Welcome to flange bronze bushing supplier viiplus.com MPTZ, MPTSZ, MPTNZ, MPIZ, MPITZ, MPCZ
Measuring Oilless Bearings
Quite often we receive questions on how to properly measure the dimensions of oilless bearings. The following explanation will assist you in measuring these types of bushing. It will also help when requesting quotations for this type of product.
Measurement of center hole spacing
Some inspectors often put forward such or other questions about the measurement of center hole distance in their work: How to detect the center distance of step hole? How to measure the center distance of vertical axis? Oblique hole center distance and hole center distance and how to check and so on. The location accuracy of the hole center distance is the key to the overall assembly and shaft drive quality to a large extent, so how to correctly detect the hole center distance to ensure the validity and accuracy of the detection results is very important.
Curabitur non nulla sit amet nisl tempus.
If the two holes are on the same horizontal plane or the same vertical plane, there are two measuring methods:
- Vernier caliper to measure the center hole distance: one is to measure the maximum distance between the inner surfaces of the two holes A when the diameters of the two holes D1 and D2 are measured above, and the center distance between the two holes is:L=A-1/2*(D1*D2)
- Another method is to measure the minimum distance B between the inner surfaces of the two holes when the inner diameters D1 and D2 of the two holes are measured. Then, the center distance between the two holes is:L=B+1/2(D1+D2)
- Or, directly use the following formula to calculate the center distance of the two holes:L=1/2A+1/2B
- Measuring the center distance between two parallel holes in the same plane: the hole distance can be measured directly with the hole distance vernier caliper. Choose vernier calipers with different sizes of conical measuring heads according to the size of the aperture. During measurement, the measuring head axis of the measuring ruler must be parallel to the center line of the hole. The reading on the measuring ruler is the size of the center distance of the hole.
- Using the center distance/side center distance vernier caliper can also detect the center of the hole to a side of the center distance size, table reading is the value of the center distance, very convenient.
Measuring the center distance between two parallel holes on step surface
Measuring the center distance between two parallel holes on the step surface, the hole distance vernier calipers are adjustable height direction vernier calipers,
Measuring the center distance of two vertical intersecting holes with the usage block and mandrel
(1) The center distance of two vertical intersecting holes is detected by mandrel and measuring block group
- Partial view of a worm gear box. ф 50H7 is used for installing the worm shaft. The two holes are perpendicular to each other and the center distance is 75±0.023mm. The center distance of the two vertical intersecting holes can be detected by using a mandrel and a group of measuring blocks.
- Before the test, two mandels with small clearance are prepared according to two holes ф 30H7 and ф 50H7. The straightness error of the two mandrels should be small, and the surface roughness value should be small. When testing, insert two mandrels into two corresponding vertical intersecting holes. When the equivalent block (or group of gauge blocks) can be inserted between the two mandrel busbars without falling down, the clearance between the mandrel busbars can be detected by the amount block. Then record the size of the measuring block, according to the size of the measuring block and the diameter of the mandrel (must be measured perpendicular to the horizontal diameter value) to calculate the center distance.
(2) Platform detection method to measure the center distance of two vertical intersecting holes
When inspecting the center distance of box hole, measuring tools and auxiliary devices are used: inspection plate, jack and adjustable jack, spindle, digital height ruler (can be clamped percentage or dial meter), etc. The diameter of D1 and D2 mandrel is inserted into the corresponding hole, and then placed in the jack leveling; With the dial gauge height ruler at plate Colonel zero, move the measuring head to the highest point of the busbar of mandrel 1 and measure the busbar height H1. Move the height ruler to one end of mandrel 2, zero the height ruler here, move the measuring head to the highest point of the busbar of mandrel 2, measure the busbar height H2; According to the values of two diameters and two bus heights, the center distance A can be calculated.
Measuring method for center distance of inclined hole
- Test the distance between the intersection of inclined hole and a vertical plane (center distance)
- The center distance of inclined hole can not be measured directly due to its high precision and special dimension Angle, so indirect measurement method is generally adopted
The center distance of inclined hole can not be measured directly due to its high precision and special dimension Angle, so indirect measurement method is generally adopted. Insert mandrel in φ hole without room; A standard cylinder with a diameter of D3 (inspection rod) is placed between the Angle formed by the right Angle of the test mandrel and the workpiece by the side; When H value (the distance from the farthest prime line of the standard cylinder to the measuring plane of the plate) is measured by the quantity block group and the dial meter, the measured distance H of the center of the inclined hole can be calculated according to the following formula:
h=H-d3/2-(d3/2)/tanβ/2-d/2/cosγ=H-d3/2-d3/2tanβ/2-d/2cosγ
In the formula, β - the acute Angle formed by the test spindle prime line and the right Angle edge of the measured workpiece, which can be obtained by converting the measured right Angle and γ Angle;
The actual Angle of γ - 15° Angle can be measured directly;
D -- Check spindle diameter;
D3 -- Standard cylinder diameter.
Binocular measurement of hole spacing
The light from point A outside the independent optical axis enters the compound prism from below and is cast to point B on the translucent surface I. It is then divided into two ways: one reaches point A1 on the image plane from C, D, E and F; The other goes from G,H,K to A2 on the image plane. A1 and. A2 is point-symmetric with respect to the optical axis. Obviously if A is A small hole, you will see images of two small holes in the field of view (shown in the lower left image). When point A coincides with the principal optical axis, A point is seen in the field of view at position O'. Obviously, if A is A small hole and the center of the hole coincides with the main optical axis, then we can see A small hole image in the field of view, and the center of the small hole image is at the position O'.
When measuring a part, moving the table vertically and horizontally brings the two distant images closer together until they coincide. At this point, the horizontal and horizontal reading of the table instrument (x, Y) is the coordinate of the center of the hole. If the vertical and horizontal coordinates of the center of the two holes are respectively (X1y1) and (x2y2), the distance between the center of the two holes is:
Double prism eyepiece used, one important feature, is not it a point on the axis, through the prism is divided into symmetric after two points, so using a double image eyepiece, hole center is the central microscope (i.e. no alignment) on optical axis, so will see two holes in the eyepiece like, only when I saw a hole in the eyepiece is required as has aimed at the hole center. Therefore, in the measurement of hole center distance, the center of hole can be easily determined, which shows outstanding superiority.
Generally speaking, the biimage eyepiece has higher aiming accuracy and measuring efficiency than the goniometer eyepiece in the alignment measurement (dotted line sight hole edge image).
01
Reliable Quality
Products' quality has been tested by the market in 110+ countries. And If any new demand, we’ll assess the technical feasibility and provide samples and drawings first to make sure it totally matches your requirements.
