023.30.900 Slewing Bearing
2. 023 is the standard internal gear type of the 02 series—the gear is machined into the inner bore of the inner ring, driving the pinion to mesh from within the bearing's center bore.
3. Compared to the same diameter external gear type 021 (De=1086.4, Z=133), the internal gear type has a much smaller addendum circle (De=715.2mm) than the outer diameter (1042mm), and the pinion and meshing area are completely enclosed within the bearing cavity. This layout sacrifices gear maintainability in exchange for the most compact external space—the only feasible solution in excavator undercarriages, compact drilling rigs, and space-constrained tower crane rotation.
- Product Description
023.30.900 Slewing Bearing – Internal Gear Double Row Ball Type for Excavators & Compact Cranes
Luoyang Heng Guan Bearing Technology Co., Ltd., with over 30 years of expertise in Slewing Bearing manufacturing, presents the 023.30.900 Slewing Bearing—a double row different diameter ball internal gear slewing ring specifically engineered for space-critical applications. This internal gear double row slewing bearing features a precision-machined m=8 module, Z=90 teeth on the inner ring bore (De=715.2mm), hardened to 55-62 HRC. The three-race double-row structure delivers 40-60% higher load capacity than single-row designs. With 1042mm OD × 758mm ID × 124mm height and 42CrMo forged rings, this 900mm internal gear slewing bearing double row handles 80kN tooth force for standard duty (111kN for shock/start-stop applications). Our ISO9001-certified facility produces slewing bearings from 50-10000mm diameter with precision grades P0-P4, serving customers across 50+ countries including Germany, Australia, and the United States.
The internal gear configuration offers a game-changing advantage: your drive pinion operates completely inside the bearing cavity, eliminating external space requirements. This excavator internal gear slewing bearing 900mm solution is fully interchangeable with SNIR30/900 and HSN900DM. You receive CAD drawings, installation guidance, and engineering support for seamless integration.
Technical Specifications
Basic Dimensions
Parameter | Symbol | Value |
Outer Diameter | Da | 1042 mm |
Inner Diameter | Di | 758 mm |
Tip Circle Diameter | De | 715.2 mm |
Height | H | 124 mm |
Pitch Circle Diameter | DL | 900 mm |
Ball Diameter | Dw | 30 mm |
Weight | — | ≈250 kg |
Mounting Dimensions
Parameter | Symbol | Value |
Mounting Bolt Circle (Outer) | D₁ | 998 mm |
Mounting Bolt Circle (Inner) | D₂ | 802 mm |
Number of Holes (Outer Ring) | n | 30 |
Number of Holes (Inner Ring) | n₁ | 22 |
Bolt Specification | — | M22 |
Internal Gear Data
Parameter | Symbol | Value |
Gear Type | — | Fellows Stub Involute Spur Gear |
Module | m | 8 |
Number of Teeth | Z | 90 |
Tip Circle Diameter | De | 715.2 mm |
Profile Shift Coefficient | x | +0.5 |
Tooth Width | b | 80 mm |
Pressure Angle | α | 20° |
Tooth Surface Hardness | — | 55–62 HRC (Induction Hardened) |
Maximum Tangential Force | Fz | 80,000 N |
Allowable Tooth Force | FT | 111,000 N |
Note: Use 80kN rating for standard continuous duty cycles. For excavator swing mechanisms or drilling rigs with frequent start-stop and shock loading, apply the 111kN capacity specification to ensure fatigue resistance.
Why Choose Internal Gear Configuration?
This is what most suppliers won't tell you—the internal gear double row slewing ring bearing isn't just about saving space. It solves real-world problems:
1. Maximum Space Efficiency
Your internal gear tip circle (De=715.2mm) sits far inside the 1042mm outer diameter. This means your drive pinion, motor, and gearbox fit entirely within the bearing's inner bore. You gain precious installation space for hydraulic lines, cabling, and structural components—critical in compact excavator swing bearing internal gear designs.
2. Superior Gear Protection
The meshing zone stays enclosed inside the bearing cavity. External contaminants—mud, gravel, metal chips, water jets—cannot reach the tooth flanks. This matters enormously in excavator undercarriages and drilling platforms where external gears would fail rapidly from abrasive ingress.
3. Zero Interference Installation
Unlike external gear types requiring radial clearance for pinion access, your internal gear system needs no outer perimeter space. This makes the product the only viable solution for tower crane slewing mechanisms and crawler crane internal gear slewing ring applications with envelope constraints.
4. Application Decision Guide
Choose internal gear (023 series) if your equipment is an excavator, compact drill rig, or space-limited crane requiring protected drive systems. Choose external gear (021 series) if you prioritize easy maintenance access and need maximum torque transmission with larger gear diameter.
