Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
  • F16F15/00—Suppression of vibrations in systems; Means or arrangements for avoiding or reducing out-of-balance forces, e.g. due to motion
  • F16F15/02—Suppression of vibrations of non-rotating, e.g. reciprocating systems; Suppression of vibrations of rotating systems by use of members not moving with the rotating systems
  • F16F15/023—Suppression of vibrations of non-rotating, e.g. reciprocating systems; Suppression of vibrations of rotating systems by use of members not moving with the rotating systems using fluid means
  • F16F15/0237—Suppression of vibrations of non-rotating, e.g. reciprocating systems; Suppression of vibrations of rotating systems by use of members not moving with the rotating systems using fluid means involving squeeze-film damping
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
  • F16C27/00—Elastic or yielding bearings or bearing supports, for exclusively rotary movement
  • F16C27/04—Ball or roller bearings, e.g. with resilient rolling bodies
  • F16C27/045—Ball or roller bearings, e.g. with resilient rolling bodies with a fluid film, e.g. squeeze film damping
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
  • F16C19/00—Bearings with rolling contact, for exclusively rotary movement
  • F16C19/02—Bearings with rolling contact, for exclusively rotary movement with bearing balls essentially of the same size in one or more circular rows
  • F16C19/04—Bearings with rolling contact, for exclusively rotary movement with bearing balls essentially of the same size in one or more circular rows for radial load mainly
  • F16C19/06—Bearings with rolling contact, for exclusively rotary movement with bearing balls essentially of the same size in one or more circular rows for radial load mainly with a single row or balls
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
  • F16C2380/00—Electrical apparatus
  • F16C2380/26—Dynamo-electric machines or combinations therewith, e.g. electro-motors and generators

