JP2011190831A - Circulation mechanism of gear lubricant - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To stably rotate a gear without causing vibrations and unevenness for a long time. <P>SOLUTION: A plurality of through holes 12 are formed in a gear 1. A first groove 14 is formed in one face of the gear 1 toward a radially outward direction of the gear 1 from the through hole 12. A first side wall 14a of the first groove 14 is inclined to a downstream direction in a rotating direction by an angle α with respect to a straight line L connecting the centers of the gear 1 and through hole 12. A second groove 15 is formed on the other face of the gear 1 toward a radially outward direction of the gear 1 from the through hole 12. A second side wall 15a of the second groove 15 is inclined to an upstream direction in a rotating direction by an angle β with respect to the straight line L connecting the centers of the gear 1 and through hole 12. When the gear 1 rotates, lubricant not shown in the figure is circulated by moving to a tooth part 13 along the first side wall 14a of the first groove 14, to the through-hole 12 from the tooth part 13 along the second side wall 15a of the second groove 15 and to the first groove 14 through the through-hole 12. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a gear lubricant circulation mechanism.

  For example, in an image forming apparatus such as a facsimile, a printer, or a copying machine, the rotational force of a motor is used in a mechanism for rotating a developing device, a photosensitive member, etc., a mechanism for rotating paper, etc. It transmits to a driven part using a gear transmission mechanism.

  The gear transmission mechanism is usually required to reduce operating noise and improve durability when the device is driven. In addition, from the viewpoint of obtaining high image quality, the image forming apparatus is required to rotate stably with no uneven rotation speed and to generate no vibration. For this reason, generally, a lubricant such as grease is applied to the rotating portion of the gear transmission mechanism. However, there is a problem that the lubricant gradually decreases as the apparatus is used.

  Therefore, in Patent Document 1, for example, a pair of circumferential ribs are formed on the side surface of the gear, a groove portion is formed between the pair of circumferential ribs, and a lubricant is held in the groove portion so that the side surface of the gear There has been proposed a technique in which a lubricant is always present in a sliding portion in contact with a side surface of a gear.

JP 2001-228660

  However, even in the proposed technique of Patent Document 1, it is considered that the lubricant gradually decreases when the apparatus is used for a long period of time, and the gear wears and vibrates. In particular, in a gear having a large rotational load, the lubricant is easily depleted, vibration does not occur over a long period of time, and there is still a problem of being able to rotate stably without unevenness.

  The present invention has been made in view of such conventional problems, and an object of the present invention is to cause a gear transmission mechanism to stably rotate a gear without causing vibrations over a long period of time. It is in.

  As a result of intensive studies to achieve the above object, the present inventor has obtained the knowledge that the lubricant should be circulated between both side surfaces in the thickness direction of the gear, and has made the present invention. That is, the gear lubricant circulation mechanism according to the present invention is formed in a plurality of through holes formed in the disk-shaped gear and on one surface of the gear from the through hole toward the outer side in the radial direction of the gear. The first groove, the second groove formed on the other surface of the gear from the through hole toward the outer side in the radial direction of the gear, and the first side wall on the downstream side in the rotation direction of the first groove are the center of the gear. The second side wall on the downstream side in the rotational direction of the second groove portion is inclined with respect to the straight line connecting the center of the through hole with respect to the straight line connecting the center of the through hole. Inclined in the upstream direction, at least a part of the first groove portion, the second groove portion, and the through hole is filled with lubricant, and the gear rotates along the first side wall of the first groove portion by rotating the gear. Move to the tooth portion formed on the outer periphery of the second groove, and further along the second side wall of the second groove portion from the tooth portion. Te moved in the through hole, and wherein the circulating moves to the first groove through the through hole.

  Here, from the viewpoint of circulating the lubricant more efficiently, the shape of the first groove portion and the second groove portion is a shape in which the width in the circumferential direction widens from the through hole toward the outer side in the radial direction of the gear. preferable.

  Moreover, it is preferable that the opening facing the first groove portion of the through hole is positioned on the downstream side in the rotation direction with respect to the opening facing the second groove portion, and the through hole is inclined with respect to the rotation axis.

  The image forming apparatus according to the present invention is an image forming apparatus that transmits a rotational driving force to a driven part by a plurality of gears, and the lubricant applied to the gears is any one of the first to third aspects. It circulates using the circulation mechanism of a gear lubricant, It is characterized by the above-mentioned.

  In the gear lubricant circulation mechanism according to the present invention, as the gear rotates, the lubricant flows and circulates through the first groove portion, the second groove portion, and the through hole, so that the gear causes vibration for a long period of time. Without any unevenness, it will rotate stably. As a result, the image forming apparatus according to the present invention can stably obtain a high-quality image for a long period of time.

1 is a schematic diagram illustrating an example of an image forming apparatus to which a gear lubricant circulation mechanism according to the present invention is applied. Sectional drawing which shows an example of the circulation mechanism of the gear lubricant which concerns on this invention. FIG. 3 is a side view of one side of the gear shown in FIG. 2. The other side view of the gearwheel shown in FIG. The side view which shows the other example of the circulation mechanism of the gear lubricant which concerns on this invention.

