JP2016208574A - Traction machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a traction machine as an elevator traction machine in which temperature rise of a bearing is reduced by suppressing a frictional heat generated by the rotation of a shaft during operation.SOLUTION: The traction machine comprises two bearings for rotatably supporting a shaft of a motor, two bearing support parts for respectively supporting the outer circumferences of the two bearings, a support base for supporting the motor and the two bearing support parts, and a control device for controlling an operation condition of the motor. The traction machine further comprises a temperature measuring instrument for measuring a temperature of an outer race of a bearing on a side remote from the motor, of the two bearings or a temperature of a bearing support part for supporting the bearing, and a table heating device installed on the support table and heating the support table. The control device causes the table heating device to operate on the basis of the measured value of the temperature measuring instrument.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an elevator hoist.

  In a hoisting machine for a large elevator, the temperature of the bearing rises during operation, and the bearing may be damaged. One of the causes of the temperature rise of the bearing is mechanical loss of the bearing, and frictional heat is generated in the bearing due to rotation of the shaft, and the temperature of the bearing rises.

  In a conventional elevator hoisting machine, there is a technique of cooling a shaft and a rotor using a refrigerant as a technique for preventing damage to a bearing due to a temperature rise during operation. For example, a method has been studied in which a shaft end of a rotor is supported by a bearing, a bearing box is formed, a refrigerant chamber is provided in the bearing box, and an axial hole is provided inside the rotating shaft (Patent) Reference 1). With this configuration, the bearing and the rotor are cooled with the refrigerant, thereby preventing the bearing from being damaged.

JP 2007-336646

  When cooling with a refrigerant to prevent damage to the bearings, it is necessary to secure a flow path for the refrigerant on the rotating shaft, which requires drilling to secure the flow path, etc. Parts are also required. Such a special cooling mechanism is required for elevator hoisting machines, which have a large loading capacity (capacity) and are driven at a high speed. A lot of processing time is required.

  In addition, when using a refrigerant, it is premised that a seal is provided to prevent the refrigerant from leaking. However, since the environment where the hoist is installed is often dusty and the seal may be broken, It is necessary to assume that there is a leak. Therefore, maintenance may become complicated and it may be difficult to maintain quality.

  In addition, when the amount of heat generated by the hoisting machine is large, it is necessary to circulate the refrigerant even when the elevator is not in operation, so a device for forcibly circulating the refrigerant is also required. It becomes complicated and it is difficult to ensure long-term reliability.

  Further, when carrying out maintenance of the cooling unit, it is necessary to rework the flange surface that contacts the seal part and the seal in order to ensure the sealing performance of the refrigerant. May be required.

  In the hoist according to the present invention, a motor including a stator, a rotor, and a shaft, two bearings that rotatably support the shaft, two bearing support portions that respectively support the outer circumferences of the two bearings, A support base that supports the motor and the two bearing support portions, and a control device that controls the operating state of the motor, and further supports the temperature of the outer ring of the bearing farther from the motor or the bearing of the two bearings. Equipped with a temperature measuring device that measures the temperature of the bearing support base and a base heating device that is installed on the support base and heats the support base, and the control device operates the base heating device based on the measured value of the temperature measuring device It is something to be made.

  The present invention provides a bearing in the radial direction and the axial direction due to the temperature difference between the inner and outer rings of the bearing and the thermal expansion in the axial direction of the shaft by arranging a heater as a base heating device on the base of the hoist and the bearing. A change in the gap can be suppressed. For this reason, without using a cooling mechanism using a refrigerant, overloading of the bearing can be prevented to prevent damage to the bearing, the life of the bearing can be prolonged, and the reliability of the device can be improved.

It is a cross-sectional schematic diagram of the winding machine which shows Embodiment 1 of this invention. It is a side view of the winding machine which shows Embodiment 1 of this invention. It is a block diagram which shows the structure of the control system of Embodiment 1 of this invention. It is a cross-sectional schematic diagram which shows the state of a bearing. It is a cross-sectional schematic diagram of the winding machine showing Embodiment 2 of the present invention. It is a cross-sectional schematic diagram of the winding machine showing Embodiment 3 of the present invention. It is a cross-sectional schematic diagram of the hoisting machine which shows the modification of Embodiment 3 of this invention. It is a schematic diagram which shows the support structure of the support base which shows the modification of Embodiment 3 of this invention.