Definitions

• the invention relates to techniques for damping vibration in a rotating shaft.
• an oil film damper is placed in a rotary bearing to prevent vibration of the shaft.
• a conventional turbocharger has a shaft which rotates at a high rotational velocity.
• the shaft is supported by an angular ball bearing and damper.
• a lubricating oil is filled in a gap created between the damper and a side brake and the angular ball bearing is stably supported by the damping effect of the oil film.
• the amount of the supplied lubricating oil is constant regardless of the rotational velocity the shaft. It is possible for vibration of the shaft to occur at particular rotational velocities.
• the present invention relates to a damping device for damping vibration in a rotating shaft.
• a damping device for damping vibration in a rotating shaft.
• an electric motor for a vehicle equipped with a damping device for example, an electric motor for a vehicle equipped with a damping device.
• Embodiments of the invention control vibrations by creating a fluid film in the support element of the rotating shaft. The fluid film is maintained over all operational speeds of the shaft by a fluid firm creating element.
• a damping device may include a fluid film creating element which creates a fluid film between a roller bearing which rotatably supports a rotating shaft and a roller bearing support element which supports the roller bearing, and a fluid body supplying means which supplies a fluid body to the fluid film creating element.
• the fluid body supplying means increases the supply amount of the fluid body which is supplied to the fluid film creating element when the number of the rotating shaft is relatively large.
• a damping device may include a fluid film creating element which creates a fluid film between the roller bearing and the roller bearing support element and a fluid body supplying means which supplies the fluid body to the fluid film creating element.
• the fluid body supplying means increases the supply amount of the fluid body to the fluid film creating element when the rotating shaft rotates at a relatively high speed. As a result, resonance can be prevented even when the rotational velocity of the rotating shaft is changed.
• a damping device comprises a fluid film creating element which creates a fluid film between a roller bearing which rotatably supports a rotating shaft and a roller bearing support element which supports the roller bearing and a fluid supply element.
• the fluid supply element supplies a fluid body to the fluid film creating element and increases the supply amount of the fluid body which is supplied to the fluid film creating element when a rotational velocity of the rotating shaft is relatively high.
• a system comprises an electric motor for a vehicle that supplies a driving force for the vehicle by rotating a rotating shaft, roller bearings that rotatably support the rotating shaft, a housing that supports the roller bearings, a circular-shaped member that creates an oil film between at least one of the roller bearings and the housing and an oil pump that supplies oil to the circular-shaped member.
• the oil pump increases the supply of the oil when the rotating shaft rotates at a relatively high rotational velocity.
• a method comprises providing a supply of oil to a circular-shaped member that creates an oil film between at least one roller bearing and a housing, wherein the at least one roller bearing supports a rotating shaft and adjusting the supply of oil relative to a rotational velocity of the rotating shaft.
• Figure 1 is a cross-sectional view illustrating the structure of the electric motor for a vehicle of a first exemplary embodiment.
• Figure 2 is an enlarged perspective view illustrating the structure of oil film damper of the electric motor for a vehicle of the first exemplary embodiment.
• Figure 3 is an enlarged cross-sectional view illustrating element A of Figure 1 to explain the structure of oil film damper of the electric motor for a vehicle of the first exemplary embodiment.
• Figure 4 is a cross-sectional view of the structure of the electric motor for a vehicle of a second exemplary embodiment.
• Figure 5 is a cross-sectional view of the structure of the electric motor for a vehicle of a third exemplary embodiment.
• Figure 6 is a cross-sectional view of the structure of the electric motor for a vehicle of a fourth exemplary embodiment.
• Figure 7 is a rheogram showing the relationship among the rotational velocity of the electric motor, amount of the oil which is supplied to the oil film damper 15 and the resonance property of the electric motor.
• Figure 8 is a block diagram illustrating the structure of the electric motor for a vehicle of a fifth exemplary embodiment.
