31results about How to "Small sectional area" patented technology

An electric vehicle includes plurality of batteries accommodated in a rear portion of a battery box, and an electric part is accommodated in an electric part accommodating chamber provided in a front portion of the battery box. Cooling air supplied from a cooling fan to the rear portion of the battery box cools the batteries having a large thermal resistance, while being passed through a first cooling air passage around outer peripheries of the batteries at a low flow rate. A second cooling air passage having a smaller sectional area than that of the first cooling air passage is provided below the electric part accommodating chamber, and cooling fins protruding downwards from the electric part are exposed within the second cooling air passage. The second cooling air passage extends continuously the first cooling air passage in a downstream direction of airflow, so that cooling air which has first cooled the batteries then cools the electric part having a smaller thermal resistance, while being passed through the second cooling air passage at a higher flow rate than that in the first cooling air passage.

A vibrating electrode plate 24 that senses a sound pressure faces a counter electrode plate 25 to constitute a capacitance type acoustic sensor. In the counter electrode plate 25, acoustic perforations 31 are opened in order to pass vibration, and plural projections 36 are provided on a surface facing the vibrating electrode plate 24. An interval between the projections 36 is decreased in a region where the vibrating electrode plate 24 has high flexibility to easily generate local sticking with the counter electrode plate 25. The interval between the projections 36 is increased in a region where the vibrating electrode plate 24 has low flexibility to hardly generate local sticking with the counter electrode plate 25. The projections thus arranged prevent firm fixing of the vibrating electrode plate to the counter electrode plate and interruption of vibration of the vibrating electrode plate.

A skateboard assembly and a skateboard having the same are provided. The skateboard assembly includes a truck and a frame. The truck includes a pivot that has two oppositely extending axial sections, and the frame includes a pivot hole, and a first segment and a second segment extending at two sides of the pivot hole, wherein the first segment and the second segment include an angle and each of the first and second segments has an end far from the pivot hole provided with an axle.

A liquid ejecting head that includes a fluid channel formation substrate and pressure generation units. The fluid channel formation substrate is made of a silicon single crystal substrate having a crystal face orientation of. The fluid channel formation substrate has a plurality of separate flow channels that include at least pressure generation chambers demarcated by partition walls, each of the pressure generation chambers being in communication with a nozzle opening that ejects liquid drops. The fluid channel formation substrate further has a communication portion that is in communication with each of the separate flow channels. The pressure generation units are provided so as to correspond to the pressure generation chambers and generate a pressure change in the pressure generation chambers so as to cause ejection of liquid drops.

A connecting terminal includes an external terminal connecting portion, having an end surface to connect an external terminal thereto and located at a second principal surface side of a second circuit board faces, and a substrate-fixed portion which is securely connected to a first circuit board. A seal attachment portion is provided on a portion of the external terminal connecting portion including the end surface to attach thereto a seal member to seal a gap between the portion and the case. The connecting terminal includes a reduced sectional area portion having a sectional area smaller than an area of the top end surface in a region close to a plurality of electronic components arranged on the second circuit board on the external terminal connecting portion. The reduced sectional area portion is provided from the seal attachment portion to an end in the opposite side of the end surface.

Means of solution: Optical protrusions 23 of nano-size for restricting reflection of light and protection columns 24 for preventing crushing of the optical protrusions 23 are provided on a surface of a film substrate 22. The protection columns 24 have a frustum shape. When a ratio of a projection area in which all of lateral surfaces of a single protection column24 are projected on a surface of the film substrate 22 from a direction that is perpendicular to the surface of the film substrate 22 to a divided area on the surface of the film substrate 22 with respect to the single protection column 24 is defined to be a lateral surface projection occupying area rate, the lateral surface projection occupying area rate of the antireflection film is not more than 0.25% and not less than 0.01%.

To provide a muffler for a compact combustion engine, which is simple in structure and effective to sufficiently reduce the temperature of exhaust gases while avoiding contact with an external air, an exhaust guide passage 7 for communicating the exhaust gases (G) to a discharge port (63) is provided within an interior hollow of a muffler housing 6 defining an exhaust chamber (61) therein, and a side wall of this exhaust guide passage (7) is constituted by a portion (6W) of the muffler housing (6) and a duct wall (71) jointed to the muffler housing (6).

The present invention provides a current transformer for a compound-type gas-insulated switchgear which can be arranged on either side of a circuit-breaker. To the lower end of an insulating support structure 11, an operating apparatus 12 is connected, and to the upper end a metal container 13 is connected. To the upper part of the metal container 13, a first ceramic bushing 14a, in which a circuit-breaker 1 is housed and a second porcelain bushing 14b in which a disconnector 2 is housed, are connected. The circuit- breaker 1 and the disconnector 2 are opening/closing-operated by the operating apparatus 12. Current transformers 21a, 21b are set at both ends of the ceramic bushing 14a. The current transformers 21a, 21b are composed of current detect means 22a, 22b, sensor units 23a, 23b, power-feeding current transformers 25a, 24b and an integrating unit 25. The integrating unit is set in a housing part for the operating apparatus, and the sensor units 23a, 23b and integrating unit are connected to each other with insulators 26a, 26b which house optical fibers.

