JP2016080043A - Gear and manufacturing method of driving device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce an amount of a peeling piece of a coating layer, in a technology in which backlash is adjusted with the coating layer.SOLUTION: A gear 10 includes: a gear body 11 rotating around a rotational axis; a plurality of teeth 12 provided around the gear body 11 along the rotational direction of the rotation axis; and a coating layer 13 formed only in a part of a region in a tooth width direction among the tooth surfaces of the teeth 12.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a technique for adjusting gear backlash.

  For example, in an apparatus using gears such as an automobile drive device, appropriate backlash management is required to reduce noise. As a method for managing the backlash, a method using a shim (spacer, liner) is conventionally known. That is, in this method, a shim is sandwiched between two gears when the gears are assembled. Then, after the drive device is assembled, the shim is extracted. However, this method has a problem that the shim cannot be removed or the shim is forgotten.

  Patent Documents 1 to 3 all disclose a technique for adjusting backlash by assembling using a gear having a coating layer (film) formed on a tooth surface and rotating the gear after assembly to peel off the coating layer. doing.

JP 2002-266986 A Japanese translation of PCT publication No. 2004-515732 JP 2010-38220 A

  The coating layer is used for adjusting the backlash, and becomes unnecessary after the assembly is completed. However, the techniques of Patent Documents 1 to 3 have a problem that a large amount of peeling pieces of the coating layer are generated.

  On the other hand, this invention provides the technique which reduces the quantity of the peeling piece of a coating layer in the technique which adjusts backlash using a coating layer.

  The present invention relates to a gear main body that rotates around a rotation shaft, a plurality of teeth provided around the gear main body along a rotation direction of the rotation shaft, and a tooth width direction of tooth surfaces of the plurality of teeth. And a resin coating layer formed on only a part of the gear.

  The resin coating layer may be formed in only a part of the tooth surface including the center in the tooth width direction.

  The present invention also provides a gear body that rotates about a rotation shaft, a plurality of teeth provided around the gear body along the rotation direction of the rotation shaft, and a tooth width of tooth surfaces of the plurality of teeth. A step of preparing a first gear having a resin coating layer formed in only a part of a direction, a step of preparing a second gear meshing with the first gear, and the first gear and the second gear. A driving method including assembling the driving device so that a tooth surface of the second gear is in contact with the resin coating layer of the first gear, and removing the resin coating layer of the first gear in the driving device. An apparatus manufacturing method is provided.

  In the step of removing the resin coating layer, the resin coating layer may be removed by rotating the first gear and the second gear.

  According to the present invention, the amount of peeling pieces of the coating layer can be reduced.

The figure which shows the outline | summary of the drive device 1 which concerns on one Embodiment. 3 is a flowchart showing a method for manufacturing the drive device 1. The figure which shows the structure of the gearwheel 10. FIG. The figure which illustrates the formation position of the coating layer 13 in a tooth surface. The figure which illustrates the state after step S2. The figure which illustrates the state after step S3.

  FIG. 1 is a diagram illustrating an outline of a drive device 1 according to an embodiment. The drive device 1 includes a gear (gear) 10, a gear 20, and a shaft 30. The drive device 1 is, for example, a balancer device that includes an oil pump. That is, in this case, the shaft 30 is a balance shaft, the gear 10 is a balance shaft gear attached to the balance shaft, and the gear 20 is an oil pump gear for driving the oil pump. In order to suppress rattling noise between the gear 10 and the gear 20, it is required to narrow backlash between the gear 10 and the gear 20. In FIG. 1, elements other than the gear 10, the gear 20, and the shaft 30 are not shown for the sake of simplicity.

  FIG. 2 is a flowchart showing a method for manufacturing the drive device 1.

  In step S1, the gear 10 and the gear 20 are prepared. In this example, the gear 10 and the gear 20 are bevel gears (helical gears).

  FIG. 3 is a view showing the structure of the gear 10. The gear 10 includes a gear body 11, teeth 12, and a coating layer 13. The gear body 11 is fitted or joined to the shaft 30 and rotates with the rotation of the shaft 30. The gear body 11 has a substantially disk shape. The gear body 11 has a plurality of teeth 12 extending in the radial direction on the outer peripheral portion. A coating layer 13 is formed on the tooth surface of the tooth 12. The gear body 11 and the teeth 12 are made of an iron-based material such as steel, for example. Alternatively, the gear body 11 and the teeth 12 may be made of a material other than iron such as copper, aluminum, or an alloy based on these.

  FIG. 4 is a diagram illustrating the formation position of the coating layer 13 on the tooth surface. The coating layer 13 is formed only in a part of the tooth surface of the tooth 12 in the tooth width direction. In this example, the coating layer 13 is formed only around the central portion in the tooth width direction. The coating layer 13 is not formed at both ends in the tooth width direction, and the base material is exposed. The coating layer 13 is, for example, any one of polyamide-imide resin, polyimide resin, diisocyanate-modified, BPDA-modified, or sulfone-modified resin, polyamide resin, epoxy resin, polyether ether ketone resin, or phenol resin of these resins. It is formed as described above. The coating layer 13 may contain additives in addition to the resin composition. The coating layer 13 is formed by pad printing, for example. The coating layer 3 may be formed by spraying, roll transfer, tumbling, dipping, brushing, or screen printing.