• Figure 9 is a flowchart showing the oil amount controlling process of the electric motor for a vehicle of the fifth exemplary embodiment.
• Figure 10 is a rheogram showing the relationship between the rotational velocity and the load of the electric motor of the electric motor for a vehicle of the fifth exemplary embodiment.
• Figure 11 is a rheogram showing the relationship between the rotational velocity and the load of the electric motor of the electric motor for a vehicle of a sixth exemplary embodiment.
• Figure 12 is a rheogram showing the relationship between the rotational velocity and the load of the electric motor of the electric motor for a vehicle of a seventh exemplary embodiment.
• Figure 13 is a view of the relation of the supply amount of the oil to the oil film damper by the valve switch-over of the electric motor for a vehicle of the seventh exemplary embodiment.
• Figure 14 is a flowchart showing the oil amount controlling process of the electric motor for a vehicle of an eighth exemplary embodiment.
• Figure 15 is a view indicating the ranges of the acceleration used in the oil amount controlling process of the electric motor for a vehicle of the eighth exemplary embodiment.
• Figure 16 is a flowchart showing the oil amount controlling process of the electric motor for a vehicle of a ninth exemplary embodiment.
• Figure 17 is a block diagram illustrating the structure of the electric motor for a vehicle of a tenth exemplary embodiment.
• FIG. 1 is a cross-sectional view illustrating a structure of the damping device, the electric motor for a vehicle and the driving device for a vehicle of the first exemplary embodiment.
• electric motor for a vehicle 1 of the present embodiment is integrally connected to reduction gear 3 equipped with oil pump 2.
• reduction gear 3 equipped with oil pump 2.
• bearings 13 and 14 On the center shaft of cylindrical housing 10, both ends of rotating shaft 11 are rotatably supported by two bearings, bearings 13 and 14.
• Bearing 13 has oil film damper 15 which prevents resonance of the rotating body by an oil film and retainer 16 is placed in reduction gear 3 of bearing 14.
• oil film damper 15 which prevents resonance of the rotating body by an oil film and retainer 16 is placed in reduction gear 3 of bearing 14.
• angular ball bearings may be used as bearings 13 and 14.
• retainer 16 is placed in one of bearings 14 so as to facilitate the positioning of electric motor for a vehicle 1, but oil film damper 15 may be placed in line in bearings 13 and 14.
• Figure 1 shows a cross-sectional view of electric motor for a vehicle 1 which is viewed from its rear side and a cross-sectional view of oil pump 2 and reduction gear 3 which are viewed from the front side of the vehicle.
• a stator is created on the inner wall of housing 10 by circular-shaped stator core 17 and coil 18 which is placed on stator core 17.
• Rotor 19 made from a circular- shaped iron core and fixed to rotating shaft 11 is placed on the inner wall of stator core 17.
• the iron core constituting rotor 19 is created by laminating a plurality of thin plates made of magnetic material such as iron in the direction of rotating shaft 11.
• Oil pump 2 absorbs the oil inside reduction gear 3 as rotating shaft 21 rotates and discharges the oil to oil path 23 supplying it to oil film damper 15.
• Oil pump 2 may be a pump such as a vane pump, which can absorb and discharge the oil as rotating shaft 21 rotates.
• Rotating shaft 21 of oil pump 2 is connected to rotating shaft 11 of electric motor for a vehicle 1 so that rotating shaft 21 can integrally rotate with rotating shaft 11.
• oil is stored inside housing 10 and in a case located in reduction gear 3 respectively so that rotating shaft 11 of electric motor for a vehicle 1 and rotating shaft 21 of oil pump 2 are immersed.
• oil film damper 15 As shown in Figure 2, in oil film damper 15, oil puddle concave element 42, a fluid film creating element, is created in the entire circumference of circular-shaped race 41 and bearing 13 is engaged in the inner circumference. Oil film damper 15 is inserted into rotating shaft inserting hole 43 of housing 10. As shown in Figure 3, outer race 51 of bearing 13 is fixed to the inner side of race 41, bearing ball 52 and inner race 53 are placed inside outer race 51 and rotating shaft 11 is engaged in and rotatably supported by the inner side of inner race 53.
• Oil is supplied through oil supply entrance 45 to oil puddle concave element 42 of race 41 lubricating bearing 13 as well as preventing resonance caused by rotating shaft 11.
• Figure 2 has only one oil supply entrance 45, several oil supply entrances may be created. In this case, oil supply entrances 45 may be arranged around rotating shaft inserting hole 43 in a radial manner.
