JP2016145735A - Arbor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vibration measurement device capable of acquiring a precise measurement result, even to a water pump bearing, in which finishing processing of a shaft end is not performed.SOLUTION: An arbor 17 is configured so that, a hole 17a parallel to a rotation shaft is provided on one end of a columnar shape, the other end is formed into a taper shape, and an elastic body disk formed of a disk-shaped elastic body, a disk-shaped base part, and a shaft, is arranged on a bottom part of the hole 17a. An end face of the elastic body disk presses a shaft end of a water pump bearing 13, thereby the elastic body absorbs inclination of a shaft end face, and prevents inclination of the shaft.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an inspection machine for detecting scratches and foreign matters inside a bearing for a rolling bearing mainly used for a cooling water pump of an internal combustion engine.

  Conventionally, as a vibration measuring device for a rolling bearing, a driving means for rotationally driving an outer ring or an inner ring, a vibration pickup for detecting vibration or elastic wave of the outer ring or the inner ring, and a frequency converter for analyzing a signal detected by the vibration pickup are provided. What you have is known.

  The vibration measuring device having the above configuration analyzes the detected vibration (displacement, velocity, acceleration fluctuations and elastic waves) and, for example, a bearing ring (inner ring or outer ring) or a rolling element (various rollers or balls) of a rolling bearing. The surface of the rolling surface is checked for scratches, surface roughness, webiness, shape defects, foreign matter contamination, etc., and in an endurance test or the like, the bearing is monitored for abnormalities.

  For example, the vibration measuring device described in Patent Document 1 applies a radial load to the outer ring or shaft of a water pump bearing or the like, and drives the bearing in a state where the clearance between the rolling element and the raceway ring is locally eliminated. The vibration evaluation of a single bearing is performed. Further, for bearings having a contact angle (for example, ball bearings), the bearing is driven with an axial load corresponding to the size of the bearing applied, and vibration evaluation of the bearing alone is performed. .

Japanese Patent Laid-Open No. 5-10835

  When the water pump bearing is incorporated in the internal combustion engine, the front and rear end faces of the shaft are often not used. In that case, since the finishing process is not performed on the end face of the shaft, the flatness of the end face and the perpendicularity to the rotation axis are not guaranteed. For this reason, in a workpiece having a low flatness or perpendicularity of the shaft end surface, the shaft may be inclined when the shaft end for applying an axial load is applied in order to apply a preload to the rolling elements. If the shaft is tilted, a moment load is applied to the bearing, and a correct measurement result may not be obtained. The present invention has been made in view of these problems, and an object of the present invention is to provide a vibration measuring apparatus capable of obtaining an accurate measurement result even for a water pump bearing in which a shaft end is not finished. There is to do.

The object of the present invention is achieved by the following constitution.
(1) A hole parallel to the rotation axis is provided at one end of the columnar shape, and the other end is tapered. The disk-shaped elastic body, the disk-shaped base portion, and the elastic disk composed of the shaft are Arbor located at the bottom of the hole.
(2) The arbor according to (1), wherein the elastic disk is attached in a replaceable manner.
(3) The arbor according to (1) or (2), wherein the elastic body is any one of NBR, EPDM, chloroprene rubber, urethane rubber, silicone rubber, fluororubber neoprene rubber or fluororubber.

  Even if an axial load is applied to the shaft, the shaft does not tilt, and a correct vibration measurement result is obtained.

1 is a schematic diagram showing an embodiment according to the present invention. It is a fragmentary sectional view which shows the structure of the arbor which concerns on this invention. 2A shows a disassembled state of the arbor, and FIG. 2B shows a state where the arbor is assembled.

  FIG. 1 shows an embodiment of the present invention. The water pump bearing 13 for measuring vibration includes an outer ring 3 having double-row outer ring raceways 2 and 2 on the inner peripheral surface, a shaft 14 having double-row inner ring raceways 4 and 4 on the outer peripheral surface, and the outer ring raceways. 2 and 2 and a plurality of balls 12 and 12 provided between the inner ring raceways 4 and 4 so as to freely roll. At the time of measurement, one of the shafts 14 is fitted into a hole 17a provided at one end (the left end surface in FIG. 1) of an arbor 17 that constitutes a driving device together with the spindle 15, the electric motor 16, and the like.

