A battery retaining system for a portable oxygen concentrator includes a first rail configured to receive a first slide of a battery, a second rail configured to receive a second slide of the battery, the second rail being spaced apart from the first rail so as to form a channel configured to receive the battery, and a flexible stiffening mechanism configured to impart a biasing force on a surface of the battery when the battery is received within the channel. The flexible stiffening mechanism includes a protrusion projecting from the first rail at least partially towards the second rail and a slit positioned behind the protrusion and configured to facilitate travel of the protrusion fore and aft.

A battery retaining system for a portable oxygen concentrator includes a first rail configured to receive a first slide of a battery, a second rail configured to receive a second slide of the battery, the second rail being spaced apart from the first rail so as to form a channel configured to receive the battery, and a flexible stiffening mechanism configured to impart a biasing force on a surface of the battery when the battery is received within the channel. The flexible stiffening mechanism includes a protrusion projecting from the first rail at least partially towards the second rail and a slit positioned behind the protrusion and configured to facilitate travel of the protrusion fore and aft.

A method for regulating the temperature at an outlet channel of a compressor or a vacuum element, comprising providing a pressure regulating valve on a influence channel, said influence channel being in direct fluid communication with the compressor or vacuum element, said valve regulating the pressure within the compressor or vacuum element by adjusting the volume of fluid flowing between a process channel and the compressor or vacuum element relative to the difference between the pressure value within said compressor or vacuum element and a set pressure value, and comprises starting the compressor or vacuum element and starting a pre-purge cycle by connecting the inlet channel to a supply of a purge gas for a preselected time interval; connecting the influence channel to a process channel; and disconnecting the inlet channel from the process channel, for maintaining a set temperature within the vacuum element for a selected time interval.

A method for regulating the temperature at an outlet channel of a compressor or a vacuum element, comprising providing a pressure regulating valve on a influence channel, said influence channel being in direct fluid communication with the compressor or vacuum element, said valve regulating the pressure within the compressor or vacuum element by adjusting the volume of fluid flowing between a process channel and the compressor or vacuum element relative to the difference between the pressure value within said compressor or vacuum element and a set pressure value, and comprises starting the compressor or vacuum element and starting a pre-purge cycle by connecting the inlet channel to a supply of a purge gas for a preselected time interval; connecting the influence channel to a process channel; and disconnecting the inlet channel from the process channel, for maintaining a set temperature within the vacuum element for a selected time interval.

The invention relates to a method used to control a scroll compressor having a first and a second spiral, in particular that are arranged one inside the other. The first spiral can be moved by a motor relative to the second spiral for a decompression or compression operation of the scroll compressor. The invention reduces vibration (actual acceleration forces) in the scroll compressor to allow for a longer service life by adapting a torque curve of the motor on the basis of measured acceleration forces on the scroll compressor which, in turn, is based on the position and/or positional angle of the first spiral relative to the second spiral such that the acceleration forces are reduced below a threshold or minimized.

The invention relates to a method used to control a scroll compressor having a first and a second spiral, in particular that are arranged one inside the other. The first spiral can be moved by a motor relative to the second spiral for a decompression or compression operation of the scroll compressor. The invention reduces vibration (actual acceleration forces) in the scroll compressor to allow for a longer service life by adapting a torque curve of the motor on the basis of measured acceleration forces on the scroll compressor which, in turn, is based on the position and/or positional angle of the first spiral relative to the second spiral such that the acceleration forces are reduced below a threshold or minimized.

A method including: determining a cooling value; and comparing the cooling value to an activation point of a lead compressor. The lead compressor is in a tandem set of scroll compressors of a cooling system. The tandem set of compressors comprises a lag compressor. The method further includes: activating the lead compressor when the cooling value is greater than the activation point; activating the lag compressor subsequent to activating the lead compressor; and determining whether conditions exist including: an alarm associated with the lag compressor being generated, and the lead compressor being deactivated. The method further includes deactivating the lag compressor when at least one of the conditions exists in the cooling system.

A method of operating an exhaust gas recirculation pump for an internal combustion engine including: providing an EGR pump assembly including an electric motor coupled to a roots device having rotors, the EGR pump operably connected to an internal combustion engine; providing an EGR control unit lined to the EGR pump assembly; providing sensors linked to the EGR control unit; determining if a motor speed is within a predetermined target (step SI), wherein when the motor speed is within the predetermined target then; determining if a motor torque is within a predetermined target (step S2) wherein when the motor torque is within the predetermined target then; determining if a motor temperature is within a predetermined target (step S3) wherein when the motor temperature is within the predetermined target then; maintaining operation of the exhaust gas recirculation pump.

A method of operating an exhaust gas recirculation pump for an internal combustion engine including: providing an EGR pump assembly including an electric motor coupled to a roots device having rotors, the EGR pump operably connected to an internal combustion engine; providing an EGR control unit lined to the EGR pump assembly; providing sensors linked to the EGR control unit; determining if a motor speed is within a predetermined target (step SI), wherein when the motor speed is within the predetermined target then; determining if a motor torque is within a predetermined target (step S2) wherein when the motor torque is within the predetermined target then; determining if a motor temperature is within a predetermined target (step S3) wherein when the motor temperature is within the predetermined target then; maintaining operation of the exhaust gas recirculation pump.

Repeated cycles each consist of a pump down phase and a holding phase, wherein a start timepoint of each cycle is the timepoint when a rise in an inlet pressure of the pump is sufficiently large and the time extending between two consecutive cycle start timepoints is a cycle time. A control method includes determining a start of a next cycle during a present cycle, wherein it is preferable that the present cycle directly precedes the next cycle. The method further includes controlling the pump to accelerate to a maximum allowed speed during the holding phase of the present cycle before the start of the next cycle such that at the start of the next cycle full pump capacity is available.