• oil pump 2 increases the amount of the oil supplied in relation to the rotational velocity. Therefore, when the rotational velocity is high which requires more oil, it is possible to supply a large amount of oil. Therefore, it is possible to prevent resonance of rotating shaft 11 in any rotational velocity.
• Figure 7 is a rheogram showing the relationship among the rotational velocity of the electric motor (rotational velocity of rotating shaft 11), amount of oil which is supplied to oil film damper 15 (hereinafter called oil amount) and resonance property of the electric motor (vibration property of rotating shaft 11).
• the center point of the circle represents the rotational velocity of the electric motor and the oil amount when resonance is generated.
• the size of the diameter of the circle represents resonance ratio.
• the 1st to 3rd rotation vibrations which are the vibration property of the electric motor are the frequency when the vibration wave is analyzed ( Figure 7 shows up to the 3rd rotation vibration).
• the electric motor can rotate with rotational velocity B without generating the 3rd rotation resonance (the rotational velocity within the range of under bar B has a high decrease rate).
• the 1st rotation resonance and 2nd rotation resonance have low decrease rate and cannot decrease resonance generated in ⁇ 2 and ⁇ 3.
• the rotational velocity (rotational velocity of rotating shaft 11) of the electric motor increases based on the oil amount.
• the increase property of the oil amount to the increase of the rotational velocity that is, the property of oil pump 2 becomes the property of range D of the figure.
• the oil supplied from oil pump 2 to oil film damper 15 as described above is discharged into the case located in reduction gear 3 passing through electric motor for a vehicle 1 as shown with the arrows.
• the oil stored in the case in reduction gear 3 is absorbed into oil pump 2 after lubricating reduction gear 3 and discharged to oil path 23 and circulates.
• the oil is stored in the case inside housing 10 or in the case located in reduction gear 3 so that rotating shaft 11 of electric motor for a vehicle 11 and rotating shaft 21 of oil pump 2 are immersed.
• the electric motor for a vehicle 1 of the present embodiment has oil pump 2 which is connected to rotating shaft 11 and oil pump 2 changes the amount and pressure of the oil which is supplied to oil film damper 15 based on the rotational velocity of rotating shaft 11. As a result, in conjunction with the rotational velocity of rotating shaft 11, oil pump 2 can prevent resonance of rotating shaft 11 at any rotational velocity.
• Figure 4 is a cross-sectional view illustrating the structure of the electric motor for a vehicle of the second exemplary embodiment. As shown in Figure 4, according to the present embodiment, oil pump 2 is placed inside housing 10 of electric motor for a vehicle IA so that oil path 61 through which oil is supplied from oil pump 2 to oil film damper 15 passes through housing 10. Since other structures are the same as those of the first exemplary embodiment, their explanation is omitted.
• Oil pump 2 shown in Figure 4 is a pump made for absorbing and discharging the oil in relation to the rotational velocity of rotating shaft 11 in a manner similar to the first exemplary embodiment. Therefore, as shown with the arrows in Figure 4, the oil pump absorbs the oil which passes through electric motor for a vehicle IA and discharges it to oil path 61 with the amount and pressure of the oil which are relative to the rotational velocity of rotating shaft 11.
• Oil path 61 is placed in the axial direction of rotating shaft 11 inside housing 10 and supplies the oil which is discharged from oil pump 2 to oil film damper 15.
• oil path 61 for supplying oil from oil pump 2 to oil film damper 15 is placed in an axially extending direction inside housing 10. Therefore, it is possible to cool down electric motor for a vehicle IA by the oil used for preventing resonance of rotating shaft 11.
• Figure 5 is a cross-sectional view illustrating the structure of the electric motor for a vehicle of the third exemplary embodiment.
• oil pump 2 is placed inside housing 10 of electric motor for a vehicle IB and the location of the oil pump 2 is in the side of oil film damper 15.
• the present embodiment is different from the first exemplary embodiment in that it has oil path 71 which supplies oil from reduction gear 3 to oil pump 2. Since other structures are the same as those of the first exemplary embodiment, their explanation is omitted.
