A rotary engine where the rotor cavity has a peripheral inner surface having a peritrochoid configuration defined by a first eccentricity and the rotor has a peripheral outer surface having a peritrochoid inner envelope configuration defined by a second eccentricity larger than the first eccentricity. Also, a rotary engine where the rotor cavity has a peripheral inner surface having a peritrochoid configuration defined by an eccentricity, and a rotor with a peripheral outer surface between adjacent ones of the apex portions being inwardly offset from a peritrochoid inner envelope configuration defined by the eccentricity. The engine may have an expansion ratio with a value of at most 8. The rotary engine may be part of a compound engine system.

A rotary machine, for directing a quantity of fluid from an inlet to an outlet, comprises one or more elliptical or near-elliptical rotors having planetary rotation within a housing. The interior cavity of the housing comprises an inverse apex region that is in contact with the rotor during its rotation. In various embodiments the rotor and housing can be symmetric or asymmetric in cross-section. Features are described that can improve the operation of the machine for various end-use applications. Such features include cut-outs that are fluidly connected to the inlet or outlet ports of the machine, mechanisms for reducing variation in output flow rate from the rotary machine, linings for the interior cavity of the housing, pressure relief mechanisms, dynamic apex seals and other sealing mechanisms.

An adding system for fire-extinguishing units is disclosed for producing a mixture of extinguishing agent and extinguishing agent additive (premix) by adding an extinguishing agent additive, e.g., a foaming agent, to an extinguishing agent, e.g., water, the adding system comprising a motor, which can be driven by the extinguishing agent stream, an adding pump, which can be driven by the motor, an adding line, and an extinguishing agent additive line. The invention increases the operational reliability of an adding system for fire-extinguishing units by the outer wall of the working chamber of the motor being in the form of a rotation motor, which can also have the shape of a logarithmic spiral. Furthermore, the wall of the drainage housing of the motor, which is in the form of a rotation motor, can have a through-slot for letting the extinguishing agent in and/or out. Moreover, the inlet of the adding pump can be arranged such that the extinguishing agent additive can flow into the adding pump substantially parallel to the movement direction of the pistons of the adding pump. Finally, the adding pump can have an integrated relief valve.

Provided is an internal gear pump. The shape of any one of a plurality of external teeth and a plurality of internal teeth of the pump is formed on the basis of formulae (1)-(5). Formula (1): r=ro−dr.Math.cos θ, Formula (2): Px=(ro−dr)+1/4 dr{1−cos (2θ)}, Formula (3): Py=1/4 dr{−2θ+sin (2θ)}, Formula (4): Qx=Px−r.Math.cos θ, Formula (5): Qy=Py+r.Math.sin θ.

A vane pump with a pump housing in which a cam ring is constructed or arranged, and wherein a rotor is provided that is mounted in the cam ring so that it can rotate about a rotational axis , wherein the cam ring has an inner contour with a variable radius that varies between a maximum radius and a minimum radius in the circumferential direction about the rotational axis , wherein, in the radial gap between the inner contour and the rotor , a number of lift sections is constructed with pump chambers constructed in these sections, and wherein vane elements are mounted on the rotor , wherein these elements slide against the inner contour of the cam ring and limit the pump chambers in the circumferential direction. According to the invention, the radius of the inner contour varies about the rotational axis according to the function: r=r.sub.0+a.Math.sin(n.Math.φ), where r.sub.0=(r.sub.max+r.sub.min)/2, a =(r.sub.max−r.sub.min)/2, and φ=phase angle of the radius (r) between (r.sub.min) and (r.sub.max) in the direction of rotation of the rotor .

A scroll compressor with a stationary scroll, an orbiting scroll, and a discharge port through which a fluid that has been compressed by both the scrolls is discharged. An end plate of the orbiting scroll is provided with an end-plate side stepped portion formed such that, along a spiral of a spiral wrap, the height thereof increases toward a central side of the spiral and decreases toward an outer end side thereof. A spiral wrap of the stationary scroll is provided with a wall-portion side stepped portion formed corresponding to the end-plate side stepped portion such that the height thereof decreases toward the central side of the spiral and increases toward the outer end side thereof. A pair of compression chambers which face each other, the ventral side compression chamber communicates with the discharge port before the dorsal side compression chamber communicates with the discharge port.

The disclosure discloses a method for determining reasonable design area of roots pump rotor profile of roots pump and its application, and belongs to the field of mechanical design. According to the method of the disclosure, after a relation between the roots pump rotor profile and performance parameters is established, constraint conditions for avoiding a closed volume and undercutting are further determined, so that a reasonable design region of a roots pump rotor blade peak curve is determined. Reference is given when the roots pump rotor profile is designed, i.e., the rotor profile with the blade peak curve being not within the reasonable design region inevitably causes the problem of closed volume or undercutting in application, so that the design of the rotor profile that causes the closed volume or undercutting can be avoided when the roots pump rotor profile is designed. The problem that the design unreasonableness of the rotor profile is not found until the design is completed is solved, so that the design efficiency of the rotor profile is improved.

A scroll compressor with a stationary scroll, an orbiting scroll, and a discharge port through which a fluid that has been compressed by both the scrolls is discharged. An end plate of the orbiting scroll is provided with an end-plate side stepped portion formed such that, along a spiral of a spiral wrap, the height thereof increases toward a central side of the spiral and decreases toward an outer end side thereof. A spiral wrap of the stationary scroll is provided with a wall-portion side stepped portion formed corresponding to the end-plate side stepped portion such that the height thereof decreases toward the central side of the spiral and increases toward the outer end side thereof. A pair of compression chambers which face each other, the ventral side compression chamber communicates with the discharge port before the dorsal side compression chamber communicates with the discharge port.

The disclosure discloses a method for determining reasonable design area of roots pump rotor profile of roots pump and its application, and belongs to the field of mechanical design. According to the method of the disclosure, after a relation between the roots pump rotor profile and performance parameters is established, constraint conditions for avoiding a closed volume and undercutting are further determined, so that a reasonable design region of a roots pump rotor blade peak curve is determined. Reference is given when the roots pump rotor profile is designed, i.e., the rotor profile with the blade peak curve being not within the reasonable design region inevitably causes the problem of closed volume or undercutting in application, so that the design of the rotor profile that causes the closed volume or undercutting can be avoided when the roots pump rotor profile is designed. The problem that the design unreasonableness of the rotor profile is not found until the design is completed is solved, so that the design efficiency of the rotor profile is improved.

A rotary machine, for directing a quantity of fluid from an inlet to an outlet, comprises one or more elliptical or near-elliptical rotors having planetary rotation within a housing. The interior cavity of the housing comprises an inverse apex region that is in contact with the rotor during its rotation. In various embodiments the rotor and housing can be symmetric or asymmetric in cross-section. Features are described that can improve the operation of the machine for various end-use applications. Such features include cut-outs that are fluidly connected to the inlet or outlet ports of the machine, mechanisms for reducing variation in output flow rate from the rotary machine, linings for the interior cavity of the housing, pressure relief mechanisms, dynamic apex seals and other sealing mechanisms.