JP2013210084A - Speed reduction device for cold storage warehouse - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a speed reduction device for a cold storage warehouse, which more effectively prevents oil leakage and life of which is more extended.SOLUTION: In a speed reduction device 14 for a cold storage warehouse which is used in the cold storage warehouse, a flow point of a lubricating agent contained in the speed reduction device 14 is at least 10°C lower than a target freeze temperature in the cold storage warehouse, and a viscosity of a base oil at the maximum temperature of the lubricating agent during a test run prior to an actual operation of the cold storage warehouse is equal to or higher than 15 cSt.

Description

  The present invention relates to a reduction gear used in a refrigerated warehouse.

  Since the inside of the freezer warehouse for storing fresh food and the like is set at a very low temperature, a transport device such as a storage shelf or a transport table that is movably installed inside the freezer warehouse has a gear motor as its drive source, In particular, it is necessary to ensure in some form the good operation of the speed reducer using the lubricant.

  Since the speed reducer (or gear motor) is used as a component for driving a transfer device or the like in a refrigerated warehouse, in order to perform a test operation of the transfer device or the like, it is allowed to run at room temperature for a suitable time. It may be operated in a (non-frozen state).

  Therefore, in Patent Document 1, the first oil seal having a temperature characteristic capable of sealing the rotation shaft of the speed reducer in the refrigeration warehouse, and the low temperature side limit temperature are incorporated inside the speed reducer of the first oil seal, Disclosed is a reduction gear (gear motor) provided with a second oil seal having a temperature characteristic higher than that of the first oil seal and designed to prevent oil leakage during both test operation and operation in a freezer warehouse. Yes.

JP 2011-130650 A

  However, even if the two types of oil seals as described above are provided, tooth surface damage and abrasion powder are generated during the test operation, and the speed reducer (gear motor) is actually incorporated into a transport device or the like in the refrigeration warehouse. The fact is that early oil leaks may still occur when operating, and early damage to the reducer itself may sometimes occur.

  The present invention has been made to solve such problems, and obtains a speed reducer for a refrigerated warehouse that can more effectively prevent oil leakage and extend the life of the speed reducer. That is the issue.

  The present invention provides a reduction gear for a freezer warehouse used in a freezer warehouse, wherein the lubricant encapsulated in the reducer has a pour point that is at least 10 ° C. lower than a target freezing temperature in the freezer warehouse, and a freezer The above-mentioned problem is solved by adopting a configuration in which the viscosity of the base oil at the maximum temperature of the lubricant during the test operation before the full-scale operation of the warehouse is 15 cSt or more.

  The “reduction gear” in the above-described configuration of the present invention is used in the form of a “gear motor” integrated with a motor in addition to a single reduction gear, and the reduction gear whose motor shaft also serves as the input shaft of the reduction gear Is also included.

  In the present invention, a lubricant having a pour point lower than the target refrigeration temperature by 10 ° C. or more is used as the lubricant for the reduction gear. In addition, the lubricant has a characteristic that the viscosity of the base oil at the maximum temperature of the lubricant during the test operation is 15 cSt or more.

  As a result, an oil film can be formed well on the tooth surface during a test operation at room temperature, so that damage to the tooth surface of the speed reduction mechanism during the test operation can be minimized, and therefore the tooth surface is damaged. It is possible to enter a cryogenic operation in an actual refrigerated warehouse with a clean lubricant (not mixed with wear powder). Therefore, the original lubrication performance suitable for extremely low temperatures can be exhibited over a long period of time.

  According to the present invention, it is possible to obtain a speed reducer for a refrigerated warehouse that can more effectively prevent oil leakage and extend the life of the speed reducer for a longer time.

Sectional drawing of the gear motor provided with the reduction gear for freezing warehouses which concerns on an example of embodiment of this invention. An enlarged sectional view of the main part of the gear motor

  Hereinafter, an example of an embodiment of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a cross-sectional view of a gear motor provided with a reduction gear for a refrigerated warehouse according to an example of an embodiment of the present invention, and FIG. 2 is an enlarged cross-sectional view of a main part of the gear motor. In this example, the target refrigeration temperature of the refrigeration warehouse (not shown) is −25 ° C.