• Oil pump 2 shown in Figure 5 is a pump made for absorbing and discharging the oil in relation to the rotational velocity of rotating shaft 11 in a manner similar to the first exemplary embodiment. As shown with the arrows in Figure 5, oil pump 2 absorbs the oil which passes from reduction gear 3 through oil path 71 and discharges it to oil film damper 15 with the amount and pressure of the oil which are relative to the rotational velocity of rotating shaft 11. [0055] The oil which recycles oil film damper 15 passes through electric motor for a vehicle 1 and is discharged to reduction gear 3. Then, after passing from reduction gear 3 through oil path 71, the oil is again absorbed by oil pump 2 and discharged to oil film damper 15 and recycles.
• reduction gear 3 is connected to the end where oil film damper 15 of rotating shaft 11 is not placed and oil pump 2 is placed in the end where oil film damper 15 of rotating shaft 11 is placed.
• the oil which lubricates oil film damper 15 passes through the electric motor for a vehicle IB and is discharged to reduction gear 3. Therefore, it is possible to use the inside of the electric motor for a vehicle as the oil path.
• the oil for preventing resonance of rotating shaft 11 it is possible to cool down electric motor for a vehicle IB.
• FIG. 6 is a cross-sectional view illustrating the structure of the electric motor for a vehicle of the fourth exemplary embodiment.
• the present embodiment is different from the first exemplary embodiment in that oil film damper 81 and oil pump 2 are placed in the side of reduction gear 3 of rotating shaft 11 and retainer 83 is placed in the opposite side of rotating shaft 11. Since other structures are the same as those of the first exemplary embodiment, their explanation is omitted.
• Oil pump 2 shown in Figure 6 is a pump made for absorbing and discharging the oil in relation to the rotational velocity of rotating shaft 11 in a manner similar to the first exemplary embodiment. As shown with the arrows in Figure 6, oil pump 2 absorbs the oil which lubricates oil film damper 81 and discharges it with the amount and pressure of the oil which are relative to the rotational velocity of rotating shaft 11.
• oil pump 2 may absorb it from reduction gear 3 and recycle it.
• the electric motor for a vehicle 1C of the present embodiment has oil film damper 81 and oil pump 2 in the end which is connected to reduction gear 3 of rotating shaft 11. Therefore, the space between rotor 19 and stator core 17 of the electric motor for a vehicle 1C can be easily maintained dry and no viscosity resistance is generated by oil between rotor 19 and stator core 17.
• FIG 8 is a block diagram illustrating the structure of the electric motor for a vehicle of the fifth exemplary embodiment.
• the present embodiment has switching valve 91 for adjusting the amount of oil which is discharged from oil pump 2 and control element 92 (control means) which controls the amount of oil by controlling oil pump 2 and switching valve 91 based on the rotational velocity and torque (load) of electric motor for a vehicle ID. Since other structures are the same as those of the first exemplary embodiment, their explanation is omitted.
• a valve control signal which is transmitted from control element 92 controls the switch-over of the valve flow path and the destination of the supply of the oil which is discharged from oil pump 2 is controlled by this switch-over of the flow path.
• Control element 92 detects the rotational velocity of rotating shaft 11 and the torque on rotating shaft 11 and controls the torque on electric motor for a vehicle ID. At the same time, control element 92 transmits the valve control signal to switching valve 91 and controls the switch-over of the valve flow path.
• control element 92 may detect the torque on rotating shaft 11 by placing a torque sensor on the electric motor for a vehicle ID or detect the torque on rotating shaft 11 by calculating the rotational velocity of reduction gear 3 and the current value which is supplied to electric motor for a vehicle ID.
• control element 92 of the electric motor for a vehicle of the fifth exemplary embodiment determines whether or not the rotational velocity of rotating shaft 11 is threshold and predetermined value of the rotational velocity Rl or higher (S901). When the rotational velocity of rotating shaft 11 is threshold value Rl or higher, control element 92 determines whether or not the torque on the rotating shaft 11 is threshold and predetermined load value Tl or lower (S902).
• control element 92 switches over switching valve 91 so that oil is supplied toward oil film damper 15 and the amount of the oil discharged from oil pump 2 is increased in accordance with the rotational velocity of rotating shaft 11 (S903) thereby ending the oil amount controlling process of the present embodiment.
• area Sl wherein the number for the rotation of rotating shaft 11 is threshold value Rl or higher and the torque is threshold load value Tl or lower is the area wherein switching valve 91 is switched over so that the oil is supplied toward oil film damper 15 and the discharged amount of the oil from oil pump 2 is increased in accordance with the rotational velocity.