A semiconductor device is equipped with fuses each made of a conductive material vertically extended through an insulator layer employed in the semiconductor device. Holes are formed which vertically penetrate the insulator layer. Sidewalls are formed on their corresponding wall surfaces of the holes. The holes formed with the sidewalls are buried with a conductive material.

A double-oar square-tube marine propulsor device relates to a ship propulsor. The double-oar square-tube marine propulsor device comprises a left main shaft, a left propeller, a right main shaft, a right propeller and a square-tube-shaped housing. The left main shaft is mounted on the left plate of the square-tube-shaped housing through a bearing. The left end of the left main shaft is oriented to the left front direction and is arranged at the left outer side of the square-tube-shaped housing, and the right end is connected with the left propeller in the square-tube-shaped housing. The left propeller and the right propeller are symmetrical in a left-and-right direction. An included angle between the rotating plane of the left propeller and the rotating plane of the right propeller is smaller than 150 DEG. The rotating plane of the left propeller is perpendicular with the top board and the base board of the square-tube-shaped housing. The square-tube-shaped housing is in compact matching with the left propeller and the right propeller. A power is transmitted to the left propeller and the right propeller respectively through the left main shaft and the right main shaft. The rotation directions of the left propeller and the right propeller are opposite. Compared with a traditional marine propulsor, the double-oar square-tube marine propulsor device has advantages of higher efficiency and small resistance when a same flow is realized.

The invention discloses a rotary motor. The rotary motor is a double-layer Halbach type excitation rotary motor which can assist in decreasing manufacturing cost. The rotary motor comprises permanent magnets of which the sections are rectangle-shaped and are vertical to the rotation shaft; the permanent magnets are distributed annularly; the permanent magnets of which the sections are rectangle-shaped are distributed at intervals and are separated from each other by the same angle so as to form a ring-shaped structure; filling materials are inserted in wedge-shape slots between adjacent magnets; and the filling materials are composed of a non-magnetic material and a non-electric conduction material. With the above technical schemes of the invention adopted, the rotary motor can be manufactured with low cost. The permanent magnets of which the sections are rectangle-shaped and are vertical to the rotation shaft, are adopted, and therefore, cost for manufacturing the rotary motor can be decreased; the permanent magnets are used in such a manner, so that the consumption of magnets can be decreased, and resources can be saved; the filling materials are inserted between the adjacent permanent magnets, and therefore, the positions of the permanent magnets can be determined conveniently, and the permanent magnets can have sections vertical to the rotation shaft.

The invention discloses a flame-retardant power cable, and belongs to the technical field of cables. The technical key points are that the flame-retardant power cable comprises a cable main body, a filling layer is arranged in the middle of the cable main body, and a carbon fiber layer, an aerogel felt layer, an ethylene-propylene copolymer and a halogen-free flame-retardant jacket are sequentially arranged on the outer side wall of the filling layer from inside to outside. A polyvinyl chloride column body is arranged in the middle of the filling layer, a plurality of uniformly distributed alumina fiber blocking edges are fixedly connected to the outer side wall of the polyvinyl chloride column body, and conductor main bodies are arranged between every two adjacent alumina fiber blocking edges. An alumina fiber coating and rock wool are sequentially arranged on the inner side wall of the halogen-free flame-retardant outer sleeve from outside to inside. The polyvinyl chloride cylinders reinforce the non-deformability of a power cable, facilitate the protection to the conductors and prevent the conductors from being broken, and the polyvinyl chloride cylinders are made of ultra-light high-temperature heat-insulating materials, so that the flame-retardant performance of the power cable is further enhanced, the flame-retardant effect is achieved inside and outside the power cable, and the safety performance of the power cable is improved.

The invention provides a symmetric double-stage propelling device for a ship, which relates to ship propelling devices. The symmetric double-stage propelling device for the ship comprises a left front engine, a right front engine, a left rear engine, a right rear engine, a left front propeller, a right front propeller, a left rear propeller, a right rear propeller and a square tube-shaped housing. The left front propeller, the right front propeller, the left rear propeller and the right rear propeller are symmetrically mounted within the square tube-shaped housing in pairs. A front angle between the rotating plane of the left front propeller and the rotating plane of the right front propeller is not more than 150 DEG. The rotating planes of the left front propeller, the right front propeller, the left rear propeller and the right rear propeller are all vertical to a top plate and a bottom plate of the square tube-shaped housing. The left front propeller, the right front propeller, the left rear propeller and the right rear propeller rotate under the driving of power so as to suck the water ahead of them into the square tube-shaped housing and then extrude the water from the backside of the square tube-shaped housing. Compared with the traditional ship propeller, the symmetric double-stage propelling device for the ship, provided by the invention, has the advantages of large thrust face, high efficiency and low resistance.