  The gear motor 10 for a refrigerated warehouse is obtained by integrating a motor 12 and a reduction gear 14 by fastening a motor casing (motor cover) 12A and a reduction gear casing 14A with bolts 11. The motor 12 includes a fan 13 on the non-load side.

  The speed reducer 14 includes an input shaft 16 that is also used as a motor shaft of the motor 12 (supported by a bearing 28), a hypoid pinion 18 that is integrally formed with the input shaft 16, a hypoid gear 20 that meshes with the hypoid pinion 18, Is provided. The hypoid gear 20 is incorporated in the intermediate shaft 22, and an intermediate pinion 24 integrally formed with the intermediate shaft 22 meshes with the output gear 26. Then, the rotation of the output gear 26 is output to the outside as the rotation of the output shaft 27.

  In the speed reducer 14 according to this embodiment, the temperature of the lubricant is approximately 95 even if it is operated for 1 hour or more at room temperature by setting the thickness and size of the speed reducer casing 14A, the capacity of the fan 13, and the like. Characteristics that can be maintained at or below ° C. are obtained. “Normal temperature” refers to a range of 20 ° C. ± 15 ° C. (5-35 ° C.) (JIS Z 8703).

  In the gear motor 10 according to this embodiment, the input shaft 16 of the speed reducer 14 is composed of a cryogenic oil seal 30 composed of silicone rubber, nitrile rubber or the like, and acrylic rubber, nitrile rubber, fluorine rubber or the like. It is sealed by two kinds of oil seals, that is, a normal temperature oil seal 32. The output side of the speed reducer 14 is sealed only by a cryogenic oil seal 36 (made of the same material as the input side) disposed adjacent to the bearing 34 of the output shaft 27. This is because on the output side, the rotational speed is low, and damage due to wear powder hardly causes a problem, so the cost is reduced. However, a normal temperature oil seal may also be provided in the output shaft (rotary shaft) seal, and in this case, the effect of further extending the life of the oil seal can be obtained.

  Here, the lubricant encapsulated in the speed reducer 14 will be described in detail.

  In the speed reducer 14, the lubricant is sealed in the space Sp <b> 1 in the speed reducer 14 in FIG. 1. As this lubricant, the “pour point” is at least 10 ° C. lower than the target refrigeration temperature in the freezer warehouse (−25 ° C. in this embodiment), and in the test operation before the full-scale operation of the freezer warehouse. Those having the characteristic that the viscosity of the base oil at the maximum temperature of the lubricant (95 ° C. in this embodiment) is 15 cSt or more are used.

  Here, the “pour point” is an index indicating the fluidity of the lubricant at a low temperature. A pure substance changes from a liquid to a solid at a constant temperature (melting point), but a lubricant that is a multi-component mixture does not show a clear melting point. Therefore, an index called “pour point” is used instead of the melting point. Is used. According to JIS K2269, the pour point of the lubricant is: “The sample taken in the test tube is preheated to 46 ° C. and then cooled by the prescribed method, and measurement starts at a temperature 10 ° C. higher than the expected pour point. Each time the temperature falls by 2.5 ° C., the test tube is taken out of the cooling bath and observed, and a temperature at which the test tube does not move at all for 5 seconds is obtained even when the test tube is turned sideways. ". In the present embodiment, this “pour point” is set to −40 ° C. (the target refrigeration temperature is −25 ° C., but is 10 ° C. or more and sufficiently lower than that).

  Although the target refrigeration temperature of the refrigerated warehouse according to the present embodiment is -25 ° C, the lubricant pour point is set to -40 ° C in the reducer 14 operating in such a refrigerated warehouse. Lubricants used tend to remain hard in the initial stage of operation. For this reason, formation of a good oil film following subtle vibrations and vibrations of the shaft and tooth surface, and oil seals 30, 32, 36 This is because the familiarity may not be performed well at the beginning of the operation, and this may cause a decrease in the durability of the tooth surface and oil leakage.