• Threshold value Rl is, for example, 6000-8000 rpm and threshold load value Tl is, for example, 1-2 N/m.
• switching valve 91 is switched over to supply the oil to reduction gear 3. As a result, it is possible to decrease the torque on oil pump 2 and reduce the torque for driving oil pump 2. Therefore, the torque of electric motor for a vehicle ID can be used for running a vehicle.
• the supply amount of the oil to oil film damper 15 is increased only when the rotational velocity increases and the load is low in the electric motor for a vehicle ID.
• switching valve 91 is switched over to oil film damper 15 so that the oil is supplied to oil film damper 15 and the amount of the oil supplied to oil film damper 15 is increased in accordance with the rotational velocity.
• the state wherein the rotational velocity is large and the load is low is that of immediately after the clutch of the driving wheels is disengaged to make the transition from 4WD to 2WD or the vehicle is running gentle downhill, that is, the state wherein the electric motor is running despite the decrease of the load on the electric motor.
• FIG. 11 is a rheogram showing the relationship between the rotational velocity and torque in the electric motor for a vehicle of the sixth exemplary embodiment. As shown in Figure 11, the present embodiment is different from the fifth exemplary embodiment in that as the rotational velocity of rotating shaft 11 increases, the threshold load value is gradually increased. Since other structures are the same as those of the fifth exemplary embodiment, their explanation is omitted.
• control element 92 when the rotational velocity of rotating shaft 11 exceeds threshold value R2 but is less than threshold value Rl, control element 92 changes the threshold load value so that the threshold load value is gradually increased from 0 to threshold load value Tl. [0076] Also, when the rotational velocity of rotating shaft 11 is threshold value Rl or higher, control element 92 changes the threshold load value so that the threshold load value is increased gradually from threshold load value Tl as the rotational velocity of rotating shaft 11 increases.
• the threshold load value which is the threshold for determining whether or not the supply amount of oil is increased is gradually increased as the rotational velocity increases.
• the area wherein the supply amount of oil is increased is expanded from area Sl of Figure 10 to area S2 and at the same time the supply amount of oil can be increased in area S3.
• the threshold load value is gradually increased. Therefore, it is possible to effectively produce the resonance damping effect by oil film damper 15 in the area where the rotational velocity is large.
• the threshold load value is gradually increased from 0 as the rotational velocity of rotating shaft 11 increases. As a result, even if the rotational velocity is small, it is possible to effectively produce the resonance damping effect by oil film damper 15.
• Figure 12 is a rheogram showing the relationship between the rotational velocity and the torque of the electric motor for a vehicle of the seventh exemplary embodiment.
• the present embodiment is different from the fifth exemplary embodiment in that transition area S4 is created outside area Sl, wherein the switch-over amount of switching valve 91 is changed so that the relation of the oil supplied to oil film damper 15 is gradually increased. Since other structures are the same as those of the fifth exemplary embodiment, their explanation is omitted.
• the relation of the supply amount of the oil to oil film damper 15 by switching valve 91 is set as 100 % by control element 92 in area Sl wherein the rotational velocity is threshold value Rl or higher and the torque is threshold load value Tl or lower. Then, all the oil which is discharged from oil pump 2 based on the rotational velocity is supplied to oil film damper 15.
• control element 92 controls the oil amount by continuously changing the switch-over ratio of switching valve 91 0-100 % as shown in Figure 13 so that the relation of the oil amount supplied to oil film damper 15 is gradually increased.
• Transition area S4 has either a range wherein the rotational velocity of rotating shaft 11 is less than threshold value Rl and threshold value R2 or higher, or a range wherein the torque on rotating shaft 11 is more than threshold load value Tl and threshold load value Tl or lower.
• Figure 14 is a flowchart showing the oil amount controlling process which is conducted by control element 92 of the electric motor for a vehicle of the eighth exemplary embodiment.