  The film thickness of the coating layer 13 is preferably about ½ of the backlash design value. For example, if the design value of the backlash is 40 to 80 μm, the film thickness of the coating layer 13 is 20 to 40 μm.

  Further, as will be described later, the coating layer 13 only needs to be present when the gear 10 is assembled, and it is preferable that the coating layer 13 disappears when operating as the drive device 1 of the finished product. Ideally, all of the coating layer 13 is preferably peeled off or worn away. In other words, the bonding strength (adhesive strength) between the coating layer 13 and the tooth surface of the gear 10 does not need to be strong, and is strong enough to peel off when the driving device 1 is operated to rotate the gear 10 and the gear 20 several times. It is preferable that it is joined.

  The detailed structure of the gear 20 is not shown. The gear 20 meshes with the gear 10 and has a structure without a coating layer.

  Refer to FIG. 2 again. In step S <b> 2, the gear 10 and the gear 20 are assembled to the drive device 1.

  FIG. 5 is a diagram illustrating a state after step S2. The gear 10 and the gear 20 are assembled so that the tooth surface of the gear 20 is in contact with the coating layer 13 of the gear 10 (or by pressing the gear 20 against the coating layer 13). At this time, the distance between the tooth surface of the gear 10 and the tooth surface of the gear 20 is a distance corresponding to the thickness of the coating layer 13.

  Refer to FIG. 2 again. In step S3, the coating layer 13 is removed. In this example, the coating layer 13 is removed by operating the driving device 1, that is, by rotating the gear 10 and the gear 20. When the gear 10 and the gear 20 are rotated, the coating layer 13 is peeled from the tooth surface of the tooth 12 by the force applied to the coating layer 13 through the tooth surface of the gear 20. Alternatively, the coating layer 13 is worn by the frictional force between the tooth surface of the gear 20 and the coating layer 13.

  FIG. 6 is a diagram illustrating a state after step S3. The coating layer 13 has been removed from the state of FIG. Therefore, the distance between the tooth surface of the gear 10 and the tooth surface of the gear 20, that is, the backlash, is a distance corresponding to about twice the thickness of the coating layer 13.

  For example, when the film thickness of the coating layer 13 is 20 to 40 μm, it is expected that the backlash between the gear 10 and the gear 20 is 40 to 80 μm, which is twice as much. According to the present embodiment, there is no problem of forgetting to remove the shim or remaining of the shim in the driving device, and the coating layer 13 is not formed uniformly on the entire tooth surface of the tooth 12, but in the width direction. In this case, the coating layer is formed only in a part of the region, and the peeled pieces of the coating layer can be reduced as compared with the case where the coating layer is uniformly formed on the entire tooth surface.

  Further, when the coating layer 13 is uniformly formed on the entire tooth surface of the tooth 12, when the tooth surface of the gear 20 and the tooth surface of the gear 10 come into contact with each other, only the vicinity of the end portion with which the contact is made. There is a possibility that the coating layer 13 peels off and the coating layer 13 does not peel off at the opposite end. However, if the coating layer 13 is formed only around the central portion in the tooth width direction as shown in FIG. 4, it is possible to reduce the possibility that the coating layer does not peel off and remains at the end portion that does not contact each other. .

  The present invention is not limited to the above-described embodiment, and various modifications can be made. For example, the position where the coating layer 13 is formed on the tooth surface of the gear 10 is not limited to the periphery of the center portion in the tooth width direction. The coating layer 13 is formed only at the end portion in the tooth width direction and may not be formed around the center portion in the tooth width direction.

  In the embodiment, the gear 10 has the example having the resin coating layer, but the gear 20 may have the resin coating layer. In this case, the gear 10 may have a resin coating layer or may not have a resin coating layer.

  The drive device 1 is not limited to a balancer device provided with an oil pump. The driving device 1 may be an electronic device such as a copying machine or a printer, or a driving device used for a robot. The gears 10 and 20 are not limited to bevel gears, and may be gears of other shapes such as spur gears.

DESCRIPTION OF SYMBOLS 1 ... Drive device, 10 ... Gear, 11 ... Gear body, 12 ... Teeth, 13 ... Coating layer, 20 ... Gear, 30 ... Shaft

Claims (4)

A gear body that rotates about a rotation axis;
A plurality of teeth provided around the gear body along the rotation direction of the rotation shaft;
A gear having a resin coating layer formed on only a part of the tooth surface of the plurality of teeth in the tooth width direction. The gear according to claim 1, wherein the resin coating layer is formed in only a part of the tooth surface including a center in the tooth width direction. A gear body that rotates around the rotation shaft, a plurality of teeth provided around the gear body along the rotation direction of the rotation shaft, and only a part of the tooth surfaces of the plurality of teeth in the tooth width direction. Preparing a first gear having a resin coating layer formed in a region;
Preparing a second gear meshing with the first gear;
Assembling the first gear and the second gear to a drive device such that the tooth surface of the second gear is in contact with the resin coating layer of the first gear;
Removing the resin coating layer of the first gear in the driving device. The method for manufacturing a drive device according to claim 3, wherein in the step of removing the resin coating layer, the resin coating layer is removed by rotating the first gear and the second gear.

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