  As described above, the maximum temperature of the lubricant during the test operation before the full-scale operation of the freezer warehouse is 95. In this embodiment, the lubricant temperature is 95 even when the speed reducer 14 is operated at room temperature for 1 hour or more. Since it has such characteristics that it can be maintained at or below ° C., this temperature of 95 ° C. is regarded as the “maximum temperature of test operation before full-scale operation”. That is, in the present embodiment, the maximum temperature when operating at room temperature for at least 1 hour, that is, the viscosity of the base oil of the lubricant at 95 ° C. is set to be 15 cSt or more. The numerical value of “15 cSt or more” is based on the fact that the inventor has confirmed that a malfunction may actually occur at “5 to 10 cSt”, for example.

The “viscosity” is an index representing the ease of flow of the lubricant (viscosity, smoothness). Specifically, when a plate having an area of 1 cm ² is moved at a speed V = 1 cm / s at an oil film thickness h = 1 cm of the lubricant, the viscosity of the fluid is such that the resistance is 1 dyne. Is defined as a viscosity of 0.1 Pascal · second. This is referred to as “absolute viscosity”, and a value obtained by dividing the absolute viscosity by the density of the lubricant is usually used as the “kinematic viscosity”. The numerical value in this embodiment also means a numerical value in “kinematic viscosity”. The unit of kinematic viscosity is cSt (mm ² / s).

  As the lubricant, basically any kinematic viscosity lubricant can be prepared by mixing a high viscosity oil and a low viscosity oil. Depending on the temperature, the viscosity increases as the temperature decreases, and decreases as the temperature increases. Usually, a lubricant having good characteristics at an extremely low temperature is extremely low in an environment of 95 ° C. However, in the present embodiment, a viscosity of 15 cSt is intentionally provided in this 95 ° C. environment.

  Specifically, in this embodiment, poly alpha olefin (synthetic oil) is adopted as the base oil. By including, for example, lithium or the like in the thickener, the viscosity at 95 ° C. (15 cSt) can be realized. This lubricant has good viscosity-temperature characteristics (high flowability at low temperature and viscosity does not decrease much even at high temperature), excellent oxidation stability and lubricity, and relatively good resistance to high temperatures. And a lubricant having characteristics consistent with the gist of the present invention.

  The seal lubricant enclosed in the oil seals 30, 32, 36 of the speed reducer 14 may be basically the same as the lubricant enclosed in the speed reducer 14, but in this embodiment, the seal lubricant is used. The pour point is the same as the lubricant enclosed in the speed reducer 14, but the consistency is smaller (harder) than the lubricant enclosed in the speed reducer 14, while the viscosity is A lubricant that is lower than the lubricant enclosed in 14 is used. That is, to say roughly, “a lubricant that is harder but more sloppy than the lubricant encapsulated in the speed reducer 14. This is the oil seal 30 of the speed reducer 14, The seal lubricants 32 and 36 are less likely to leak when the oil seal is easier to assemble if they have a lower consistency (hardness) than the lubricant sealed in the speed reducer 14. In addition, it is because it is possible to further improve the efficiency of the speed reducer 14 if it has a lower viscosity characteristic, by the way, the consistency is an indicator for displaying the external hardness of the lubricant. And “viscosity” is slightly different. There are a number of methods for measuring the penetration, but in any case, using a specified consistency meter, a constant weight of a cylinder suspended in contact with the surface of the lubricant is allowed to penetrate the lubricant for 5 seconds, This is a numerical value indicating how much the cone sinks into the lubricant. In JIS K2220, the specific measurement method is defined, and the results are classified into 9 levels.

  Next, the operation of the speed reducer 14 for a refrigerated warehouse will be described.