• the present embodiment is different from the fifth exemplary embodiment in that whether or not oil is supplied to oil film damper 15 is determined based on the speed of the vehicle equipped with the electric motor for a vehicle, whether the vehicle is running uphill or downhill and the acceleration of the vehicle while it is running uphill or downhill. Since other structures are the same as those of the fifth exemplary embodiment, their explanation is omitted.
• Control element 92 obtains the speed of the vehicle equipped with the electric motor for a vehicle from the speed sensor and determines whether or not the speed is a predetermined and threshold speed (regulated speed) or faster (S 1401). When the speed of the vehicle is less than the threshold speed value, it is considered that the rotational velocity of rotating shaft 11 is small. Therefore, switching valve 91 is switched over to reduction gear 3 so that the oil is supplied to reduction gear 3 (S 1402) thereby ending the oil amount controlling process of the present embodiment.
• regulated speed regulated speed
• the slope of the road where the vehicle is running is detected based on the information obtained from a sensor which detects the inclination state of the vehicle such as a gyro sensor and it is determined whether or not the road is uphill (S 1403).
• a sensor which detects the inclination state of the vehicle such as a gyro sensor and it is determined whether or not the road is uphill (S 1403).
• the acceleration of the vehicle is in a range of acceleration al-a2 shown in Figure 15 (S 1404).
• switching valve 91 is switched over so that the oil is supplied to oil film damper 15 and the amount of the oil discharged by oil pump 2 is increased based on the rotational velocity of rotating shaft 11 (S 1405) thereby ending the oil amount controlling process of the present embodiment.
• step S 1406 when it is determined that the vehicle is not running downhill in step S 1406 and that acceleration is in a range of a5-a6 shown in Figure 15 (S 1408), it is considered that the rotational velocity of rotating shaft 11 is large and the load is low. Therefore, switching valve 91 is switched over so that oil is supplied to oil film damper 15 and the amount of the oil discharged by oil pump 2 is increased based on the rotational velocity of rotating shaft 11 (S 1405) thereby ending the oil amount controlling process of the present embodiment.
• step S 1407 when the acceleration is not in a range of a3 -a4 in step S 1407 and when the acceleration is not in a range of a5-a6 in step S 1408, it is considered that the rotational velocity of rotating shaft 11 is large but the load is not low. Therefore, switching valve 91 is switched over so that oil is supplied to reduction gear 3 and the discharge pressure of oil pump 2 is not increased but kept small (S 1402) thereby ending the oil amount controlling process of the present embodiment.
• Figure 16 is a flowchart showing the oil amount controlling process which is conducted by control element 92 of the electric motor for a vehicle of the ninth exemplary embodiment.
• the present embodiment is different from the eighth exemplary embodiment in that whether oil is supplied to oil film damper 15 is determined based on the rotational velocity of the electric motor for a vehicle instead of the speed of the vehicle. Since other structures and the processes are the same as those of the eighth exemplary embodiment, their explanation is omitted.
• the eighth exemplary embodiment when the speed of the vehicle is less than the threshold speed value, it is considered that the rotational velocity of rotating shaft 11 is not large and oil is not supplied to oil film damper 15. However, there is a case where the rotational velocity increases even when the speed of the vehicle is slow.
• control element 92 determines whether or not the rotational velocity of rotating shaft 11 is a predetermined and threshold value of higher
• step S 1601 when the rotational velocity of rotating shaft 11 is less than the threshold value, switching valve 91 is switched over so that oil is supplied to reduction gear 3 and the discharge pressure of oil pump 2 is not increased but kept small (S 1602) thereby ending the oil amount controlling process of the present embodiment.
• step S 1601 when it is determined in step S 1601 that the rotational velocity of rotating shaft 11 is the threshold value or lower, whether or not the vehicle is running uphill by detecting the slope of the road where the vehicle is running based on the information obtained from the gyro sensor (S 1603).
• S 1603 When it is determined that the vehicle is running uphill, whether or not the acceleration of the vehicle detected by the acceleration sensor is in a range of al-a2 shown in Figure 15 is determined (S 1604).
• the acceleration is in a range of al-a2
• switching valve 91 is switched over so that oil is supplied to oil film damper 15 and the amount of the oil discharged by oil pump 2 is increased based on the rotational velocity of rotating shaft 11 (S 1605) thereby ending the oil amount controlling process of the present embodiment.