Embodiment 1 FIG.
FIG. 1 is a schematic sectional view of a hoisting machine 100 according to Embodiment 1 for carrying out the present invention, and FIG. 2 is a side view of FIG. The motor 1 of the hoisting machine 100 includes a rotor 2 and a stator 3. A shaft 4 is fixed to the rotor 2, the shaft 4 is rotatably supported by a bearing 5 and a bearing 5a, and a sheave 8 positioned between the bearing 5 and the bearing 5a is fixed to the shaft 4. Then, wrap the rope around the sheave 8 and raise and lower the elevator car. The bearing 5a is accommodated in a support pedestal 6 that supports a motor-side bearing, and the bearing 5 is accommodated in a support pedestal 7 that supports an end-side bearing. The motor 1, the support pedestal 6, and the support pedestal 7 are fixed on the support frame 9. The support frame 9 is a combination of I-shaped steels in a rectangular frame shape, and is a table that supports the entire hoisting machine 100. The motor 1, the support base 6, and the support base 7 are arranged so as to straddle the inside of the frame. Are supported on two sides parallel to the axis 4. In addition, the support frame 9 of FIG. 1 is drawn as a front view.

  The heater 10a is fixed to the surface of the support base 6 of the motor side bearing, and indirectly heats the bearing 5a by energization. The heater 10b is fixed to the surface of the support base 7 of the end bearing and similarly heats the bearing 5 indirectly by energization. The heaters 10c are respectively installed on two sides parallel to the axis 4 of the support frame 9, and can directly heat the two sides. The heater 10c fixed to the support frame 9 is intended to adjust the amount of thermal expansion in the direction of the axis 4 with respect to the support frame 9 by heating the two sides.

As the heater 10a, the heater 10b, and the heater 10c (hereinafter collectively referred to as the heater 10), a ribbon heater may be used, and a plate-like or film-like heater may be used. Further, an annular ribbon heater surrounding the outer periphery of the bearing may be used to heat the periphery of the bearing. The heater 10 may be fixed with a heat-resistant string or wire, or may be mechanically fixed with a bolt or the like. When it is desired to fix the heater 10 firmly, a plate-like or rod-like heater may be embedded in the motor-side bearing and the end bearing support base.
FIG. 3 is a block diagram showing the configuration of the control system of the first embodiment. A temperature sensor 11 is installed on the support pedestal 7 and measures the temperature sequentially. The temperature sensor 11 may be a thermocouple. The hoisting machine 100 is provided with a control device CT, which collects temperature data of the temperature sensor 11, collects data of the outside air temperature, and controls energization of the heater 10. This control device may be incorporated as a system associated with the motor drive control device.

  FIG. 4 is a schematic cross-sectional view showing the state of the bearing 5 located on the end side of the shaft 4, and schematically shows the positional relationship between the inner ring 51, the rolling elements 52, and the outer ring 53. Usually, the bearing has internal gaps formed in the radial direction and the axial direction, and FIG. 4A shows a state in which the positions of the inner ring 51, the rolling element 52, and the outer ring 53 have appropriate gaps. On the other hand, when the shaft 4 is rotating, frictional heat is generated in the bearing, so that the temperatures of the inner ring 51, the rolling elements 52, and the outer ring 53 rise. At this time, since the outer ring side is exposed to the air and cooled, the temperature is lower than that of the inner ring 51. For this reason, as shown in FIG. 4B, if the difference between the amount of expansion of the inner ring 51 in the radial direction of the shaft 4 and the amount of expansion of the outer ring 53 becomes larger than the internal clearance of the bearing, the internal clearance will not disappear. Get smaller. As a result, a frictional force is generated in the radial direction of the shaft, and the bearing load increases accordingly.

On the other hand, when the temperature of the shaft 4 rises due to frictional heat of the bearing 5, the shaft 4 extends in the axial direction. FIG. 4C shows a state where the shaft 4 is extended and the inner ring 51 and the outer ring 53 are displaced. Usually, since the inner ring 51 is firmly fixed to the shaft 4 by shrink fitting or the like, the inner ring 51 fixed to the shaft 4 moves in the axial direction together with the shaft 4, and the thermal expansion amount is larger than the clearance in the axial direction of the bearing. Then, a force due to thermal expansion is generated in the axial direction, and the load on the bearing increases accordingly. The increase in load on these bearings also occurs when the temperature difference between the inner ring 51 and the outer ring 53 increases due to the extremely low external temperature. If it will be in the state shown in FIG.4 (b) and FIG.4 (c), the load of the bearing 5 will increase and problems, such as a bearing life shortening or a bearing being damaged, will arise.
In order to suppress the overload of the bearing due to thermal expansion due to the temperature difference between the inner and outer rings and the temperature rise of the shaft as described above, in the first embodiment, the bearing is heated by heating the support frame and the support pedestal of the bearing. To control the load to an appropriate range.