  The speed reducer 14 (or the gear motor 10) is used as a component for driving the transfer device or the like in the refrigerated warehouse, and is therefore operated for a suitable time for a test operation of the transfer device or the like. The This test operation is normally performed at room temperature (non-frozen state). In some cases, the temperature is gradually lowered from the normal temperature to the target refrigeration temperature during the test operation. Since the temperature of the freezer warehouse is lowered at a very low speed to prevent condensation (it is said to be 1 ° C per day when the temperature is below 0 ° C), as a result, lubrication of the reducer 14 for the freezer warehouse The agent may be run for a long time at a temperature significantly higher than the target refrigeration temperature.

  However, the lubricant having the optimum characteristics at the cryogenic temperature in the freezer warehouse is too low in viscosity during such a test operation, which may cause early damage due to the difficulty of forming an oil film on the tooth surface, or It is thought that the oil seal was damaged due to an increase in wear powder accompanying the tooth surface damage. In other words, the tooth surface and the oil seal have already been considerably damaged at the stage of actual operation in the freezing environment. In particular, when the speed reduction mechanism of the speed reducer 14 is constituted by an orthogonal speed reduction mechanism such as a hypoid pinion 18 and a hypoid gear 20 that transmit power by meshing with slipping as in this embodiment, the problem occurs. (It is understood that a worm reduction mechanism that transmits power by meshing with slipping is also in the same situation).

  However, according to the present embodiment, the lubricant enclosed in the speed reducer 14 reaches the maximum temperature during the test operation before the full speed operation of the speed reducer 14 (when it is continuously operated for 1 hour or more at room temperature). The viscosity of 15 cSt is ensured even at 95 ° C., which is a low temperature). In general, the “temperature when operating at room temperature for at least 1 hour” can be regarded as “a temperature that does not increase any further even if continuous operation is performed”. Therefore, the setting of the present embodiment is basically a setting in which a sufficient oil film is always formed on the tooth surface and damage is prevented even when the test operation at room temperature is performed almost without limitation. Therefore, generation | occurrence | production of abrasion powder is also minimal, and the vicious circle which the further damage generate | occur | produces by the influence of the said abrasion powder or the oil seals 30, 32, and 36 are damaged is also suppressed.

  As a result, when operation is actually started in a refrigerated environment in a refrigerated warehouse, operation can be started literally in the same state as a new product. The point is -40 ° C. or lower, and the characteristic that the target refrigeration temperature is significantly lower than the target refrigeration temperature by 10 ° C. or higher). The life of the speed reducer 14 can also be extended.

  In particular, in this embodiment, the oil seals 30 and 32 are also provided with the oil seal 32 for room temperature in addition to the oil seal 30 for cryogenic temperature. However, since this can be satisfactorily captured by the oil seal 32 for room temperature, oil leakage during the test operation can be prevented well, and the wear powder also sneaks into the sliding portion of the oil seal 30 for cryogenic temperature. The sealing function can be maintained satisfactorily for a long time even during operation at the freezing temperature.

  Further, the sealing lubricant enclosed in the oil seals 30, 32, 36 of the speed reducer 14 has the same pour point as the lubricant enclosed in the speed reducer 14, but the consistency is the same. The lubricant is smaller (harder) than the lubricant enclosed in the inside, and the viscosity is lower than that of the lubricant enclosed in the speed reducer 14 (the same as the lubricant in the speed reducer 14). As compared with the case where the lubricant is used as it is, assembly of the oil seal is easier and leakage is less likely to occur, and the efficiency can be further improved.

  In the above-described embodiment, the pour point of the lubricant is set to a value sufficiently lower than the target refrigeration temperature (−40 ° C. or lower). However, in the present invention, the pour point is not necessarily lowered so far. It does not have to be. However, from the viewpoint as described above, it is preferable to use a lubricant having a low pour point at least 10 ° C. higher than the target refrigeration temperature.