Load Capacity & Performance
Parameter | Symbol | Value |
Static Axial Load Rating | C₀ₐ | ≈2,580 kN |
Static Radial Load Rating | C₀ᵣ | Contact engineering team |
Tilting Moment Capacity | Mₜ | Contact engineering team |
Maximum Rotational Speed | nₘₐₓ | Application-dependent |
The double-row ball configuration distributes loads across upper and lower raceways, delivering exceptional axial and moment rigidity. Our heat-treated 42CrMo raceways (58-62 HRC) ensure L10 life exceeding 10,000 operating hours under rated load.
Target Applications
10-30 Ton Excavators
The heavy duty internal gear double row slewing bearing is the industry standard for excavator swing drives. Your pinion meshes from inside, avoiding track frame interference while the sealed design blocks mud and debris—extending service life by 40% compared to exposed external gears.
Compact Crawler Cranes
Space-constrained upper structures demand internal gear layout. The mini excavator internal gear slew ring frees outer envelope space for boom mounting and counterweight positioning while maintaining full 360° rotation capability.
Rotary Drilling Rigs
Power head rotation platforms benefit from internal gear protection—the meshing surface remains isolated from drilling slurry and soil contamination, ensuring consistent torque transmission throughout multi-shift operations.
Small Tower Cranes
Tower crane internal gear slewing bearing double row configurations reduce overall turret diameter. This compact footprint matters critically in urban construction sites with limited working radii.
Intelligent Turntables & Indexing Platforms
Emerging automation applications utilize slewing bearing m8 z90 internal gear double row for precision positioning systems requiring IP65+ protection and low-noise operation.
Piling Machines & Concrete Pump Trucks
Internal gear drive minimizes swing radius on confined jobsites while delivering the 111kN shock-load capacity needed for hydraulic pile-driver reaction forces.
Series Comparison
Feature | 020.30.900 | 021.30.900 | 023.30.900 |
Gear Type | Non-Gear | External Gear | Internal Gear |
Gear Position | — | Outer ring OD | Inner ring bore |
Module / Teeth | Custom drive | m=8, Z=133 | m=8, Z=90 |
Tip Circle Diameter | — | De=1086.4 mm | De=715.2 mm |
Weight | ~250 kg | ~250 kg | ~337 kg |
Swing Radius | N/A | Larger | Most compact |
Pinion Access | — | External (easy service) | Internal bore only |
Best Applications | Servo positioners | Standard cranes, wind yaw | Excavators, compact cranes, drilling rigs |
SNIR30/900 & HSN900DM Cross Reference
The 023.30.900 Slewing Bearing provides 100% dimensional interchangeability with SNIR30/900, SNIR30/900Y, and HSN900DM models. Mounting bolt patterns, raceway geometry, and gear parameters match OEM specifications. You can retrofit this bearing without modifying your housing, pinion, or hydraulic motor mounting. Supply our engineering team with your existing bearing markings—we'll verify compatibility and provide certified dimension reports before production.
OEM & Custom Manufacturing Capabilities
Heng Guan Bearing operates advanced CNC vertical lathes, quenching machines, gear shapers, and large-diameter hobbing equipment. We handle:
· Custom gear module (m=4 to m=16) and tooth count modifications
· Non-standard bolt hole patterns and flange interfaces
· Special coatings (zinc-nickel for marine, epoxy for chemical plants)
· Reverse engineering services with on-site measurement—no drawings required
Our 50+ engineer team provides load calculation, FEA analysis, and application-specific heat treatment protocols. Production capacity spans 50-10000mm diameter with P0/P6/P5/P4 precision grades.
FAQ
Q: Can this bearing handle excavator shock loads during rock breaking?
A: Yes. The 111kN tooth force rating specifically accommodates impact forces from hydraulic breakers and sudden bucket loading. Double-row ball design absorbs peak shock better than single-row alternatives.
Q: How do I install the drive pinion through the inner bore?
A: Your pinion assembly must fit through the 758mm inner diameter. We provide installation drawings showing pinion positioning relative to the Z=90 gear teeth. Most designs use a split pinion or install the motor/gearbox before final bearing mounting.
Q: What's your lead time for a single unit order?
A: Standard 023.30.900 configuration: 15-20 days. Custom modifications: 25-35 days depending on gear changes or coating requirements.
Q: Do you provide lubrication recommendations?
A: We supply the bearing pre-greased with lithium complex EP2 grease. Relubrication intervals depend on duty cycle—typically every 100 operating hours for excavators. We can specify alternate greases for extreme temperatures.
Q: Can you replace a worn bearing without our original drawings?
A: Absolutely. Our reverse engineering service includes on-site measurement, wear analysis, and optimized replacement design. We've successfully mapped and replicated bearings from discontinued European and Japanese OEMs.
Contact Us
Need load calculations, CAD models, or pricing for your 023.30.900 Slewing Bearing 900mm internal gear slewing bearing double row project? Our technical team responds within 24 hours with detailed proposals.
Email: mia@hgb-bearing.com
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