Disclosed is unit brake, which is equipped with a cylinder apparatus in which a clutch mechanism that switches between transmitting or cutting off a biasing force of a spring brake part is disposed, is capable of preventing a braking force due to the spring brake part from unintentionally decreasing due to a meshing section of the clutch mechanism disengaging, and is of a size that can replace an existing unit brake, and maintains the performance of bearings in the clutch mechanism even with long-term use. The clutch mechanism of the unit brake includes: a nut member that rotatably screws on a spindle that is positioned in an area that communicates with the atmosphere, and is movably supported in a direction opposite to braking; a clutch that is disposed in a direction opposite to braking with respect to the nut member, and faces the nut member in the vicinity of the spindle; a clutch box that is formed in a cylinder shape, and houses the nut member and clutch on the inside; and bearings that rotatably support the nut member on the inside of the clutch box.

Disclosed is unit brake, which is equipped with a cylinder apparatus in which a clutch mechanism that switches between transmitting or cutting off a biasing force of a spring brake part is disposed, is capable of preventing a braking force due to the spring brake part from unintentionally decreasing due to a meshing section of the clutch mechanism disengaging, and is of a size that can replace an existing unit brake, and maintains the performance of bearings in the clutch mechanism even with long-term use. The clutch mechanism of the unit brake includes: a nut member that rotatably screws on a spindle that is positioned in an area that communicates with the atmosphere, and is movably supported in a direction opposite to braking; a clutch that is disposed in a direction opposite to braking with respect to the nut member, and faces the nut member in the vicinity of the spindle; a clutch box that is formed in a cylinder shape, and houses the nut member and clutch on the inside; and bearings that rotatably support the nut member on the inside of the clutch box.

A rail brake includes a rigid enclosure which mounts under a crane so as to dispose the base end of the enclosure over and adjacent a rail. A spring carriage is mounted for vertical translation within the enclosure. Springs are mounted between the spring carriage and the top of the enclosure so that the springs are compressed when the spring carriage is elevated. A brake shoe is mounted under the carriage. Actuators are mounted between the spring carriage and the base end of the enclosure. Extension of the actuators compress the springs and elevate the brake shoe from the rail. Retraction allows the springs to drive the brake shoe against the rail. Elevation of the brake shoe aligns a pair of spline joints between the sides of the brake shoe and corresponding channel walls underneath the enclosure. Removable elongate keys provide the locking splines in the pair of spline joints.

A regenerative power-amount estimation device according to an embodiment includes a regenerative power-amount estimation model for each brake notch switching configured to include a transient response of an electric brake corresponding to a switching operation of a brake notch for each switching operation of the brake notch in an operation of railway vehicles. A regenerative power-amount estimation part is configured to estimate an expected amount of regenerative power acquired for a brake plan being temporal transition data of the brake notch, based on the regenerative power-amount estimation model for each brake notch switching.

A piston assembly for reducing clearance volume in a reciprocating compressor for compensating for piston tilt and improving the volumetric efficiency of the compressor includes a piston located within a piston cylinder, the piston having a first end and a second end, a wrist pin associated with the first end of the piston, and a cylinder head/valve assembly associated with the second end of the piston, wherein at least a portion of the second end of the piston includes an angled portion. The piston having the angled portion can be used with oil free cylinders and trunk type pistons. The piston can also be used in a multiple stage, multiple cylinder compressor including a series of piston assemblies. A method of increasing the volumetric efficiency of a reciprocating compressor can also be achieved using the piston having an angled portion.

A valve assembly is dimensioned for interconnection between a pressurized gas supply system and a pressurized gas braking system of a rail vehicle. The valve assembly can include a valve housing and a valve body. The valve housing can include a housing wall that at least partially defines a housing chamber and includes a plurality of communication ports in fluid communication with the housing chamber. The valve body is supported within the housing chamber for sliding movement relative to the housing wall. The valve body can be displaced between a plurality of positions in which different ones of the communication ports are in fluid communication with one another. A pressurized gas system and a rail vehicle are also included.

A valve assembly is dimensioned for interconnection between a pressurized gas supply system and a pressurized gas braking system of a rail vehicle. The valve assembly can include a valve housing and a valve body. The valve housing can include a housing wall that at least partially defines a housing chamber and includes a plurality of communication ports in fluid communication with the housing chamber. The valve body is supported within the housing chamber for sliding movement relative to the housing wall. The valve body can be displaced between a plurality of positions in which different ones of the communication ports are in fluid communication with one another. A pressurized gas system and a rail vehicle are also included.

A transport vehicle for traveling in a low-pressure environment structure is provided. The transport vehicle may include a deployable decelerator configured to deploy from the transport vehicle to decrease a distance between the transport vehicle and the low-pressure environment structure and a communication network that monitors and collects a plurality of operation parameters from the transport vehicle and the low-pressure environment structure to control deployment of the deployable decelerator based on a plurality of predetermined triggering events.

A transport vehicle for traveling in a low-pressure environment structure is provided. The transport vehicle may include a deployable decelerator configured to deploy from the transport vehicle to decrease a distance between the transport vehicle and the low-pressure environment structure and a communication network that monitors and collects a plurality of operation parameters from the transport vehicle and the low-pressure environment structure to control deployment of the deployable decelerator based on a plurality of predetermined triggering events.

A parking brake system for a rail vehicle (100) contains a brake actuator (120) for receiving a parking-brake command (cmd.sub.P) and producing an electric brake-force signal (BF). A brake unit (200) contains first and second pressing members (211, 212) and a rotatable member (110) being mechanically linked to a wheel (105) of the rail vehicle (100). When receiving the electric brake-force signal (BF), the brake unit (200) causes the first and second pressing members (211, 212) to apply a braking force to the rotatable member (110) to keep the wheel (105) immobile. A gear assembly (220) in the brake unit (200) operates mechanically on the first and second pressing members (211; 212). In response to the electric brake-force signal (BF), an electric motor (230) acts on the gear assembly (220) to cause the first and second pressing members (211; 212) to attain a specified position interrelationship. An acceleration sensor (125) registers movements of the rail vehicle (100). If movements of the rail vehicle (100) above a magnitude threshold level are registered during a period when the parking-brake command (cmd.sub.P) has instructed the at least one wheel (105) to be immobile, the brake actuator (120) reproduces the electric brake-force signal (BF) to reapply the braking force to the rotatable member (110).