  In order to estimate the state of the bearing, it is necessary to measure and record the relationship between the rotational speed during operation and the temperature rise of the bearing in advance. For example, the temperature of the surfaces of the shaft 4 and the support base 7 is measured in a non-contact manner using a radiation thermometer during operation. At this time, it is considered that the temperature of the shaft 4 is substantially equal to the temperature of the inner ring of the bearing, and the temperature of the surface of the pedestal is substantially equal to the temperature of the outer ring of the bearing, and the temperature difference until the radius gap G becomes zero from the normal state is tested. Calculate it automatically. At the same time, the ambient temperature of the bearing is measured and used as a reference. The temperature increase amount of the inner ring and the temperature increase amount of the outer ring with respect to the ambient temperature are measured, and the temperature increase amount of the pedestal when reaching the temperature difference where the gap becomes zero is measured. This data is used as reference data.

During operation, the temperature of the surface of the support pedestal 7 is continuously measured by the temperature sensor 11 and the temperature difference between the surrounding environment of the hoisting machine and the support pedestal 7 is monitored. If the ambient environment temperature before operation is TE0, the temperature of the pedestal before operation is TD0, the ambient environment temperature during operation is TE1, and the temperature of the pedestal during operation is TD1, then (TD1-TD0)-(TE1-TE0) A value becomes the temperature rise of the support base 7 accompanying a driving | operation. From the rotation speed and the temperature rise value, it can be determined whether or not the temperature difference ΔT between the inner ring and the outer ring with respect to the reference data is appropriate.
A value smaller than the temperature difference ΔT at which the gap is zero is set as the upper limit value, and when ΔT reaches the upper limit value, the heater 10b is energized and heated. Then, when the temperature difference becomes substantially equal to the appropriate value, the energization of the heater 10b is cut off.

  Note that the support pedestal 7 on the end side as viewed from the motor has been described. Similarly, the temperature difference of the bearing pedestal 6 on the motor side is measured in advance, and the temperature of the pedestal during operation is monitored to energize the heater 10a. By doing, it can suppress that the clearance of the radial direction of a bearing becomes small. Further, it is not always necessary to adopt the same configuration for the bearings on both sides, and it is only necessary to install a heater or the like only in a necessary portion due to the load state of the bearing, temperature rise, or the like.

  For the thermal expansion of the shaft 4, the thermal expansion amount of the shaft 4 is calculated from the temperature increase amount of the pedestal of the bearing being monitored, and when the predetermined temperature increase amount is reached, the hoisting machine support frame The heater 10c installed at 9 is energized, and the current of the heater 10c is cut off when the initial axial gap approaches and ΔT becomes appropriate. A temperature sensor may be installed on the support frame 9 in order to control the heater 10c. These temperature control models may be created as appropriate based on the actual configuration of the hoist.

  As described above, heating the bearing support pedestal prevents the radial bearing gap from becoming close to zero and increasing the radial load. At the same time, an increase in the axial load can be prevented by heating the support frame 9 of the hoisting machine. By using these methods to prevent damage to the bearing, it is possible to extend the life of the bearing and improve reliability.

Further, in the present invention, since the radial clearance and the axial clearance are ensured, a heater is installed on the bearing base and the support frame of the hoisting machine, and the temperature is measured. Although it is configured, it is not always necessary to take two measures. For example, when there is a margin in the radial load, it is not necessary to install the heater 10 and the temperature sensor 11 on the bearing support base.
In the method of preventing the heat generation of the bearing by the cooling mechanism, the configuration of the equipment is complicated, whereas in the method of the present invention, it is only necessary to thermally expand the pedestal according to the heat generation of the bearing, so no special processing is required. It is. In other words, since the overload of the bearing due to the thermal expansion of the hoisting machine can be prevented with only the heater, the sensor, and their control devices, the reliability of the equipment can be improved using an inexpensive configuration. Further, since a special cooling mechanism is unnecessary, maintenance costs can be suppressed.