The arbor 17 is fitted and fixed in a tapered hole 18 formed at the center of one end surface (right end surface in FIG. 1) of the spindle 15. The spindle 15 is rotatably supported inside the bearing 19. This bearing 19 is preferably a static pressure gas bearing, a magnetic bearing, a superconducting bearing, etc.
A structure that does not generate vibration as the spindle 15 rotates is used.

The spindle 15 supported by the bearing 19 in this manner is freely rotatable by the electric motor 16. In the case of the illustrated embodiment, a belt 23 is stretched between a driven pulley 21 fixed to the center of the other end surface of the spindle 15 and a driving pulley 22 fixed to the output shaft of the electric motor 16. When the electric motor 16 is energized, the spindle 15 is rotated at a constant speed of, for example, about 1800 revolutions per minute.

In addition, by devising the tension and material of the belt 23, the spindle 15 is prevented from vibrating when the spindle 15 is driven to rotate by the electric motor 16. In addition to the illustrated embodiment, the spindle 15 and the output shaft of the electric motor 16 can be arranged concentrically, and the spindle 15 can be driven to rotate via a magnet coupling or the like.

  The pressurizing mechanism 24 is provided with its end face facing the end face of the outer ring 3 of the water pump bearing 13 supported by the arbor 17. The pressure mechanism 24 includes a pressure cylinder 25 and a pressure jig 26. A proximal end portion of a rod 29 is fixed to a pressure piston 28 fitted to the pressure cylinder 25, and a pressure jig 26 is coupled to the distal end portion of the rod 29. When performing vibration measurement, compressed air or hydraulic oil is injected into the pressurizing chamber 33 of the pressurizing cylinder 25 to pressurize the pressurizing piston 28, and an axial load is applied to the outer ring 3 via the rod 29 and the pressurizing jig 26. To load.

  The converter 36, which is a detector that measures the vibration of the water pump bearing 13, is arranged so that the tip 37 is in contact with the surface of the outer ring 3. The converter 36 detects minute vibrations generated due to the presence of scratches and foreign matter inside the rotating water pump bearing 13 as radial displacement of the surface of the outer ring 3 and converts it into an electrical signal. Send to amplifier 38. Any detector other than the converter 36 may be used as long as it can detect the vibration, such as a displacement meter and an accelerometer. The electric signal amplified by the amplifier 38 is sent to the control device 39, where the electric signal is determined as a vibration measurement result, and a non-defective product or a defective product is determined. The control device 39 controls operations of the pressurizing mechanism 24, the electric motor 16, the amplifier 38, a transport device (not shown), and the like.

  FIG. 2 is a partial cross-sectional view showing the arbor 17. 2A shows a disassembled state of the arbor 17, and FIG. 2B shows a state where the arbor 17 is assembled. In order to fit the shaft 14 to one end of the arbor 17, a hole 17 a parallel to the rotation shaft is provided, and the inner diameter of the hole 17 a is set slightly larger than the outer diameter of the shaft 14. A small-diameter hole 17b is provided on the bottom surface of the hole 17a, and a screw hole 17c is provided in the radial direction of the shaft 14 in the vicinity of the central portion in the axial direction of the small-diameter hole 17b. The other end of the arbor 17 has a tapered shape and is fitted into a tapered hole 18 provided in the shaft of the spindle 15.

  An elastic disk 30 is inserted into the hole 17a of the arbor 17. The elastic disk 30 includes an elastic body 30a, a base 30b, and a shaft 30c. The elastic disk 30 is inserted into the hole 17a, and the shaft 30c is pressed and fixed from the screw hole 17c using the set screw 31. As the material of the elastic body 30a, NBR (nitrile butadiene copolymer), EPDM (ethylene propylene), chloroprene rubber, urethane rubber, silicone rubber, or fluorine rubber can be used. For the hardness of the material used for the elastic body 30a, several types of elastic disk 30 are prepared and selected as necessary so that an appropriate material can be selected according to the model number of the water pump bearing 13. For example, a hard rubber is selected because a large axial load is required for a large water pump bearing.