  Hereinafter, the gear lubricant circulation mechanism according to the present invention will be described in more detail with reference to the drawings. However, the present invention is not limited to these embodiments.

  FIG. 1 is a schematic diagram showing an example of an image forming apparatus 100 according to the present invention. The image forming apparatus 100 shown in FIG. 1 includes an image reader unit 110 that mainly reads a document image and a printer unit 120 that prints the read image. The image reader unit 110 is a known unit that reads an image of a document placed on a document glass plate (not shown) by moving a scanner. In the color specification model, red, green, and blue are separated into three colors, converted into electrical signals for each color by a CCD image sensor (not shown), and sent to the control unit 121 built in the printer unit 120.

  In the control unit 121, the image data is subjected to various processes and then converted into image data of reproduction colors of cyan (C), magenta (M), yellow (Y), and black (K). Stored in the image memory. Then, it is read out for each unit scan line and becomes a drive signal for the light emitting diode of the image forming unit 122. In the figure, the reference numerals are assigned to only one color, but the image forming unit 122 corresponding to each of the four colors is provided.

  In the printer unit 120, an electrostatic latent image corresponding to the image data is formed on the surface of the photoreceptor, and a process of developing the electrostatic latent image with toner is performed for each color. These toner images are transferred onto the transfer belt 123. Note that the image forming unit 122 and the transfer belt 123 are rotationally driven by a drive mechanism that is not provided with reference numerals. The toner images transferred and superimposed on the transfer belt 123 are secondarily transferred onto the recording sheet by the secondary transfer roller 124.

  The recording sheets are pulled out one by one from the paper feed tray 125 by the paper feed roller 126, and are transported between the transfer belt 123 and the secondary transfer roller 124 (secondary transfer unit) through the path A. The recording sheet that has passed through the secondary transfer unit is heated and pressed by the fixing unit 127. As a result, the toner image is melted and fixed on the recording sheet. The recording sheet thus printed is discharged outside the apparatus.

  In the image forming apparatus 100 having such a structure, in order to obtain a high-definition image, vibration is generated in the rotational drive system such as the image forming unit 122, the transfer belt 123, the recording sheet conveying unit, and the fixing unit 127. It is important to rotate it stably without unevenness.

  FIG. 2 shows an example of a gear transmission mechanism that is preferably used in the image forming apparatus 100. In the gear transmission mechanism of FIG. 2, the shaft 3 and the shaft 4 are fixed between the substrate 21 and the substrate 22, and the gear 1 and the gear 5 are rotatably supported on the shaft 3 and the shaft 4, respectively. . The gear 5 is a two-stage gear, the small diameter gear 5a meshes with the gear 1, and the large diameter gear 5b meshes with a gear (not shown).

  A view of the gear 1 viewed from the left side of FIG. 1 is shown in FIG. 3, and a view of the gear 1 viewed from the right side is shown in FIG. As can be understood from FIG. 3, a rotation shaft hole 11 through which the shaft 3 is inserted is formed at the center of the gear 1. A tooth portion 13 is formed on the outer periphery of the gear 1. There is no limitation in particular in the kind of tooth | gear part 13, Any, such as a flat tooth, an inclined tooth, a mountain tooth, may be sufficient. The outermost solid line of the gear 1 is the tip circle, the alternate long and short dash line is the pitch circle, and the solid line is the root circle.

  In the gear 1, eight through holes 12 are formed at equal intervals in the circumferential direction on the same circumference. And the 1st groove part 14 is formed toward the radial direction outward of the gearwheel 1 from each through-hole 12. As shown in FIG. The first groove portion 14 has a so-called fan shape in which the width in the circumferential direction becomes wider toward the outer side in the radial direction of the gear 1. What is important here is that the first side wall 14a of the first groove portion 14 on the downstream side in the gear rotation direction is in the rotation direction of the gear with respect to the straight line L connecting the center of the rotation shaft hole 11 and the center of the through hole 12. The angle α is inclined to the downstream side. In FIG. 3, the gear 1 rotates clockwise. The angle at which the other side wall of the first groove portion 14 is formed is not particularly limited, but it is preferable that the first side wall 14a of the adjacent first groove portion 14 is connected to the circumferential portion of the gear 1. Thereby, as will be described later, the circulation of the lubricant is smoothly performed over the entire tooth portion 13.