Embodiment 2. FIG.
FIG. 5 is a schematic cross-sectional view of the hoisting machine 200 according to the second embodiment of the present invention. In the hoisting machine according to the first embodiment, the heater 10c is installed in the support frame 9 of the hoisting machine as a method for adjusting the axial clearance of the bearing, but in the second embodiment, the support frame is used. 9 and the support pedestal 7 of the end side bearing, the intermediate pedestal 12 is disposed, and the heater 10c is installed on the intermediate pedestal 12. The motor-side end of the intermediate pedestal 12 is fixed to the support frame 9 with bolts 13a, and is configured to easily expand to the shaft end. The bolt 13 b fixes the support base 7 to the intermediate base 12.

  When the size of the hoisting machine is large, the size of the pedestal also increases, and the amount of power consumed for raising the entire support frame 9 to a predetermined temperature by the heater 10c increases. Further, the time until the predetermined temperature is reached also increases, the bearing clearance becomes smaller, and the bearing may be overloaded in the short term.

  Therefore, by limiting the member to be thermally expanded to the intermediate pedestal 12 and configuring this portion to thermally expand, the heat capacity can be reduced and the amount of heat necessary for control can be suppressed. Therefore, by using the second embodiment, the amount of power used for control can be suppressed, and the required temperature can be reached in a relatively short time.

  According to the above configuration, even when the capacity of the hoisting machine is increased, the amount of electric power used for heater control can be suppressed, and a hoisting machine support structure with good response can be obtained. Moreover, since complicated processing is not required in terms of mechanism, it can be manufactured at low cost.

  The intermediate pedestal 12 may be made of the same material as the hoisting machine and the support pedestal, but a copper material or a copper alloy material may be used when it is desired to increase the thermal expansion amount as much as possible. In addition, as long as it can withstand the weight of the bearing support pedestal, it can operate effectively by using a material having a larger thermal expansion coefficient than the support frame 9 such as aluminum, copper, or an alloy containing any of them. Can be made. If the thermal expansion coefficient of the intermediate pedestal 12 is large, a large expansion amount can be obtained in a relatively short time, the bearing clearance can be adjusted with a small amount of power, and damage to the bearing can be suppressed. In addition, since the temperature can be lowered in a short time when the current to the heater is interrupted, it is possible to quickly follow the contraction of the hoisting machine member, and it is highly reliable by preventing damage to the bearing A hoisting machine can be obtained.

Embodiment 3 FIG.
FIG. 6 is a schematic sectional view of a hoist according to Embodiment 3 of the present invention. In the second embodiment, the intermediate pedestal is used to reach a predetermined temperature in a short time. However, as a method for adjusting the bearing clearance in a shorter time, the end bearing between the support pedestal 7 and the intermediate pedestal 12a is used. It is set as the structure which has arrange | positioned the rolling element 14. With this configuration, for example, even when the temperature of the shaft 4 suddenly rises in an emergency and the shaft 4 expands due to thermal expansion, the bearing clearance can be properly maintained.

  By arranging a plurality of cylinders in parallel as the rolling element 14, the bearing support base 7 can be easily moved in the axial direction by the movement of the rolling element 14 in the axial direction. On the intermediate pedestal 12a, holding plates P are provided at both ends, and the movement amount of the support pedestal 7 is restricted. Instead of the holding plate P, a groove that defines a range in which the rolling element 14 moves may be formed in the intermediate pedestal 12a.

  Even with a hoisting machine with a shaft length of several meters, since the instantaneous amount of axial movement is expected to be 1 mm or less, the amount of axial displacement that can be instantaneously followed by the rolling element 14 is about 1 mm. For the displacement more than that, the intermediate pedestal 12 is thermally expanded to follow the extension of the shaft 4. Further, when heated by the heater 10c, depending on the ambient temperature, slipping occurs between the support base 6 of the motor side bearing and the support base 7 of the end bearing and the hoisting machine support base 9, and the bolt is loosened. However, by arranging the rolling element 14, the above-mentioned problem of slipping is reduced, so that the reliability of the hoisting machine can be improved.