  Next, functions and effects of the arbor according to the present invention will be described. A transport device (not shown) transports the water pump bearing 13 to a measurement position facing the arbor 17, and the shaft 14 is inserted into the hole 17 a of the arbor 17. In this state, compressed air or hydraulic oil is injected into the pressure chamber 33 of the pressure cylinder 25 to pressurize the pressure piston 28, and an axial load is applied to the outer ring 3 via the rod 29 and the pressure jig 26. . As a result, the entire water pump bearing 13 is slightly displaced toward the arbor 17, and the end face of one end of the shaft 14 and the elastic disk 30 come into contact with each other. A plurality of balls 12 incorporated in the water pump bearing 13 are prestressed by being pressed from the shaft 14 and the outer ring 3.

  Next, with the probe 37 of the converter 36 in contact with the outer peripheral surface of the outer ring 3, the electric motor 16 is operated to rotate the spindle 15, and thus the shaft 14 is rotated. As a result, the plurality of balls 12 inside the bearing rotate and move while being in contact with the respective surfaces of the outer ring raceway 2 and the inner ring raceway 4, so that if the balls 12, the outer ring raceway 2 and the inner ring raceway 3 are damaged, vibrations occur. Appears as The vibration is converted into an electric signal by the converter 36 and sent to the amplifier 38. The electric signal amplified by the amplifier 38 is sent to the control device 39, and the non-defective product and the defective product are determined according to a predetermined determination standard using the electric signal as a vibration measurement result.

  By the way, in the state where the water pump bearing 13 is incorporated in the internal combustion engine, the front and rear end faces of the shaft 14 are often not used, and thus the end face of the shaft 14 may not be finished. In the shaft 14 where the end face is not finished, the flatness of the end face and the perpendicularity to the rotation axis are not guaranteed. When the flatness or perpendicularity of the end face is low, the shaft may tilt when the end face is pushed to apply an axial load in order to apply a preload. If the shaft is tilted, a moment load is generated on the bearing, and a correct measurement result may not be obtained. The arbor 17 according to the present invention can solve this problem.

  That is, when the arbor 17 according to the present invention is used, the momentum load is applied to the shaft 14 even when the flatness of the end surface of the shaft 14 and the perpendicularity to the rotating shaft are low due to the action of the elastic body provided on the elastic disc 30. It is possible to press without generating. As a result, the shaft 14 does not tilt, and a correct vibration measurement result can be obtained.

2 Outer ring raceway 3 Outer ring 4 Inner ring raceway 12 Ball (rolling element)
13 Water pump bearing 14 Shaft 15 Spindle 16 Electric motor 17 Arbor 17a Hole 17b Small diameter hole 17c Screw hole 18 Tapered hole 19 Bearing 21 Driven pulley 22 Drive pulley 23 Belt 24 Pressure mechanism 25 Pressure cylinder 26 Pressure jig 28 Addition Pressure piston 29 Rod 30 Elastic disk 30a Elastic body 30b Base 30c Shaft 31 Set screw 36 Converter 37 Measuring element 38 Amplifier 39 Control device

Claims (3)

A hole parallel to the rotation axis is provided at one end of the columnar shape, and the other end is tapered, and a disk-shaped elastic body, a disk-shaped base, and an elastic disk composed of a shaft are provided at the bottom of the hole. Arbor placed in the. The arbor according to claim 1, wherein the elastic disk is attached in a replaceable manner. The arbor according to claim 1 or 2, wherein the elastic body is any one of NBR, EPDM, chloroprene rubber, urethane rubber, silicone rubber, fluorine rubber neoprene rubber, or fluorine rubber.

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