  On the other hand, on the right side surface of the gear 1 shown in FIG. 4, second groove portions 15 are formed from the respective through holes 12 outward in the radial direction of the gear 1. Similarly to the first groove 14, the shape of the second groove 15 is a so-called fan shape in which the width in the circumferential direction increases toward the outer side in the radial direction of the gear 1. Unlike the first groove 14, the second side wall 15 a of the second groove 15 on the downstream side in the rotation direction of the gear 1 rotates with respect to a straight line L connecting the center of the rotation shaft hole 11 and the center of the through hole 12. The angle β is inclined upstream in the direction. The inclination angle β is not particularly limited but is preferably an acute angle. In FIG. 4, the gear 1 rotates counterclockwise. The formation angle of the other side wall of the second groove portion 15 is not particularly limited, but from the viewpoint of smoothly circulating the lubricant over the entire tooth portion, the second side wall 15a of the adjacent second groove portion 15 and the gear It is preferable that the connection is made at one circumferential portion.

  In the gear 1 having such a structure, a lubricant (not shown) such as grease is filled in the first groove portion 14, the second groove portion 15, and the through hole 12. When the gear 1 starts to rotate, the lubricant is pressed against the first side wall 14a on the downstream side in the rotation direction of the first groove portion 14 on the left side surface of the gear 1 shown in FIG. . As described above, the first side wall 14a is inclined at the angle α to the downstream side in the rotation direction with respect to the straight line L connecting the center of the rotation shaft hole 11 and the center of the through hole 12, so that the lubricant is the gear 1. Toward the outer side in the radial direction and move to the tooth portion 13.

  On the other hand, on the right side surface of the gear 1 shown in FIG. 4, when the gear 1 starts to rotate, the lubricant is pressed against the second side wall 15a on the downstream side in the rotation direction of the second groove portion 15 by the inertia force of the lubricant itself. . As described above, the second side wall 15a is inclined at an angle β to the upstream side in the rotation direction with respect to the straight line L connecting the center of the rotation shaft hole 11 and the center of the through hole 12, so that the lubricant is the gear 1. It moves toward the inner side in the radial direction of the through hole 12. Thus, the lubricant circulates from the first groove portion 14 to the tooth portion 13, from the tooth portion 13 to the second groove portion 15, from the second groove portion 15 to the through hole 12, and from the through hole 12 to the first groove portion 14. . As a result, there is no risk of the lubricant depleted in the tooth portion 13, and the gear 1 does not generate vibration over a long period of time and rotates stably without unevenness.

  In the case where the gear 1 is a bevel gear, it is desirable to form the bevel teeth so that the first groove side of the tooth surface is upstream of the second groove side in the rotation direction of the gear.

  FIG. 5 shows another embodiment of a gear used in the circulation mechanism according to the present invention. In addition, the same code | symbol is attached | subjected to the same part and member as the gearwheel shown in FIG. The gear 1a in this figure is different from the gear 1 in FIG. 2 in that the opening 12a facing the first groove 14 of the through hole 12 is downstream of the opening 12b facing the second groove 15 in the rotational direction of the gear 1a. The through hole 11 is located on the side and is inclined with respect to the rotation axis. Thereby, when the gear 1a starts to rotate, the lubricant in the through hole 12 moves from the second groove side to the first groove side by the inertial force, and the lubricant circulates more smoothly.

  In the gear lubricant circulation mechanism according to the present invention, as the gear rotates, the lubricant flows and circulates through the first groove portion, the second groove portion, and the through hole, so that the gear causes vibration for a long period of time. It is useful because it rotates stably without unevenness.

DESCRIPTION OF SYMBOLS 1 Gear 11 Rotating shaft hole 12 Through-hole 12a Opening 12b Opening 13 Tooth part 14 1st groove part 14a 1st side wall 15 2nd groove part 15a 2nd side wall

Claims (4)

A plurality of through-holes formed in the disc-shaped gear, a first groove formed on one surface of the gear from the through-hole toward the radially outer side of the gear, and a through-hole on the other surface of the gear The second groove portion formed radially outward from the gear and the first side wall on the downstream side in the rotation direction of the first groove portion are downstream in the rotation direction with respect to a straight line connecting the center of the gear and the center of the through hole. The second side wall on the downstream side in the rotation direction of the second groove portion is inclined in the upstream direction with respect to the straight line connecting the center of the gear and the center of the through hole,
A lubricant is filled in at least a part of the first groove portion, the second groove portion, and the through hole,
As the gear rotates, the lubricant moves along the first side wall of the first groove portion to the tooth portion formed on the outer periphery of the gear, and further penetrates from the tooth portion along the second side wall of the second groove portion. A gear lubricant circulation mechanism, wherein the gear lubricant circulation mechanism moves to the hole, moves to the first groove through the through hole, and circulates.   2. The gear lubricant circulation mechanism according to claim 1, wherein the first groove portion and the second groove portion have a shape in which a circumferential width increases from a through hole toward a radially outer side of the gear.   The opening of the said through-hole facing the 1st groove part is located in the rotation direction downstream rather than the opening which faced the 2nd groove part, The said through-hole is inclined with respect to the rotating shaft. Gear lubricant circulation mechanism.   In an image forming apparatus that transmits a rotational driving force to a driven part by a plurality of gears, the lubricant applied to the gears is circulated using the gear lubricant circulation mechanism according to any one of claims 1 to 3. An image forming apparatus.