  In the above embodiment, the “maximum temperature of the lubricant during the test operation before the full-scale operation of the refrigeration warehouse” is used, and the “temperature when operated at room temperature for at least 1 hour (95 ° C.)” is virtually satisfied. Were able to perform unlimited test runs. However, it is known in advance that the test operation time is relatively limited (although 95 ° C. is almost the maximum temperature of the lubricant if a general reduction gear is normally operated). In such a case, the maximum temperature suitable for the actual test operation may be used as the “maximum temperature of the lubricant during the test operation before the full-scale operation of the freezer warehouse”. For example, if it is considered sufficient to anticipate “80 ° C.” as the maximum temperature during the test operation before full-scale operation, it is only necessary to ensure “viscosity of 15 cSt at 80 ° C.”. In this case, since the applicable temperature range of the lubricant can be further narrowed, there is a possibility that a lubricant with improved characteristics during refrigeration operation or a lower-cost lubricant may be used. On the other hand, for example, when the “temperature” in the installation area is very high, or when it is necessary to frequently perform a heavy test operation, the maximum temperature during the test operation before full operation is higher than 95 ° C. The value (for example, 100 ° C.) should be satisfied and “viscosity of 15 cSt at 100 ° C.” should be ensured.

  In the above embodiment, since the hypoid speed reduction mechanism that is an orthogonal speed reduction mechanism (with slippage) is employed as the speed reduction mechanism of the speed reducer, the effect of the present invention has been obtained particularly remarkably. However, the speed reduction mechanism of the speed reducer is not limited to the orthogonal speed reduction mechanism having slip. For example, it may be a bevel orthogonal speed reduction mechanism with little slippage or a parallel axis speed reduction mechanism. Furthermore, a planetary gear reduction mechanism may be used. In either case, a corresponding effect can be obtained.

  Further, in the above embodiment, two types of oil seals for normal temperature and extremely low temperature are prepared, and as the seal lubricant, the pour point is the same as the lubricant enclosed in the speed reducer. The degree is smaller (harder) than the grease lubricant enclosed in the reduction gear, and the viscosity is lower than that of the grease lubricant enclosed in the reduction gear. However, in the present invention, the oil seal and the seal lubricant are not particularly required to adopt the above configuration. Rather, according to the present invention, the burden of the oil seal is reduced, so that the structure of the oil seal may be further simplified.

  In addition, in the present invention, the specific configuration (composition) of the lubricant is also qualitatively described as “a test where the pour point is at least 10 ° C. lower than the target refrigeration temperature in the refrigeration warehouse and the refrigeration warehouse is in full operation. If the characteristic that the viscosity of the base oil at the maximum temperature of the lubricant during operation is 15 cSt or more is obtained, there is no particular limitation.

DESCRIPTION OF SYMBOLS 10 ... Gear motor for refrigeration warehouse 12 ... Motor 14 ... Reduction gear

Claims (7)

In the reducer for a freezer warehouse used in a freezer warehouse,
The lubricant encapsulated in the speed reducer has a pour point that is at least 10 ° C. lower than the target refrigeration temperature in the freezer warehouse, and the base oil at the maximum temperature of the lubricant during the test operation before the full operation of the freezer warehouse. A speed reducer for a freezer warehouse, wherein the viscosity is 15 cSt or more. In claim 1,
The said pour point is set to -40 degrees C or less. The reduction gear for freezer warehouses characterized by the above-mentioned. In claim 1 or 2,
The maximum temperature of the lubricant during the test operation is set to the temperature at which the lubricant is operated at room temperature for at least 1 hour or more. In claim 3,
The maximum temperature of the lubricant during the test operation is set to 95 ° C. A speed reducer for a freezer warehouse. In any one of Claims 1-4,
The speed reducer for the freezer warehouse, wherein the speed reduction mechanism of the speed reducer comprises an orthogonal speed reduction mechanism that transmits power by meshing with slipping. In any one of Claims 1-5,
The seal lubricant of the oil seal of the reducer has the same pour point as the lubricant enclosed in the reducer, but has a consistency lower than that of the lubricant enclosed in the reducer. Reducer for refrigerated warehouses. In any one of Claims 1-6,
The oil lubricant seal lubricant of the speed reducer has the same pour point as the lubricant encapsulated in the speed reducer, but has a lower viscosity than the lubricant encapsulated in the speed reducer. Reducer for warehouse.

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