Products > Submersible pumps > TSURUMI Japan > Sewage pumps > Unique features

A - Tsurumi Stuffing Box - absolutely watertight !


The stuffing box is located at the cable entry section and takes the part of sealing off water.

As the cable counductors consist of twisted wires, water may penetrate into the motor by the capillary phenomenon when cable sheath or insulation is damaged or when the end of the cable is submerged. The construction is such that a certain part of the insulation of each conductor is peeled and filled with rubber or epoxy resin for the complete sealing.

B - Miniature Protector (actuating temp.: 115° ±5°C)

Located near or in the stator windings, a bi-metal device snaps open in case of overcurrent in one or more of the three motor windings and in case of too high motor temperature. This triggers a self-resetting cut-off in pumps wound for direct-on-line starting, the user´s magnetic contactor in other pumps.

C - Ball bearings of highest quality

Due to the high quality of the shaft and the bearrings all pumps can be run horizontally when entirely submerged.

D - Double mechanical SiC in oil bath

The gliding of a flat lapped ring rotating with the shaft along a similar fixed ring, both below and above an oil bath, assumes the crititical role of withstanding pumping pressure and preventing water from seeping into the motor. The seals of all Tsurumi sewage pumps, even in the 400W-class, have sealing rings of Silicon Carbide. No other material has greater hardness, selflubrication is slightly better than that of directly comparable materials. Resistance to temperature fluctuation and corrosion is also the best available. 

• A Motor side
• B Sealing face
• C Impeller side
• D Upper stationary part
• E Upper rotary part
• F Oil chamber
• G Spring 
• H Lower rotary part
• I Lower stationary part

E - The patented Oil Lifter

- a special guide vane -  is attached inside the oil chamber. With the motor rotation oil is pumped up. Therfore even at low oil level lubrication and cooling of the mechanical seal is secured.

F - Impeller

A variety of types are available, depending on applications, i.e. open type, closed type, non-clog type and vortex type.