摘要:
A rotor core (12) of a squirrel-cage rotor of an induction motor is housed in a recess (14) of a mold (18) of a conductor casting apparatus (10). A composite cylinder device (68) is fixed on the upper side of the mold (18) or on the side remoter from the pouring gate thereof, and the rotor core 12 is held in a predetermined position in the recess 14 by one piston (70). The other piston (72) locally pressurizes a molten metal that fills an end-connector ring cavity (66) defined between the rotor core (12) and the recess (14) on the side remoter from the pouring gate.
摘要:
A control method and apparatus for actuating an induction motor which is capable of generating a sufficiently large output in a wide speed region. In such an induction motor, each of Y-connection phase windings of the induction motor is divided into two split windings 5t and 3t at a predetermined split ratio (for example, 5:3). When a rotational speed of the induction motor is in a low speed region, only the changeover switch MC2 is turned on to supply exciting current to both of the split windings 5t and 3t. When the rotational speed of the induction motor is in a middle speed region, only the changeover switch MC3 is turned on to exclusively supply exciting current to the split windings 5t. Furthermore, when the rotational speed of the induction motor is in a high speed region, only the changeover switch MC1 is turned on to exclusively supply exciting current to the split windings 3t. With this arrangement, three different numbers of turns can selectively be used with respect to each phase winding so that relatively large number of turns can be used for the rotation in the low speed region, while relatively small number of turns can be used for the rotation in the high speed region in order to accomplish the desired control the actuation of the induction motor.
摘要:
The invention relates to an apparatus for casting a conductor of a cage rotor of an induction motor. A rotor core (13) comprising a laminated steel sheets is housed in a recess portion of a casting mold, an upper end portion thereof is held by a holding portion (70) and molten metal is supplied into a plurality of slots formed in the rotor core, thereby forming a plurality of conductor rods and a pair of end rings connecting the ends of the conductor rods with one another. The holding portion (70) comprises a cup (72) and a cylinder (73), and an axial dimension of the cup (72) is selected in correspondence to an axial dimension of the rotor core (13) housed in the recess portion of the casting mold. Further, by using a double cylinder (77, 79) in the holding portion (70), a rotor having higher quality can be obtained. For this reason, the same conductor casting apparatus can be used for casting the conductor of the rotor having different axial lengths and qualities depending on specifications.
摘要:
An air-cooled type electric motor (20) includes a rotor, a stator includes a stator core (28), and a front support member (32) and a rear support member (34) arranged at both axial ends of the stator core (28). A plurality of air passages (42), extending continuously in an axial direction, are provided in the stator core (28), the front support member (32), and the rear support member (34). A centrifugal blower unit (50) is placed at further rear side of the rear support member (34). Because the centrifugal blower unit (50) has a large pressure rise, air, surrounding the motor and sufficient to cause an effective cooling, can be made to flow into the air passages (42) with a smaller diameter. A drive section (56) of the blower unit (50) is fixed directly to the rear support member (34) by bolts (72). Consequently, an electric wire (74) for the drive section (56) extends through the interior space of the motor (20), and is connected to a terminal box (48). In this manner, the blowing capacity, and the moisture-proofing of the terminal box, can be improved.
摘要:
An air-cooled motor has a motor body in which a through hole is formed in a rotary shaft, a supply section for supplying a fluid to the through hole, a cylindrical member surrounding the supply section, and a cooling fan provided on the side opposite the motor body with respect to the cylindrical member. A window is provided in the cylindrical member or at least a part of the cylindrical member is made of a transparent material so that the supply section can be visually observed.
摘要:
A spindle protective structure capable of reliably detecting coolant leakage from a jointing device and protecting a spindle. A flow sensor is provided in the line of a drain pipe for discharging coolant leaking from the rotary joint, so that an alarm is made when the flow of coolant in the drain pipe exceeds a predetermined value. Since the coolant leaking from the jointing device is detected directly and an alarm is outputted, coolant leakage can be found out more quickly than by observing visually whether the flow of coolant jetting from a tip of a tool is normal or not.
摘要:
A spindle protective structure in a spindle-through coolant feeder capable of preventing coolant form invading a spindle and a spindle motor for an excessive overflow of coolant. Coolant is supplied into a through hole formed axially in the spindle or a shaft connected to the spindle through a stationary member and a rotary member of a rotary joint supported by a housing. A seal member having elasticity is provided on a circumferential surface of the spindle or the shaft. Coolant which leaks through the seal member is splashed by a fringer provided in the housing. When a large amount of coolant is overflowed in the housing, a pressure of the coolant in a first chamber of the housing increases to press a lip of the seal member towards the circumferential surface of the spindle or the shaft to prevent leakage of coolant into a second chamber of the housing. Thus, the excessive overflow of coolant is prevented from invading the spindle and the spindle motor for a long enough time for an operator to take countermeasure for the leakage of coolant.
摘要:
An air passage extending in the axial direction of a motor shaft is formed in a plurality of places in the peripheral wall of a motor housing. An extension tube is fixed to a rear end of the motor housing to provide a space for mounting a rotary joint for connecting a coolant feed pipe to the end of a through hole in the motor shaft, and the extension tube is used as an exhaust (ventilation) passage so that the motor can be cooled with air introduced into the air passage through the tube by using a fan provided on a rear end of the extension tube.
摘要:
When an operation of a motor cannot be continued due to a large amount of heat generated when the motor is rotated at a high speed and under a high load, the motor is usually cooled by adopting a cooling structure using a coolant with a high cooling performance. It is, however, difficult to cast a casing with a complex channel, and the manufacturing costs are high. According to the present invention, through channels (15a, 15a) are formed along a central casing (10) of a motor casing consisting of a main central casing (10), a front end casing and a rear end casing (12, 14) when casting, and each through channel (15a, 15b) is communicated via communication holes (16a, 16b, 18a, 18b) drilled in the front end casing (12) and in the rear end casing (14), so that the whole of the casing can be fully cooled.
摘要:
A rolling bearing system provided with an inner ring including a first raceway surface, an outer ring including a second raceway surface, a rolling element retained between the inner ring and the outer ring and capable of rolling along the first raceway surface and the second raceway surface, and a lubricant storage section incorporated in a bearing structure. The lubricant storage section includes a grease tank arranged between the inner and outer rings for storing a grease, and a grease pressing mechanism for pushing the grease stored in the grease tank out of the grease tank to supply the grease to the rolling element and the first and second raceway surfaces. The inner ring includes a first extending surface adjoining the first raceway surface, and the outer ring includes a second extending surface adjoining the second raceway surface and facing the first extending surface. The grease tank is housed in an annular space defined between the first and second extending surfaces.