Rockford Ball Screw offers a selection of robust bearing supports for our ball screw products.

Bearing Mounts & Supports


Bearing Mounts

RBS offers one of the most complete lines of standard bearing mounts in the industry. Mounts can be shipped loose for customer installation or preassembled to the screw at our factory. If shipped loose, please note that the bearings have an interference fit to the shaft and that installation procedures in accordance with those recommended by rolling element bearing manufacturers need to be implemented. Please consult our factory for additional details.

Types of Standard Mounts:

  • Fixed Angular- model BMF
  • Simple Angular- model BM
  • Simple Radial- model BMR


Simple Radial Bearing Mounts (BMR Bearing Mounts)

The BMR series bearing mounts are SIMPLE RADIAL supports utilizing shielded Radial ball bearings for supporting radial load components. These bearing mounts are NOT intended to support axial load components of force. Please consult Rockford Ball Screw’s engineering Tech Team for application assistance if required.

BMR uses a deep groove radial ball bearing. The BMR mount is well suited for high duty cycle conditions where frictional forces may cause a thermal transfer of energy into the screw assembly. The resulting thermal migration will cause the screw to expand axially and occasionally can lead to catastrophic failure.

Overview of BMR:

  • Considered "simple" support
  • Float of the bearing in the housing allows for shaft expansion
  • Standard end machining available
  • Predrilled for face or foot mounting

Click for BMR Dimensions

1) The BM series bearing mounts are universally precision machined to allow either foot or face mounting.

2) The BM series bearing mounts are to be considered as “SIMPLE” support for column loading and critical speed calculations.

Note: Dimensions shown for screws without corresponding bearing mounts are for references only. Black Triangles in chart indicate Ball Screws, Red triangles are for ACME Screws.


Simple Angular Bearing Mounts (BM Bearing Mounts)

The BM series bearing mounts are SIMPLE supports that utilize a set of Angular Contact ball bearings mounted back to back. These bearing mounts are designed to support radial and axial load components of force. Please consult Rockford Ball Screw’s engineering Tech Team for application assistance if required.

BM uses a set of angular contact bearings.

  • Can support a combination of radial and axial loads
  • Considered "simple" support
  • Standard end machining available
  • Predrilled for face or foot mounting
  • Contact us for bearing support capacities

Click for BM Dimensions

1) The BM series bearing mounts are universally precision machined to allow either foot or face mounting.

2) The BM series bearing mounts are to be considered as “SIMPLE” support for column loading and critical speed calculations.

Note: Dimensions shown for screws without corresponding bearing mounts are for references only. Black Triangles in chart indicate Ball Screws, Red triangles are for ACME Screws.


Fixed Angular Bearing Mounts (BMF Bearing Mounts)

The BMF series bearing mounts are FIXED RIGID supports that utilize a set of spaced Angular Contact ball bearings. These bearing mounts are designed to support both radial and axial load components of force. Please consult Rockford Ball Screw’s engineering Tech Team for application assistance if required.

BMF uses a set of spaced angular contact bearings.

  • Able to achieve greater comprehensive column strength by decreasing the effective length in the column buckling equations
  • Increases angular dynamic systemic stiffness, thereby increasing the first order harmonic frequency and increasing the critical speed capability
  • Standard end machining
  • Standard bearing support includes a two (2) bearing configuration
  • Available with up to four (4) bearings for more demanding applications; contact us for alternative bearing configurations
  • Predrilled for foot mount only
  • Predrilled for taper pin reaming to suit final assembly location

Click for BMF Dimensions

1) The BMF series bearing mounts are precision machined for foot mounting and pre-drilled for taper pins.

2) The BMF series bearing mounts are to be considered as “FIXED” support for column loading and critical speed calculations.

Note: Dimensions shown for screws without corresponding bearing mounts are for references only. Black Triangles in chart indicate Ball Screws, Red triangles are for ACME Screws.


Bearing Supports

Every screw assembly functionally requires a means of supporting the rotational axis of the screw and absorbing the radial and axial force components, e.g.

  • Bearing support utilizing rolling element bearings
  • Sleeve and rolling element bearing combination
  • Static screw mounted into a structure with a rotating nut

It is recommended that only axial force vectors are transmitted directly into the axis of the ball screw to obtain optimal and, in some instances, functional performance & longevity. All of our bearing mounts are furnished sealed and greased from the factory.

Custom Bearing Supports

Rockford Ball Screw works closely with our customers to design, engineer, and manufacture custom bearing supports for unique applications. Custom bearing support examples:

  • Tapered roller bearing
  • Thrust bearing arrangements
  • Spherical roller bearings
  • Multiple angular contact bearing stacks
  • Contact Rockford Ball Screw to request a thorough review of your application