• step S 1603 when it is determined in step S 1603 that the vehicle is not running uphill, it is determined whether or not the vehicle is running downhill (S 1606).
• switching valve 91 is switched over so that oil is supplied to oil film damper 15 and the amount of the oil discharged by oil pump 2 is increased based on the rotational velocity of rotating shaft 11 (S 1605) thereby ending the oil amount controlling process of the present embodiment.
• step S 1606 when it is determined in step S 1606 that the vehicle is not running downhill and that the acceleration is in a range of a5-a6 shown in Figure 15, it is considered that the load on rotating shaft 11 is low. Therefore, switching valve 91 is switched over so that oil is supplied to oil film damper 15 and the amount of the oil discharged by oil pump 2 is increased based on the rotational velocity of rotating shaft 11 (S 1605) thereby ending the oil amount controlling process of the present embodiment.
• the acceleration is not in a range of a3-a4 in step S 1608 and when the acceleration is not in a range of a5-a6 in step S 1609, it is considered that the load on rotating shaft 11 is not low.
• switching valve 91 is switched over so that oil is supplied to reduction gear 3 and the discharge pressure of oil pump 2 is not increased but kept small (S 1602) thereby ending the oil amount controlling process of the present embodiment.
• switching valve 91 is switched over and oil is supplied either to oil film damper 15 or to reduction gear 3. Therefore, it is possible to effectively prevent resonance of rotating shaft 11 depending on the running condition of the vehicle.
• FIG 17 is a block diagram illustrating the structure of the electric motor for a vehicle of the tenth exemplary embodiment. As shown in Figure 17, the present embodiment is different from the fifth exemplary embodiment in that clutch 171 is placed between electric motor for a vehicle IE and oil pump 2 and switching valve 91 is omitted. Since other structures are the same as those of the fifth exemplary embodiment, their explanation is omitted.
• clutch 171 transmits the rotation of rotating shaft 11 to oil pump 2 and the engagement strength of the clutch is controlled by the clutch strength controlling signal from control element 92 and the rotational velocity of oil pump 2 is controlled.
• rotating shaft 11 is connected to oil pump 2 through clutch 171 and the engagement strength of clutch 171 is controlled by control element 92. Therefore, it is possible to easily control the rotational velocity of oil pump 2. As a result, it is possible to supply a proper amount of the oil to oil film damper 15.
• the exemplary embodiments describe the case wherein the oil film damper is placed in one end of the rotating shaft of the electric motor for a vehicle. However, it is possible to place the oil film damper in both ends of the rotating shaft. [0109] Furthermore, the exemplary embodiments describe the case wherein the damping device of the present invention is used for an electric motor for a vehicle. However, the present invention is not limited to these embodiments, but can be used for the case wherein resonance of the rotating shaft such as a turbine is prevented. [0110] Moreover, the exemplary embodiments describe the case wherein the oil pump is connected to the rotating shaft directly or through the clutch.
• the present invention is not limited to these embodiments, but can be used for the case wherein the rotating shaft of the oil pump is not connected to the rotating shaft of the electric motor and the oil pump is placed in a different body other than the electric motor for a vehicle.
• the rotating shaft of the oil pump is not connected to the rotating shaft of the electric motor and the oil pump is placed in a different body other than the electric motor for a vehicle.

Landscapes

• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Physics & Mathematics (AREA)
• Acoustics & Sound (AREA)
• Aviation & Aerospace Engineering (AREA)
• Support Of The Bearing (AREA)
• Electric Propulsion And Braking For Vehicles (AREA)
• Motor Or Generator Frames (AREA)
• Connection Of Motors, Electrical Generators, Mechanical Devices, And The Like (AREA)

Priority Applications (1)

Applications Claiming Priority (4)

Publications (2)

Family

ID=36619409

Family Applications (1)

Country Status (2)

Cited By (2)

Families Citing this family (3)

Citations (4)

Family Cites Families (5)

• 2005
  • 2005-10-07 JP JP2005295449A patent/JP4760281B2/ja not_active Expired - Fee Related
  • 2005-10-11 WO PCT/IB2005/003015 patent/WO2006051361A1/en active Application Filing

Patent Citations (4)

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events