US 5,877,433 A · Bearing preload measuring method and apparatus

Abstract

In a duplex bearing 10 in which a preload is applied to balls 14a and 14b interposed between an outer race 11 and first and second inner races 12 and 13 by tightening a nut 16, a preload jig 19 fitted to the lower end of the second inner race 13 is turned by a motor 21 and applied with an axial load by a rod 31. The rod 31 has a load detector 31 at the middle. Position sensors 24 and 25, each of which is adapted to detect an amount of displacement in the direction of axis, are provided at the ends of the outer race 11 and the second inner race 13, respectively. A rotation detecting sensor 33 adapted to detect a rotational position is provided below the lower surface of the preload jig 9. Under the condition that the axial load is applied to the extent that measuring loads are FH and FL, the amounts of average displacement XAH and XAL of the outer race 11, and the amounts of average displacement XBH and XBL are detected, and the amounts of displacement .DELTA.XH and .DELTA.XL which are the differences between those amounts are calculated, so that the aimed rigidity KA is calculated by utilizing the amounts of displacement .DELTA.XH and .DELTA.XL thus calculated.

Claims12

Dependent claims

A bearing preload measuring method for measuring a preload of a bearing which is assembled by applying in an axial direction the preload onto at least one of the top surface and the bottom surface thereof, wherein said bearing is one of a duplex bearing and a double row bearing, said method comprising the steps of:

applying in the axial direction a first relative measuring load (FH) between the inner and outer races;
measuring an amount of first relative displacement (.DELTA.XH) in the axial direction between said inner race and said outer race which is generated by said first relative measuring load (FH);
applying in the axial direction a second relative measuring load (FL) between the inner and outer races, said second relative measuring load (FL) being different in magnitude from said first relative measuring load (FL);
measuring an amount of second relative displacement (.DELTA.XL) in the axial direction between said inner race and said outer race which is generated by said second relative measuring load (FL);
calculating a difference of displacement in the axial direction between the amount of said first relative displacement (.DELTA.XH) and the amount of said second relative displacement (.DELTA.XL);
and
calculating a preload of said bearing according to said difference of displacement in the axial direction through a comparative predetermined relationship between an axial load applied onto one of said duplex bearing and said double raw bearing and an axial displacement of said one which is generated by the application of said axial load.

4 more elements

A bearing preload measuring method for measuring a preload of a bearing in which a negative gap is formed by applying a preload to rolling elements in an axial direction which are interposed between an inner race and an outer race thereof, wherein said bearing is one of a duplex bearing and a double row bearing, said method comprising the steps of:

applying in the axial direction a first relative a measuring load (FH) between the inner and outer races;
measuring an amount of first relative displacement (.DELTA.XH) in the axial direction between said inner race and said outer race which is generated by said first relative measuring load (FH);
applying in the axial direction a second relative measuring load (FL) between the inner and outer races, said second relative measuring load (FL) being different in magnitude from said first relative measuring load (FL);
measuring an amount of second relative displacement (.DELTA.XL) in the axial direction between said inner race and said outer race which is generated by said second relative measuring load (FL);
calculating a difference of displacement in the axial direction between the amount of said first relative displacement (.DELTA.XH) and the amount of said second relative displacement (.DELTA.XL);
calculating a rigidity (KA) of said bearing according to said difference thus calculated;
and
calculating a preload (Fa) of said bearing according to said rigidity (KA) thus calculated and a contact angle (.alpha.) of said rolling elements.

5 more elements

A bearing preload measuring apparatus adapted to measure the preload of a bearing in which a negative gap is formed by applying a preload to rolling elements in the direction of axis which are interposed between an inner race and an outer race, wherein said bearing is one of a duplex bearing and a double row bearing, said apparatus comprising:

load setting means for setting a first relative measuring load and a second relative measuring load;
pressurizing means for applying said first and second relative measuring loads between said inner and outer races to increase and decrease said negative gap;
a displacement detecting means for detecting an amount of first relative displacement between said inner and outer races in an axial direction while said first relative measuring loads are being applied and also detecting an amount of second relative displacement between said inner and outer races in an axial direction while said second relative measuring loads are being applied;
displacement difference calculating means for calculating a difference between the amounts of first and second relative displacement in the axial direction;
rigidity calculating means for calculating a rigidity of said bearing according to said difference thus calculated;
and
a preload calculating means for calculating a preload (Fa) of said bearing according to said rigidity (KA) thus calculated and a contact angle (.alpha.) of said rolling elements.

4 more elements

Dependencies are inferred from the claim text.

Bearing preload measuring method and apparatus

Life of this patent

Bearing preload measuring method and apparatus

Life of this patent

Abstract

Claims12