A traction device including a ring member, a carrier, and a sun member and an electric motor, wherein the electric motor is coupled to at least one of the ring member, the carrier, and the sun member.

It is described a compound planetary friction drive comprising a first sun wheel (2) and planetary wheels (3), wherein said first sun wheel (2) engages said planetary wheels (3), which planetary wheels (3) are arranged with two outer parts (3b) having a first radius (r1) and a central part (3a) having a second radius (r2), wherein the second radius (r2) differs from the first radius (r1) and transition regions (3c) are provided between the outer parts (3b) and the central part (3a), and wherein an outer ring annulus (1) and a central ring annulus (5) are provided that are in driving engagement with the planetary wheels (3), wherein the outer ring annulus (1) has two parts between which, along the length of the planetary wheels (3), the central ring annulus (5) is disposed, wherein the first sun wheel (2) is in frictional engagement with the outer parts (3b) of the planetary wheels (3), said outer parts (3b) of the planetary wheels (3) are in frictional engagement with the parts of the outer ring annulus (1) and the central ring annulus (5) is in frictional engagement with the central part (3a) of the planetary wheels (3), wherein the planetary wheels (3) are both hollow and compressible uninterruptedly along their entire length spanning the outer parts (3b), the transition regions (3c) and the central part (3a).

It is described a compound planetary friction drive comprising a first sun wheel (2) and planetary wheels (3), wherein said first sun wheel (2) engages said planetary wheels (3), which planetary wheels (3) are arranged with two outer parts (3b) having a first radius (r1) and a central part (3a) having a second radius (r2), wherein the second radius (r2) differs from the first radius (r1) and transition regions (3c) are provided between the outer parts (3b) and the central part (3a), and wherein an outer ring annulus (1) and a central ring annulus (5) are provided that are in driving engagement with the planetary wheels (3), wherein the outer ring annulus (1) has two parts between which, along the length of the planetary wheels (3), the central ring annulus (5) is disposed, wherein the first sun wheel (2) is in frictional engagement with the outer parts (3b) of the planetary wheels (3), said outer parts (3b) of the planetary wheels (3) are in frictional engagement with the parts of the outer ring annulus (1) and the central ring annulus (5) is in frictional engagement with the central part (3a) of the planetary wheels (3), wherein the planetary wheels (3) are both hollow and compressible uninterruptedly along their entire length spanning the outer parts (3b), the transition regions (3c) and the central part (3a).

It is described a compound planetary friction drive comprising a first sun wheel (2) and planetary wheels (3), wherein said first sun wheel (2) engages said planetary wheels (3), which planetary wheels (3) are arranged with two outer parts (3b) having a first radius (r1) and a central part (3a) having a second radius (r2), wherein the second radius (r2) differs from the first radius (r1) and transition regions (3c) are provided between the outer parts (3b) and the central part (3a), and wherein an outer ring annulus (1) and a central ring annulus (5) are provided that are in driving engagement with the planetary wheels (3), wherein the outer ring annulus (1) has two parts between which, along the length of the planetary wheels (3), the central ring annulus (5) is disposed, wherein the first sun wheel (2) is in frictional engagement with the outer parts (3b) of the planetary wheels (3), said outer parts (3b) of the planetary wheels (3) are in frictional engagement with the parts of the outer ring annulus (1) and the central ring annulus (5) is in frictional engagement with the central part (3a) of the planetary wheels (3), wherein the planetary wheels (3) are both hollow and compressible uninterruptedly along their entire length spanning the outer parts (3b), the transition regions (3c) and the central part (3a).

It is described a compound planetary friction drive comprising a first sun wheel (2) and planetary wheels (3), wherein said first sun wheel (2) engages said planetary wheels (3), which planetary wheels (3) are arranged with two outer parts (3b) having a first radius (r1) and a central part (3a) having a second radius (r2), wherein the second radius (r2) differs from the first radius (r1) and transition regions (3c) are provided between the outer parts (3b) and the central part (3a), and wherein an outer ring annulus (1) and a central ring annulus (5) are provided that are in driving engagement with the planetary wheels (3), wherein the outer ring annulus (1) has two parts between which, along the length of the planetary wheels (3), the central ring annulus (5) is disposed, wherein the first sun wheel (2) is in frictional engagement with the outer parts (3b) of the planetary wheels (3), said outer parts (3b) of the planetary wheels (3) are in frictional engagement with the parts of the outer ring annulus (1) and the central ring annulus (5) is in frictional engagement with the central part (3a) of the planetary wheels (3), wherein the planetary wheels (3) are both hollow and compressible uninterruptedly along their entire length spanning the outer parts (3b), the transition regions (3c) and the central part (3a).

There is described a multistage friction/traction speed adapter. A first drive can include a plurality of free rollers orbiting around a sun element within a frame, transmitting their orbiting movement to guided rollers which do not contact the sun element or the frame. The guided rollers are driven in the orbiting movement and transmit the rotary movement to a carrier via corresponding pins which engage with the carrier. A second drive can include rollers having radial position variation which is prevented from being transmitted to the carrier by providing accommodation at the pin level, either by providing a bushing around the pins with a bore that is eccentric relative to its outer surface, either by engaging the pins into the carriers in portions thereof which are made more flexible. A friction/traction gear at an angle is also disclosed.

A multi-stage planetary roller power transmission device includes a high-speed power transmission mechanism including a first sun shaft, a first fixed ring, first planetary rollers disposed between the first sun shaft and the first fixed ring with a first negative clearance, first support shafts, and an annular first carrier into which the first support shafts are press-fitted; and a low-speed power transmission mechanism including a second sun shaft, a second fixed ring, second planetary rollers disposed between the second sun shaft and the second fixed ring with a second negative clearance, second support shafts, and an annular second carrier into which the second support shafts are press-fitted. A clearance amount of the first negative clearance and a clearance amount of the second negative clearance are equal to each other, and the number of the first planetary rollers is smaller than the number of the second planetary rollers.

A control drum system for a nuclear reactor including a reactor core, including an ex-core reflector including a plurality of cylindrical apertures, a plurality of control drum assemblies, each control drum assembly including a drive shaft, a drum cylinder affixed to a bottom end of the drive shaft, and a planetary gear attached to a top end of the drive shaft, wherein each drum cylinder is rotatably received in a cylindrical aperture, a first control drum drive motor operably connected to a first control drum assembly, and an annular ring gear that is operably connected to the planetary gear of each of the control drum assemblies so that all the control drum assemblies rotate simultaneously.

An accessory drive pulley assembly is configured to transfer rotational power from an engine crankshaft to one or more vehicle accessories. The accessory drive pulley has an inner race rotatable about an axis and having an outer surface. An outer race is located radially outward from the inner race and has an inner surface facing the inner race. A wedge plate is located radially between the outer surface and the inner surface. The wedge plate is configured to expand and contract radially to selectively lock and unlock the inner race with the outer race. When locked, an associated pulley can rotate at a different speed than when unlocked.

An accessory drive pulley assembly is configured to transfer rotational power from an engine crankshaft to one or more vehicle accessories. The accessory drive pulley has an inner race rotatable about an axis and having an outer surface. An outer race is located radially outward from the inner race and has an inner surface facing the inner race. A wedge plate is located radially between the outer surface and the inner surface. The wedge plate is configured to expand and contract radially to selectively lock and unlock the inner race with the outer race. When locked, an associated pulley can rotate at a different speed than when unlocked.