the intermediate gears and includes a forward portion for driving a fan drive shaft and an aft portion.

The invention relates to a pulling tool for use in a wellbore or tubing for pulling cable. The pulling tool comprises a propulsion module (64) having a main section (1) and a propulsion arm (2) hinged to the main section (1). The propulsion arm includes a propulsion wheel (6, 37) with a gear system. An electric motor (8) drives the propulsion wheel (6, 37) via the gear system. The gear system may include a harmonic gear or a compound split ring epicyclic gear. The invention further comprises a propulsion module (64) of a pulling tool including such a gear system.