  FIG. 7 is a schematic cross-sectional view showing a modification of the hoist according to Embodiment 3 of the present invention. In the example shown in FIG. 6, a cylinder is used as the rolling element 14, but it is not necessary to be limited to this shape, and a rolling element 14 a having a fan-like columnar body as shown in FIG. 7 may be arranged. FIG. 7 shows three fan-shaped columnar rolling elements 14a arranged in parallel. By taking the shape shown in FIG. 7, the position of the contact point between the rolling element 14a and the end support pedestal 7 does not change, so that the rolling element 14a has a relative position between the support pedestal 7 of the end bearing and the intermediate pedestal 12a. Long-term reliability can be ensured without causing a shift and without causing the rolling elements 14a to come into contact with each other and the operation to become unstable.

  FIG. 8 is a schematic diagram showing a support structure of a support base according to another modification of the third embodiment. This support structure is characterized in that a groove having a curved surface on which the rolling element 14b is loosely positioned is provided as a mating surface on the intermediate pedestal 12b side of the cylindrical rolling element 14b. In the example shown in FIGS. 6 and 7, the rolling element 14 is in contact with the plane on the intermediate pedestal. However, if the rolling element 14b is arranged as shown in FIG. 8, the rolling elements 14b are in contact with each other. Long-term reliability can be ensured. Further, a groove having a curved surface may be provided on the support pedestal 7 side above the rolling element 14b in FIG. 8 to suppress slippage of the rolling element 14b. Similar modifications can be applied to the configurations of FIGS.

With the above configuration, even when the temperature rises instantaneously and the thermal expansion of the intermediate pedestal 12b due to the heating of the heater 10 cannot follow, the rolling element 14 absorbs the elongation of the shaft 4 so that the bearing 5 is excessively large. Since it is possible to prevent the load from being applied, the reliability of the hoisting machine can be improved.
In the above example, the rolling element 14 and the intermediate pedestal 12 are replaceable parts. When used for a long period of time, if the hardness of the member is set as follows: bearing support pedestal> rolling element ≧ intermediate pedestal, However, reliability can be ensured over a long period of time without damaging the equipment.
Further, when the pedestal is suddenly heated with the heater, the amount of electric power to be used is increased. However, the pedestal can be moved in a short time by arranging the rolling elements, and the power consumption can be reduced.

  The present invention can be used not only for elevator hoisting machines, but also for hoisting machines used for hoists and agricultural equipment.

DESCRIPTION OF SYMBOLS 1 Motor 2 Rotor 3 Stator 4 Shaft 5, 5a Bearing 8 Sheave 6 Support base 7 Support base 9 Support frame 10, 10a, 10b, 10c Heater 11 Temperature sensor 12 Intermediate base 14 Rolling element 51 Inner ring 52 Rolling body 53 Outer ring CT controller

Claims (6)

A motor comprising a stator, a rotor and a shaft;
Two bearings rotatably supporting the shaft;
Two bearing support portions that respectively support the outer circumferences of the two bearings;
A support base for supporting the motor and the two bearing support portions;
A control device for controlling the operating state of the motor;
A hoisting machine comprising:
A temperature measuring device for measuring a temperature of an outer ring of a bearing far from the motor among the two bearings or a temperature of a bearing support supporting the bearing;
A table heating device installed on the support table to heat the support table and thermally expand the support table in the direction of the shaft;
With
The said control apparatus operates the said table | surface heating apparatus based on the measured value of the said temperature measuring device, The winding machine characterized by the above-mentioned. The support base includes a frame having four sides,
The two bearing support portions are supported on two opposite sides of the frame,
The hoist according to claim 1, wherein the table heating device is provided on each of the two opposing sides. It is further equipped with a temperature measuring device that measures the ambient temperature,
The hoist according to claim 1 or 2, wherein the control device operates the table heating device using a measurement value of the temperature measuring device. The support base includes an intermediate pedestal that supports the bearing support portion on the side far from the motor among the two bearing support portions,
The intermediate pedestal includes a fixed portion fixed to the support base and supports the bearing support portion on the side farther from the motor than the fixed portion,
The hoist according to any one of claims 1 to 3, wherein the base heating device is installed on the intermediate pedestal. The hoist according to claim 4, wherein the support base includes a rolling element that supports the intermediate base. The hoisting machine according to any one of claims 1 to 5, further comprising an outer ring heating device that heats an outer ring side of a bearing far from the motor among the two bearings.